79667665 Siemens Power Engineering Guide Transmission Distribution

Power Engineering Guide Transmission and Distribution

Power Engineering Guide Transmission and Distribution

For further information to each chapter:

High Voltage Design of Air-insulated Outdoor Substations Fax.: ++49-9131-73 18 58 Gas-insulated Swichgear for Substations Fax.: ++49-9131-73 46 62 Gas-insulated Transmission Lines Fax.: ++49-9131-734490 Circuit Breakers for 72 kV up to 800 kV Fax.: ++49-3 03 86-2 58 67 High-voltage Direct Current Transmission Fax.: ++49-9131-73 35 66 Power Compensation in Transmission Systems Fax.: ++49-9131-73 45 54 Power Compensation in Distribution Systems Fax.: ++49-9131-73 13 74 Surge Arresters Fax.: ++49-3 03 86-2 67 21 Worldwide Service for High- and Mediumvoltage Switchgear and Substations Fax.: ++49-9131-73 44 49

Medium Voltage Primary Distribution Fax.: ++49-9131-73 46 39 Containerized Switchgear Fax.: ++49-68 94-89 12 94 Secondary Distribution Fax.: ++49-9131-73 46 36

Your local representative:

Medium Voltage Devices Fax.: ++49-9131-73 46 54

Low Voltage SIVACON Fax.: ++49-3 41-4 47 04 00

Transformers Distribution Transformers Fax.: ++49-70 21-50 85 48 Power Transformers Fax.: ++49-9 11-4 34 2147

Power Cables Low- and Medium-Voltage Cables Fax.: ++49-9131-73 24 55 and ++49-9131-7310 92 High- and Extra High Cables Fax.: ++49-9131-73 47 44 Accessories for Low- and Medium-Voltage Cables Fax.: ++49-23 31-35 7118 Accessories for High-Voltage Cables Fax.: ++49-23 31-35 71 18

Protection and Substation Control Fax.: ++49-911-4 33-85 89

Power Systems Control Distributed by: Siemens Aktiengesellschaft Power Transmission and Distribution Group International Business Development, Dept. EV IBD

SCADA/EMS/DMS Fax.: ++49-9 11-4 33-81 22 Control Room Technology Fax.: ++49-911-433-8183

P.O. Box 3220 D-91050 Erlangen Phone: ++49 - 9131-73 45 40 Fax: ++49-9131-73 45 42

Energy Metering

Power Transmission and Distribution group online: http://www.siemens.ev.de

Power Network Telecommunication Fax.: ++49-89-722-2 44 53 or ++49-89-7 22-4 1982

Fax.: ++49-9 11-4 33-80 37

Overhead Power Lines Fax.: ++49-9131-72 95 93

System Planning Fax.: ++49-9131-73 44 45

High-Voltage Power Transmission Systems Fax.: ++49-9131-734672

Siemens Power Engineering Guide · Transmission & Distribution

Contents

Foreword General Introduction

High Voltage

Medium Voltage

Low Voltage

Transformers

Power Cables

Protection and Substation Control

Power Systems Control

Energy Metering

Overhead Power Lines

System Planning

High-Voltage Power Transmission Systems Annex: Conversion Factors and Tables Supplement: Facts and Figures Adress Index of Local Siemens Partners

Siemens Power Engineering Guide · Transmission & Distribution

Quality and Environmental Policy

Quality – Our first priority Transmission and distribution equipment from Siemens means worldwide activities in engineering, design, development, manufacturing and service. The Power Transmission and Distribution Group of Siemens AG, with all of its divisions and relevant locations, has been awarded and maintains certification to DIN/ISO 9001 (EN 29001). Certified quality Siemens Quality Management System gives our customers confidence in the quality of Siemens products and services. Certified to be in compliance with DIN/ISO 9001 (EN 29001), it is the registered proof of our reliabilty.

Siemens Power Engineering Guide · Transmission & Distribution

Foreword by the Executive Management

Siemens AG is one of the world’s leading international electrical and electronics companies. With 370 000 employees in more than 190 countries worldwide, the company is divided into various groups. The Power Transmission and Distribution Group of Siemens with 22 500 employees around the world plans, develops, designs, manufactures and markets products, systems and complete turn-key electrical infrastructure installations. These involve high-voltage and HVDC, medium-voltage and lowvoltage components and systems, switchyards, switchgear and switchboards, transformers, cables, telecontrol systems and protection relays, network and substation control, powerfactor correction and load-flow management system. Also included are the required software, application engineering and technical services. The group owns a growing number of engineering and manufacturing facilities. Presently we account for 57 plants and more than 70 joint ventures in more than 100 countries throughout the world. All plants are, or are in the process of being certified to ISO 9000/9001 practices. This is of significant benefit for our customers. Our local manufacturing capability makes us strong in global sourcing, since we manufacture products to IEC as well as ANSI/NEMA standards in plants at various locations around the world.

This Power Engineering Guide is devised as an aid to electrical engineers who are engaged in the planning and specifying of electrical power generation, transmission, distribution, control, and utilization systems. Care has been taken to include the most important application, performance, physical and shipping data of the equipment listed in the guide which is needed to perform preliminary layout and engineering tasks for industrial- and utility-type installations. The equipment listed in this guide is designed, rated, manufactured and tested in accordance with the International Electrotechnical Commissions (IEC) recommendations. However, a number of standardized equipment items in this guide are designed to take other national standards into account besides the above codes, and can be rated and tested to ANSI/ NEMA, BS, CSA, etc. On top of that, we manufacture a comprehensive range of transmission and distribution equipment specifically to ANSI/NEMA codes and regulations. Two thirds of our product range is less than five years old. For our customers this means energy efficiency, environmental compatibility, reliability and reduced life cycle cost. For details, please see the individual product listings or inquire. Whenever you need additional information to select suitable products from this guide, or when questions about their application arise, simply call your local Siemens office.

Siemens Power Transmission and Distribution Group is capable of providing everything you would expect from an electrical engineering company with a global reach. The Power Transmission and Distribution Group is prepared and competent, to perform all tasks and activities involving transmission and distribution of electrical energy. Siemens Power Transmission and Distribution Group is active worldwide in the field of power systems and components, protection, management and communication systems (details shown in supplement “Facts and Figures“). Siemens’ service includes the setting up of complete turnkey installations, offers advice, planning, operation and training and provides expertise and commitment as the complexity of this task requires. Backed by the experience of worldwide projects, Siemens can always offer its customers the optimum cost-effective concept individually tailored to their needs. We are there – wherever and whenever you need us – to help you build plants better, cheaper and faster.

Klaus Voges Vice President Siemens Aktiengesellschaft Power Transmission and Distribution

Siemens Power Engineering Guide · Transmission & Distribution

General Introduction – Transmission and Distribution

The sum of experience for integral solutions The world’s population is on the increase and the demand for electrical energy in the developing and newly industrializing nations is growing rapidly. Safe, reliable and environmentally sustainable power transmission and distribution is therefore one of the great challenges of our time. Siemens is making an important contribution towards solving this task, with futureoriented technologies for the construction, modernization and expansion of power systems at all voltage levels. The Siemens Power Engineering Guide Transmission and Distribution gives a short summary of the activities and products of the Power Transmission and Distribution Group. Transmission and distribution networks are the link between power generation and the consumers, whose requirements for electrical energy determine the actual generation. Industry, trade and commerce as well as public services (transportation and communication systems including data processing), not to mention the private sector (households), are highly dependent upon a reliable and adequate energy supply of high quality at utmost economical conditions. These are the basic conditions for installation and operation of transmission and distribution systems. Transmission The transmission of electrical energy from the generating plants, which are located under the major constraints of primary energy supply, cooling facilities and environmental impact, to the load centers, whose locations are dictated by high-density urban or industrial areas, requires a correspondingly extensive transmission system. These mostly interconnected systems, e.g. up to 550 kV, balance the daily and seasonal differences between local available generating capacity and load requirements and transport the energy to the individual regions of demand. For long-distances and/or high-capacity transmission, extra-high-voltage levels up to 800 kV or DC transmission systems are in use. In interconnected transmission systems, more and more substations for the subtransmission systems with high-voltage levels up to 145 kV are needed as close as possible to the densely populated areas, feeding the regional supply of urban or industrial areas. This calls for space-saving enclosed substations and the application of EHV and/or HV cable systems.

Power generation

Remote hydro-electric power station

Generator unit transformer

Long-distance transmission EHV AC up to 800 kV or HV DC

Interconnected transmission system up to 550 kV

HV/HV transformer level feeding the subtransmission systems

Subtransmission system up to 145 kV Regional supply system

Internal supply system

Regional supply system

Urban and/or industrial areas, also with local power stations

Large industrial complexes also with own power generation

Rural areas

HV/MV Step-down transformer level

Main substation with transformers up to 63 MVA HV switchgear

MV switchgear

Fig. 1: Transmission: Principle configuration of transmission system

Siemens Power Engineering Guide · Transmission & Distribution

General Introduction – Transmission and Distribution

Distribution In order to feed local medium-voltage distribution systems of urban, industrial or rural distribution areas, HV/MV main substations are connected to the subtransmission systems. Main substations have to be located next to the MV load center for economical reasons. Thus, the subtransmission systems of voltage levels up to 145 kV have to penetrate even further into the populated load centers. The far-reaching power distribution system in the load center areas is tailored exclusively to the needs of users with large numbers of appliances, lamps, motor drives, heating, chemical processes, etc. Most of these are connected to the lowvoltage level. The structure of the low-voltage distribution system is determined by load and reliability requirements of the consumers, as well as by nature and dimensions of the area to be served. Different consumer characteristics in public, industrial and commercial supply will need different LV network configurations and adequate switchgear and transformer layout. Especially for industrial supply systems with their high number of motors and high costs for supply interruptions, LV switchgear design is of great importance for flexible and reliable operation. Independent from individual supply characteristics in order to avoid uneconomical high losses, however, the substations with the MV/LV transformers should be located as close as possible to the LV load centers and should therefore be of compact design. The superposed medium-voltage system has to be configured to the needs of these substations and the available sources (main substation, generation) and leads again to different solutions for urban or rural public supply, industry and large building centers. Despite the individual layout of networks, common philosophy should be an utmost simple and clear network design to obtain ■ flexible system operation ■ clear protection coordination ■ short fault clearing time and ■ efficient system automation. The wide range of power requirements for individual consumers from a few kW to some MW, together with the high number of similar network elements, are the main characteristics of the distribution system and the reason for the comparatively high specific costs. Therefore, utmost standardization of equipment and use of maintenancefree components are of decisive importance for economical system layout. Siemens components and systems cater to these requirements based on worldwide experience in transmission and distribution networks.

Main substation with transformers up to 63 MVA HV switchgear

MV switchgear

Local medium-voltage distribution system

Feeder cable

Spot system

Connection of large consumer

Industrial supply and large buildings

Ring type Public supply

Medium voltage substations MV/LV substation looped in MV cable by load-break switchgear in different combinations for individual substation design, transformers up to 1000 kVA LV fuses

Circuit breaker Loadbreak switch Consumer-connection substation looped in or connected to feeder cable with circuit breaker and load-break switches for connection of spot system in different layout

MV/LV transformer level

Low-voltage supply system Public supply with pillars and house connections internal installation

Large buildings with distributed transformers vertical LV risers and internal installation per floor

Consumers

Fig. 2: Distribution: Principle configuration of distribution systems

Siemens Power Engineering Guide · Transmission & Distribution

Industrial supply with distributed transformers with subdistribution board and motor control center

General Introduction – Transmission and Distribution

Protection, operation and control Safe, reliable and economical energy supply is also a matter of fast, efficient and reliable system protection, data transmission and processing for system operation. The components required for protection and operation benefit from the rapid development of information and communication technology. Modern digital relays provide extensive possibilities of selective relay setting and protection coordination for fast fault clearing and minimized interruption times. Additional extensive system data and information are generated as an essential basis for systems supervision and control. Powerful data processing and management system have been developed. Modular and open structures, full-graphics user interface as well as state-of-the-art applications are a matter of course. Siemens network control systems assure a complete overview of the current operating conditions – from the interconnected grid right up to the complete distribution network. This simplifies system management and at the same time makes it more reliable and more economical. The open architecture of the power system control offers great flexibility for expansion to meet all the demands made and can be integrated into existing installations without any problems. Visualization of system behavior and supply situation by advanced control room equipment assist the highly responsible function of systems operators. Overall solutions – System planning Of crucial importance for the quality of power transmission and distribution is the integration of diverse components to form overall solutions. Especially in countries where the increase in power consumption is well above the average besides the installation of generating capacity, construction and extension of transmission and distribution systems must be developed simultaneously and together with equipment for protection, supervision and control. Also, for the existing systems, changing load structure and/ or environmental regulations, together with the need for replacement of aged equipment will require new installations. Integral power network solutions are far more than just a combination of products and components. Peculiarities in urban development, protection of the countryside and of the environment, and the suitability for expansion and harmonious integration in existing networks are just a few of the factors which future-oriented power system planning must take into account.

Power system substation Power system switchgear Unit protection – Overcurrent – Distance – Differential etc. Other unit

Unit switching interlocking Control Other unit

Unit coordination level

Substation coordination level Substation protection

Substation control

Data processing

Switchgear interlocking

Data and signal input/output

Automation

Power network telecommunication systems

Other substations

Power line carrier communication

Other substations

Fiber-optic communication

System coordination level SCADA functions

Power and scheduling applications

Distribution management functions Grafical information systems

Network analysis

Training simulator

Control room equipment

Fig. 3: Protection, operation and control: Principle configuration of operation, protection and communication systems Siemens Power Engineering Guide · Transmission & Distribution

High-voltage Switchgear for Substations

Introduction High-voltage substations form an important link in the power transmission chain between generation source and consumer. Two basic designs are possible: Air-insulated outdoor switchgear of open design (AIS) AIS are favorably priced high-voltage substations for rated voltages up to 800 kV which are popular wherever space restrictions and environmental circumstances do not have to be considered. The individual electrical and mechanical components of an AIS installation are assembled on site. Air-insulated outdoor substations of open design are not completely safe to touch and are directly exposed to the effects of weather and the environment (Fig. 1).

Fig. 1: Outdoor switchgear

Gas-insulated indoor or outdoor switchgear (GIS) GIS compact dimensions and design make it possible to install substations up to 550 kV right in the middle of load centers of urban or industrial areas. Each circuitbreaker bay is factory assembled and includes the full complement of isolator switches, grounding switches (regular or make-proof), instrument transformers, control and protection equipment, interlocking and monitoring facilities commonly used for this type of installation. The earthed metal enclosures of GIS assure not only insensitivity to contamination but also safety from electric shock (Fig. 2).

Fig. 2: GIS substations in metropolitan areas

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Siemens Power Engineering Guide · Transmission & Distribution

High-voltage Switchgear for Substations

A special application of gas-insulated equipment are: Gas-insulated transmission lines (GIL) Gas-insulated transmission lines (GIL) are always used where high-voltage cables come up against the limits of their performance. High-voltage switchgear is normally combined with transformers and other equipment to complete transformer substations in order to

Major components, e.g. transformer Substation Control Control and monitoring, measurement, protection, etc.

■ Step-up from generator voltage level

to high-voltage system (MV/HV) ■ Transform voltage levels within the

high-voltage grid system(HV/HV)

Civil Engineering Buildings, roads, foundations

Design

AC/DC es ri auxililia

Fire protection

Env

ab

gh

iron pro menta tec tion l

tn

in

g

n

tio

tila

Po

Li

n Ve

les Contro la signal c nd ables

Ancillary equipment frequ. Carrier- ent equipm

rge s Su erter i dv g in rth em a E st sy

rc

of distribution system (HV/MV)

we

■ Step-down to medium-voltage level

The High-Voltage Division plans and constructs individual high-voltage switchgear installations or complete transformer substations, comprising high-voltage switchgear, medium-voltage switchgear, major components such as transformers, and all ancillary equipment such as auxiliaries, control systems, protective equipment, etc., on a turnkey basis or even as general contractor. The spectrum of installations supplied ranges from basic substations with single busbar to regional transformer substations with multiple busbars or 1 1/2 circuit-breaker arrangement for rated voltages up to 800 kV, rated currents up to 8000 A and short-circuit currents up to 100 kA, all over the world. The services offered range from system planning to commissioning and after-sales service, including training of customer personnel. The process of handling such an installation starts with preparation of a quotation, and proceeds through clarification of the order, design, manufacture, supply and cost-accounting until the project is finally billed. Processing such an order hinges on methodical data processing that in turn contributes to systematic project handling. All these high-voltage installations have in common their high-standard of engineering, which covers power systems, steel structures, civil engineering, fire precautions, environmental protection and control systems (Fig. 3).

Structural Steelwork Gantries and substructures

Fig. 3: Engineering of high-voltage switchgear

Every aspect of technology and each work stage is handled by experienced engineers. With the aid of high-performance computer programs, e.g. the finite element method (FEM), installations can be reliably designed even for extreme stresses, such as those encountered in earthquake zones. All planning documentation is produced on modern CAD systems; data exchange with other CAD systems is possible via standardized interfaces. By virtue of their active involvement in national and international associations and standardization bodies, our engineers are always fully informed of the state of the art, even before a new standard or specification is published. Our own high-performance, internationally accredited test laboratories and a certified QA system testify to the quality of our products and services.

Siemens Power Engineering Guide · Transmission & Distribution

Milestones along the road to certification: ■ 1983: Introduction of a quality system on the basis of Canadian standard CSA Z299 Level 1. ■ 1989: Certification in accordance with DIN ISO 9001 by the German Association for Certification of Quality Systems (DQS) ■ 1992: Accreditation of the test laboratories in accordance with DIN EN 45001 by the German Accreditation Body for Technology (DATech). A worldwide network of liaison and sales offices, along with the specialist departments in Germany, support and advise our customers in all matters of switchgear technology. Siemens has for many years been a leading supplier of high-voltage equipment, regardless of whether AIS, GIS or GIL has been concerned. For example, outdoor substations of longitudinal in-line design are still known in many countries under the Siemens registered tradename “Kiellinie”. Back in 1968, Siemens supplied the world’s first GIS substation using SF6 as insulating and quenching medium. Gas-insulated transmission lines have featured in the range of products since 1976.

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Design of Air-insulated Outdoor Substations

Standards Air-insulated outdoor substations of open design must not be touched. Therefore, air-insulated switchgear (AIS) is always set up in the form of a fenced-in electrical operating area, to which authorized persons have access only. Relevant IEC specifications apply to outdoor switchgear equipment. Insulation coordination, including minimum phaseto-phase and phase-to-ground clearances, is effected in accordance with IEC 71. Outdoor switchgear is directly exposed to the effects of the environment such as the weather. Therefore it has to be designed based on not only electrical but also environmental specifications. Currently there is no international standard covering the setup of air-insulated outdoor substations of open design. Siemens designs AIS in accordance with DIN/VDE standards, in line with national standards or customer specifications. The German standard DIN VDE 0101 (erection of power installations with rated voltages above 1 kV) demonstrates typically the protective measures and stresses that have to be taken into consideration for airinsulated switchgear. Protective measures Protective measures against direct contact, i. e. protection in the form of covering, obstruction or clearance and appropriately positioned protective devices and minimum heights. Protective measures against indirect touching by means of relevant grounding measures in accordance with DIN VDE 0141. Protective measures during work on equipment, i.e. during installation must be planned such that the specifications of DIN VDE 0105 (e.g. 5 safety rules) are complied with ■ Protective measures during operation,

e.g. use of switchgear interlock equipment ■ Protective measures against voltage surges and lightning strike ■ Protective measures against fire, water and, if applicable, noise insulation.

Stresses ■ Electrical stresses, e.g. rated current, short-circuit current, adequate creepage distances and clearances ■ Mechanical stresses (normal stressing), e.g. weight, static and dynamic loads, ice, wind ■ Mechanical stresses (exceptional stresses), e.g. weight and constant loads in simultaneous combination with maximum switching forces or shortcircuit forces, etc. ■ Special stresses, e.g. caused by installation altitudes of more than 1000 m above sea level, or earthquakes

The design of a substation determines its accessibility, availability and clarity. The design must therefore be coordinated in close cooperation with the customer. The following basic principles apply: Accessibility and availability increase with the number of busbars. At the same time, however, clarity decreases. Installations involving single busbars require minimum investment, but they offer only limited flexibility for operation management and maintenance. Designs involving 1 1/2 and 2 circuit-breaker arrangements assure a high redundancy, but they also entail the highest costs. Systems with auxiliary or bypass busbars have proved to be economical. The circuit-breaker of the coupling feeder for the auxiliary bus allows uninterrupted replacement of each feeder circuit-breaker. For busbars and feeder lines, mostly wire conductors and aluminum are used. Multiple conductors are required where currents are high. Owing to the additional shortcircuit forces between the subconductors (pinch effect), however, multiple conductors cause higher mechanical stressing at the tension points. When wire conductors, particularly multiple conductors, are used higher short-circuit currents cause a rise not only in the aforementioned pinch effect but in further force maxima in the event of swinging and dropping of the conductor bundle (cable pull). This in turn results in higher mechanical stresses on the switchgear components. These effects can be calculated in an FEM simulation (Fig. 4).

Variables affecting switchgear installation Switchgear design is significantly influenced by: ■ Minimum clearances (depending on rated voltages) between various active parts and between active parts and earth ■ Arrangement of conductors ■ Rated and short-circuit currents ■ Clarity for operating staff ■ Availability during maintenance work, redundancy ■ Availability of land and topography ■ Type and arrangement of the busbar disconnectors

Vertical displacement in m -0.6 -0.8 -1.0 -1.2 -1.4 -1.6 -1.8 Horizontal displacement in m

-2.0 -2.2 -1.4

-1.0

-0.6

-0.2

0

0.2

0.6

1.0

1.4

Fig. 4: FEM calculation of deflection of wire conductors in the event of short circuit

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Siemens Power Engineering Guide · Transmission & Distribution

Design of Air-insulated Outdoor Substations

When rated and short-circuit currents are high, aluminum tubes are increasingly used to replace wire conductors for busbars and feeder lines. They can handle rated currents up to 8000 A and short-circuit currents up to 80 kA without difficulty. Not only the availability of land, but also the lay of the land, the accessibility and location of incoming and outgoing overhead lines together with the number of transformers and voltage levels considerably influence the switchgear design as well. A one- or two-line arrangement, and possibly a U arrangement, may be the proper solution. Each outdoor switchgear, especially for step-up substations in connection with power stations and large transformer substations in the extra-highvoltage transmission system, is therefore unique, depending on the local conditions. HV/MV transformer substations of the distribution system, with repeatedly used equipment and a scheme of one incoming and one outgoing line as well as two transformers together with medium-voltage switchgear and auxiliary equipment, are more subject to a standardized design from the individual power supply companies.

Dimensions in mm

Top view 6500 A

B 6500

C

D Section A-B

Section C-D 2500 8000

7000

6500 13300 27000

7500 13300

Fig. 5: Substation with withdrawable circuit-breaker

Dimensions in mm 2500

Section A-A R1 S1 T1 T2 S2 R2

8000 20500

Preferred designs

8400 48300

19400 Top view

The multitude of conceivable designs include certain preferred versions, which are dependent on the type and arrangement of the busbar disconnectors: H arrangement The H arrangement is preferrably used in applications for feeding industrial consumers. Two overhead lines are connected with two transformers and interlinked by a single-bus coupler. Thus each feeder of the switchgear can be maintained without disturbance of the other feeders. This arrangement guarantees a high availability. Special layout for single busbars up to 145 kV (withdrawable circuit-breaker arrangement) Further to the H arrangement that is built in many variants, there are also designs featuring withdrawable circuit-breakers without disconnectors for this voltage range. The circuit-breaker is moved electrohydraulically from the connected position into the disconnected position and viceversa. In comparison with a single busbar with rotary disconnectors, roughly 50% less ground space is required (Fig. 5).

6500 End bay

9000 4500

A

Normal 9000 bay A Fig. 6: Substation with rotary disconnector, in-line design

In-line longitudinal layout, with rotary disconnectors, preferable up to 170 kV The busbar disconnectors are lined up one behind the other and parallel to the longitudinal axis of the busbar. It is preferable to have either wire-type or tubular busbars located at the top of the feeder conductors. Where tubular busbars are used, gantries are required for the outgoing overhead lines only. The system design requires only two conductor levels and is therefore clear. If, in the case of duplicate busbars, the second busbar is arranged in U-form relative to the first busbar, it is possible to arrange feeders going out on both sides of the busbar without a third conductor level (Fig. 6).

Siemens Power Engineering Guide · Transmission & Distribution

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Design of Air-insulated Outdoor Substations

Central tower layout with rotary disconnectors, normally only for 245 kV The busbar disconnectors are arranged side by side and parallel to the longitudinal axis of the feeder. Wire-type busbars located at the top are commonly used; tubular busbars are also conceivable. This arrangement enables the conductors to be easliy jumpered over the circuit-breakers and the bay width to be made smaller than that of in-line designs. With three conductor levels the system is relatively clear, but the cost of the gantries is high (Fig. 7).

Dimensions in mm 3000 12500 9000 7000

18000

17000

17000

16000 Diagonal layout with pantograph disconnectors, preferable up to 245 kV The pantograph disconnectors are placed diagonally to the axis of the busbars and feeder. This results in a very clear, spacesaving arrangement. Wire and tubular conductors are customary. The busbars can be located above or below the feeder conductors (Fig. 8).

Fig. 7: Central tower design

Dimensions in mm

Section Bus system

1 1/2 circuit-breaker layout, preferable up to 245 kV The 1 1/2 circuit-breaker arrangement assures high supply reliability; however, expenditures for equipment are high as well. The busbar disconnectors are of the pantograph, rotary and vertical-break type. Vertical-break disconnectors are preferred for the feeders. The busbars located at the top can be of wire or tubular type. Of advantage are the equipment connections, which are very short and allow even in the case of multiple conductors that high short-circuit currents are mastered. Two arrangements are customary: ■ External busbar, feeders in line with three conductor levels ■ Internal busbar, feeders in H arrangement with two conductor levels (Fig. 9).

By-pass bus

13300 10000 8000

28000

48000

10000

10400 Top view 5000 18000 4000 4000 5000

Fig. 8: Busbar area with pantograph disconnector of diagonal design, rated voltage 420 kV

Dimensions in mm 4000

17500

8500

48000

29000

18000

Fig. 9: 1 1/2 circuit-breaker design

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Siemens Power Engineering Guide · Transmission & Distribution

Design of Air-insulated Outdoor Substations

Planning principles For air-insulated outdoor substations of open design, the following planning principles must be taken into account: ■ High reliability – Reliable mastering of normal and exceptional stresses – Protection against surges and lightning strikes – Protection against surges directly on the equipment to be protected (e.g. transformer, HV cable) ■ Good clarity and accessibility

– Clear conductor routing with few conductor levels – Free accessibility to all areas (no equipment located at inaccessible depth) – Adequate protective clearances for installation, maintenance and transportation work – Adequately dimensioned transport routes ■ Positive incorporation into surroundings

– As few overhead conductors as possible – Tubular instead of wire-type busbars – Unobtrusive steel structures – Minimal noise and disturbance level ■ EMC grounding system

for modern control and protection ■ Fire precautions and environmental

protection – Adherence to fire protection specifications and use of flame-retardant and nonflammable materials – Use of environmentally compatible technology and products For further information please contact: Fax: ++ 49 - 9131- 73 18 58

Siemens Power Engineering Guide · Transmission & Distribution

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Gas-insulated Switchgear for Substations

Common characteristic features of switchgear installation Because of its small size and outstanding compatibility with the environment, SF6 insulated switchgear (GIS) is gaining constantly on other types. Siemens has been a leader in this sector from the very start. The concept of SF6 -insulated metal-enclosed high-voltage switchgear has proved itself in more than 64,000 bay operating years in over 5,500 installations in all parts of the world. It offers the following outstanding advantages.

Protection of the environment The necessity to protect the environment often makes it difficult to erect outdoor switchgear of conventional design, whereas buildings containing compact SF6-insulated switchgear can almost always be designed so that they blend well with the surroundings. SF6-insulated metal-enclosed switchgear is, due to the modular system, very flexible and can meet all requirements of configuration given by network design and operating conditions.

Each circuit-breaker bay includes the full complement of disconnecting and grounding switches (regular or make-proof), instrument transformers, control and protection equipment, interlocking and monitoring facilities, commonly used for this type of installation (Fig. 10). Beside the conventional circuit-breaker field, other arrangements can be supplied such as single-bus, ring cable with loadbreak switches and circuit-breakers, singlebus arrangement with bypass-bus, coupler, bay for triplicate bus. Combined circuitbreaker and load-break switch feeder, ring cable with load-break switches, etc. are furthermore available for the 145 kV level.

Small space requirements The availability and price of land play an important part in selecting the type of switchgear to be used. Siting problems arise in ■ Large towns ■ Industrial conurbations ■ Mountainous regions with narrow valleys ■ Underground power stations In cases such as these, SF6-insulated switchgear is replacing conventional switchgear because of its very small space requirements. Full protection against contact with live parts The all-round metal enclosure affords maximum safety to the personnel under all operating and fault conditions. Protection against pollution Its metal enclosure fully protects the switchgear interior against environmental effects such as salt deposits in coastal regions, industrial vapors and precipitates, as well as sandstorms. The compact switchgear can be installed in buildings of simple design in order to minimize the cost of cleaning and inspection and to make necessary repairs independent of weather conditions. Free choice of installation site The small site area required for SF6-insulated switchgear saves expensive grading and foundation work, e.g. in permafrost zones. Other advantages are the short erections times and the fact that switchgear installed indoors can be serviced regardless of the climate or the weather. Fig. 10: Typical circuit arrangements of SF 6-switchgear

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Siemens Power Engineering Guide · Transmission & Distribution

Gas-insulated Switchgear for Substations

The development of the switchgear is always based on an overall production concept, which guarantees the achievement of the high technical standards required of the HV switchgear whilst providing the maximum customer benefit. This objective is attained only by incorporating all processes in the quality management system, which has been introduced and certified according to DIN EN ISO 9001 (EN 29001).

Main product range of GIS for substations SF6 switchgear up to 550 kV (the total product range covers GIS from 66 up to 800 kV rated voltage).

3400

5000

4480

3200

3800

5170

500

Switchgear type

8DN9

8DP3

8DQ1

Details on page

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1/11-1/12

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1200

2200

3600

Bay width

[mm]

Rated voltage

[kV]

up to 145

up to 300

up to 550

Rated power frequency withstand voltage

[kV]

up to 275

up to 460

up to 740

Rated lightning impulse withstand voltage

[kV]

up to 650

up to 1050

up to 1550

Rated switching impulse withstand voltage

[kV]

–

up to 850

up to 1250

Rated normal current busbars

[A]

up to 3150

up to 5000

up to 6300

Rated normal current

[A]

up to 2500

up to 4000

up to 4000

feeder Rated breaking current

[kA]

up to 40

up to 50

up to 63

Rated short-time withstand current (1s)

[kA]

up to 40

up to 50

up to 63

Rated peak withstand current

[kA]

up to 100

up to 135

up to 170

SF6-gas pressure [bar] (gauge) switchgear

up to 4.3

up to 4.0

up to 4.3

SF6-gas pressure (gauge) circuitbreaker

up to 6.0

up to 6.0

up to 6.5

> 20 years

> 20 years

> 20 years

[bar]

Inspection All dimensions in mm Fig. 11: Main product range

Siemens Power Engineering Guide · Transmission & Distribution

Siemens GIS switchgear meets all the performance, quality and reliability demands such as Compact space-saving design means uncomplicated foundations, a wide range of options in the utilization of space, less space taken up by the switchgear. Minimal weight by lightweight construction through the use of aluminum-alloy and the exploitation of innovations in development such as computer-aided design tools. Safe encapsulation means an outstanding level of safety based on new manufacturing methods and optimized shape of enclosures. Environmental compatibility means no restrictions on choice of location by means of minimum space requirement, extremely low noise emission and effective gas sealing system (leakage < 1% per year per gas compartment). Economical transport means simplified and fast transport and reduced costs because of maximum possible size of shipping units. Minimal operating costs means the switchgear is practically maintenance-free, e.g. contacts of circuit-breakers and disconnectors designed for extremely long endurance, motor-operated mechanisms self-lubricating for life, corrosion-free enclosure. This ensures that the first inspection will not be necessary until after 25 years of operation. Reliability means our overall product concept which includes, but is not limited to, the use of finite elements method (FEM), threedimensional design programs, stereolithography, and electrical field development programs assures the high standard of quality. Smooth and efficient installation and commissioning transport units are fully assembled and tested at the factory and filled with SF6 gas at reduced pressure. Plug connection of all switches, all of which are motorized, further improve the speediness of site installation and substantially reduce field wiring errors. Routine tests All measurements are automatically documented and stored in the EDP information system, which enables quick access to measured data even if years have passed.

1/9

Gas-insulated Switchgear for Substations

SF6-insulated switchgear up to 145 kV, type 8DN9 The clear bay configuration of the lightweight and small 8DN9 switchgear is evident at first sight. Control and monitoring facilities are easily accessible in spite of the compact design of the switchgear. The horizontally arranged circuit-breaker forms the basis of every bay configuration. The operating mechanism is easily accessible from the operator area. The other bay modules – of single-phase encapsulated design like the circuit-breaker module – are located on top of the circuit-breaker. The three-phase encapsulated passive busbar is partitioned off from the active equipment. Thanks to “single-function” assemblies (assignment of just one task to each module) and the versatile modular structure, even unconventional arrangements can be set up out of a pool of only 20 different modules. The modules are connected to each other by a standard interface which allows an extensive range of bay structures. The switchgear design with standardized modules and the scope of services mean that all kinds of bay structures can be set up in a minimal area. The compact design permits the supply of double bays fully assembled, tested in the factory and filled with SF6 gas at reduced pressure, which guarantees smooth and efficient installation and commissioning. The following major feeder control level functions are performed in the local control cabinet for each bay, which is integrated in the operating front of the 8DN9 switchgear: ■ Fully interlocked local operation and state-indication of all switching devices managed reliably by the Siemens digital switchgear interlock system ■ Practical dialogue between the digital feeder protection system and central processor of the feeder control system ■ Visual display of all signals required for operation and monitoring, together with measured values for current, voltage and power ■ Protection of all auxiliary current and voltage transformer circuits ■ Transmission of all feeder information to the substation control and protection system Factory assembly and tests are significant parts of the overall production concept mentioned above. Two bays at a time undergo mechanical and electrical testing with the aid of computer-controlled stands.

1

2

3

4

5

6

7 8

17

9

16

10

15 11 14 12

13

1 2 3 4 5 6 7 8 9

Busbar I Busbar II Busbar disconnector I Busbar disconnector isolator II Grounding switch Make-proof grounding switch Cable isolator Voltage transformer Cable sealing end

10 11 12 13 14 15 16

Current transformer Grounding switch Circuit-breaker Hydraulic storage cylinder Electrohydraulic operating unit Oil tank Circuit-breaker control with gas monitoring unit 17 Local control cabinet

1 2 3

4 5 12 10 7

11 6

9

Fig. 12: Switchgear bay 8DN9 up to 145 kV

Fig. 13: 8DN9 switchgear for operating voltage 145 kV

1/10

Siemens Power Engineering Guide · Transmission & Distribution

Gas-insulated Switchgear for Substations

SF6-insulated switchgear up to 300 kV, type 8DP3 A switchgear system with entirely individual enclosure of all modules for the threephase system. Similar to the design concept of the 8DN9 switchgear, a horizontally arranged circuitbreaker has been chosen to be the base unit for the 8DP3 switchgear although the encapsulation is entirely single-phase instead of three-phase (busbar). Making use of the experience gained with previous 145 kV GIS, the current transformer was integrated in the circuit-breaker enclosure. Mounted on top of the circuit-breaker tank are housings containing disconnectors, or grounding switches, or both devices. Depending on the application up to two grounding switches can be installed in these enclosures. One grounding switch serves as a work-in-progress grounding device for the circuit-breaker, whereas the other external switch may be of the standard slow-moving type or be equipped with a spring-drive mechanism to achieve “fault making” capabilities. This feature is often required at incoming or outgoing feeder terminations. The standard design is arranged to accommodate the double-bus-bar circuits primarily used. Naturally all other common circuit requirements for this voltage level, such as double or single bus with bypass and the 1 1/2 circuit-breaker arrangement, can be fulfilled as well. Care has been taken to design the bus sections in such a way that the standard width of each bay, including the associated busbar section, does not exceed 2.2 m. This solution allows preassembly and testing at the factory to a large extent. For example, a complete 245 kV bay of the GIS type 8DP3 can be shipped pre-tested and only requiring a minimum amount of installation work on site. Circuit-breaker modules with one interrupter unit will meet the requirements for operating voltages up to 245 kV normally. Voltages above 245 kV, however, as well as high switching capacities require circuitbreaker units with two interrupter units per pole.

4

3

2

1

18 17 16

15

5

14

6

7 1 2 3 4 5 6 7 8 9

8

9

10

Busbar disconnector II Busbar II Busbar disconnector I Busbar I Grounding switch Local control cabinet Gas monitoring unit Circuit-breaker control unit Oil tank

11 10 11 12 13 14 15 16 17 18

12

13

Electrohydraulic operating unit Hydraulic storage cylinder Circuit-breaker Current transformer Cable sealing end Voltage transformer Make-proof grounding switch Cable disconnector Grounding switch

4 2 3

1 5 12 13 18 17 16

15

14

Fig. 14: Switchgear bay 8DP3 up to 245 kV

Fig. 15: Complete 8DP3 bay for operating voltage 245 kV being unloaded at site

Siemens Power Engineering Guide · Transmission & Distribution

1/11

Gas-insulated Switchgear for Substations

Fig. 16: 8DP3 switchgear for operating voltage 245 kV and 40 kA

4

3

2

1

18

Fig. 17: 8DP3 switchgear for operating voltage 245 kV and 50 kA

17 16 15

14 5 13

6

7 1 2 3 4 5 6 7 8 9

Busbar disconnector II Busbar II Busbar disconnector I Busbar I Grounding switch Local control cabinet Gas monitoring unit Circuit-breaker control unit Oil tank

8 10 11 12 13 14 15 16 17 18

9

10

11

12

Electrohydraulic operating unit Hydraulic storage cylinder Circuit-breaker Current transformer Cable sealing end Voltage transformer Make-proof grounding switch Cable disconnector Grounding switch

4 2 3

1 5 12 13 18 17 16

15

14

Fig. 18: Switchgear bay 8DP3 up to 300 kV

1/12

Siemens Power Engineering Guide · Transmission & Distribution

Gas-insulated Switchgear for Substations

SF6-insulated switchgear up to 550 kV, type 8DQ1

9 8

7

6

5

4 3 2 1

13

■ Circuit-breakers with two interrupter

units up to operating voltages of 550 kV and breaking currents of 63 kA (from 63 kA to 100 kA, circuit-breakers with four interrupter units have to be considered) ■ Low switchgear center of gravity by means of circuit-breaker arranged horizontally in the lower portion ■ Utilization of the circuit-breaker transport frame as supporting device for the entire bay ■ The use of only a few modules and combinations of equipment in one enclosure reduces the length of sealing faces and consequently lowers the risk of leakage

11 10

12

A modular switchgear system for high power switching stations with individual enclosure of all modules for the threephase system. The design concept of the 8DQ1 switchgear follows in principle that of the 8DP3 for voltages above 245 kV, i.e. the base unit for the switchgear forms a horizontally arranged circuit-breaker on top of which are mounted the housings containing disconnectors, grounding switches, current transformers, etc. The busbar modules are also single-phase encapsulated and partitioned off from the active equipment. As a matter of course the busbar modules of this switchgear system are passive elements, too. Additional main characteristic features of the switchgear installation are:

1 2 3 4 5 6 7 8

Busbar disconnector I Busbar I Busbar II Busbar disconnector II Grounding switch Circuit-breaker Voltage transformer Make-proof grounding switch 9 Cable disconnector

14 10 11 12 13 14 15 16 17 18

15

16 17 18

Grounding switch Current transformer Cable sealing end Local control cabinet Gas monitoring unit (as part of control unit) Circuit-breaker control unit Electrohydraulic operating unit Oil tank Hydraulic storage cylinder

2 3 1

4 5 6 11 10 9 8

7

12

Fig. 19: Switchgear bay 8DQ1 up to 550 kV

Fig. 20: 8DQ1 switchgear for operating voltage 420 kV

Siemens Power Engineering Guide · Transmission & Distribution

1/13

Gas-insulated Switchgear for Substations

Scope of supply and battery limits

Air conditioning system 26.90 Relay room

23.20

Gas-insulated switchgear type 8DN9

Grounding resistor

15.95 13.8 kV switchgear Shunt reactor 11.50

Cable duct 8.90 Compensator

Radiators 40 MVA transformer

2.20

-1.50 Fig. 21: Special arrangement for limited space. Sectional view of a building showing the compact nature of gas-insulated substations

1/14

For all types of GIS Siemens supplies the following items and observes these interface points: ■ Switchgear bay with circuit-breaker interrupters, disconnectors and grounding switches, instrument transformers, and busbar housings as specified. For the different feeder types, the following battery limits apply: – Overhead line feeder: the connecting stud at the SF6-to-air bushing without the line clamp. – Cable feeder: according to IEC 859 the termination housing, conductor coupling, and connecting plate are part of the GIS delivery, while the cable stress cone with matching flange is part of the cable supply (see Fig. 24 on page 1/18). – Transformer feeder: connecting flange at switchgear bay and connecting bus ducts to transformer including any compensator are delivered by Siemens. The SF6to-oil bushings plus terminal enclosures are part of the transformer delivery, unless agreed otherwise (see Fig. 25 on page 1/18)*. ■ Each feeder bay is equipped with grounding pads. The local grounding network and the connections to the switchgear are in the delivery scope of the installation contractor. ■ Initial SF6-gas filling for the entire switchgear as supplied by Siemens is included. All gas interconnections from the switchgear bay to the integral gas service and monitoring panel are supplied by Siemens as well. ■ Hydraulic oil for all circuit-breaker operating mechanisms is supplied with the equipment. ■ Terminals and circuit protection for auxiliary drive and control power are provided with the equipment. Feeder circuits and cables, and installation material for them are part of the installation contractor’s supply. ■ Local control, monitoring, and interlocking panels are supplied for each circuitbreaker bay to form completely operational systems. Terminals for remote monitoring and control are provided. ■ Mechanical support structures above ground are supplied by Siemens; embedded steel and foundation work is part of the installation contractor’s scope. * Note: this interface point should always be closely coordinated between switchgear manufacturer and transformer supplier.

Siemens Power Engineering Guide · Transmission & Distribution

Gas-insulated Switchgear for Substations

Some examples for special arrangement

Transformer

Overhead line OHL

Gas-insulated switchgear – usually accommodated in buildings (as shown in a towertype substation) – is expedient whenever the floor area is very expensive or restricted or whenever ambient conditions necessitate their use (Fig. 21). For smaller switching stations, or in cases of expansion when there is no advantage in constructing a building, a favorable solution is to install the substation in a container (Fig. 22).

-Z2

-Z1 -051 -08

-09 -Z2

-Z1

3500 -T1 -00

-Z2 -08 -09 -T5 -T2 -052

-T5 -T2

-00

-052

-T1 -051 -Z1

Mobile containerized switchgear – even for high voltage At medium-voltage levels, mobile containerized switchgear is the state of the art. But even high-voltage switching stations can be built in this way and economically operated in many applications. The heart is the metal-enclosed SF6-insulated switchgear, installed either in a sheet-steel container or in a block house made of prefabricated concrete elements. In contrast to conventional stationary switchgear, there is no need for complicated constructions, mobile switching stations have their own ”building“. Mobile containerized switching stations can be of single or multi-bay design using a large number of different circuits and arrangements. All the usual connection components can be employed, such as outdoor bushings, cable adapter boxes and SF6 tubular connections. If necessary, all the equipment for control and protection and for the local supply can be accommodated in the container. This allows extensively independent operation of the installation on site. Containerized switchgear is preassembled in the factory and ready for operation. On site, it is merely necessary to set up the containers, fit the exterior system parts and make the external connections. Shifting the switchgear assembly work to the factory enhances the quality and operational reliability. Mobile containerized switchgear requires little space and usually fits in well with the environment. Rapid availability and short commissioning times are additional, significant advantages for the operators. Considerable cost reductions are achieved in the planning, construction work and assembly.

5806 Transformer Fig. 22: Containerized 8DN9 switchgear with stub feed in this example

Building authority approvals are either not required or only in a simple form. The installation can be operated at various locations in succession, and adaptation to local circumstances is not a problem. These are the possible applications for containerized stations: ■ Intermediate solutions for the

modernization of switching stations ■ Low-cost transitional solutions when

tedious formalities are involved in the new construction of transformer substations, such as in the procurement of land or establishing cable routes ■ Quick erection as an emergency station in the event of malfunctions in existing switchgear ■ Switching stations for movable, geothermal power plants 145 kV GIS in a standard container The dimensions of the new 8DN9 switchgear made it possible to accommodate all active components of the switchgear (circuit-breaker, disconnector, grounding switch) and the local control cabinet in a standard container. The floor area of 20 ft x 8 ft complies with the ISO 668 standard. Although the container is higher than the standard dimension of 8 ft, this will not cause any problems during transportation as proven by previously supplied equipment. German Lloyd, an approval authority, has already issued a test certificate for an even higher container construction.

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 23: 8DP3 switching bay being hoisted into a container

The standard dimensions and ISO corner fittings will facilitate handling during transport in the 20 ft frame of containership and on a low-loader truck. Operating staff can enter the container through two access doors. GIS up to 300 kV in a container The 8DP3 switchgear requires a container with a length of 7550 mm, a width of 2800 mm and a height of 3590 mm. In any case, the container equipment can include full thermal insulation, lighting and an air-conditioning and ventilation unit.

1/15

Gas-insulated Switchgear for Substations

Specification guide for metal-enclosed SF6-insulated switchgear The points below are not considered to be comprehensive, but are a selection of the important ones. General These specifications cover the technical data applicable to metal-enclosed SF6 gasinsulated switchgear for switching and distribution of power in cable and/or overhead line systems and at transformers. Key technical data are contained in the data sheet and the single-line diagram attached to the inquiry. A general “Single-line diagram” and a sketch showing the general arrangement of the substation and the transmission line exist and shall form part of a proposal. The switchgear quoted shall be complete to form a functional, safe and reliable system after installation, even if certain parts required to this end are not specifically called for. Applicable standards All equipment shall be designed, built, tested and installed to the latest revisions of the applicable IEC standards (IECPubl. 517 “High-voltage metal-enclosed switchgear for rated voltages of 72.5 kV and above”, IEC-Publ. 129 “Alternating current disconnectors (isolators) and grounding switches”, IEC-Publ. 56 “Highvoltage alternating-current circuit-breakers”). IEEE P 468-1 Gas-Insulated Substation (GIS) Standards. Other standards are also met. Local conditions The equipment described herein will be installed indoors. Suitable lightweight, prefabricated buildings shall be quoted if available from the supplier. Only a flat concrete floor will be provided by the buyer with possible cutouts in case of cable installation. The switchgear shall be equipped with adjustable supports (feet). If steel support structures are required for the switchgear, these shall be provided by the supplier.

1/16

For design purposes indoor temperatures of – 5 °C to +40 °C and outdoor temperatures of – 25 °C to +40 °C shall be considered. For parts to be installed outdoors (overhead line connections) the applicable conditions in IEC-Publication 517 or IEEE 0468-1 shall also be observed. Work, material and design Field welding at the switchgear is not permitted. Factory welders must be specially qualified personnel under continuous supervision of the associated welding society. Material and process specifications needed for welding must meet the applicable requirements of the country of manufacture. Maximum reliability through minimum amount of erection work on site is required. Subassemblies must be erected and tested in the factory to the maximum extent. The size of the sub-assemblies shall be only limited by the transport conditions. The material and thickness of the enclosure shall be selected to withstand an internal arc and to prevent a burn-through or puncturing of the housing within the first stage of protection, referred to a shortcircuit current of 40 kA. Normally exterior surfaces of the switchgear shall not require painting. If done for aesthetic reasons, surfaces shall be appropriately prepared before painting, i.e. all enclosures are free of grease and blasted. Thereafter the housings shall be painted with no particular thickness required but to visually cover the surface only. The interior color shall be light (white or light grey). In case painted the outside color of the enclosures shall be grey preferably; however, manufacturer’s standard paint color is acceptable. A satin mat finish with a high scratch resistance is preferred. All joints shall be machined and all castings spotfaced for bolt heads, nuts and washers. Assemblies shall have reliable provisions to absorb thermal expansion and contractions created by temperature cycling. For this purpose metal bellows-type compensators shall be installed. They must be provided with adjustable tensioners. All solid post insulators shall be provided with ribs (skirts). Horizontally mounted bushings require cleaning openings in the enclosure.

For supervision of the gas within the enclosures, density monitors with electrical contacts for at least two pressure levels shall be installed at a central and easily accessible location (central gas supervisory cabinet) of each switchgear bay. The circuit- breakers, however, might be monitored by density gauges fitted in circuitbreaker control units. The manufacturer guarantees that the pressure loss within each individual gas compartment – and not referred to the total switchgear installation only – will be not more than 1% per year per gas compartment. Each gas-filled compartment shall be equipped with static filters of a capacity to absorb any water vapor penetrating into the switchgear installation over a period of at least 20 years. Long intervals between the necessary inspections shall keep the maintenance cost to a minimum. A minor inspection shall only become necessary after ten years and a major inspection preferably after a period exceeding 20 years of operation unless the permissible number of operations is met at an earlier date, e.g. 6,000 operations at full load current or 20 operations at rated short-circuit current.

Siemens Power Engineering Guide · Transmission & Distribution

Gas-insulated Switchgear for Substations

Arrangement and modules Arrangement The arrangement shall be single-phase enclosed preferably. The assembly shall consist of completely separate pressurized sections designed to minimize the risk of damage to personnel or adjacent sections in the event of a failure occurring within the equipment. Rupture diaphragms shall be provided to prevent the enclosures from uncontrolled bursting and suitable deflectors provide protection for the operating personnel. In order to achieve maximum operating reliability, no internal relief devices may be installed because adjacent compartments would be affected. Modular design, complete segregation, arc-proof bushings and “plug-in” connection pieces shall allow ready removal of any section and replacement with minimum disturbance of the remaining pressurized switchgear. Busbars All busbars shall be three-phase or singlephase enclosed and be plug-connected from bay to bay. Circuit-breakers The circuit-breaker shall be of the single pressure (puffer) type with one interrupter per phase*. Heaters for the SF6 gas are not permitted. The circuit-breaker shall be arranged horizontally and the arc chambers and contacts shall be freely accessible. The circuit-breaker shall be designed to minimize switching overvoltages and also to be suitable for out-of-phase switching. The specified arc interruption performance must be consistent over the entire operating range, from line-charging currents to full short-circuit currents. The complete contact system (fingers, clusters, jets, SF6 gas) shall be designed to withstand at least 20 operations at full short-circuit rating without the necessity to open the circuit-breaker for service or maintenance. The maximum tolerance for phase disagreement shall be 3 ms, i.e. until the last pole has been closed or opened, respectively after the first. A highly reliable hydraulic operating mechanism shall be employed for closing and opening the circuit-breaker. A standard station battery required for control and tripping may also be used for recharging the hydraulic operating mechanism.

* two interrupters for voltages exceeding 245 kV

The hydraulic storage cylinder will hold sufficient energy for all standard closeopen duty cycles. The control system shall provide alarm signals and internal interlocks, but inhibit tripping or closing of the circuit-breaker when there is insufficient energy capacity in the hydraulic storage cylinder, or the SF6 density within the circuit-breaker has dropped below a minimum permissible level. Disconnectors All three-phase isolating switches shall be of the single-break type. DC motor operation (110, 125, 220 or 250 V), completely suitable for remote operation, and a manual emergency drive mechanism is required. Each motor-drive shall be self-contained and equipped with auxiliary switches in addition to the mechanical indicators. Life lubrication of the bearings is required. Grounding switches Work-in-progress grounding switches shall generally be provided on either side of the circuit-breaker. Additional grounding switches may be used for the grounding of bus sections or other groups of the assembly. DC motor operation (110, 125, 220 or 250 V), completely suitable for remote operation, and a manual emergency drive mechanism is required. Each motor drive shall be self-contained and equipped with auxiliary position switches in addition to the mechanical indicators. Life lubrication of the bearings is required. High-speed grounding switches Make-proof high-speed grounding switches shall generally be installed at cable and overhead-line terminals. DC motor operation (110, 125, 220 or 250 V), completely suitable for remote operation, and a manual emergency drive mechanism is required. Each motor drive shall be self-contained and equipped with auxiliary position switches in addition to the mechanical indicators. Life lubrication of the bearings is required. These switches shall be equipped with a rapid closing mechanism to provide faultmaking capability. Instrument transformers Current transformers (C. T.) shall be of the dry-type design not using epoxy resin as insulation material. Cores shall be provided with the accuracies and burdens as shown on the SLD. Voltage transformers shall be of the inductive type, with ratings up to 200 VA. They shall be foil-gas-insulated and removable without disturbing the gas compartment to which they are attached.

Siemens Power Engineering Guide · Transmission & Distribution

1/17

Gas-insulated Switchgear for Substations

Cable terminations Single- or three-phase, SF6 gas-insulated, metal-enclosed cable-end housings shall be provided. The stress cone and suitable sealings to prevent oil or gas from leaking into the SF6 switchgear are part of the cable manufacturer’s supply. A mating connection piece, which has to be fitted to the cable end, will be made available by the switchgear supplier. The cable end housing shall be suitable for oil-type, gas-pressure-type and plasticinsulated (PE, PVC, etc.) cables as specified on the SLD, or the data sheets. Facilities to safely isolate a feeder cable and to connect a high-voltage test cable to the switchgear or the cable shall be provided.

Fig. 27: Typical arrangements of bay termination modules

Control An electromechanical or solid-state interlocking control board shall be supplied as a standard for each switchgear bay. This failsafe interlock system will positively prevent maloperations. Mimic diagrams and position indicators shall give clear demonstration of the operation to the operating personnel. Provisions for remote control shall be supplied.

Fig. 25: Transformer/reactor termination module – These termination modules form the direct connection between the GIS and oil-insulated transformers or reactance coils. They can be matched economically to various transformer dimensions by way of standardized modules.

Overhead line terminations

Tests required

Terminations for the connection of overhead lines shall be supplied complete with SF6-to-air bushings, but without line clamps.

Partial discharge tests All solid insulators fitted into the switchgear shall be subjected to a routine partial discharge test prior to being installed. No measurable partial discharge is allowed at 1.1 line-to-line voltage (approx. twice the phase-to-ground voltage). Tolerance: max. 0.4 µV measured at 60 ohms (less than 1 pC). This test ensures maximum safety against insulator failure, good longterm performance and thus a very high degree of reliability.

Fig. 24: Cable termination module – Cable termination modules conforming to IEC are available for connecting the switchgear to high-voltage cables. The standardized construction of these modules allows connection of various cross-sections and insulation types. Parallel cable connections for higher rated currents are also possible using the same module.

Pressure tests Each enclosure of the switchgear shall be pressure-tested to at least double the service pressure, so that the risk of material defects will be fully excluded. Leakage tests Leakage tests are performed on the subassemblies shall ensure that the flanges and covers faces are clean, and that the guaranteed leakage rate will not be exceeded. Power frequency tests Fig. 26: Outdoor termination module – High-voltage bushings are used for transition from SF 6-to-air as insulating medium. The bushings can be matched to the particular requirements with regard to arcing and creepage distances. The connection with the switchgear is made by means of variabledesign angular-type modules.

1/18

Each assembly shall be subjected to power-frequency withstand tests to verify the correct installation of the conductors and also the fact that the insulator surfaces are clean and the switchgear as a whole is not polluted inside.

Siemens Power Engineering Guide · Transmission & Distribution

Gas-insulated Switchgear for Substations

Additional technical data The supplier shall point out all dimensions, weights and other applicable data of the switchgear that may affect the local conditions and handling of the equipment. Drawings showing the assembly of the switchgear shall be part of the quotation. Instructions Detailed instruction manuals about installation, operation and maintenance of the equipment shall be supplied by the contractor in case of an order. For further information please contact: Fax: ++ 49-9131-7-3 46 62

Fig. 28: 8DN9 circuit-breaker control cubicle with gas monitoring devices

Fig. 31: Double-bay arrangement of 8DN9 switchgear being loaded for transport

Fig. 29: OHL connection of a 420 kV system

Fig. 32: 8DP3 cable termination modules

Fig. 30: 8DN9 circuit-breaker operating mechanism with plug connections of control circuits

Fig. 33: 8DP3 transformer termination modules

Siemens Power Engineering Guide · Transmission & Distribution

1/19

Gas-insulated Transmission Lines (GIL)

Introduction For high-power transmission systems where overhead lines are not suitable, alternatives are gas-insulated transmission lines (GIL). The GIL exhibits the following differences in comparison with cables: ■ High power ratings (transmission capacity up to 3000 MVA per System) ■ Suitable for long distances (100 km and more without compensation of reactive power) ■ High short-circuit withstand capability (including internal arc faults) ■ Possibility of direct connection to gasinsulated switchgear (GIS) and gas-insulated arresters without cable entrance fitting ■ Multiple earthing points possible ■ Not inflammable The innovations in the latest Siemens GIL development are the considerable reduction of costs and the introduction of buried laying technique for GIL for long-distance power transmission. SF6 has been replaced by a gas mixture of SF6 and N 2 as insulating medium.

Fig. 34: GIL arrangement in the tunnel of the Wehr pumped storage station (4000 m length, in service since 1975)

Siemens experience Back in the 1960s with the introduction of sulphur hexafluoride (SF6) as an insulating and switching gas, the basis was found for the development of gas-insulated switchgear (GIS). On the basis of GIS experience, Siemens developed SF6 gas-insulated lines to transmit electrical energy too. In the early 1970s initial projects were planned and implemented. Such gas-insulated lines were usually used within substations as busbars or bus ducts to connect gas-insulated switchgear with overhead lines, the aim being to reduce clearances in comparison to air-insulated overhead lines. Implemented projects include GIL laying in tunnels, in sloping galleries, in vertical shafts and in open air installation. Flanging as well as welding has been applied as jointing technique.

1/20

Fig. 35: Siemens lab prototype for dielectric tests

The gas-insulated transmission line technique has proved a highly reliable system in terms of mechanical and electrical failures. Once a system is commissioned and in service, it can run reliably without any dielectrical or mechanical failures reported over the course of 20 years. For example, one particular Siemens GIL will not undergo its scheduled inspection after 20 years of service, as there has been no indication of any weak point. Fig. 34 shows the arrangement of six phases in a tunnel.

Basic design In order to meet mechanical stability criteria, gas-insulated lines need minimum cross-sections of enclosure and conductor. With these minimum cross-sections, high power transmission ratings are given. Due to the gas as insulating medium, low capacitive loads are assured so that compensation of reactive power is not needed, even for long distances of 100 km and more.

Siemens Power Engineering Guide · Transmission & Distribution

Gas-insulated Transmission Lines (GIL)

Several development tests have been carried out in Siemens test labs as well as in cooperation with the French utility company Electricité de France (EDF). Dielectric tests have been undertaken on a lab prototype as shown in Fig. 35. Results of these investigations show that the bulk of the insulating gas for industrial projects involving a considerable amount of such a substance should be nitrogen, a nontoxic natural gas.

Rated voltage

up to 550 kV

Rated current lr

2000–4600 A

Transmission capacity

1500–3000 MVA

Overload capacity

2.2*lr for 10 min. 1.9*lr for 1 h

Capacitance

≈ 60 nF/km

Typical length

1–100 km

Gas mixture SF6/N2 ranging from

10%/90% up to 35%/65%

Laying

directly buried in tunnels/ sloping galleries/ vertical shafts open air installation

Fig. 36: GIL technical data

Reduction of SF6 content However, another insulating gas should be added to nitrogen in order to improve the insulating capability and to minimize size and pressure. A N2/SF6 gas mixture with high nitrogen content (and sulphur hexafluoride portion as low as possible) was finally chosen as insulating medium. To determine the percentage of SF6 an optimization process was needed to find the best possible ratio between SF6 content, gas pressure and enclosure diameter. The basic behaviour of N2/SF 6 gas mixtures shows that with an SF6 content of only 15–25%, an insulating capability of 70–80% of pure SF6 can be attained at the same gas pressure. The technical data of the GIL are shown in Fig. 36.

P/MCD

Technical data

Fig. 37: GIL laying technique

Jointing technique In order to improve the gas-tightness and to facilitate laying, flanges have been avoided as jointing technique. Instead, welding has been chosen to join the various GIL construction units. The welding process is highly automated, with the use of an orbital welding machine to ensure high quality of the joints. This orbital welding machine contributes to high productivity in the welding process and therefore speeds up laying. The reliability of the welding process is controlled by an integrated computerized quality assurance system. Anti-corrosion protection Directly buried gas-insulated transmission lines will be safeguarded by a passive and active corrosion protection system. The passive corrosion protection system comprises a PE or PP coating and assures at least 40 years of protection. The active corrosion protection system provides protection potential in relation to the aluminum sheath. An important requirement taken into account is the situation of an earth fault with a high current of up to 63 kA to earth. Laying The most recently developed Siemens GILs are scheduled for directly buried laying. The laying technique must be as compatible as possible with the landscape and must take account of the sequence of

Siemens Power Engineering Guide · Transmission & Distribution

seasons. The laying techniques for pipelines have been developed over many years and have proved reliable. The highvoltage gas-insulated transmission line needs special treatment where the pipeline technique has to be adapted. The laying process is illustrated in Fig. 37. The assembly area needs to be protected against dust, particles, humidity and other environmental factors that might disturb the dielectric system. Clean assembly therefore plays a major role in setting up cross-country GILs under normal environmental conditions. The combination of clean assembly and productivity is enhanced by a high level of automation of the overall process. A clean assembly tent is essential. References Siemens has gathered experience with gas-insulated transmission lines at rated voltages of up to 550 kV and with system lengths totalling more than 30 km. The first GIL stretch built by Siemens is the connection of the turbine generator/ pumping motor of a pumped storage station with the switchyard. The 420 kV GIL is laid in a tunnel through a mountain and has a length of 4000 m (Fig. 34). This connection was commissioned in 1975 at the Wehr pumped storage station in the Black Forest in Southern Germany.

For further information please contact: Fax ++ 49-9131-7-34490

1/21

Circuit Breakers for 72 kV up to 800 kV

Introduction SF6-insulated circuit breakers Circuit breakers are the main module of both AIS and GIS switchgear. They have to meet high requirements in terms of: ■ Reliable opening and closing ■ Consistent quenching performance with rated and short-circuit currents even after many switching operations ■ High-performance, reliable maintenancefree operating mechanisms. Technology reflecting the latest state of the art and years of operating experience are put to use in constant further development and optimization of Siemens circuit breakers. This makes Siemens circuit breakers able to meet all the demands placed on high-voltage switchgear. The comprehensive quality system, ISO 9001 certified, covers development, manufacture, sales, installation and aftersales service. Test laboratories are accredited to EN 45001 and PEHLA/STL.

Main construction elements Each circuit breaker bay for gas-insulated switchgear includes the full complement of isolator switches, grounding switches (regular or proven), instrument transformers, control and protection equipment, interlocking and monitoring facilities, commonly used for this type of installation (See chapter GIS, page 1/8 and following). Circuit breakers for air-insulated switchgear are individual components and are assembled together with all individual electrical and mechanical components of an AIS installation on site. All Siemens circuit breaker types, whether air- or gas-insulated, consist of the same components of a parts family, i.e.: ■ Interrupter unit ■ Operating mechanism ■ Sealing system ■ Operating rod ■ Control elements.

Interrupter units

Sealing systems

Control elements

Operating mechanism

Parts family

Fig. 38: Circuit breaker parts family

1/22

Siemens Power Engineering Guide · Transmission & Distribution

Circuit Breakers for 72 kV up to 800 kV

Breaker in closed position

Precompression

Gas flow during arc quenching

Breaker in open position

1 1 Upper terminal plate

2

2 Fixed tubes 3 Moving contact

3 6

tube Arc

4

4 Blast cylinder 5 Blast piston 6 Arc-quenching nozzles

5

7 Lower terminal

2

plate

8 Operating rod

8

7

Fig. 39: The interrupter unit

The interrupter unit Current-path assembly The conducting path is made up of the terminal plates (1 and 7), the fixed tubes (2) and the spring-loaded contact fingers arranged in a ring in the moving contact tube (3). Arc-quenching assembly The fixed tubes (2) are connected by the contact tube (3) when the breaker is closed. The contact tube (3) is rigidly coupled to the blast cylinder (4), the two together with a fixed annular piston (5) in between forming the moving part of the break chamber. The moving part is driven by an operating rod (8) to the effect that the SF6 pressure between the piston (5) and the blast cylinder (4) increases. When the contacts separate, the moving contact tube (3), which acts as a shutoff valve, releases the SF6. An arc is drawn between one nozzle (6) and the contact tube (3). It is driven in a matter of milliseconds between the nozzles (6) by the gas jet and its own electrodynamic forces and is safely extinguished.

The blast cylinder (4) encloses the arcquenching arrangement like a pressure chamber. The compressed SF6 flows radially into the break by the shortest route and is discharged axially through the nozzles (6). After arc extinction, the contact tube (3) moves into the open position. In the final position, handling of test voltages in accordance with IEC and ANSI is fully guaranteed, even after a number of short-circuit switching operations.

The operating mechanism

Major features

All hydraulically operated Siemens circuit breakers have a uniform operating mechanism concept, whether for 72 kV circuit breakers with one interrupter unit per pole or breakers from the 800 kV level with four interrupter units per pole. Identical operating mechanisms (modules) are used for single or triple-pole switching of outdoor circuit breakers. The electrohydraulic operating mechanisms have proved their worth all over the world. The power reserves are ample, the switching speed is high and the storage capacity substantial. The working capacity is indicated by the permanent self-monitoring system.

■ Erosion-resistant graphite nozzles ■ Consistently high dielectric strength ■ Consistent quenching capability across

the entire performance range ■ High number of short-circuit breaking

operations ■ High levels of availability ■ Long maintenance intervals.

Siemens Power Engineering Guide · Transmission & Distribution

The operating mechanism is a central module of the high-voltage circuit breakers. Two different mechanism families are available for Siemens circuit breakers: ■ Electrohydraulic mechanism for all AIS and GIS types ■ Spring-stored energy mechanism for AIS types up to 170 kV. The electrohydraulic operating mechanism

1/23

Circuit Breakers for 72 kV up to 800 kV

The force required to move the piston and piston rod is provided by differential oil pressure inside a sealed system. A hydraulic storage cylinder filled with compressed nitrogen provides the necessary energy. Electromagnetic valves control the oil flow between the high- and low-pressure side in the form of a closed circuit. Main features: ■ Plenty of operating energy ■ Long switching sequences ■ Reliable check of energy reserves

at any time ■ Switching positions are reliably

■ ■ ■ ■

maintained, even when the auxiliary supply fails Excessive strong foundations Low-noise switching No oil-leakage and consequently environmentally compatible Maintenancefree.

Fig. 41: Q-range operating unit for GIS circuit breaker 8DN9

Description of function ■ Closing:

The hydraulic valve is opened by electromagnetic means. Pressure from the hydraulic storage cylinder is thereby applied to the piston with two different surface areas. The breaker is closed via couplers and operating rods moved by the force which acts on the larger surface of the piston. The operating mechanism is designed to ensure that, in the event of a pressure loss, the breaker remains in the particular position. ■ Tripping: The hydraulic valve is changed over electromagnetically, thus relieving the larger piston surface of pressure and causing the piston to move onto the OFF position. The breaker is ready for instant operation because the smaller piston surface is under constant pressure. Two electrically separate tripping circuits are available for changing the valve over for tripping.

Fig. 40: Operating unit of the Q-range AIS circuit breakers

Fig. 42: Operating cylinder with valve block and magnetic releases

Monitoring unit and hydraulic pump with motor

P

P

P

P

Oil tank Hydraulic storage cylinder

M

M

N2

Operating cylinder Operating piston Main valve Auxiliary switch

Pilot control Releases

On

Off

Fig. 43: Schematic diagram of a Q-range operating mechanism

1/24

Siemens Power Engineering Guide · Transmission & Distribution

Circuit Breakers for 72 kV up to 800 kV

The spring-stored energy operating mechanism Optional to the hydraulic operating mechanism, Siemens circuit breakers for voltages up to 170 kV can be equipped with springstored energy operating mechanisms. These drives are based on the same principle, which has been proving its worth in Siemens low and medium voltage circuit breakers for decades. The design is simple and robust with few moving parts and a vibration-isolated latch system of highest reliability. All components of the operating mechanism, the control and monitoring equipment and all terminal blocks are arranged compact and yet clear in one cabinet. Depending on the design of the operating mechanism, the energy required for switching is provided by individual compression springs (i.e. one per pole) or by springs that function jointly on a triple-pole basis. The principle of the operating mechanism with charging gear and latching is identical on all types. The differences between mechanism types are in the number, size and arrangement of the opening and closing springs.

1 2 3 4 5 6 7

1

2

10

8 9 10 11 12 13 14 15 16

6

11

17 18

7

12 13

3 9

4 5

Corner gears Coupling linkage Operating rod Closing release Cam plate Charging shaft Closing spring connecting rod Closing spring Hand-wound mechanism Charging mechanism Roller level Closing damper Operating shaft Opening damper Opening release Opening spring connecting rod Mechanism housing Opening spring

Major features at a glance

14

■ Uncomplicated, robust construction ■ ■ ■ ■ ■

with few moving parts Maintenancefree Vibration-isolated latches Load-free uncoupling of charging mechanism Ease of access 10,000 operating cycles

15 16 17 8 18

Fig. 44

Fig. 45: Combined operating mechanism and monitoring cabinet

Siemens Power Engineering Guide · Transmission & Distribution

1/25

Circuit Breakers for 72 kV up to 800 kV

Circuit breakers for air-insulated switchgear standard live-tank breakers The construction All circuit breakers are of the same general design, as shown in the illustrations. They consist of the following main components: 1) Interrupter unit 2) Closing resistor (if applicable) 3) Operating mechanism 4) Insulator column (AIS) 5) Operating rod 6) Breaker base 7) Control unit The simple design of the breakers and the use of many similar components, such as interrupter units, operating rods and control cabinets, ensure high reliability because the experience of many breakers in service could be used for the improvement of the design. The interrupter unit for example has proven its reliability in more than 60,000 units all over the world. The control unit includes all necessary devices for circuit-breaker control and monitoring, such as:

Fig. 46: 145 kV circuit breaker 3AQ1FG with triple-pole spring stored-energy operating mechanism

Fig. 47: 800 kV circuit breaker 3AT5

■ Pressure/SF6 density monitors ■ Gauges for SF6 and hydraulic pressure ■ ■ ■ ■ ■

(if applicable) Relays for alarms and lockout Antipumping devices Operation counters (upon request) Local breaker control (upon request) Anticondensation heaters.

Transport, installation and commissioning are performed with expertise and efficiency. The tested circuit breaker is shipped in the form of a small number of compact units. If desired, Siemens can provide appropriately qualified personnel for installation and commissioning.

Fig. 48: 245 kV circuit breaker 3AQ2

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Siemens Power Engineering Guide · Transmission & Distribution

Circuit Breakers for 72 kV up to 800 kV

1 1

7

2

3

5 6

2 8

5 1 2 3 4

Interrupter unit Closing resistor Valve unit Electrohydraulic operating mechanism 5 Insulator columns 6 Breaker base 7 Control unit

9 13 12 10 11 4

3 4 1 Interrupter unit 2 Arc-quenching nozzles 3 Moving contact 4 Filter 5 Blast piston 6 Blast cylinder 7 Bell-crank mechanism 8 Insulator column 9 Operating rod 10 Hydraulic operating mechanism 11 ON/OFF indicator 12 Oil tank 13 Control unit

7 6 Fig. 49: Type 3AT4/5

1 2 5 6 3

7 8

10

11

4

Fig. 51: Type 3AQ2

1 2 3 4 5 6 7 8 9 10 11

Interrupter unit

Arc-quenching nozzles Moving contact Filter Blast cylinder Blast piston Insulator column Operating rod Hydraulic operating mechanism

Control unit SF6 density monitor

9

Fig. 50: Type 3AQ1-E Siemens Power Engineering Guide · Transmission & Distribution

1/27

Circuit Breakers for 72 kV up to 800 kV

h

h

d

d

Type

3AP1/3AQ1

Electrical data Rated voltage Interrupter units per pole Type of operating mechanism Standards Rated power frequency withstand voltage 1 min Rated lightning impulse withstand voltage 1.2/50 µs Switching impulse withstand voltage 250/2500 µs Rated current up to Rated-short-time current (1–3 s) Rated peak withstand current Autoreclosure Break time 3AP/3AQ 3AT Rated duty cycle Auxiliary power supply for operating mechanism motor Control voltages

72.5

123

145 170 1 Spring-stored-energy/Electrohydraulic

245

[kV]

140

230

275

325

460

[kV]

325

550

650

750

1050

[kV] [A] [kA] [kA]

For rated voltage < 300 kV, no tests with switching impulse withstand voltage prescribed 4000 4000 4000 4000 4000 40 40 40 40/50 50 100 100 100 100/125 125 Triple-pole or single- and triple-pole 3 cycles (3AP/3AQ)

48…250= or ~120…240 V/50 Hz, 120…280 V/60 Hz 48…250 V=

Basic design Minimum striking distance Minimum creepage distance Circuit breaker weight approx. Main dimensions: Depth d Height h

[mm] [mm] [kg] [mm] [mm]

700 1813 1350 660 3810

1250 3625 1500 660 4360

1250 3625 1500 660 4360

1500 4250 2000 1280 4065

2200 6150 3000 1280 5485

Maintenance Inspection due after

25 years or 6000 operating cycles The values stated are nominal (VDE, IEC). Other values on request.

Fig. 52: Product range/ratings

1/28

Siemens Power Engineering Guide · Transmission & Distribution

Circuit Breakers for 72 kV up to 800 kV

d

d

h

h

3AQ2/3AT2/3AT3*

245

300

3AT4/3AT5*

362 2 Electrohydraulic DIN VDE, IEC, ANSI

420

550

362

460

435

520

610

800

450/520

1050

1050

1175

1425

1550

1175

4000 50/80 125/200

850 4000 50/63 125/160

950 4000 50/63 125/160

1050 4000 50/63 125/160

420

550 4

765/800

520/610

620/760

830/1100

1425

1550

2100

1050 4000 80 200

1175 4000 80 200

1425/1550 4000 63 160

3300 9075 14700 6830 6000

3800 10190 19200 7505 6550

5000 13860 23400 9060 8400

Electrohydraulic

1175 950 4000 4000 50/63 80 125/160 200 Single- and triple-pole 2cycles (3AT)

O-0,3 sec-CO-3 min-CO or CO-15 sec-CO 48…250 V= or ~ 280/120…500/298 48…250 V=

2200 6150/6050 3600/5980 2995/4060 3790/4490

2750/2200 7875/6050 4390/6430 3895/4025 4385/4490

2750/2200 7875/7165 5010/9090 3695/4280 4400/9300

3300 10375/9075 5500/8600 4195/4280 10500/10100

3800 13750 12500 5135 13690

25/20 years or 6000 operating cycles

2700 7165 14400 6830 4990

20 years or 6000 operating cycles * with closing resistor

Siemens Power Engineering Guide · Transmission & Distribution

1/29

Circuit Breakers for 72 kV up to 800 kV

Circuit breakers in dead-tank design Bushings

For certain substation designs, dead-tank circuit breakers might be required instead of the standard live-tank breakers. For these purposes Siemens can offer the dead-tank circuit breaker types.

Current transformers

Main features at a glance Reliable opening and closing ■ Proven contact and arc-quenching

system ■ Consistent quenching performance

with rated and short-circuit currents even after many switching operations ■ Similar uncomplicated design for all voltages

Pressure gauges

High performance, reliable operating mechanisms ■ Easy-to-actuate spring operating

Interrupters

mechanisms ■ Hydraulic operating mechanisms with on-line monitoring Economy ■ Perfect finish ■ Simplified, quick installation process ■ Long maintenance intervals ■ High number of operating cycles ■ Long service life

Control cabinet and SE-4 spring mechanism

Individual service ■ Close proximity to the customer ■ Order specific documentation

Base legs

■ Solutions tailored to specific problems ■ After-sales service available promptly

worldwide The right qualifications ■ Expertise in all power supply matters ■ 30 years of experience with SF6-insulat-

ed circuit breakers ■ A quality system certified to ISO 9001, covering development, manufacture, sales, installation and after-sales service ■ Test laboratories accredited to EN 45001 and PEHLA/STL

1/30

Fig. 53: SPS-circuit breaker 145 kV

Subtransmission breaker Type SPS power circuit breakers are designed as general, definite-purpose breakers for application at maximum rated voltages of 121 and 145 kV. Rated interrupting capacities are 20, 25, 31.5 or 40 kA. Continuous current ratings are up to 3000 A (Fig. 53).

Siemens Power Engineering Guide · Transmission & Distribution

Circuit Breakers for 72 kV up to 800 kV

Transmission class puffer Type TCP (transmission class puffer) breakers are designed as general, definitepurpose breakers for application at maximum rated voltages of 121, 145, 169 and 242 kV. Rated interrupting capacities for the 121 and 145 kV breakers are 20, 25, 31.5, 40 or 50 kA. The 169 and 242 kV units have interrupting ratings of up to 60 kA. Continuous current ratings are up to 3000 A. The breakers are designed and tested to meet ANSI, IEEE, NEMA, IEC standards (Fig. 54/55). Features are: ■ Dead-tank construction ■ State-of-the-art interrupter design ■ Extension of the high quality, reliable

SP-72.5 breaker SE-4 spring mechanism ■ Light weight, simple design ■ Porcelain bushings ■ Bushing current transformers

(space for 3 per bushing) ■ Low operating pressure ■ Tested and verified for seismic appli-

cation ■ Minimal noise ■ 40 °C / –50 °C application ■ Shipped fully assembled.

Savings in installation

Fig. 54: TCP-circuit breaker 145 kV

■ Factory preassembly, testing and timing

with no internal field adjustments ■ Minimal gas handling. Shipped with

0.5 bar positive pressure ■ Minimal transportation and equipment

handling. Truck shipment to site ■ Easy access for final wiring ■ Negligible foundation loading ■ Location of control cabinet allows for

easy, direct breaker replacement for system upratings ■ Compact design allows use of existing foundations.

Fig. 55: SP-circuit breaker 72.5 kV

Siemens Power Engineering Guide · Transmission & Distribution

1/31

Circuit Breakers for 72 kV up to 800 kV

The construction The type SPS breaker consists of three identical pole units mounted on a common support frame. The opening and closing force of the SE-4 spring operating mechanism is transferred to the moving contacts of the interrupter through a system of connecting rods and a rotating seal at the side of each phase. The tanks and the porcelain bushings are charged with SF6 gas at a nominal pressure of 5.5 bar. The SF6 serves as both insulation and arc-quenching medium. A control cabinet mounted at one end of the breaker houses the spring operating mechanism and breaker control components. Interrupters are located in the aluminum housings of each pole unit. The interrupters use the latest Siemens puffer arcquenching system. The spring operating mechanism is the same design as used with the Siemens SP breakers. This design has been in service for years, and has a well documented reliability record. Customers can specify up to four (in some cases, up to six) bushing type current transformers (CT) per phase. These CTs, mounted externally on the aluminum housings, can be removed without disturbing the bushings. Operating mechanism The type SE-4 mechanically and electrically tripfree spring mechanism is used on type SPS breakers. The type SE-4 closing and opening springs hold a charge for storing ”open-close-open“ operations (Fig. 56). A weatherproof control cabinet has a large door, sealed with rubber gaskets, for easy access during inspection and maintenance. Anticondensation units (475 W) offer continuous inside/outside temperature differential for prevention of condensation.

Transformer terminal blocks

SF6 monitoring equipment

Control terminal blocks

Control panel

Auxiliary switch

Closing mechanism

Closing spring

Motor

Fig. 56: Operating mechanism

Included in the control cabinet are necessary auxiliary switches, cutoff switch, latch check switch, alarm switch and operation counter. The control relays and three control knife switches (one each for the control, heater and motor) are mounted on a control panel. Terminal blocks on the side and rear of the housing are available for control and transformer wiring. The SE-4 is ideally suited for high-speed reclosing. Reclosing speeds of 10 cycles from the instant of initial tripping impulse until the current is reestablished are common. For further information please contact: Fax: ++49 -3 03 86 -2 58 67

1/32

Siemens Power Engineering Guide · Transmission & Distribution

Circuit Breakers for 72 kV up to 800 kV

The new 3AT2/3-DT Circuit Breaker Composite insulators The new 3AT2/3-DT is available with bushings made from composite insulators – this has many practical advantages. The SIMOTEC® composite insulators manufactured by Siemens consist of a basic body made of epoxy resin reinforced glass fibre tubes. The external tube surface is coated with vulcanised silicone. As is the case with porcelain insulators, the external shape of the insulator has a multished profile. Field grading is implemented by means of a specially shaped screening electrode in the lower part of the composite insulator. The bushings and the metal tank of the circuit breaker surround a common gas volume. The composite insulator used on the bushing of the 3AT2/3-DT is a onepiece insulating unit. Compared with conventional housings, composite insulators offer a wide range of advantages in terms of economy, efficiency and safety. Interrupter unit The 3AT2/3-DT pole consists of two breaking units in series impressive in the sheer simplicity of their design. The tried and tested Siemens contact system with double graphite nozzles guarantees faultless operation, consistently high arc-quenching capacity and a long operating life, even at high switching frequencies. Thanks to constant further development, optimisation and consistent quality assurance, Siemens arc-quencing systems meet all the requirements placed on modern high voltage technology. Hydraulic Drive The operating energy required for the 3AT2/3-DT interrupters is provided by the hydraulic drive, which is manufactured inhouse by Siemens. The functional principle of the hydraulic drive constitutes a technically clear solution which offers certain fundamental advantages. Hydraulic drives provide high amounts of energy economically and reliably. In this way, even the most demanding switching requirements can be mastered in short opening times.

Fig. 57: The new 3AT2/3-DT circuit breaker with SIMOTEC composite insulator bushings

Siemens hydraulic drives are maintenancefree and have a particulary long operating life. They meet the strictest criteria for enviromental acceptability. In this respect, too, Siemens hydraulic drives have proven themselves through decades of operation. For further information please contact: Fax: ++ 49 - 3 03 86 - 2 58 67

Siemens Power Engineering Guide · Transmission & Distribution

1/33

Circuit Breakers for 72 kV up to 800 kV

d d

h h

Type

SP/SPS*

SPS

Electrical data Rated voltage

[kV]

72.5

121

145

Interrupter units per pole

1

1

1

Type of operating mechanism

Spring-stored-energy

Standards

ANSI/IEEE/NEMA/IEC

Rated power frequency withstand voltage

1 min

[kV]

160

260

310

Rated lightning impulse withstand voltage

1.2/50 µs [kV]

350

550

650

Rated current up to

[A]

3000

3000

3000

Rated-short-time current (1–3 s) Rated peak withstand current

[kA] [kA]

20/31.5/40 54/85/108

20/25/31.5/40 54/67/85/108

20/25/31.5/40 54/67/85/108

[cycles]

3

3

3

Autoreclosure

Triple-pole

Break time Rated duty cycle

O-CO-15 s-CO

Auxiliary power supply for operating mechanism motor

250/125 VDC or 110/230 VAC single-phase

Control voltages

125/250 VDC

Basic design Minimum striking distance [mm]

480 (730)

1160

1160

[mm]

1280 (1850)

2360

2360

Circuit breaker weight approx.

[kg]

1750

3250

3250

Main dimensions:

[mm] [mm]

1600 (2400) 3330 (3500)

2100 2780

2100 2780

Minimum creepage distance Depth d Height h

Maintenance Inspection due after

6 years/2000 operating cycles

* The design of these breakers is slightly different. For details please inquire.

Fig. 58: Product range/ratings

1/34

Siemens Power Engineering Guide · Transmission & Distribution

Circuit Breakers for 72 kV up to 800 kV

d

d

h

h

TCP*

3AT2/3-DT

121

145

169

242

550

1

1

1

1

2

Electrohydraulic

Hydraulic

ANSI/IEEE/NEMA/IEC

ANSI/IEC

260

310

365

425

860

550

650

750

900

1800

3000

3000

3000

3000

4000

20/31.5/40/50 54/85/108/135

20/31.5/40/50/63 54/85/108/135/170

63 170

Triple-pole 3

Single- and triple-pole 3

3

3

2

O-CO-15 s-CO

O-0.3 s-CO-3 s-CO or CO-15 s-O

250/125 VDC or 110/230 VAC single-phase

60…250 VDC or 120…380 VAC

125/250 VDC

60…250 VDC

1190

1190

1620

1620

4460

2330

2330

3550

3550

11000

4300

4300

5500

5500

21800

2330 4036

2330 4036

2590 4780

2590 4780

2250 (single-pole) 8440

25 years

Siemens Power Engineering Guide · Transmission & Distribution

1/35

High-voltage Direct Current Transmission

HVDC Where AC technology reaches its limits, DC expands the possibilities, e.g. ■ For economic transmission of bulk

power over long distances ■ For power across the sea over a

distance of ≈ 50 km

■ For the connection of asynchronous

power grid systems ■ For the connection of synchronous but

weak power grid systems ■ For additional active power exchange

without increasing the short-circuit power ■ For the increase of transmission capacity on existing rights-of-way. Siemens offers HVDC systems as ■ Back-to-Back (B/B) ■ Cable Transmission (CT) and ■ Long-distance Transmission Systems

(LD). Back-to-Back (B/B): To connect asynchronous high voltage power systems or systems with different frequencies. To stabilize weak AC links or to supply even more active power, where the AC system reaches the short-circuit capability.

Fig. 59: Interconnected system operation

Cable transmission (CT): To transmit power across the sea with cables to supply islands/offshore platforms from the mainland and vice versa.

Fig. 60: Cable transmission

Long-distance transmission (LD): To transmit bulk power over long distances, e.g. 1000 km and more.

Fig. 62: Earthquakeproof, fire-retardent thyristor valves in Sylmar East, Los Angeles, CA

Special features

Turnkey service Experienced staff is prepared to design and install the whole HVDC system on a trurnkey basis and ready for operation. Siemens is also able to assist in finding a proper project financing.

Valve technology ■ Simple, easy-to-maintain mechanical

design ■ Use of fire-retardant, self-extinguish-

ing material

General services

■ Minimized number of electrical

connections ■ Minimized number of components ■ Avoidance of potential sources of failure ■ ”Parallel“ cooling for the valve levels ■ Oxygen-saturated cooling water. After about 20 years of operation the valves have demonstrated the superiority of these design criteria as well as excellent reliability. Control system High-performance standard system with many applications in different fields. Use of ”state-of-the-art“ microprocessor systems for all functions. Redundant design for fault-tolerant systems.

Studies for: ■ System dynamic response ■ Load flow and reactive power balance ■ HVDC system basic design ■ Interference of radio and PLC ■ Harmonic voltage distorsion ■ Insulation coordination ■ Assistance for drafting the specification ■ Maintenance ■ Upgrading/replacement of components/ redesign for older schemes, e.g. mercury-arc valves or relay-based controls ■ General support from the very beginning of a HVDC planning to assistance during operation. Typical values

Filter technology Single-, double- and triple-tuned as well as high-pass passive filters, or any combination thereof, can be installed. Active filters, mainly for the DC circuit, are available. Wherever possible, identical filters are selected so that the performance does not significantly change when one filter has to be switched off.

Typical values are found in but not limited to the following ranges: B/B: 100 ... 600 MW CT: 100 ... 800 MW LD: 300 ... 3000 MW (bipolar) Where the lower value is mainly determined by economic aspects and the upper value is limited by the constraints of the connected networks.

Fig. 61: Long-distance transmission

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Siemens Power Engineering Guide · Transmission & Distribution

High-voltage Direct Current Transmission

Rehabilitation and modernization of existing HVDC stations The integration of state-of-the-art microprocessor systems or thyristors allows the owner better utilization of his investment, e.g. ■ Higher availability ■ Fewer outages ■ Fewer losses ■ Better performance values ■ Less maintenance.

Higher availability means more operating hours, better utilization and higher profits for the owner. The new Man-Machine Interface (MMI) system enhances the user friendliness and increases the reliability considerably due to the operator guidance. This excludes a maloperation by the operator, because an incorrect command will be ignored by the MMI. For further information please contact: Fax: ++49 - 9131-73 35 66

Fig. 63: HVDC outdoor valves, 533 kV

MMI

GPS LAN VCS Pole 1

SER

MMI GPS OLC CLC VBE VCS SER

Man-machine Interface Global Positioning System Open Loop Control Closed Loop Control Valve Base Electronics Valve Cooling Systems Sequence of Event Recording TFR Transient Fault Recording LAN Local Area Network

OLC Pole 1

OLC SC

CLC VBE Pole 1

Communication link to the remote station

TFR

OLC Pole 2 CLC VBE Pole 2

DC Protection

VCS Pole 2 Communication link to the load dispatch center

TFR

Communication link to the remote station

DC Yard

Fig. 64: Man-machine Interface with structure of HVDC control system

Siemens Power Engineering Guide · Transmission & Distribution

1/37

Power Compensation in Transmission Systems

Introduction In many countries increasing power consumption leads to growing and more interconnected AC power systems. These complex systems consist of all types of electrical equipment, such as power plants, transmission lines, switchgear transformers, cables etc., and the consumers. Since power is often generated in those areas of a country with little demand, the transmission and distribution system has to provide the link between power generation and load centers. Wherever power is to be transported, the same basic requirements apply:

Types of reactive power compensation Parallel compensation Parallel compensation is defined as any type of reactive power compensation employing either switched or controlled units, which are connected parallel to the transmission network at a power system node. In many cases switched compensation (reactors, capacitor banks or filters) can provide an economical solution for reactive power compensation using conventional switchgear.

■ Power transmission must be economical ■ The risk of power system failure must

be low

1

■ The quality of the power supply must

be high However, transmission systems do not behave in an ideal manner. The systems react dynamically to changes in active and reactive power, influencing the magnitude and profile of the power systems voltage.

In comparison to mechanically-switched reactive power compensation, controlled compensation (SVC, Fig. 65) offers the advantage that rapid dynamic control of the reactive power is possible within narrow limits, thus maintaining reactive power balance. Fig. 66 is a general outline of the problemsolving applications of SVCs in high-voltage systems. Series compensation Series compensation is defined as insertion of reactive power elements into transmission lines. The most common application is the series capactior. By providing continuous control of transmission line impendance, the Advanced Series Compensation (ASC, Fig. 67) scheme offers several advantages to conventional fixed series capacitor installations. These advantages include continuous control of the desired compensation level, direct smooth control of power flow within the network and improved capacitor-bank protection.

Voltage control Reactive power control Overvoltage limitation at load rejection Improvement of AC-system stability Damping of power oscillations Reactive power flow control Increase of transmission capability Load reduction by voltage reduction Subsynchronous oscillation damping

Examples: ■ A load rejection at the end of a long-dis-

tance transmission line will cause high overvoltages at the line end. However, a high load flow across the same line will decrease the voltage at its end. ■ The transport of reactive power through a grid system produces additional losses and limits the transmission of active power via overhead lines or cables. ■ Load-flow distribution on parallel lines is often a problem. One line could be loaded up to its limit, while another only carries half or less of the rated current. Such operating conditions limit the actual transmittable amount of active power. ■ In some systems load switching and/or load rejection can lead to power swings which, if not instantaneously damped, can destabilize the complete grid system and then result in a “Black Out”. Reactive power compensation helps to avoid these and some other problems. In order to find the best solution for a grid system problem, studies have to be carried out simulating the behavior of the system during normal and continuous operating conditions, and also for transient events. Study facilities which cover digital simulations via computer as well as analog ones in a transient network analyser laboratory are available at Siemens.

4

2 1 2 3 4

4

3

Transformer Thyristo-controlled reactor (TCR) Fixed connected capacitor/filter bank Thyristor-switched capacitor bank (TSC)

Fig. 65: Typical single-line diagram of static VAr compensator (SVC)

Damping circuit

Fig. 66: Duties of SVCs

Damping circuit

Circuit breaker

MOV arrester

Thyristor valve

Circuit breaker

MOV arrester

MOV arrester

Conventional series capacitor 40 Ω

Conventional series capacitor 55 Ω

Reactors ASC 15 to 60 Ω Fig. 67: Advanced Series Compensation (ASC). Example: Single-line diagram ASC Kayenta

1/38

Siemens Power Engineering Guide · Transmission & Distribution

Power Compensation in Transmission Systems

Further information please contact:

Comparison of reactive power compensation facilities

Fax: ++ 49 - 9131-73 45 54

Below are the characteristics and application areas of series and parallel compensation and the influence on various parameter such as short-circuit rating, transmission phase angle and voltage behavior at the load.

Behavior of compensation element Compensation element 1

Location

Shunt capacitor

E

2

Shunt reactor

4

Static VAr compensator (SVC)

E

Series capacitor

Little influence

Voltage rise

Little influence

High

Voltage stabilization at high load

Little influence

Voltage drop

Little influence

Low

Reactive power compensation at low load; limitation of temporary overvoltage

Little influence

Controlled

Little influence

Limited by control

Reactive power and voltage control; damping of power swings to improve system stability

Increased

Very good

Much smaller

(Very) low

Long transmission lines with high transmission power rating

Reduced

(Very) slight

(Much) larger

(Very) high

Short lines, limitation of S. C. power

Variable

Very good

Much smaller

(Very) low

Long transmission lines; Power flow distribution between parallel lines and SSR damping

U

Series reactor

Advanced series compensation (ASC) scheme

Voltage after load rejection

SVC U

E

6

Transmission phase angle

U

E

5

Voltage influence

Good for

U

E

3

Shortcircuit level

U

ASC

E

U

Fig. 68: Components for reactive power compensation

Siemens Power Engineering Guide · Transmission & Distribution

1/39

Power Compensation in Distribution Systems

Possible applications

Introduction

SIPCON-S 1. Active filtering

SIPCON (Siemens Power Conditioner) is a system for the improvement of power quality in low- and medium-voltage distribution networks. This system fits within the general framework of EQM equipment (Energy Quality Management). The tremendous progress of recent years, with regards to the rating and price of power semiconductor technology, is reflected in this system. Using the same hardware, there are various SIPCON configurations. Each configuration is coupled to the electrical network in a different manner and has one or more specific tasks to fulfill.

Areas of application The manner in which SIPCON is coupled to the network is dependent on the tasks the system will perform. To distinguish between the various configurations, the initial of the coupling method is attached to the name SIPCON, leading to the names SIPCON-P (parallel), SIPCON-S (series) and SIPCON-U (unified). In general, the SIPCON-P is intended for conditioning of the current flowing from a load into the network. It improves the network current. The SIPCON-S improves the quality of the voltage supplied by the network to the load. It improves the supply voltage quality. The SIPCON-U is a combination of the other two variants and unites their capabilities.

SIPCON-P improves network currents The coupling of the SIPCON-P is threephase, in parallel to the network and the load (Fig. 69).To fullfill its control task, improvement of the network current, the SIPCON-P injects currents into the PCC (point of common coupling).

SIPCON-P Grid

Load PCC Coupling inductivity

IGBT converter DC link capacitor Fig. 69: SIPCON-P connection

1/40

Grid

The current flowing from the load into the network is measured and divided into fundamental and harmonic components. The SIPCON-P injects currents such that load harmonic currents are exclusively exchanged between the SIPCON-P and the load, Harmonic currents thus do not flow on the network side.

Load Transformer

Diode bridge

IGBT converter DC link capacitor

Fig. 70: SIPCON-S connection

2. Dynamic reactive power compensation The SIPCON-P can dynamically supply stepless reactive power, in both capacitive and inductive modes. It is possible to go from no-load operation to nominal operation in about two network periods. Power factor control (cos ϕ-control) is also possible in this mode.

Possible applications 1. Voltage sags and swells It is possible for the SIPCON-S to add an additional voltage component to the network voltage, thereby compensating voltage sags and swells.

3. Active load balancing

2. Harmonic reduction Besides the fundamental voltage it is also possible to generate harmonic voltages. If the supply voltage contains harmonic distortion, the SIPCON-S can add up to three discrete voltage harmonics to the network voltage. The load thus sees a less distorted supply voltage.

SIPCON-P can inject both positive- and negative-sequence currents into the PCC. It is thus possible to eliminate negativesequence currents associated with unbalanced load conditions, thereby performing active load balancing. 4. Flicker compensation Variation in the brightness of lighting systems that is uncomfortable to humans is called flicker. Flicker is caused by sudden, stochastic load current peaks which cause voltage drops at the PCC across the network impedance. A special flicker algorithm has been developed for SIPCON-P, whereby the peak load currents are exchanged between the SIPCON-P and the load, rather than supplied by the network.

SIPCON-U improves the network currents and the supply voltage

5. Active power exchange An energy source can be connected to the DC link capacitor, thus allowing energy transfer into the network from the converter. The SIPCON-P injects energy in a very network-friendly manner, causing practically no harmonics below 3 kHz.

SIPCON-S improves the supply voltage

The SIPCON-U is a combination of the SIPCON-P and SIPCON-S systems. The DC link capacitors of both systems are connected in parallel, forming a single DC link capacitor used by both systems (Fig. 71). The SIPCON-U is in fact a UPFC (Unified Power Flow Controller) for distribution networks. The possible applications of such a system are given by the union of the features of each single system. In addition, the SIPCON-U can transfer active power in both directions, so that one SIPCON-U can be used to compensate both voltage sags and swells.

SIPCON-U Grid

The series-connected SIPCON-S is coupled directly into the power flow via a transformer (Fig. 70). The SIPCON-S can be viewed as a controlled voltage source connected in series with the network.

Load Transformer

Coupling inductivity IGBT converter

IGBT converter DC link capacitor

Fig. 71: SIPCON-U

Siemens Power Engineering Guide · Transmission & Distribution

Power Compensation in Distribution Systems

Power Factor Correction and Harmonic suppression

Incoming feeder from power system

UPh 20 kV

Basic principles The vast majority of electrical loads draw not only active power but also reactive power which, in the case of motors and transformers, for example, is required for magnetization and, in the case of static converters, as control and communication reactive power. Generators, overhead transmission lines, cables, transformers and switchgear are required for generation and distribution of electric power. In addition to active power, reactive power must also be generated and distributed. This is uneconomical, and the less reactive power a plant consumes, i.e. the higher its power factor cosϕ is, the lower are the power costs for the plant. The load on the electrical distribution system can be reduced by installing powerfactor correction capacitors close to the loads in the low-voltage system since the reactive power is then supplied by the capacitors. The transmission losses are less, the power costs are lower and expensive uprating of the distribution system can be avoided since more active power can now be transmitted by the existing equipment. Capacitors may be employed for individual compensation, for group compensation or for centralized compensation. It has become standard practice for many utilities to specify a power factor greater than or equal to 0.9. Harmonics As a result of continuing development of power electronic equipment, the number of converter-fed loads has increased considerably in recent years. Advanced technology employing thyristors is now common to a broad range of applications. For example, drives with variable speed and output can be operated more economically by using converter-fed motors.

IL I(5) I(7)

I(1)

ϕt 400 V

Ib

Iw

π

0

2π

M Fig. 72: Principle of power factor correction employing low voltage power capacitors

The converter current is composed of a series of sinusoidal currents, with a fundamental power frequency component and a series of harmonics, whose frequency is an integer multiple of the power frequency. The harmonic currents are injected in the three-phase power supply system. As a result, harmonic voltages, which appear across the power system impedances, are superimposed on the fundamental frequency and thus distort the system voltage. This can lead to disturbances in the system and may cause failure of other loads. Design and operation of filter circuits The effect of harmonic currents on the power supply system can be reduced to a significant extent by connecting filter circuits which comprise series resonant circuits employing reactors in series with capacitors. The resonant circuits are tuned so as to present an impedance for the individual harmonic currents, which is almost zero and thus negligible in comparison to the impedance of the power system. The harmonic currents of the converters are thus largely absorbed by the filter circuits. Only the remainder flows into the power supply system. So the voltage is distorted to a lesser degree and interference with other loads is largely obviated. Power-factor correction by means of inductive-type capacitors The use of inductive-type capacitors for power-factor correction is often necessary in order to avoid resonance effects. Their design is similar to that of filter circuits, but their resonant frequency lies below the 5th harmonic.

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 73: Resolving of converter current into fundamental-frequency and harmonic components

Primary distribution system Transformer

to power system

Low-voltage

from to filter converter circuits ΣI(υ) υ=5

M Converter

υ=7

υ= 11,13

Filter circuits or inductive-type capacitors

Fig. 74: Removing the harmonic currents by means of filter circuits or inductive-type capacitors

As a result, the capacitor unit presents an inductive reactance to all the harmonics contained in the converter current so that resonant frequencies cannot occur. Inductive-type capacitors and power-factor correction units should be selected and employed in the same manner as normal capacitors and control units. It is recommended that inductive-type capacitors be used for cases where more than 20% of the load is made up of equipment which generates harmonics (Fig. 74). For further information please contact: Fax: ++ 49 - 9131-7 3 13 74

1/41

Surge Arresters

The main task of an arrester is to protect equipment from the effects of overvoltages. During normal operation, it should have no negative effect on the power system. Moreover, the arrester must be able to withstand typical surges without incurring any damage. Nonlinear resistors with the following properties fulfill these requirements: ■ Low resistance during surges so that overvoltages are limited ■ High resistance during normal operation, so as to avoid negative effects on the power system and ■ Sufficient energy absorption capability for stable operation With this kind of nonlinear resistor, there is only a small flow of current when continuous operating voltage is being applied. When there are surges, however, excess energy can be quickly removed from the power system by a high discharge current. Nonlinear resistors, whether comprising silicon (SiC) carbide or the metal oxide (ZnO), have proved especially suitable for this. These two kinds of resistors have different degrees of nonlinearity. Fig. 75 shows the current/voltage characteristics of both types. When SiC resistors are used, series gaps have to be connected in series to the resistors, whereby the series gaps separate the resistors from the power system under power-frequency voltage conditions. Otherwise, an excessively large amount of current would flow with this kind of resistor during normal operation. In order to stabilize the sparkover voltage of the series gaps, RC control devices are used (Fig. 76). The nonlinearity of ZnO is considerably more pronounced than of SiC. For this reason, MO arresters, as the arresters with ZnO resistors are known today, normally do not need series gaps. Siemens has many years of experience with arresters – whether SiC or MO-based – in low-voltage systems, distribution systems and transmission systems. They are usually used for protecting transformers, generators, motors, capacitors, traction vehicles, cables and substations. There are special applications such as the protection of ■ Equipment in areas subject to

earthquakes or heavy pollution ■ Surge-sensitive motors and dry-type transformers ■ Generators in power stations with arresters which posses a high degree of short-circuit current strength ■ Gas-insulated high-voltage metalenclosed switchgear (GIS)

1/42

SiC

Arrester voltage referred to continuous operating voltage Û/ÛC

ZnO Rated voltage ÛR Continuous operating voltage ÛC

2

1 20 °C 115 °C 150 °C

0

10-4

10-3

10-2

10-1

1

10

102

103

104

Current through arrester Ia [A] Fig. 75: Current/voltage characteristics of non-linear SiC and ZnO resistors

SiC arrester

MO arrester

Series spark gap and RC control

SiC discharge resistor

MO discharge resistor

Fig. 76: Equivalent circuit diagrams of the two kinds of arresters ■ Thyristors in HVDC transmission

installations ■ Static compensators ■ Airport lighting systems ■ Electric smelting furnaces in the glass

and metals industries ■ High-voltage cable sheaths ■ Test laboratory apparatus.

Siemens Power Engineering Guide · Transmission & Distribution

Surge Arresters

Flange with gas diverter nozzle Seal Pressure relief diaphragm Compressing spring

Metal oxide resistors

Composite polymeric housing FRP tube/silicone sheds

Fig. 78: Cross section of a polymeric-housed arrester

Fig. 77: Measurement of residual voltage on porcelain-housed (foreground) and polymeric-housed (background) arresters

The availability of both technologies, SiC and MO, ensures that arresters can be inexpensively provided for any kind of overvoltage problem whatsoever. Due to the different ways in which they work and their different operating characteristics, each kind of arrester technology has its own very specific advantages. Because of the simpler base materials and manufacturing procedures of SiC resistors, SiC arresters are less expensive than MO arresters, especially for distribution systems. In addition, the special current/ voltage characteristic of SiC is more favourable for certain applications. It makes sense to use SiC arrester where the qualities of the MO arrester cannot be fully exploited. MO arresters are best used in high and extra-high-voltage power systems with solid neutral earthing. Here, the very low protection level and the high energy ab-

sorption capability provided during switching surges are especially important. For high voltage levels, the simple construction of MO arresters is always an advantage. In contrast, SiC arresters for higher voltages are becoming increasingly complicated in structure and therefore less economical. Another very important advantage of MO arresters is their high degree of reliability when used in areas with a problematic climate, for example in coastal and desert areas, or regions affected by heavy industrial air pollution. Furthermore, some special applications have become possible only with the introduction of MO arresters. One instance is the protection of capacitor banks in series reactive-power compensation equipment which requires extremly high energy absorption capabilities. Fig. 77 shows two Siemens MO arresters with different types of housing. In addition to what has been usual up to now – the porcelain housing – Siemens offers also the latest generation of high-voltage surge arresters with polymeric housing. Fig. 78 shows the sectional view of such an arrester. The housing consists of a fiberglass-reinforced plastic tube with insulating sheds made of silicone rubber. The advantages of this design are absolutely safe and reliable pressure relief characteristics, high mechanical strength even after pressure relief and excellent pollution-resistant

Siemens Power Engineering Guide · Transmission & Distribution

properties. The very good mechanical features mean that Siemens arresters with polymeric housing (type 3EQ/R) can serve as post insulators as well. The pollutionresistant properties are the result of the water-repellent effect (hydrophobicity) of the silicone rubber, which even transfers its effects to pollution. The polymeric-housed high-voltage arrester design chosen by Siemens and the highquality materials used by Siemens provide a whole series of advantages including long life and suitability for outdoor use, high mechanical stability and ease of disposal. Please find an overview about the complete range of Siemens arresters in Fig. 79a and 79b. For further information please contact: Fax: ++ 49 - 3 03 86 -2 67 21

1/43

Surge Arresters

Silicon Carbide (SiC) (gapped type) 3EG4 3EE1 3EA1

3EA2

3EF1 3EF2 3EF3

3EC2

3EE2

3EH2

Application

Overhead line systems

Distribution systems, switchgear

Distribution systems, generators, motors, electric furnaces, 6 arrester connections, power plants

Overhead line systems

Surge limiters, motors, dry-type transformers, airfield lighting systems

DC systems, traction systems, vehicles

Distribution systems, generators, motors, electric furnaces, 6 arrester connections, power plants

DistriDistribution bution systems, sysmetaltems, enclosed switchgasgear insulated switchgear (GIS) with plugin connection

Maximum system voltage

1

24

36

1

12

4

36

52

Maximum rated voltage [kVr]

1

24

42

1

12

4

45

Nominal discharge current

5

5

1

5

1

10

Maximum energy absorption capability (thermal stability condition) [kJ/kVr]

–

0.3

2.1

–

0.8 0.8 4

Maximum long duration discharge current, 2 ms [A]

150

150 (1ms)

700

150

Maximum pressure relief current [kA]

5A 20 Disconnector

300

Housing material

Polymeric

Porcelain

Type

Metal Oxide MO (gapless type) 3EG5

3EG6

3EK5

3EK6

Distribution systems, switchgear

Distribution systems, switchgear

Distribution systems, switchgear

36

24

36

36

52

45

30

45

45

10

5

5/10

5/10

10

10

–

15

2.2

2.2

2.2

5

4.5

200 200 1300

800

1700

200

200

250

500

300

5A Disconnector

40

20

300

16

20

16

20

20

Polymeric

Polymeric Porcelain Polymeric

Porcelain

Porcelain

Metal

Porcelain

Polymeric

Porcelain

Polymeric

[kV]

[kA]

Porcelain

Fig. 79a: Low- and medium-voltage arresters

1/44

Siemens Power Engineering Guide · Transmission & Distribution

Surge Arresters

Silicon Carbide (SiC) (gapped type) 3EM2

Type

Metal Oxide MO (gapless type)

3EP1

3EP2

3EP3

3EQ1-B

3EQ1

3EQ2

3EQ3 3ER3

3EP2-K

3EP2-K3

3EP3-K

Application

Transmission systems, substations

Transmission systems, substations

Transmission systems, substations

Transmission systems, substations, HVDC, SVC

DC systems, traction systems, vehicles

Transmission systems, substations

Transmission systems, substations

Transmission systems, substations, HVDC, SVC

Transmission systems, substations, metalenclosed gasinsulated switchgear (GIS)

Transmission systems, substations, metalenclosed gasinsulated switchgear (GIS, threephase)

Transmission systems, substations, metalenclosed gasinsulated switchgear (GIS)

Maximum system voltage

245

170

420

765

25

245

525

525

170

170

525

216

180

384

612

37 (AC) 4 (DC)

225

444

444

168

168

444

10

10

20

20

10

10

20

20

20

20

20

Maximum line discharge class

2

2

4

5

3

3

5

5

4

4

5

Maximum energy absorption capability (thermal stability condition) [kJ/kVr]

2.1

5

10

20

8

8

13

20

10

10

13

Maximum long duration discharge current, 2 ms [A]

700

500

1200

3900

800

800

1600

3900

1200

1200

1600

Maximum pressure relief current [kA]

50/63

40

50/63

100

40

40

63

80

63

63

63

Maximum permissible cantilever moment [kNm]

12.5*

2.1*

12.5*

34*

2

20** 4.6** 60** (> 50 % after pressure relief)

–

–

–

Housing material

Porcelain

Porcelain

Porcelain

Porcelain

Polymeric

Polymeric

Metal

Metal

Metal

Maximum rated voltage Nominal discharge current

[kV]

[kVr]

[kA]

* Dynamic load acc. to DIN 48113

Polymeric

Polymeric

** 1.5 · M.M.L. acc. to IEC 36/118/CD

Fig. 79b: High-voltage arresters

Siemens Power Engineering Guide · Transmission & Distribution

1/45

Worldwide Service for High- and Medium-voltage Switchgear and Substations

Siemens provides services for ■ ■ ■ ■

Circuit-breakers and devices SF6-insulated switchgear Air-insulated switchgear plants Personnel training.

Scope of service: ■ Maintenance contracts

– for switchgear and substations ■ Regular maintenance

■

■

■

■ ■

■

Fig. 80: Extended visual check on site

– visual inspection – extended visual inspection – overhaul Emergency troubleshooting – simply call Phone: ++ 49 - 9131- 74 33 33 Mobile: ++ 49 - 171- 3 37 86 53 Fax: ++ 49 - 9131- 73 44 49 Fault detection and repair – by experts who will go to the site on short notice Spare parts delivery – Reliable, quick and specifically for each serial number Documentation – for spare parts and maintenance kits Assistance in final disposal – classification, storage, organization of final disposal Personnel training for e.g. – high voltage, medium voltage, low voltage – protection and control, generator, transformer, cable accessories – interlocking device, station control systems.

For further information please contact: Fax: ++ 49 - 9131-73 44 49 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 Number of years

Visual inspection: to be carried out by suitably trained customer personnel or Siemens maintenance staff Extended visual inspection: to be carried out by suitably trained customer personnel or Siemens maintenance staff Overhaul: to be carried out by Siemens maintenance staff together with customer personnel Fig. 81: View of the internal components of control unit of an outdoor type high-voltage circuit-breaker

1/46

Fig. 82: Example for a maintenance plan (high voltage, number of years in operation with normal switching frequencies) Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Switchgear

Introduction Primary and secondary distribution stands for the two basic functions of the mediumvoltage level in the distribution system (Fig. 1).

‘Primary distribution’ means the switchgear installation in the HV/MV transformer main substations. The capacity of equipment must be sufficient to transport the electrical energy from the HV/MV transformers input (up to 63 MVA) via busbar to the outgoing distribution lines or cable feeders. The switchgear in these main substations is of high importance for the safe and flexible operation of the distribution system. It has to be very reliable during its lifetime, flexible in configuration, easy to operate with a minimum of maintenance. The type of switchgear insulation (air or SF6) is determined by local conditions, e.g. space available, economic considerations, building costs, environmental conditions and the relative importance of maintenance. Design and configuration of the busbar are determined by the requirements of the local distribution system. These are: ■ The number of feeders is given by the

outgoing lines of the system ■ The busbar configuration depends on

the system (ring, feeder lines, opposite station, etc.) ■ Mode of operation under normal conditions and in case of faults ■ Reliability requirements of consumer, etc. Double busbars with longitudinal sectionalizing give the best flexibility in operation. However, for most of the operating situations, single busbars are sufficient if the distribution system has adequate redundancy (e.g. ring-type system). If there are only a few feeder lines which call for higher security, a mixed configuration is advisable. It is important to prepare enough spare feeders or at least space in order to extend the switchgear in case of further development and the need of additional feeders. As these substations, especially in densely populated areas, have to be located right in the load center, the switchgear must be space-saving and easy to install. The installation of this switchgear needs thorough planning in advance, including the system configuration and future area development. Especially where existing installations have to be upgraded, the situation of the distribution system should be analyzed for simplification (system planning and architectural system design).

2/2

‘Secondary distribution’ is the local area supply of the individual MV/LV substations or consumer connecting stations. The power capacity of MV/LV substations depends on the requirements of the LV system. To reduce the network losses, the transformer substations should be installed directly at the load centers with its typical transformer ratings of 400 kVA to max. 1000 kVA. Due to the great number of stations, they must be space-saving and maintenance-free. For high availability, MV/LV substations are mostly looped in by load-break switches. The line configuration is mostly of the open-operated ring type or of radial strands with opposite switching station. In case of a line fault, the disturbed section will be switched free and the supply is continued by the second side of the line. This calls for reliable switchgear in the substations. Such transformer substations can be prefabricated units or single components, installed in any building or rooms existing on site, consisting of medium-voltage switchgear, transformers and low-voltage distribution. Because of the extremely high number of units in the network high standardization of equipment is necessary. The most economical solution for such substations should have climate-independent and maintenancefree equipment, so that operation of equipment does not require any maintenance during its lifetime. Consumers with high power requirements have mostly their own distribution system on their building area. In this case, a consumer connection station with metering is necessary. Depending on the downstream consumer system, circuit breakers or loadbreak switches have to be installed. For such transformer substations nonextensible and extensible switchgear, for instance RMUs, have been developed using SF6 gas as insulation and arc-quenching medium in the case of load-break systems (RMU), and SF6-gas insulation and vacuum as arc-quenching medium in the case of extensible modular switchgear, consisting of load break panels with or without fuses, circuit-breaker panels and measuring panels.

Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Switchgear

Subtransmission up to 145 kV

Main substation

HV/MV transformers up to 63 MVA

Primary distribution MV up to 36 kV

Secondary distribution

open ring

closed ring

Diagram 1:

Substation

Diagram 2:

Customer station with circuit breaker incoming panel and load break switch outgoing panels

Diagram 3:

Extensible switchgear for substation with circuit-breakers e.g. Type 8DH

Fig. 1: Medium voltage up to 36 kV – Distribution system with two basic functions: Primary distribution and secondary distribution

Siemens Power Engineering Guide · Transmission & Distribution

2/3

Primary Distribution Selection Criteria and Explanations

General

Single busbar with bus-tie breaker

Double busbars with dual-feeder breakers

Double busbars with single-feeder breakers

Double-busbars switchboard with single busbar feeders

Codes, standards and specifications Design, rating manufacture and testing of our medium-voltage switchboards is governed by international and national standards. Mainly all applicable IEC recommendations and narrative VDE/DIN standards apply to our products, whereby it should be noted that in Europe all national electrotechnical standards have been harmonized within the framework of the current IEC recommendations. Our major products in this section comply specifically with the following code publications: ■ IEC 298 AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 72.5 kV ■ IEC 694 Common clauses for highvoltage switchgear and controlgear standards ■ IEC 56 High-voltage alternating-current circuit breakers ■ IEC 265-1 High-voltage switches ■ IEC 470 High-voltage alternating current contactors ■ IEC 129 Alternating current disconnectors (isolators) and grounding switches ■ IEC 185 Current transformers ■ IEC 186 Voltage transformers ■ IEC 282 High-voltage fuses In terms of electrical rating and testing, other national codes and specifications can be met as well, e.g. ANSI C37, 20C, BS 5227, etc. In case of switchgear manufactured outside of Germany in Siemens factories or workshops, certain local standards can also be met; for specifics please inquire. Busbar system Switchgear installations for normal service conditions are preferably equipped with single-busbar systems. These switchboards are clear in their arrangement, simple to operate, require relatively little space, and are low in inital cost and operating expenses. Double-busbar switchboards can offer advantages in the following cases: ■ Operation with asynchronous feeders ■ Feeders with different degrees of impor-

tance to maintain operation during emergency conditions ■ Isolation of consumers with shock loading from the normal network

2/4

Fig. 2: Basic basbar configurations for medium voltage switchgear ■ Balancing of feeders on two systems

during operation ■ Access to busbars required during operation. In double-busbars switchboards with dual feeder breakers it is possible to connect consumers of less importance by singlebusbar panels. This guarantees the high availability of a double-busbar switchboard for important panels as, e.g. incoming feeders, with the low costs and the low space requirement of a single-busbar switchboard for less important panels. These composite switchboards can be achieved with the types 8BK20, 8BJ50 and 8DC11. Type of insulation The most common insulating medium has been air at atmospheric pressure, plus some solid dielectric materials. Under severe climatic conditions this requires precautions to be taken against internal contamination, condensation, corrosion, or reduced dielectric strength in high altitudes.

Since 1982, insulating sulfur-hexafluoride gas (SF6-gas) at slight overpressure has also been used inside totally encapsulated switchboards as insulating medium for medium voltages to totally exclude these disturbing effects. All switchgear types in this section, with the exception of the gas-insulated models 8D, use air as their primary insulation medium. Ribbed vacuum-potted epoxy-resin post insulators are used as structural supports for busbars and circuit breakers throughout. In the gas-insulated metal-clad switchgear 8D, all effects of the environment on highvoltage-carrying parts are eliminated. Thus, not only an extremely compact and safe, but also an exceptionally reliable piece of switchgear is available. The additional effort for encapsulating and sealing the high-voltage-carrying parts requires a higher price – at least in voltage ratings below 24 kV. For a price comparison, see the curves on the following page (Fig. 3, 4).

Siemens Power Engineering Guide · Transmission & Distribution

Primary Distribution Selection Criteria and Explanations

Enclosure, Compartmentalization IEC Publ. 298 subdivides metal-enclosed switchgear and controlgear into three types: ■ Metal-clad switchgear and controlgear ■ Compartmented switchgear and controlgear ■ Cubicle switchgear and controlgear. Thus “metal-clad” and “cubicle” are subdivisions of metal-enclosed switchgear, further describing construction details. In metal-clad switchgear the components are arranged in 3 seperate compartments as: ■ Busbar compartment ■ Circuit-breaker compartment ■ Feeder-circuit compartment

with earthed metal partitions between each compartment. Whereas the cubicle switchgear (type 8BJ50) has no compartments within the panel. The protection against contact with live busbar is granted by a removeable protective barrier. The protective barrier can be inserted into the panel without opening the front door and fulfills the conditions for partitions according IEC 298. IEC 298-1990-12 Annex AA specifies a “Method for testing the metal-enclosed switchgear and controlgear under conditions of arcing due to an internal fault“. Basically, the purpose of this test is to show that persons standing in front of, or adjacent to a switchboard during internal arcing are not endangered by the effects of such arcs. All switchboards described in this section have successfully passed these type tests. Isolating method To perform maintenance operations safely, one of two basic precautions must be taken before grounding and short-circuiting the feeder: ■ 1. Opening of an isolator switch with

clear indication of the OPEN condition. ■ 2. Withdrawal of the interrupter carrier

from the operating into the isolation position. In both cases, the isolation gap must be larger than the sparkover distance from live parts to ground to avoid sparkover of incoming overvoltages across the gap. The first method is commonly found in fixed mounted interrupter switchgear, whereas the second method is applied in withdrawable switchgear. Withdrawable switchgear has primarily been designed to provide a safe environment for maintenance work on circuit inter-

Single busbar

Double busbar

! Percentage (8BK20 = 100)

! Percentage (8BK20 = 100)

160

160

130 120 110 100 90 80 70 0

130 120 110 100 90 80 70 0

8BK20 8DA10 8DC11 8BJ50 7.2

12

15 24 kV

36 Voltage

8BK20 8DB10 8BJ50 7.2

12

15 24 kV

36 Voltage

Fig. 3: Price relation

Fig. 4: Price relation

rupters and instrument transformers. Therefore, if interrupters and instrument transformers are available that do not require maintenance during their lifetime, the withdrawable feature becomes obsolete. With the introduction of maintenancefree vacuum circuit-breaker bottles, and instrument transformers which are not subject to dielectric stressing by high voltage, it is possible and safe to utilize totally enclosed, fixed-mounted and gas-insulated switchgear. Models 8DA, 8DB and 8DC described in this section are of this design. Due to their much fewer moving parts and their total shielding from the environment, they have proved to be much more reliable. All air-insulated switchgear models in this section except the 8FG10 are of the withdrawable type.

and it is recommended for all generalpurpose applications. If high numbers of switching operations are anticipated (especially autoreclosing in overhead line systems and switching of high-voltage motors), their use is indicated. They are available in all ratings – see selection matrix on page 2/66–2/67 for all power switchgear listed in this section. Due to their freedom of maintenance these breakers can be installed inside totally enclosed and gas-insulated switchgear.

Switching device Depending on the switching duty in individual switchboards and feeders, basically the following types of primary switching devices are used in the switchgear cubicles in this section: (Note: Not all types of switching devices can be used in all types of cubicle.)

■ 1. Vacuum circuit-breakers ■ 2. Vacuum contactors in conjunction

with HRC-fuses ■ 3. Vacuum switches or gas-insulated

three-position switch disconnector in conjunction with HRC-fuses. To 1: Vacuum circuit breaker In the continuing strive for safer and more reliable medium-voltage circuit breakers, the vacuum interrupter is clearly the first choice of buyers of new circuit breakers on a worldwide basis. It is maintenancefree up to 10,000 operating cycles without any limitation by time

Siemens Power Engineering Guide · Transmission & Distribution

To 2: Vacuum contactors Vacuum contactors with rated current up to 450 A are used for frequent switching operations in motor, transformer, and capacitor bank feeders. They are type-tested, extremely reliable and compact devices and they are totally maintenancefree. Since contactors cannot interrupt fault currents, they must always be used with currentlimiting fuses to protect the equipment connected. Vacuum contactors can be installed in the metal-enclosed, metal-clad switchgear type 8BK20 and 8BK30. To 3: Vacuum switches or … Vacuum switches and gas-insulated threeposition switch disconnectors in primary distribution switchboards are used mostly for small transformer feeders such as auxiliary transformers or load center substations. Because of their inability to interrupt fault currents they must always be used with current-limiting fuses. Vacuum switches can be installed in the air-insulated switchboard type 8BK20 and 8BJ50. Gasinsulated three-position switch disconnectors can be installed in the switchboard type 8DC11. For details of these switching devices see the following pages!

2/5

Primary Distribution Selection Matrix

Standards

Insulation

Busbar system

Single busbar

Type-tested indoor switchgear to DIN VDE 0670, Part 6 IEC 298

Air-insulated

Generator circuit-breaker

Enclosure, compartmentalization

Isolating method

Metal-enclosed, cubicle-type

Draw-out section

Metal-enclosed, metal-clad

Draw-out section

Metal-enclosed, metal-clad

Draw-out section

Metal-enclosed, metal-clad

Draw-out section

Metal-enclosed, metal-clad

Draw-out section

Metal-enclosed, cubicle-type

Draw-out section

Metal-enclosed, metal-clad

Draw-out section

Triple-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Single-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Triple-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Single-pole metal-enclosed, metal-clad

Disconnector, fixed-mounted

Metal-enclosed, cubicle-type

Disconnector, fixed-mounted

Double busbar

Single busbar

SF6-insulated

Double busbar

Switchgear to DIN VDE 0101

Air-insulated

Generator circuit-breaker

Containerized switchgear equipped with air-insulated or SF6-insulated switchgear

Fig. 5: Primary Distribution Selection Matrix

2/6

Siemens Power Engineering Guide · Transmission & Distribution

Primary Distribution Selection Matrix

Switching device

Switchgear type

Technical data

Page

Maximum rated short-time current [kA], 1/3 s

Maximum busbar rated current [A]

Maximum feeder rated current [A]

7.2 kV

12 kV

17.5/24 36 kV kV

7.2 kV

7.2 kV

8BJ50

40

40

25

2500 2500

2500

8BK20

50

50

25

4000 4000

2500

8BK30

50

50

–

–

4000 4000

–

Vacuum circuit-breaker

8BK40

63

63

63**

–

5000 5000

Vacuum circuit-breaker

8BK41

80

80

80**

–

Vacuum circuit-breaker

8BJ50

40

40

25

–

8BK20

50

50

25

Vacuum circuit-breaker Switch-disconnector

8DC11

25

25

25

Vacuum circuit-breaker

8DA10

40

40

Vacuum circuit-breaker Switch-disconnector

8DC11

25

Vacuum circuit-breaker

8DB10

Vacuum circuit-breaker

8FG10

Vacuum circuit-breaker Vacuum switch

Vacuum circuit-breaker Vacuum switch Vacuum contactor

–

31.5*

12/15 17.5/24 36 kV kV kV –

12/15 17.5/24 36 kV kV kV

–

2500

2500

2000

4000

4000

2000 2500*

–

400

400

5000** –

5000

5000

2500*

2/8

2/12

Vacuum contactor

Vacuum circuit-breaker Vacuum switch Vacuum contactor

8FF1

–

–

2500 2500

2500

–

4000 4000

2500

–

1250 1250

1250

40

40

3150 3150

25

25

–

40

40

40

40

80

80

80**

31.5*

–

–

–

–

–

2/17

5000** –

2/20

12 500 12500 12500** –

2/24

2 500

2500

2000

4000

4000

2000 2500*

2/12

–

1250

1250

1250

2/26

3150

2500

2500

2500

2500 2500

2/32

1250 1250

1250

–

1250

1250

1250

2/26

3150 3150

3150

2500

2500

2500

2500 2500

–

–

–

–

2500*

–

–

12 500 12 500 12500** –

2/8

2/32

2/39

2/41

ratings acc. to the installed switchgear type * 36 kV panel: metal enclosed, compartmented

Siemens Power Engineering Guide · Transmission & Distribution

–

** up to 17.5 kV

2/7

Air-insulated Switchgear Type 8BJ50

Cubicle-type switchgear 8BJ50, air-insulated ■ From 7.2 to 24 kV ■ Single- and double-busbar ■ ■ ■ ■ ■ ■ ■

(back-to-back or face-to-face) Air-insulated Type-tested Metal-enclosed Cubicle-type Withdrawable vacuum breaker Vacuum switch optional For indoor installation

Specific features ■ General-purpose switchgear ■ Circuit breaker mounted on horizontal

slide behind front door ■ Cable connections from front

Safety of operating and maintenance personnel ■ All switching operations behind closed ■ ■ ■ ■ ■

doors Positive and robust mechanical interlocks Arc-fault-tested metal enclosure Complete protection against contact with live parts Line test with breaker inserted (option) Maintenancefree vacuum breaker

Tolerance to environment ■ Sealed metal enclosure with optional

gaskets ■ Complete corrosion protection

and tropicalization of all parts (option) ■ Vacuum-potted ribbed epoxy-insulators

with high tracking resistance General description 8BJ50 switchboards consist of metal enclosed cubicles of air-insulated switchgear with withdrawable vacuum circuit breakers. The breaker carriage is fully interlocked with the interrupter and the stationary cubicle. It is manually moved in horizontal direction from the “Connected” position behind the closed front door and without the use of auxiliary equipment. A fully isolated low-voltage compartment is integrated. All commonly used feeder circuits and auxiliary devices are available. The switchgear cubicles and interrupters are factory-assembled and type-tested as per the applicable standards.

2/8

Fig. 6: Panel of cubicle-type switchgear 8BJ50 (inter-cubicle partition removed)

Fig. 7: Cross section through cubicle-type switchgear 8BJ50

Stationary part

“Disconnected/Test” position. To this effect, the arc- and pressure-proof front door remains closed. To remove the switching element completely from its cubicle, a central service truck is used. Inspection can easily and safely be carried out with the circuit breaker in the “Disconnected/Test” position. All electrical and mechanical parts are easily accessible in this position. Mechanical spring-charge and contactposition indicators are visible through the closed door. Local mechanical ON/OFF pushbuttons are actived through the door as well. For complete remote control, the circuitbreaker carriage can be equipped for motor operation.

The cubicle is built as a self-supporting structure, bolted or riveted together from rolled galvanized steel sheets and profiles. Cubicles for rated voltages up to 24 kV are of identical construction. A removable protective barrier is used for shielding the busbars without isolating them in order, e.g., to work inside the cubicle. The protective barrier can be inserted into the panel without opening the front door and fulfills the conditions for partitions according IEC 298. Therefore, this partition provides same safety features as a metal-clad design. Any overpressure inside the cubicle resulting from fault arcing is released by pressure relief flaps. To reduce internal arcing times and thus consequential damages, pressure switches can be installed that trip the incoming feeder circuit breaker(s) in less than 100 msec. This is an economic alternative to busbar differential protection. Breaker carriage The carriage normally supports a vacuum circuit breaker with the associated operating mechanism and auxiliary devices. Vacuum switches, with or without HV HRC fuses, are optional. By manually moving the carriage with the spindle drive it can be brought into a distinct “Connected” and

Low-voltage compartment All protective relays as well as monitoring and control devices of a feeder can be accommodated in a metal-enclosed LV compartment on top. Device mounting plates, cabling troughs and the central LV terminal strip(s) are located behind a separate lockable door. Full or partial plexiglass windows, or mimic diagrams are available for these doors.

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BJ50

Main enclosure The totally enclosed and sealed cubicle permits installation in most equipment rooms. With the degree of protection of IP4X/IP3XD, the switchgear is safeguarded against internal contamination, small animals and rodents, and naturally against contact with live parts. This eliminates the usual reasons for arc faults. Busbars and primary disconnects Rectangular busbars drawn from pure copper are used exclusively. They are mounted in standard cast-resin bushings supported in the inter-cubicle partitions. The taps to the upper fixed isolating contact are mounted on ribbed, cast-resin post insulators which are sized to take up the dynamic forces resulting from short circuits. The fixed isolating contacts are silverplated stubs. The movable parts of the line and loadside primary disconnects have flat, springloaded and silver-plated hemispherical pressure contacts for low contact resistance and good ventilation. The parallel connecting arms are designed to increase contact pressure during short circuits.

Fig. 8: Double busbar: back-to-back arrangement (cross section)

Instrument transformers Up to three multicore block-type current transformers plus three single-phase potential transformers can be installed within the termination zone. The C.T.s carry the cable-connecting bars and lugs, and the fixed contacts of the grounding switch. All common burden and accuracy ratings of instrument transformers are available. Bus bar metering PTs can be fixed installed within the busbar zone or in a metering cubicle, withdrawable PTs and optionally with current-limiting fuses. Cable and bar connections Cables and bars are connected from below; entrance from above requires an auxiliary structure behind the cubicle. Single-phase or three-phase solid-dielectric cables can be connected from the front of the cubicle; stress cones are installed conveniently inside the cubicle. Make-proof grounding switches with manual operation can be installed below the C.T.s, engaging contacts behind the cable lugs. Operation of the fully interlocked grounding switch is possible only with the breaker carriage in the “Disconnected/ Test” position.

Fig. 9: Double busbar: face-to-face arrangement (cross section)

Interlocking system

Degrees of protection

A series of sturdy mechanical interlocks forces the operator into the only safe operating sequence of the switchgear, positively preventing the following: ■ Moving the carriage with the breaker closed and protective barrier inserted. ■ Switching the breaker in any but the locked “Connected” or “Disconnected/ Test” position. ■ Engaging the grounding switch with the carriage in the “Connected” position, and moving the carriage into this position with the grounding switch engaged.

Degree of protection IP 4X: In the “Connected” and the “Disconnected/Test” position of the carriage, the switchgear is totally protected against contact with live parts by objects larger than 1 mm in diameter.

Siemens Power Engineering Guide · Transmission & Distribution

2/9

Air-insulated Switchgear Type 8BJ50

Installation The switchboards are shipped in sections of up to three cubicles on stable wooden pallets which are suitable for rolling and forklift handling. These sections are bolted or spot-welded to channel iron sections embedded in a flat and level concrete floor. The switchboard can be installed against the wall or freestanding. Double-busbar installations in back-to-back configuration are installed freestanding. Cable feed-in is through corresponding cutouts in the floor; plans for which are part of the switchgear supply. Three-phase (armored) cables for voltages above 12 kV require sufficient clearance below the switchgear to split up the phases (cable floor, etc.). Circuit breakers are shipped mounted on their carriages inside the switchgear cubicles. For preliminary dimensions and weights, see the table to the right.

Weights and dimensions

Rated voltage

[kV]

7.2

12

17.5/24

Width

[mm]

800

800

800/1000

Height min.

[mm]

2150

2150

2150

Depth single busbar double busbar

[mm] [mm]

1125 2250

1125 2250

1430 2860

Approx. weight incl. breaker (single busbar cubicle)

[kg]

500

500

700

Fig. 10

Technical data

Rated voltage

Rated lightningimpulse test voltage

Rated powerfrequency withstand voltage

Rated short-circuit breaking current/ short-time current (1 s or 3 s available)

Rated shortcircuit making current

[kV]

[kV]

[kV]

[kA] (rms)

[kA] (peak)

7.2

60

20

16 20 25 31.5 40*

12

75

28

16 20 25 31.5 40*

17.5/24 width 800 mm

95/125

38/50

17.5/24 width 1000 mm

95/125

38/50

Rated feeder currents

Rated busbar currents

630 [A]

1250 [A]

2000 [A]

2500 [A]

1250 [A]

40 50 63 80 100

■ ■ ■ – –

■ ■ ■ ■ ■

– – – – –

– – ■ ■ ■

■ ■ ■ ■ ■

■ ■ ■ ■ ■

40 50 63 80 100

■ ■ ■ – –

■ ■ ■ ■ ■

– – – – –

– – ■ ■ ■

■ ■ ■ ■ ■

■ ■ ■ ■ ■

16 20 25

40 50 63

■ – –

■ ■ ■

– – –

– – –

■ ■ ■

■ ■ ■

16 20 25

40 50 63

■ – –

■ ■ ■

– ■ ■

– – –

■ ■ ■

■ ■ ■

2500 [A]

* 40 kA/1 s

Fig. 11

2/10

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BJ50

8BJ50

Panel Fixed parts

Withdraw- Busbar able parts modules

Sectionalizer

Bus riser panel

Metering Busbar connection panel panel

Fig. 12: Available circuit options

Siemens Power Engineering Guide · Transmission & Distribution

2/11

Air-insulated Switchgear Type 8BK20

Metal-clad switchgear 8BK20, air-insulated ■ From 7.2 to 36/38 kV ■ Single- and double-busbar ■ ■ ■ ■ ■ ■ ■ ■ ■

(back-to-back or face-to-face) Air-insulated Type-tested Metal-enclosed Metal-clad up to 24 kV Compartmented above 24 kV Withdrawable vacuum breaker Vacuum contactor optional Vacuum switch optional For indoor installation

Specific features ■ General-purpose switchgear ■ Circuit breaker mounted on horizontal

slide behind front door ■ Cable connections from front or rear Safety of operating and maintenance personnel

Fig. 13: Metal-clad switchgear type 8BK20 (inter-cubicle partition removed)

■ All switching operations behind closed

doors ■ Positive and robust mechanical

interlocks ■ Arc-fault-tested metal enclosure ■ Complete protection against contact

with live parts ■ Line test with breaker inserted (option) ■ Maintenancefree vacuum breaker Tolerance to environment ■ Metal enclosure with optional gaskets ■ Complete corrosion protection and

tropicalization of all parts. ■ Vacuum-potted ribbed epoxy insulators

with high tracking resistance General description 8BK20 switchboards consist of metal-clad cubicles (compartmented above 24 kV) of air-insulated switchgear with withdrawable vacuum circuit breakers. Fused vacuum switches up to 24 kV/800 A and vacuum contactors up to 12 kV and 400 A can be used optionally. The breaker carriage is fully interlocked with the interrupter and the stationary cubicle. It is manually moved in horizontal direction from the ”Connected“ position behind the closed front door and without the use of auxiliary equipment. A fully isolated low-voltage compartment is integrated. All commonly used feeder circuits and auxiliary devices are available.

2/12

The switchgear cubicles and interrupters are factory-assembled and type-tested as per the applicable standards.

damages, pressure switches can be installed that trip the incoming feeder circuit breaker(s) in less than 100 msec. This is an economical alternative to busbar differential protection.

Stationary part The cubicle is built as a self-supporting structure, bolted together from rolled galvanized steel sheets and profiles. Cubicles for rated voltages up to 24 kV are of identical construction; the 36/38 kV model is larger and uses fiberglass-reinforced epoxy internal partitions, making it compartmented. Each cubicle is divided into three sealed and isolated compartments by partitions, i.e. the busbar, cable connection and circuit-breaker compartment. In the 24 kV version, the fixed contacts of the primary disconnects are located within bushings, effectively maintaining the compartmentalization in all operating conditions of the switchgear. The bushings are covered by automatic steel safety shutters upon removal of the circuit-breaker carriage from the ”Connected“ position. In the 36 kV version, the compartments are formed by internal barriers made of fiberglass-reinforced epoxy plates with individual-phase safety shutters that seal in both directions. Each compartment in every model has its own pressure-relief device. To reduce internal arcing times and thus consequential

Breaker carriage The carriage normally supports a vacuum circuit breaker with the associated operating mechanism and auxiliary devices. Vacuum contactors up to 12 kV and fused vacuum switches up to 24 kV are optional. By manually moving the carriage with the a spindle drive it can be brought into a distinct ”Connected“ and ”Disconnected/ Test“ position. To this effect, the arc- and pressure-proof front door remains closed. To remove the switching element completely from its compartment, a central service truck is used. Inspection can easily and safely be carried out with the circuit breaker in the ”Disconnected/Test“ position. All electrical and mechanical parts are easily accessible in this position. Mechanical spring-charge and contactposition indicators are visible through the closed door. Local mechanical ON/OFF pushbuttons are actived through the door as well. For complete remote control, the circuitbreaker carriage can be equipped for motor operation.

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BK20

Cable and bar connections Cables and bars are connected from below; entrance from above requires an auxiliary structure behind the cubicle. Single-phase or three-phase solid-dielectric cables can be connected from the front or the rear of the cubicle (specify); stress cones are installed conveniently inside the cubicle. Regular and make-proof grounding switches with manual operation can be installed below the C.T.s, engaging contacts behind the cable lugs. Operation of the fully interlocked grounding switch is possible only with the breaker carriage in the ”Disconnected/Test“ position. Interlocking system A series of sturdy mechanical interlocks forces the operator into the only safe operating sequence of the switchgear, preventing positively the following: ■ Moving the carriage with the breaker

closed. ■ Switching the breaker in any but the

Fig. 14: Cross-section through 8BK20 cubicle

Low-voltage compartment

Busbars and primary disconnects

All protective relays, monitoring and control devices of a feeder can be accommodated in a metal-enclosed LV compartment on top (up to 24 kV) or alongside (36/38 kV) the HV enclosure. Device-mounting plates, cabling troughs, and the central LV terminal strip(s) are located behind a separate lockable door. Full or partial plexiglass windows, or mimic diagrams are available for these doors.

Rectangular busbars drawn from pure copper are used exclusively. They are mounted on ribbed, cast-resin post insulators which are sized to take up the dynamic forces resulting from short circuits. Soliddielectric busbar insulation is available. The movable parts of the line- and loadside primary disconnects have flat, springloaded and silver-plated hemipherical pressure contacts for low contact resistance and good ventilation. The parallel connecting arms are designed to increase contact pressure during short circuits. The fixed contacts are silver-plated stubs within the circuit-beaker bushings (24 kV), or the busbar mounts (36 kV).

Main enclosure The totally enclosed and sealed cubicle permits installation in most equipment rooms. With the optional dust protection, the switchgear is safeguarded against internal contamination, small animals and rodents, and naturally against contact with live parts. This eliminates the usual reasons for arc faults. Should arcing occur, nevertheless, the arc can be guided towards the end of the lineup, where damages are repaired most easily. For the latter reason, parititions between individual cubicles of the same bus sections are normally not used.

locked ”Connected“ or ”Disconnected/ Test“ position ■ Engaging the grounding switch with the carriage in the ”Connected“ position, and moving the carriage into this position with the grounding switch engaged. Degrees of protection Degree of protection IP 4X: In the ”Connected“ and the ”Disconnected/Test“position of the carriage, the switchgear is totally protected against contact with live parts by objects larger than 1 mm in diameter. Optionally, the cubicles can be protected against harmful internal deposits of dust and against dripping water (IP 51).

Instrument transformers Up to three multicore block-type current transformers plus three single-phase potential transformers can be installed in the lower compartment; PTs optionally on withdrawable modules up to 24 kV. The C.T.s carry the cable-connecting bars and lugs, and the fixed contacts of the (optional) grounding switch. All common burden and accuracy ratings of instrument transformers are available. Busbar metering PTs with their current-limiting fuses are installed on withdrawable carriages, identically to breaker carriages.

Siemens Power Engineering Guide · Transmission & Distribution

2/13

Air-insulated Switchgear Type 8BK20

Installation The switchboards are shipped in sections of up to three cubicles on stable wooden pallets which are suitable for rolling and forklift handling. These sections are bolted or spot-welded to channel iron sections embedded in a flat and level concrete floor. Front-connected types can be installed against the wall or freestanding, rear-connected cubicles require service aisles. Double-busbar installations in back-to-back configuration are installed freestanding. Cable feed-in is through corresponding cutouts in the floor; plans for which are part of the switchgear supply. Three-phase (armored) cables for voltages above 12 kV require sufficient clearance below the switchgear to split up the phases (cablefloor, etc.). Circuit breakers are shipped mounted on their carriages inside the switchgear cubicles. For dimensions and weights, see Fig.17.

Fig. 15: Cross section through switchgear type 8BK20 in back-to-back double-busbar arrangement for rated voltages up to 24 kV

Fig. 16: Cross section through switchgear type 8BK20 in single-busbar arrangement for front cable connection and 36/38 kV 170 kV/BIL

Weights and dimensions Rated voltage

[kV]

7.2

12

15

17.5

24

36/38

Panel spacing

[mm]

800

800

800

1000

1000

1500

Width

[mm]

2050

2050

2050

2250

2250

2220

Depth front conn. without channel with channel

[mm] [mm]

1650 1775

1650 1775

1650 1775

2025 2150

2025 2150

– 2220

Depth rear conn.

[mm]

1775

1775

1775

2150

2150

2245

Approx. weight incl. breaker

[kg]

800

800

800

1000

1000

1600

Fig. 17

2/14

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BK20

Technical data Rated voltage

Lightning impulse test voltage

Power frequency test voltage

Rated shortcircuit-breaking current/short time current (1 or 3s available)

Rated shortcircuit making current

[kV]

[kV]

[kV]

[kA](rms)

[kA]

7.2

60

20

16 20 25 31.5 40* 50*

40 50 63 80 110 125

■ ■ ■ – – –

■ ■ ■ ■ ■ ■

– – ■ ■ ■ –

– – ■ ■ ■ ■

– – – – ■ ■

– – – – ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

12

75

28

16 20 25 31.5 40* 50*

40 50 63 80 110 125

■ ■ ■ – – –

■ ■ ■ ■ ■ ■

– – ■ ■ ■ –

– – ■ ■ ■ ■

– – – – ■ ■

– – – – ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

15

95

36

16 20 25 31.5 40* 50*

40 50 63 80 110 125

■ ■ ■ – – –

■ ■ ■ ■ ■ ■

– – ■ ■ ■ –

– – ■ ■ ■ ■

– – – – ■ ■

– – – – ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

■ ■ ■ ■ ■ ■

17.5

95

38

16 20 25

40 50 63

■ ■ ■

■ ■ ■

– – ■

– – –

– – –

– – –

■ ■ ■

■ ■ ■

■ ■ ■

– – –

– – –

24

125

50

16 20 25

40 50 63

■ ■ –

■ ■ ■

– ■ ■

– – –

– – –

– – –

■ ■ ■

■ ■ ■

■ ■ ■

– – –

– – –

36/38

170

70/80

16 25 31.5

40 63 80

– – –

■ ■ ■

– – –

■ ■ ■

– – –

– – –

■ ■ ■

■ ■ ■

■ ■ ■

– – –

– – –

Rated feeder current*

Rated busbar current

630 1250 2000 2500 3150 4000 1) [A] [A] [A] [A] [A] [A]

1250 2000 2500 3150 4000 [A] [A] [A] [A] [A]

*1s 1) Ventilation unit with or without fan and ventilation slots in the front of the cubicle required.

Fig. 18

Siemens Power Engineering Guide · Transmission & Distribution

2/15

Air-insulated Switchgear Type 8BK20

8BK20 switchgear up to 24 kV

Panel Fixed parts

Withdrawableparts

Busbar modules

Sectionalizer

Bus riser panel

Metering Busbar connecpanel tion panel

8BK20 switchgear 36/38 kV

Panel Fixed busbar

Withdrawableparts

Busbar modules

Sectionalizer Model 1 Two panels

Model 2 Two panels with underpass

Metering panel

Busbar connection panel (left end panel only)

On right end cubicle or bus sectonalizer

with solid-insulated busbars between two cubicles

Fig. 19: Available circuit options

2/16

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BK30

Vacuum contactor motor starters 8BK30, air-insulated From 3.6–12 kV Single-busbar Type-tested Metal-enclosed Metal-clad Withdrawable vacuum contactors and HRC current-limiting fuses ■ For direct lineup with 8BK20 switchgear ■ For indoor installation ■ ■ ■ ■ ■ ■

Specific features ■ Designed as extension to 8BK20 switch-

gear with identical cross section ■ Contactor mounted on horizontally mov-

ing truck – 400 mm panel spacing ■ Cable connection from front or rear ■ Central or individual control power trans-

former ■ Integrally-mounted electronic multifunc-

tion motor-protection relays available. Safety of operating and maintenance personnel ■ All switching operations behind closed

doors ■ Positive and robust mechanical inter-

locks ■ Arc-fault-tested metal enclosure ■ Complete protection against contact

with live parts ■ Absolutely safe fuse replacement ■ Maintenancefree vacuum interrupter

tubes Tolerance to environment

Fig. 20: Metal-clad switchgear type 8BK30 with vacuum contactor (inter-cubicle partition removed)

■ Metal enclosure with optional gaskets ■ Complete corrosion protection and tropi-

calization of all parts

Technical data

■ Vacuum-potted ribbed expoy insulators

with high tracking resistance

Rated voltage

BIL

PFWV

Maximum rating of motor

Feeder rating

Rated busbar current

[kV]

[kV]

[kV]

[kW]

[A]

1250 [A]

2000 [A]

2500 [A]

3150 [A]

4000 [A]

3.6 7.2 12

40 60 60

10 20 28

1000 2000 3000

400 400 400

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

■ ■ ■

Fig. 21

Siemens Power Engineering Guide · Transmission & Distribution

2/17

Air-insulated Switchgear Type 8BK30

Full-voltage nonreversing (FVNR)

Reduced-voltage nonreversing (RVNR) with starter (reactor starting)

Reduced-voltage nonreversing (RVNR) with external reactor autotransformer ”Korndorffer Method“

Fig. 22: Available circuits

General description

The stationary part

Busbars and primary disconnects

8BK30 motor starters consist of metalenclosed, air-insulated and metal-clad cubicles. Vacuum contactors on withdrawable trucks, with or without control power transformers, are used in conjunction with current-limiting fuses as starter devices. The truck is fully interlocked with the structure and is manually moved from the ”Connected“ to the ”Disconnected/Test“ position. A fully isolated low-voltage compartment is integrated. All commonly used starter circuits and auxiliary devices are available. The starter cubicles and contactors are factory-assembled and type-tested as per applicable standards.

The cubicle is constructed basically the same as the matching switchgear cubicles 8BK20, with the exception of the contactor truck.

Horizontal busbars are identical to the ones in the associated 8BK20 switchgear. Primary disconnects are adapted to the low feeder fault currents of these starters. Silver-plated tulip contacts with round contact rods are used.

Contactor truck Vacuum contactor, HRC fuses, and control power transformer with fuses (if ordered) are mounted on the withdrawable truck. Auxiliary devices and interlocking components, plus the primary disconnects complete the assembly.

C.T.s and cable connection

Low-voltage compartment Space is provided for regular bimetallic or electronic motor-protection relays, plus the usual auxiliary relays for starter control. The compartment is metal-enclosed and has its own lockable door. All customer wiring is terminated on a central terminal strip within this compartment.

Due to the limited let-through current of the HRC fuse, block-type C.T.s with lower thermal rating can be used. Depending on the protection scheme used, C.T.s with one or two secondary windings are installed. All commonly used feeder cables up to 300 mm2 can be terminated and connected at the lower C.T. terminals. Grounding switches or surge-voltage limiters are installed optionally below the current transformers.

Main enclosure Practically identical to the associated 8BK20 switchgear.

2/18

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BK30

Interlocking system Contactor, truck and low-voltage plugs are integrated into the interlocking system to guarantee the following safeguards: ■ The truck cannot be moved into the ”Connected“ position before the LV plug is inserted. ■ The LV plug cannot be disconnected with the truck in the ”Connected“ position. ■ The truck cannot be moved with the contactor in the ON position. ■ The contactor cannot be operated with the truck in any other but the locked ”Connected“ or ”Disconnected/Test“ position. ■ The truck cannot be brought into the ”Connected“ position with the grounding switch engaged. ■ The grounding switch cannot be engaged with the truck in the ”Connected“ position. Degrees o protection Degree of protection IP 4X: In the ”Connected“ and the ”Disconnected/Test“ positions of the truck, the starter is totally protected against contact with live parts with objects larger than 1 mm in diameter. Optionally, the starters can be protected against harmful internal deposits of dust and against dripping or spray water in the ”Operating“ position (IP 51).

Fig. 23: Cross section through switchgear type 8BK30

Weights and dimensions

Installation Identical to the procedures outlined for 8BK20 switchgear. Only the HRC fuses are shipped outside the enclosure, separately packed.

Rated voltage

[kV]

3.6

7.2

12

Width

[mm]

2 x 400

2 x 400

2 x 400

Height

[mm]

2050

2050

2050

Depth

[mm]

1650

1650

1650

Approx. weight incl. contactor

[kg]

700

700

700

Fig. 24

Siemens Power Engineering Guide · Transmission & Distribution

2/19

Air-insulated Switchgear Type 8BK40

Metal-clad switchgear 8BK40, air-insulated ■ From 7.2 to 17.5 kV ■ Single- and double-busbar ■ ■ ■ ■ ■ ■

(back-to-back or face-to-face) Air-insulated Type-tested Metal-enclosed Metal-clad Withdrawable vacuum breaker For indoor installation

Specific features ■ General-purpose switchgear for rated

feeder/busbar current up to 5000 A and short-circuit breaking current up to 63 kA ■ Circuit breaker mounted on horizontally moving truck ■ Cable connections from front Safety of operating and maintenance personnel ■ All switching operations behind closed ■ ■ ■ ■

doors Positive and robust mechanical interlocks Complete protection against contact with live parts Line test with breaker inserted (option) Maintenancefree vacuum circuit breaker

Fig. 25: Metal-clad switchgear type 8BK40 with vacuum circuit breaker 3AH (inter-cubicle partition removed)

Tolerance to environment ■ Sealed metal enclosure with optional

gaskets ■ Complete corrosion protection and tropi-

calization of all parts ■ Vacuum-potted ribbed epoxy-insulators

with high tracking resistance Generator vacuum circuit breaker panel ■ Suitable for use in steam, gas-turbine,

hydro and pumped-storage power plants ■ Suitable for use in horizontal, L-shaped

or vertical generator lead routing

Fig. 26: Cross section through type 8BK40 generator panel

2/20

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BK40

General description 8BK40 switchboards consist of metal-clad cubicles of air-insulated switchgear with withdrawable vacuum circuit breakers. The breaker truck is fully interlocked with the interrupter and the stationary cubicle. It is manually moved in horizontal direction from the ”Connected“ position behind the closed front door and without the use of auxiliary equipment. A fully isolated lowvoltage compartment is integrated. All commonly used feeder circuits and auxiliary devices are available. The switchgear cubicles and interrupters are factory-assembled and type-tested as per applicable standards. Stationary part The cubicle is built as a self-supporting structure, bolted together from rolled galvanized steel sheets and profiles. Cubicles for rated voltages up to 17.5 kV are of identical construction. Each cubicle is divided into three sealed and isolated compartments by partitions, i.e. the busbar, cable connection and circuit-breaker compartment. The fixed contacts of the primary disconnects are located within insulating breaker bushings, effectively maintaining the compartmentalization in all operating conditions of the switchgear. The bushings are covered by automatic steel safety shutters upon removal of the circuit-breaker element from the ”Connected“ position. Each compartment in every model has its own pressure-relief device. To reduce internal arcing times and thus consequential damages, pressure-switches can be installed that trip the incoming-feeder circuit breaker(s) in less than 100 msec. This is an economic alternative to busbar differential protection. Interrupter truck The truck normally supports a vacuum circuit breaker with the associated operating mechanism and auxiliary devices. By manually moving the truck with the a spindle drive it can be brought into a distinct ”Connected“ and ”Disconnected/ Test“ position. To this effect, the front door remains closed. Inspection can easily and safely be carried out with the circuit breaker in the ”Disconnected/Test“ position. All electrical and mechanical parts are easily accessible in this position.

Fig. 27: Cross-section through panel type 8BK40

Mechanical spring-charge and contact-position indicators are visible through the closed door. Local mechanical ON/OFF pushbuttons are actived through the door as well. For complete remote control, the circuit breaker carriage can be equipped for motor operation. Low-voltage compartment All protective relays, monitoring and control devices of a feeder can be accommodated in a metal-enclosed LV compartment on top the HV enclosure. Device-mounting plates, cabling troughs, and the central LV terminal strip(s) are located behind a separate lockable door. Full or partial plexiglass-windows, or mimic diagrams are available for these doors. Main enclosure The totally enclosed and sealed cubicle permits installation in most equipment rooms. With the optional dust protection, the switchgear is safeguarded against internal contamination, small animals and rodents, and naturally against contact with live parts. This eliminates the usual reasons for arc faults. Should arcing occur,

Siemens Power Engineering Guide · Transmission & Distribution

nevertheless, the arc can be guided towards the end of the lineup, where damages are repaired most easily. For the latter reason, partitions between individual cubicles of the same bus sections are normally not used. Busbars and primary disconnects Rectangular busbars drawn from pure copper are used exclusively. They are mounted on ribbed, cast-resin post insulators which are sized to take up the dynamic forces resulting from short circuits. The movable parts of the line- and loadside primary disconnects have flat, springloaded and silver-plated hemispherical pressure contacts for low contact resistance and good ventilation. The parallel connecting arms are designed to increase contact pressure during short circuits. The fixed contacts are silver-plated stubs within the circuit-breaker bushings. Instrument transformers Up to three multicore block-type current transformers plus three single-phase potential transformers can be installed in the lower compartment; PTs optionally on withdrawable modules.

2/21

Air-insulated Switchgear Type 8BK40

The C.T.s carry the cable-connecting bars and lugs, and the fixed contacts of the (optional) grounding switch. All common burden and accuracy ratings of instrument transformers are available. Busbar metering PTs with their current-limiting fuses are installed on a withdrawable truck, identical to the breaker truck. Cable and bar connections Cables and bars are connected from below; entrance from above requires an auxiliary structure behind the cubicle. Single-phase or three-phase solid-dielectric cables can be connected from the front of the cubicle; stress cones are installed conveniently inside the cubicle. Regular and make-proof grounding switches with manual operation can be installed below the C.T.s, engaging contacts behind the cable lugs. Operation of the fully interlocked grounding switch is possible only with the breaker carriage in the ”Disconnected/Test“ position.

Weight and dimensions Rated voltage

[kV]

7.2

12

15

17.5

Width

[mm]

1100

1100

1100

1100

Height

[mm]

2500

2500

2500

2500

Depth

[mm]

2300

2300

2300

2300

Approx. weight incl. breaker

[kg]

2800

2800

2800

2800

Fig. 28

Technical data Rated voltage

Lightning- Powerimpulse frequency test test voltage

Rated shortcircuitbreaking current/ short time current

Rated shortcircuitmaking current

[kV]

[kV]

[kV]

kA [rms]

[kA]

7.2

60

20

50 63

125 160

12

75

28

50 63

125 160

15

95

36

50 63

125 160

17.5

95

38

50 63

125 160

Interlocking system A series of sturdy mechanical interlocks forces the operator into the only safe operating sequence of the switchgear, preventing positively the following: ■ Moving the truck with the breaker closed. ■ Switching the breaker in any but the locked ”Connected“ or ”Disconnected/ Test“ position. ■ Engaging the grounding switch with the truck in the ”Connected“ position, and moving the truck into this position with the grounding switch engaged.

Rated feeder current

1250 2500 3150 5000 [A] [A] [A] [A]

Rated busbar current

5000 [A]

Degrees of protection Degree of protection IP 4X: In the ”Connected“ and the ”Disconnected/Test“ position of the truck, the switchgear is totally protected against contact with live parts by objects larger than 2 mm in diameter. Optionally, the cubicles can be protected against harmful internal deposits of dust and against drip water (IP 51). Installation The switchboards are shipped in sections of one cubicle on stable wooden palletts which are suitable for rolling and forklift handling. These sections are bolted or spot-welded to channel iron sections embedded in a flat and level concrete floor.

2/22

Fig. 29

Front-connected types can be installed against the wall or freestanding. Doublebusbar installations in back-to-back configuration are installed freestanding. Cable feed-in is through corresponding cutouts in the floor; plans for which are part of the switchgear supply. Three-phase (armored) cables for voltages above 12 kV require sufficient clearance below the switchgear to split up the phases (cable floor, etc.). Circuit breakers are shipped mounted on their trucks inside the switchgear cubicles. For preliminary dimensions and weights, see Fig. 28.

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BK40

8BK40 switchgear up to 17.5 kV

Panel Fixed parts

Withdraw- Metering Busbar ableparts panel modules

Sectionalizer

Bus riser panel

8BK40 generator vacuum c.b. panel

Variants

Additional parts

Optional parts

Fig. 30: Available circuit options for switchgear/generator panel type 8BK40

Siemens Power Engineering Guide · Transmission & Distribution

2/23

Air-insulated Switchgear Type 8BK41

Generator circuit breaker unit 8BK41, air-insulated ■ ■ ■ ■ ■ ■ ■

From 7.2 to 17.5 kV Air-insulated Type-tested Metal-enclosed Metal-clad Withdrawable vacuum breaker For indoor installation

Specific features ■ One cubicle 8BK40 per generator phase ■ Circuit breaker mounted on horizontally

moving truck ■ Suitable for installation in walk-in switch-

gear containers ■ Antimagnetic sheet steel for frames,

partitions and barriers Safety of operating and maintenance personnel ■ All switching operations behind closed

doors which are part of the interlocking ■ Positive and robust mechanical

Fig. 31: Metal-clad generator c. b. unit type 8BK41 (inter-cubicle partition removed)

interlocks ■ Complete protection against contact with live parts ■ Line test with breaker inserted (option) ■ Maintenancefree vacuum circuitbreaker

Weights and dimensions Rated voltage

[kV]

7.2

12

15

17.5

Tolerance to environment

Width

[mm]

3 x 1200

3 x 1200

3 x 1200

3 x 1200

Height

[mm]

2500

2500

2500

2500

Depth

[mm]

2300

2300

2300

2300

Approx. weight incl. breaker

[kg]

3 x 2800

3 x 2800

3 x 2800

3 x 2800

■ Sealed metal enclosure with optional

gaskets ■ Complete corrosion protection and tropi-

calization of all parts ■ Vacuum-potted ribbed epoxy-insulators with high tracking resistance Performance ranges

Fig. 32

■ Rated voltages from 7.2 to 17.5 kV ■ Rated short-circuit breaking currents

Installation

up to 80 kA ■ Rated currents up to 12.000 A ■ Generator ratings up to 220 MVA at 10.5 kV 285 MVA at 13.8 kV 325 MVA at 15.75 kV Applications ■ Combined-cycle power plants ■ Hydro and pumped-storage power plants ■ Heating and general industrial power

The generator c. b. unit 8BK41 is shipped divided into three single cubicles on stable wooden palletts which are suitable for rolling and forklift handling. These cubicles are bolted or spot-welded to channel iron sections embedded in a flat and level concrete floor. Circuit breakers are shipped mounted on their trucks in one packing unit. For preliminary dimensions and weights, see Fig. 32.

plants

2/24

Siemens Power Engineering Guide · Transmission & Distribution

Air-insulated Switchgear Type 8BK41

Technical data Rated voltage

Lightning impulse test voltage

Power frequency test voltage

Rated shortcircuitbreaking current/ short time current

Rated shortcircuitmaking current

Rated current

[kV]

[kV]

[kV]

kA [rms]

[kA]

7.2

60

20

40 50 63 80

110 150 190 225

–

– –

– – –

12

75

28

40 50 63 80

110 150 190 225

–

– –

– – –

15

95

36

40 50 63 80

110 150 190 225

–

– –

– – –

17.5

95

38

50 63 80

150 190 225

–

– –

4000 [A]

6300 [A]

8000 [A]

10000 [A]

12500 [A]

Fig. 33

Basic equipment

Standard equipment

6

6

4

4

Maximum equipment

6 7

5 9

5 2

2

1 2

1 2

4

2 1 2 3

3 8

1 Vacuum circuit breaker, type 3AH on truck

2 Isolating contacts 3 Grounding switch (optionally make-proof)

4 Voltage transfomer 5 Protective capacitor

7 Generator-side CT

6 Grounding switch with

9 Lightning arrester

remanence switching capacity

8 Transfomer-side CT

Fig. 34: Available circuit options for generator c. b. unit type 8BK41

Siemens Power Engineering Guide · Transmission & Distribution

2/25

SF6-insulated Switchgear Type 8DC11

Gas-insulated switchgear type 8DC11 ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

From 3.6 up to 24 kV Triple-pole primary enclosure SF6-insulated Vacuum circuit breakers, fixed-mounted Hermetically-sealed, welded, stainlesssteel switchgear enclosure Three-position disconnector as busbar disconnector and feeder earthing switch Make-proof grounding with vacuum circuit breaker Width 600 mm for all versions up to 24 kV Plug-in, single-pole, solid-insulated busbars with outer conductive coating Cable termination with external cone connection system to DIN 47 636 and CEN HD50651

Operator safety ■ Safe-to-touch and hermetically-sealed

primary enclosure ■ All high-voltage parts, including the cable

■ ■

■

■ ■

sealing ends, busbars and voltage transformers are surrounded by grounded layers or metal enclosures Capacitive voltage indication for checking for ”dead“ state Operating mechanisms and auxiliary switches safely accessible outside the primary enclosure (switchgear enclosure) Type-tested enclosure and interrogation interlocking provide high degree of internal arcing protection Arc-fault-tested acc. to IEC 298 No need to interfere with the SF 6-insulation

Fig. 35: Gas-insulated swichgear with vacuum circuit breakers

Operational reliability

General description

■ Hermetically-sealed primary enclosure

Due to the excellent experience with vacuum circuit breaker, gas-insulated switchgear, there is a worldwide rapidly increasing demand of this kind of switchgear even in the so-called low-range field. The 8DC11 is the result of the economical combination of the SF6-insulation and the vacuum technology. The insulating gas SF6 is used for internal insulation only; circuit interruption takes place in standard vacuum breaker bottles. The safety for the personnel and the environment is maximized. The 8DC11 is completely maintenancefree. The welded gas-tight enclosure of the primary part assures an endurance of 30 years without any gasworks.

■

■

■

■

■ ■ ■ ■ ■

2/26

for protection against environmental effects (dirt, moisture and insects and rodents). Degree of protection IP65 Operating mechanism components maintenancefree in indoor environment (DIN VDE 0670 Part 1000) Breaker-operating mechanisms accessible outside the enclosure (primary enclosure) Inductive voltage transformer metalenclosed for plug-in mounting outside the main circuit Toroidal-core current transformers located outside the primary enclosure, i.e. free of dielectric stress Complete switchgear interlocking with mechanical interrogation interlocks Welded switchgear enclosure, permanently sealed Minimum fire contribution Installation independent of attitude for feeders without HRC fuses Corrosion protection for all climates

Siemens Power Engineering Guide · Transmission & Distribution

SF6-insulated Switchgear Type 8DC11

1. Modular design and compact dimensions 1

The 8DC switchboards consist of: ■ The maintenancefree SF 6-gas-insulated switching module is three-phase encapsulated and contains vacuum circuit breaker and 3 position selector switch (ON/OFF/READY TO EARTH) ■ Parts for which single-phase encapsulation is essential are safe to touch, easily accessible and not located in the switching module, e.g. current and potential transformers ■ The busbars are even single-phase encapsulated, i.e. they are insulated by silicone rubber with an outer grounded coating. The plugable design guarantees a high degree of flexibility and makes also the installation of busbar c.t.s. and p.t.s. simple.

1 Low-voltage compartment 2 Busbar voltage transformer 3 Busbar current transformer

2

4 Busbar 5 SF6-filled enclosure

3 4

7

6 Three-position switch

5

7 Three-position switch operating mechanism

6

8 Circuit-breaker operating mechanism 9 Circuit-breaker (Vacuum interrupter)

8 2. Factory-assembled well-proven tested components

9

10 Current transformers

A switchgear based on well-proven components! The 8DC switchgear design is based on assembling methods and components which have been used for years in our SF6insulated Ring Main Units (RMU). For example, the stainless-steel switchgear enclosure is hermetically-sealed by welding without any gaskets. Bushings for the busbar, cable and PT connection are welded in this enclosure, as well as the bursting disc, which is installed for pressure relief in the unlikely event of an internal fault. Siemens has had experience with this technique since 1982 because 50,000 RMUs are running troublefree. Cable plugs with the so-called outer-cone system have been on the market for many years. The gas pressure monitoring system is neither affected by temperature fluctuations nor by pressure fluctuations and shows clearly whether the switchpanel is ”ready for service“ or not. The monitor is magnetically coupled to an internal gas-pressure reference cell, mechanical penetration through the housing is not required. A design safe and reliable and, of course, wellproven in our RMUs. The vacuum circuit breaker, i.e. the vacuum interrupters and the drive mechanism, is also used in our standard switchboards. The driving force for the primary contacts of the vacuum interrupters is transferred via metal bellows into the SF6-gas-filled enclosure. A technology that has been successfully in operation in more than 100,000 vacuum interrupters over 20 years.

10

11 Double cable connection with T-plugs

12

12 PT-disconnector

11

13 Voltage transformers 13

14 Cable 15 Pressure relief duct

14 15 Fig. 36: Cross section through switchgear type 8DC11

4

7

5 1 Signalling contact 2 Magnet 3

3 ”Ready for service“ indicator 4 Pressure cell

Stainless-steel enclosure filled with SF6 gas at 0.5 bar (gauge) at 20 °C

5 Red indicator: Not ready 6

6 Green indicator: Ready 7 Magnetic coupling

Fig. 37: Principle of gas monitoring (with ”Ready for service“ indicator)

Siemens Power Engineering Guide · Transmission & Distribution

2/27

SF6-insulated Switchgear Type 8DC11

3. Current and potential transformers as per user’s application

4. No gas work at site and simplified installation

5. Minimum space and maintenancefree, cost-saving factors

A step forward in switchgear design without any restriction to the existing system! New switchgear developments are sometimes overdesigned with the need for highly sophisticated secondary monitoring and protection equipment, because currentand potential-measuring devices are used with limited rated outputs. The result: Limited application in distribution systems due to interface problems with existing devices; difficult operation and resetting of parameters. The Siemens 8DC switchgear has no restrictions. Current and potential transformers with conventional characteristics are available for all kinds of protection requirements. They are always fitted outside the SF6-gas-filled container in areas of singlepole accessibility, the safe-to-touch design of both makes any kind of setting and testing under all service conditions easy. Current transformers can be installed in the cable connection compartment at the bushings and, if required additionally, at the cables (inside the cable connection compartment). Busbar CTs for measuring and protection can be placed around the silicone-rubber-insulated busbars in any panel. Potential transformers are of the metalclad plugable design. Busbar PTs are designed for repeated tests with 80% of the rated power-frequency withstand voltage, cable PTs can be isolated from the live parts by means of a disconnection device which is part of the SF6-gas-filled switching module. This allows high-voltage testing of the switchboard with AC and the cable with DC without having to remove the PTs.

The demand for reliable, economical and maintenancefree switchgear is increasing more and more in all power supply systems. Industrial companies and power supply utilities are aware of the high investment and service costs needed to keep a reliable network running. Preventive maintenance must be carried out by trained and costly personnel. A modern switchgear design should not only reduce the investment costs, also the service costs in the long run! The Siemens 8DC switchgear has been developed to fulfill those requirements. The modular concept with the maintenancefree units does not call for installation specialists and expensive testing and commissioning procedures. The switching module with the circuit breaker and the three-position isolator is sealed for life by gas-tight welding without any gaskets. All other high-voltage components are connected by means of plugs, a technology well-known from cable plugs with longlasting service and proven experience. All cables will be connected by cable plugs with external cone connection system. In case of XLPE cables, several manufacturers even offer cable plugs with an outer conductive coating (also standard for the busbars). Paper-insulated mass-impregnated cables can be connected as well by Raychem heat-shrinkable sealing ends and adapters. The pluggable busbars and PTs do not require work on SF 6 system at site. Installation costs are considerably reduced (all components are pluggable) because, contrary to standard GIS, even the site HV tests can be omitted. Factory-tested quality is ensured thanks to simplified installation without any final adjustments or difficult assembly work.

Panel dimensions reduced, cable-connection compartment enlarged! The panel width of 600 mm and the depth of 1225 mm are just half of the truth. More important is the maximized size of the 8DC switchgear cable-connection compartment. The access is from the switchgear front and the gap from the cable terminal to the switchgear floor amounts to 740 mm. There is no need for any aisle behind the switchgear lineup and a cable cellar is superfluous. A cable trench saves civil engineering costs and is fully sufficient with compact dimensions, such as width 500 mm and depth 600 mm. Consequently, the costs for the plot of land and civil work are reduced. Even more, a substation can be located closer to the consumer which can also solve cable routing problems. Busbar Features ■ Single-pole, plug-in version ■ Made of round-bar copper, silicon-

insulated ■ Busbar connection with cross pieces

and end pieces, silicon-insulated ■ Field control with the aid of electro-

■ ■ ■ ■

conductive layers on the silicon-rubber insulation (both inside and outside) External layers earthed with the switchgear enclosure to permit access Intensive to dirt and condensation Shock-hazard protected in form of metal covering Switchgear can be extended or panels replaced without affecting the SF6 gas enclosures.

Fig. 38: Plug-in busbar (front view with removed low-voltage panel)

2/28

Siemens Power Engineering Guide · Transmission & Distribution

SF6-insulated Switchgear Type 8DC11

Fig. 39: Vacuum circuit-breaker (open on operating-mechanism side)

4 5

6

7

8

2

9 3

1 Primary part SF6-insulated, with vacuum interrupter 2 Part of swtichgear enclosure 3 Operating-mechanism box (open) 4 Fixed contact element 5 Pole support 6 Vacuum interrupter 7 Movable contact element 8 Metal bellows 9 Operating mechanism

1 Fig. 40: Vacuum circuit-breaker (sectional view)

Circuit-breaker panel

Disconnector panel

Switch-disconnector panel with fuses

Busbar section

Busbar make-proof earthing switch

1)

Basic versions Vacuum circuit breaker panel and three-position disconnector

Disconnector panel with three-position disconnector

Optional equipment indicated by means of broken lines can be installed/omitted in part or whole.

Switch-disconnector panel with three-position switch disconnector and HV HCR fuses

Busbar section with 2 three-position disconnectors and vacuum circuit breaker in one panel

Busbar make-proof grounding switch

1) Current transformer; electrically, this is assigned to the switchpanel, its actual physical location, however, is on the adjacent panel.

Fig. 41: Switchpanel versions

Siemens Power Engineering Guide · Transmission & Distribution

2/29

SF6-insulated Switchgear Type 8DC11

Weights and dimensions

Technical data

Rated voltage

[kV]

7.2

Rated power-frequency withstand voltage

[kV]

20

28

36

38

Rated lightning impulse withstand voltage

[kV]

60

75

95

95

Rated short-circuit breaking current Rated short-time current, 3s

12

15

17.5

Width

[mm]

600

Height

[mm]

2250

50

Depth

single-busbar [mm] double-busbar [mm]

1225 2400

125

Weight single-busbar [kg] (approx.) double-busbar [kg]

24

Fig. 43

max. [kA]

25

25

25

25

25

Rated short-circuit making current

[kA]

63

63

63

63

40

Rated busbar current

[A]

1250

1250

1250

1250

1250

Rated feeder current

max. [A]

1250

1250

1250

1250

1250

Cable connection systems Features

Rated current of switchdisconnector panels with fuses max. fuse [A]

■ 8DC11 switchgear for thermoplastic-

■ ■ ■

100

100

100

100

100 ■

Fig. 42: Technical data of switchgear type 8DC11 ■

Climate and ambient conditions

Internal arc test

The 8DC11 fixed-mounted circuit breaker is fully enclosed and entirely unaffected by ambient conditions. ■ All medium-voltage switching devices are enclosed in a stainless-steel housing, which is welded gas-tight and filled with SF6 gas ■ Live parts outside the switchgear enclosure are single-pole enclosed ■ There are no points at which leakage currents of high-voltage potentials are able to flow off to ground ■ All essential components of the operating mechanism are made of noncorroding materials ■ Ambient temperature range: –5 to +55°C.

Tests have been carried out with 8DC11 switchgear in order to verify its behavior under conditions of internal arcing. The resistance to internal arcing complies with the requirements of: ■ IEC 298 AA ■ DIN VDE 0670 Part 601, 9.84 These guidelines have been applied in accordance with PEHLA Guideline No. 4.

2/30

700 1200

Protection against electric shock and the ingress of water and solid foreign bodies

insulated cables with cross setions up to 630 mm2 Standard cable termination height of 740 mm High connection point, simplifying assembly and cable-testing work Phase reversal simple, if necessary, due to symmetrical arrangement of cable sealing ends Cover panel of cable termination compartment earthed Nonconnected feeders: – Isolate – Ground – Secure against re-energizing (e.g. with padlock)

Types of cable termination Circuit-breaker and disconnector panels with cable T-plugs for ASG 36-400 bushings, with M16 terminal thread according to DIN 47 636 Part 6. Switch disconnector panels with elbow cable plugs for ASG 24-250 bushings, with plug-in connection according to DIN 47 636 Parts 3 and 4.

The 8DC11 fixed-mounted circuit breaker offer the following degrees of protection: ■ IP3XD for external enclosure ■ IP65 for high-voltage components of switchpanels without HV HRC fuses in accordance with: – DIN VDE 0470 Part 1 – IEC 298 and 529 – DIN VDE 0670 Part 6

Siemens Power Engineering Guide · Transmission & Distribution

SF6-insulated Switchgear Type 8DC11

1 Low voltage compartment 5 1

2 Operating mechanism 3 Cable connection 4 Current transformer

6 5 Panel link 7 8

2

6 Busbar 7 Gas compartment 8 Three-position switch 9 Voltage transformer

3 4 9

Fig. 44: Double busbar: Back-to-back arrangement (cross section)

Single cable

Double cable

Termination for surge arrester

Termination for switch disconnector panel

Fig. 45: Types of cable termination, outer cone system

Siemens Power Engineering Guide · Transmission & Distribution

2/31

SF6-insulated Switchgear Type 8DA/8DB10

Gas-insulated switchgear type 8DA/8DB10 ■ Single-busbar: type 8DA ■ ■ ■ ■ ■ ■ ■

Double-busbar: type 8DB From 7.2 to 40.5 kV Single- and double-busbar Gas-insulated Type-tested Metal-clad (encapsulated) Compartmented Fixed-mounted vacuum breaker

Specific features ■ Practically maintenancefree compact

■ ■ ■ ■

switchgear for the most severe service conditions Fixed-mounted maintenancefree vacuum breakers Only two moving parts and two dynamic seals in gas enclosure of each pole Feeder grounding via circuit breaker Only 600 mm bay width and identical dimensions from 7.2 to 40.5 kV

Safety and reliability ■ Safe to touch – hermetically-sealed ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

grounded metal enclosure. All HV and internal drive parts maintenancefree for 20 years Minor gas service only after 10 years Arc-fault-tested Single-phase encapsulation – no phase-to-phase arcing All switching operations from dead-front operating panel Live line test facility on panel front Drive mechanism and c.t. secondaries freely and safely accessible Fully insulated cable and busbar connections available Positive mechanical interlocking External parts of instrument transformers free of dielectric stresses.

Tolerance to environment ■ Hermetically-sealed enclosure protects

all high-voltage parts from the environment ■ Installation independent of altitude ■ Corrosion protection for all climates.

2/32

General description The switchgear type 8DA10 represents the successful generation of gas-insulated medium-voltage switchgear with fixed-mounted, maintenancefree vacuum circuit breakers. The insulating gas SF6 is used for internal insulation only; circuit interruption takes place in standard vacuum breaker bottles. 1. Encapsulation All high-voltage conductors and interrupter elements are enclosed in two identical cast-aluminum housings, which are arranged at 90° angles to each other. The aluminum alloy used is corrosionfree. The upper container carries the copper busbars with its associated vacuum-potted epoxy insulators, and the three-way selector switch for the feeder with the three positions ON/ISOLATED/GROUNDING SELECTED. The other housing contains the vacuum breaker interrupter. The two housings are sealed against each other, and against the cable connecting area by arc-proof and gas-tight epoxy bushings with O-ring seals. Busbar enclosure and breaker enclosures form separate gas compartments. The hermetical sealing of all HV components prevents contamination, moisture, and foreign objects of any kind – the leading cause of arcing faults – from entering the switchgear. This reduces the requirement for maintenance and the probability of a fault due to the above to practically zero. All moving parts and items requiring inspection and occasional lubrication are readily accessible. 2. Insulation medium Sulfur-hexafluoride (SF6) gas is the prime insulation medium in this swichgear. Vacuum-potted cast-resin insulators and bushings supplement the gas and can withstand the operating voltage in the extremely unlikely case of a total gas loss in a compartment. The SF6 gas serves additionally as corrosion inhibiter by keeping oxygen away from the inner components. The guaranteed leakage rate of any gas compartment is less than 1% per year. Thus no scheduled replenishment of gas is required. Each compartment has its own gas supervision by contact-pressure gauges.

3. Three-position switch and circuit breaker The required isolation of any feeder from the busbar, and its often desired grounding is provided by means of a sturdy, maintenancefree three-way switch arranged between the busbars and the vacuum breaker bottles. This switch is mechanically interlocked with the circuit breaker. The operations ”On/Isolated“ and ”Isolated/ Grounding selected“ are carried out by means of two different rotary levers. The grounding of the feeder is completed by closing the circuit breaker. To facilitate replacement of a vacuum tube with the busbars live, the switch is located entirely within the busbar compartment. The vacuum circuit breakers used are of the type 3AH described on pages 2/66 ff of this section. Mounted in the gas-insulated switchgear, the operating mechanism is placed at the switchgear front and the vacuum interrupters are located inside the gas filled enclosures. The number of operating cycles is 30,000. Since any switching that occurs arc is contained within the vacuum tube, contamination of the insulating gas is not possible. 4. Instrument transformers Toroidal-type current transformers with multiple secondary wingdings are arranged outside the metallic enclosure around the cable terminations. Thus there is no high potential exposed on these c.t.s and secondary connections are readily accessible. All commonly used burden and accuracy ratings are available. Bus metering and measuring are by inductive, gas-insulated potential transformers which are plugged into fully insulated and gas-tight bushings on top of the switchgear. 5. Feeder connections All commonly used solid-dielectric insulated single- and three-phase cables can be connected conveniently to the breaker enclosures from below. Normally, fully insulated plug-in terminations are used. Also, fully insulated and gas-insulated busbar systems of the DURESCA/GAS LINK type can be used. The latter two termination methods maintain the fully insulated and safe-to-touch concept of the entire switchgear, rendering the terminations maintenance-free as well. In special cases, air-insulated conventional cable connection is available.

Siemens Power Engineering Guide · Transmission & Distribution

SF6-insulated Switchgear Type 8DA/8DB10

8DA10 1

1 2 3 4 5 6

2 3 4

6

7 8

7 8

9 10 11 12 13

9 10 11 12

Low-voltage cubicle Secondary equipment Busbar Cast-aluminum Disconnector Operating mechanism and interlocking device for three-position switch Three-position switch C. B. pole with upper and lower bushings C. B. operating mechanism Vacuum interrupter Connection Current transformer Rack

13

Fig. 46: Schematic cross section for switchgear type 8DA10, single-busbar

8DB10

1 2 3 4 5

6 7 8 9 10 11 12 13

Fig. 47: Schematic cross section for switchtgear type 8DB10, double-busbar

Siemens Power Engineering Guide · Transmission & Distribution

2/33

SF6-insulated Switchgear Type 8DA/8DB10

6. Low-voltage cabinet All feeder-related electronic protection devices, auxiliary relays, and measuring and indicating devices are installed in metal-enclosed low-voltage cabinets on top of each breaker bay. A central terminal strip of the lineup type is also located there for all LV customer wiring. PCB-type protection relays and individual-type protection devices are normally used, depending on the number of protective functions required.

2250

7. Interlocking system The circuit breaker is fully interlocked with the isolator/grounding switch by means of solid mechanical linkages. It is impossible to operate the isolator with the breaker closed, or to remove the switch from the GROUND SELECTED position with the breaker closed. Actual grounding is done via the circuit breaker itself. Busbar grounding is possible with the available make-proof grounding switch. If a bus sectionalizer or bus coupler is installed, busbar grounding can be done via the three-way switch and the corresponding circuit breaker of these panels. The actual isolator position is positively desplayed by rigid mechanical indicators.

600 1525

Fig. 48: Dimensions of switchgear type 8DA10, single-busbar

Switchgear type 8DB10, double-busbar

850**

The double-busbar switchgear is developed from the components of the switchgear type 8DA10. Two three-position switches are used for the selection of the busbars. They have their own gasfilled components. The second busbar system is located phasewise behind the first busbar system. The bay width of the switchgear remains unchanged, depth and height of each bay are increased (see dimension drawings Fig. 49). For parallel bus couplings, only one bay is required.

2350 (2550*)

2660

*) dependent on height of frame

Fig. 49: Dimensions of switchgear type 8DB10, double-busbar

2/34

Siemens Power Engineering Guide · Transmission & Distribution

SF6-insulated Switchgear Type 8DA/8DB10

Degrees of protection

Cable cross sections for plug-in terminations

Degree of protection IP 65: By the nature of the enclosure, all highvoltage-carrying parts are totally protected against contact with live parts, dust and water jets. Degree of protection IP 3XD: The operating mechanism and the lowvoltage cubicle have degree of protection IP 3XD against contact with live parts with objects larger than 1 mm in diameter. Protection against dripping water is optionally available. Space heaters inside the operating mechanism and the LV cabinet are available for tropical climates. Installation

Plug size

Rated voltage 7.2/12/15 kV

17.5/24 kV

36 kV

Cable cross section [mm2]

[mm2]

[mm2]

1

to 240

to 185

–

2

120 to 300

95 to 300

to 185

3

400 to 630

400 to 630

240 to 500

4

up to 1200

up to 1200

up to 1200

Fig. 50

The switchgear bays are shipped in prefabricated assemblies up to 5 bays wide on solid wooden pallets, suitable for rolling, skidding and fork-lift handling. Double-busbar sections are shipped as single or double bays. The switchgear is designed for indoor operation; outdoor prefabricated enclosures are available. Each bay is set onto embedded steel profiles in a flat concrete floor, with suitable cutouts for the cables or busbars. All conventional cables can be connected, either with fully insulated plugin terminations (preferred), or with conventional air-insulated stress cones. Fully insulated busbars are also connected directly, without any HV-carrying parts exposed. Operating aisles are required in front of and (in case of double-busbar systems) behind the switchgear lineup.

Weights and dimensions

Width

[mm]

600

Height

single-busbar (8DA) double-busbar (8DB)

[mm] [mm]

2250 2350/2550

Depth

single-busbar (8DA) double-busbar (8DB)

[mm] [mm]

1525 2660

Weight per bay

single-busbar (8DA) double-busbar (8DB)

[kg] [kg]

600 1150

Fig. 51

Ambient temperature and current-carrying capacity: Rated ambient temperature (peak)

40 °C

Rated 24-h mean temperature

35 °C

Minimum temperature

–5 °C

At elevated ambient temperatures, the equipment must be derated as follows (expressed in percent of current at rated ambient conditions).

30 °C

=

110%

35 °C

=

105%

40 °C

=

100%

45 °C

=

90%

50 °C

=

80%

Fig. 52

Siemens Power Engineering Guide · Transmission & Distribution

2/35

SF6-insulated Switchgear Type 8DA/8DB10

Options for circuit-breaker feeder of switchgear type 8DA10, single-busbar

Busbar accessories Mounted on breaker housing

Mounted on current transformer housing Panel connection options Voltage transformer, nondisconnectible or disconnectible or

or

or

or

Make-proof earthing switch

1 x plug-in cable sizes 1 to 3 or Totally gas or solid-insulated bar

Cable or bar connection, nondisconnectible or disconnectible

or

Sectionalizer without additional space required

or

Busbar current transformer

or

Mounted on panel connections

Mounted on panel connections

Mounted on panel connections

3 x plug-in cable sizes 1 or 2

or

3 x plug-in cable size 3

Mounted on panel connections

5 x plug-in cable sizes 1 or 2

Mounted on panel connections

2 x plug-in cable sizes 1 to 3 with plug-in voltage transformer

Mounted on panel connections

Current transformer

or Totally solid-insulated bar with plug-in voltage transformer or Air-insulated cable termination or

Surge arrester

Air-insulated bar

Fig. 53

2/36

Siemens Power Engineering Guide · Transmission & Distribution

SF6-insulated Switchgear Type 8DA/8DB10

Options for circuit-breaker feeder of switchgear type 8DB10, double-busbar BB1 BB2

Busbar accessories

Mounted on breaker housing

Mounted on current transformer housing

BB1

BB1

BB2

or

BB2

Mounted on panel connections

Voltage transformer, nondisconnectible

Voltage transformer, disconnectible

1 x plug-in cable sizes 1 to 3 or Totally gas or solid-insulated bar

BB1

BB1

BB1

BB1

BB2

BB2

or

or and

BB2

BB1 BB2

or BB1 and BB2

or

BB2

or

BB1

Make-proof earthing switch

or

Cable or bar connection, nondisconnectible

or

Cable or bar connection, disconnectible

or

Busbar current transformer

or

Sectionalizer BB2 without additional space required

Mounted on panel connections

Mounted on panel connections

3 x plug-in cable sizes 1 or 2

3 x plug-in cable size 3 5 x plug-in cable sizes 1 or 2

Current transformer

2 x plug-in cable sizes 1 to 3 with plug-in voltage transformer

Mounted on panel connections

or Totally solid insulated bar with plug-in voltage transformer or Air-insulated cable termination or

Surge arrester

Air-insulated bar

Fig. 54

Siemens Power Engineering Guide · Transmission & Distribution

2/37

SF6-insulated Switchgear Type 8DA/8DB10

Technical data Rated voltage

[kV]

7.2

12

15

17.5

24

36

40.5

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

70

80

Rated lightning-impulse withstand voltage

[kV]

60

75

95

95

125

170

180

Rated short-circuit breaking current and rated short-time current 3s,

max. [kA]

40

40

40

40

40

40

31.5

Rated short-circuit making current

max. [kA]

110

110

110

110

110

110

80

Rated current busbar

max. [A]

3150

3150

3150

3150

3150

2500

2500

Rated current feeder

max. [A]

2500

2500

2500

2500

2500

2500

2500

Fig. 55

For further information please contact: ++ 49 - 91 31-73 46 39

2/38

Siemens Power Engineering Guide · Transmission & Distribution

Generator Switchgear Type 8FG10

Generator circuit breaker module type 8FG10 ■ From 7.2 to 17.5 kV ■ Air-insulated ■ Metal-enclosed

Applications ■ Combined-cycle power plants ■ Hydro and pumped-storage power plants ■ Heating and general industrial power

plants Safety of operating and maintenance personnel ■ All switching operations behind closed

doors which are part of the interlocking ■ Positive and robust mechanical

interlocks ■ Complete protection against contact with live parts ■ Line test with breaker inserted (option) ■ Maintenancefree vacuum breaker

Fig. 56: Metal-enclosed generator c. b. module type 8FG10 with vacuum circuit breakers 3AH

Tolerance to environment ■ Sealed metal enclosure with optional

gaskets

Generator

■ Complete corrosion protection and tropi-

Transformer

calization of all parts ■ Vacuum-potted ribbed epoxy-insulators with high tracking resistance Specific features ■ Arrangement of circuit breaker and

disconnector in the horizontal bus run without current loops ■ Suitable for indoor or outdoor installation Technical data ■ Rated voltages from 7.2 to 17.5 kV ■ Rated short-circuit breaking currents

Fig. 57: Cross section through generator c. b. module type 8FG10

up to 80 kA ■ Rated currents up to 12.500 A ■ Generator ratings up to

Weights and dimensions

220 MVA at 10.5 kV 285 MVA at 13.8 kV 325 MVA at 15.75 kV

Rated voltage

[kV]

7.2

12

15

17.5

Width

[mm]

3200

3200

3200

3200

Height

[mm]

3200

3200

3200

3200

Depth

[mm]

6300

6300

6300

6300

Approx. weight incl. breaker

[kg]

10,500

10,500

10,500

10,500

Fig. 58

Siemens Power Engineering Guide · Transmission & Distribution

2/39

Generator Switchgear Type 8FG10

Technical data Rated voltage

Lightningimpulse test voltage

Powerfrequency test voltage

Rated shortcircuitbreaking current/ short time current

Rated shortcircuitmaking current

[kV]

[kV]

[kV]

kA [rms]

[kA]

7.2

60

20

40 50 63 80

110 150 190 225

–

– –

– – –

12

75

28

40 50 63 80

110 150 190 225

–

– –

– – –

15

95

36

40 50 63 80

110 150 190 225

–

– –

– – –

17.5

95

38

50 63 80

150 190 225

–

– –

Rated current

6300 [A]

4000 [A]

8000 [A]

10000 [A]

12500 [A]

Fig. 59: Ratings for generator c.b. module type 8FG10

Generator side

Transformer side

2

1

1 3AH vacuum

3

circuit breaker

2 Disconnector Standard

3 Grounding switch (optionally make-proof)

4

4 Voltage transformer 5 Protective capacitor 6 Grounding switch

6

with remanence switching capacity

Frequent complement

7 Generator-side CT 8 Transformer-side CT 9 Lightning arrester

5

10 Disconnector for starting equipment

7

8 Maximum complement

10

9

Fig. 60: Circuit options: Generator c. b. module type 8FG10

2/40

Siemens Power Engineering Guide · Transmission & Distribution

Containerized Switchgear

Containerized switchgear and controlgear in modular design Projects in developing countries or on fasttrack schedules frequently do not allow for the use of conventionally installed electrical equipment due to the lack of facilities, skilled labor, or simply time. Modular construction of the plants has been used successfully in these cases, including the prefabrication of electrical substations, and other control and automation equipment centers. Recognized advantages of this concept are: ■ Fabrication of critical electrical subsystems under controlled conditions at manufacturer’s location ■ Pretested and commissioned subsystems, installed ready for connection of field cables ■ Shifting of some detailed engineering to the manufacturer

This results in lower overall construction periods and reduced risks in engineering and scheduling. Direct cost savings are possible. A variety of standardized and customengineered containers is available from Siemens to meet these requirements. Basically, they are metal-enclosed weatherproof enclosures in self-supporting design, sized to optimally house the specified electrical and auxiliary equipment. The containers are outfitted per customer’s specifications on the manufacturer’s premises under his direct supervision and are then shipped as single units to the jobsite. Containers are installed on flat or raised-pier foundations before the field cables are connected and the unit is placed in service. Examples of such prefabricated substations include power distribution centers, offshore platform supply systems, pipeline compressor supply and control stations, high-power variable-speed drive system supply and control equipment, diesel and

gas-turbine generating systems, telecommunications and telecontrol stations for remote and hostile locations, etc. For details on our standardized containers see the following pages. For further information please contact: ++ 49 - 68 94 - 89 12 94

Fig. 61: Packaged Substation Hauted el Hamra in the desert Sahara

Siemens Power Engineering Guide · Transmission & Distribution

2/41

Containerized Switchgear

Standard containers for switchgear Factory-assembled packaged substations ■ Walk-in switchgear containers ■ Switchgear operated from the container

aisle Application/General features Versatile product range Wide range of container dimensions Ready for connection Installation in any location, can be moved without difficulty ■ Substations (containers) can be placed together in rows ■ Fully air-conditioned and pressurized if required ■ Special versions available, e.g. with battery compartment, personnel accomodation, office space, cooking facilities, workshop, store room, standby diesel generator, etc. ■ ■ ■ ■

Fig. 62: Packaged substation type 8FF11 including complete Power Control Center

Brief description All containers are of the same basic construction. The load bearing sections are of hot-dip galvanized steel with folded edges, and welded. The frame consists of the floor, four corner uprights and several central uprights. The side walls consist of single panels placed between the central uprights. The wall panels and doors can be arranged as required. The cross beams required for the load points (e.g. where switchgear or batteries are located) can be welded into the floor frame. Large switchgear is installed preferably through a temporary opening on the front face of the substation; for this purpose one of the uprights is bolted in position rather than welded. Special features of the individual substation ranges Type 8FF11 range Wall panels in sandwich construction, with 1-mm-thick smooth outer and inner sheets; fitted and clamped from outside; wall panels removable.

Inside Wall panel

Outside Joint plate

Fig. 63: Packaged substation type 8FF11 wall element construction

Joint plate Inside Wall panel

Outside Ribbed steel plate

Fig. 64: Packaged substation type 8FF12 wall element construction

2/42

Siemens Power Engineering Guide · Transmission & Distribution

Containerized Switchgear

1

2

3

4

5

6

1 Roof rim 2 Roof structure 3 Threaded bush for transport frame 4 Filter 5 Central upright with cover strip 6 Crane lifting lug 7 Corner support 8 Grounding connection 9 Foundation reinforcement 10 Steel outer door with panic hardware

7

11 Opening bar 12 Wall panel 8

11

9

10

12

13 Floor structure

13

Fig. 65: Packaged substation, type 8FF11

Type 8FF12 range

1 2

Wall panels in sandwich construction, with 1-mm-thick smooth inner sheet; exterior consisting of continuous welded steel sections (3 mm thick). The wall panels are fixed and clamped from the inside.

3

Type 8FF13 range Special lightweight containers of small dimensions.

4 Switchgear floor 3 x U sections, 50 mm

Type 8FF14 range Special large-dimension container for major projects.

Permitted load Roof Floor structure Wall panels Colour of load bearing parts wall panel K-value of roof K-value of wall panels, doors Degree of protection Fire resistance Corrosion resistance Operating life Fig. 66

3 Wall panels inside and outside smooth, 1 mm thick, sendzimir galvanized, with primer and top coat; 60 mm thick polyester foam fillling

150 kg/m2 500 kg/m2 300 kg/m2

7

4

8

5 6

9 1 Roof inside and outside trapezoidal sections 1 mm thick, sendzimir galvanized, with primer and top coat; 100 mm thick mineral wool filling

RAL 1019 RAL 1015 0.41 W/m2 °K 0.56 W/m2 °K

2 Roof structure hot-dip galvanized and welded steel plates with folded edges, 4 mm thick

IP 54 DIN 4102 approx. 10 years approx. 20 years

5 Cross beams PE 120, distance between each beam depending on switchpanel arrangement 6 Base structure hot-dip galvanized and welded steel plates, with folded edges, 5 mm thick 7 Aisle compressed impregnated wooden floor boards, 35 mm thick 8 Cable compartment for internal wiring 9 Continuous foundations concrete (supplied by customer)

Fig. 67: Design features; packaged substation, type 8FF11

Siemens Power Engineering Guide · Transmission & Distribution

2/43

Containerized Switchgear

6. Digit

Length Length

11734 11734 10236 10236 8738 8738 7240 7240 5742 5742

Height Height

3500 3500 3250 3250 2750 2750 2500 2500

Width Width

3420 3420 3206 3206 2996 2996 2778 2778

8. Digit From switchgear flooring or aisle surface 7. Digit

5. Digit 1 = With smooth individual outer wall panels 2 = With continuous welded steel section outer wall

Order OrderNo. No. suffixes suffixes

Internal Internal dimensions* dimensions [mm] [mm]

55 44 33 22 11 44 33 22 11 44 33 22 11 11 22

Substation substation type type 11 88

22 FF

33 FF

44 11

55

66

77

8 –

*External dimensions = internal dimensions + x for length (Floor structure) x = 208 mm (Roof structure) x = 250 mm for height x = 520 mm for width x = 208 mm Fig. 68: Determining Order Nos. for packaged substation containers

Battery

Auxiliary transformer

Switchboard Fluorescent lamps

Battery charger Filter

Emergency lighting

2778

Distribution box Heater Light switch

Heater Filter fan

Filter fan

Power socket

11734

Dimensions in mm Fig. 69: Example: Plan view of packaged station (Container), type 8FF11

2/44

Siemens Power Engineering Guide · Transmission & Distribution

Containerized Switchgear

Transport

Fig. 70: Substation type 8FF11 with split-type air conditioners

Fig. 71: Substation type 8FF11 with control room, fitted sun roof and exterior lighting

The substations can be transported by road or ship. For loading and unloading, four crane lifting lugs are provided, bolted to the two roof crossbeams. Four diagonal tie bars are attached to each side; these are removed after unloading. The substations are supplied ready for connection, with all equipment installed, including the transformer. Special models in the type 8FF14 range above 18 m length are split up for transport. Installation Packaged substation containers are preferably installed individually, but they can also be arranged as shown in the illustration. If containers are combined on-site, the connecting walls are temporary and are removed prior to installation. For sea transport, the units are sealed and protected against water ingress and damage of the jointing surfaces. The substation can be placed on flat concrete or steel foundations or on raised strip or pier foundations.

Fig. 72: Substation type 8FF11 with medium-voltage and low-voltage switchgear; split double housing

Individual

Fig. 73: Substation type 8FF11 with mimic board installed

End to end

≥ 60° Side by side

L-shaped arrangement

Fig. 74: Arrangement variations substation type 8FF1

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 75: Lifting substation by single crane

2/45

Secondary Distribution Switchgear and Transformer Substations

General

Standards

Features

■ The fixed-mounted ring-main units

Maximum personnel safety The secondary distribution network with its basic design of ring-main systems with counter stations as well as radial-feed transformer substations are designed in order to reduce network losses and to provide an economical solution for switchgear and transformer substations. They are installed with an extremely high number of units in the distribution network. Therefore, high standardization of equipment is necessary and economical. The described switchgear will show such qualities. To reduce the network losses the transformer substations should be installed directly at the load centers. The transformer substations consisting of medium-voltage switchgear, transformers and low-voltage distribution can be designed as prefabricated units or single components installed in any building or rooms existing on site. Due to the large number of units in the networks the most economical solution for such substations should have climate-independent and maintenancefree equipment so that operation of the equipment does not need any maintenance work during its lifetime. For such transformer substations nonextensible and extensible switchgear, for instance RMUs, have been developed using SF6-gas as insulation and arc-quenching medium in the case of load-break systems (RMU), and SF 6-gas insulation and vacuum as arc-quenching medium in the case of extensible modular switchgear, consisting of load break panels with or without fuses, circuit-breaker panels and measuring panels. Siemens developed RMUs in accordance with these requirements. Ring-main units type 8DJ10, 8DJ20, 8DJ30, 8DJ40 and 8DH10 are type-tested, factory-finished, metal-enclosed, SF6-insulated indoor switchgear installations. They verifiably meet all the demands encountered in network operation by virtue of the following features:

2/46

type 8DJ10, 8DJ20, 8DJ30, 8DJ40 and 8DH10 comply with the following standards:

■ High-grade steel housing and cable con-

■ ■ ■

nection compartment tested for resistance to internal arcing Logical interlocking Guided operating procedures Capacitive voltage indication integrated in unit Safe testing for dead state on the closed-off operating front Locked, grounded covers for fuse assembly and cable connection compartments

IEC Standard

VDE Standard

IEC 694

VDE 0670 part 1000

IEC 298

VDE 0670 part 6

IEC 129

VDE 0670 part 2

IEC 282

VDE 0670 part 4

Safe, reliable, maintenancefree

IEC 265–1

VDE 0670 part 301

■ Corrosion-resistant hermetically welded

IEC 420

VDE 0670 part 303

IEC 56

VDE 0670 part 101–107

■ ■

■

■ ■

■

■

high-grade steel housing without seals and resistant to pressure cycles Insulating gas retaining its insulating and quenching properties throughout the service life Single-phase encapsulation outside the housing Clear indication of readiness for operation, unaffected by temperature or altitude Complete protection of the switch disconnector/fuse combination, even in the event of thermal overload of the HV HRC fuse (thermal protection function) Reliable, maintenancefree switching devices

Fig. 76

In accordance with the harmonization agreement reached by the IEC member states, that their national specifications conform to IEC Publication No. 298. For further information please contact: Fax: ++ 49 - 91 31-73 46 36

Excellent resistance to ambient conditions ■ Robust, corrosion-resistant and mainte-

nancefree operating mechanisms ■ Maintenancefree, all-climate, safe-to-

touch cable terminations ■ Creepage-proof and free from partial

discharges ■ Maintenancefree, safe-to-touch,

all-climate HV HRC fuse assembly Environmental compatibility ■ Simple, problemfree disposal of the

SF6 gas ■ Housing material can be recycled by

normal methods

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear and Transformer Substations

Primary distribution G

Secondary distribution

RMU for transformer substations Type 8DJ

Extensible switchgear for consumer substations Type 8DH or 8AA

Extensible switchgear for substations with circuit breakers Type 8DH or 8AA

Fig. 77: Secondary Distribution Network

Siemens Power Engineering Guide · Transmission & Distribution

2/47

Secondary Distribution Selection Matrix

Switchgear

Codes, standards

Type of installation

Insulation

Enclosure

Switching device

Non extensible

SF6-gas-insulated

Metal -enclosed fixed-mounted

Load-break switch

SF6 -gas-insulated

Metal -enclosed fixed-mounted

Load-break switch Vacuum c. b. Measurement panels

Air-insulated

Metal-enclosed

Load-break switch Vacuum c. b. Measurement panels

Medium-voltage indoor switchgear, type-tested according to: IEC 298 DIN VDE 0670, Part 6

Extensible

Transformer-substations

Execution of the transformer substation

Prefabricated, factory-assembled substation

Fig. 78

2/48

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Selection Matrix

Application

Switchgear type

Technical data

Page

Insulation BIL 17.5/24 7.2/12 [kV] [kV]

Design voltage Insulation

Maximum rated short-time current

[kV]

[kA] 1s

[kA] 3s

Rated current Busbar max. [A]

Feeder [A]

RMU for transformer substations

8DJ10

60/75

95/125

7.2–24

25

20

630

up to 630

2/50

Single panel, fused for one transformer

8DJ20

60/75

95/125

7.2–24

25

20

630

up to 630

2/53

Ultracompact RMU up to 12 kV

8DJ30

60/75

95/125

7.2–12

25

20

630

up to 630

2/54

RMU for extreme low substation housings

8DJ40

60/75

95/125

7.2–24

20

20

630

up to 630

2/56

7.2–15

25

20

Consumer substation c. b. switchgear

8DH10

60/75

95/125

1250

up to 630

2/58

Consumer substation c. b. switchgear

8AA20

Package substation type (Example)

8FB1

17.5–24

20

11.5

7.2–12

20

11.5

1000

up to 1000

17.5–24

16

9.3

630

up to 630

Type of housing

HV-section Medium-voltage switchgear type

Transformer rating

8FB10 8FB11 8FB12

8DJ10 8DJ20 8DJ30 8DJ40

630 kVA

60/75

95/125

8FB15 8FB16 8FB17

Siemens Power Engineering Guide · Transmission & Distribution

2/62

Page

2/64 up to 1000/1250 kVA

2/49

Secondary Distribution Switchgear Type 8DJ10

Ring-main unit type 8DJ10, 7.2–24 kV nonextensible, SF6-insulated Typical use SF6-insulated, metal-enclosed fixed-mounted Ring-main units (RMU) type 8DJ10 are used for outdoor transformer substations and indoor substation rooms with a variability of 25 different schemes as a standard delivery program. More than 55,000 RMUs of type 8DJ10 are in worldwide operation. Specific features ■ Maintenancefree, all-climate ■ SF6 housings have no seals ■ Remote-controlled motor operating

■

■ ■ ■

■

■

mechanism for all auxiliary voltages from 24 V DC to 230 V AC Easily extensible by virtue of trouble-free replacement of units with identical cable connection geometry Standardized unit variants for operatorcompatible concepts Variable transformer cable connection facilities Excellent economy by virtue of ambient condition resistant, maintenancefree components Versatile cable connection facilities, optional connection of mass-impregnated or plastic-insulated cables or plug connectors Cables easily tested without having to be dismantled

2/50

Fig. 79: Nonextensible RMU, type 8DJ10

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear Type 8DJ10

Technical data (rated values)1) Rated voltage and insulation level

[kV]

7.2

12

15

17.5

24

Rated frequency

[Hz]

50/60

50/60

50/60

50/60

50/60

Rated current of cable feeders

[A]

400/630

400/630

400/630

400/630

400/630

Rated current of transformer feeders2)

[A]

200

200

200

200

200

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

Rated lightning-impulse withstand voltage

[kV]

60

75

95

95

125

Rated short-circuit making current of cable feeder switches

[kA]

63

52

52

52

40

Rated short-circuit making current of transformer switches

[kA]

25

25

25

25

25

Rated short-circuit current, 1s

[kA]

25

21

21

21

16

Ambient temperature

[°C]

min. – 50 max. +80

min. – 50 max.+80

min. – 50 max. +80

min. – 50 max. +80

min. – 50 max. +80

1) Higher values on request 2) Depending on HV HRC fuse assembly

Fig. 80

1 2 3

1

HRC fuse boxes

2

Hermetically-scaled welded stainless steel enclosure

3

SF6 insulation/quenching gas

4

Three-position load-break switch

5

Feeder cable with insulated connection alternative with T-plug system

6

Maintenancefree stored energy

4 6 5

Fig. 81: Cross section of SF 6-insulated ring-main unit 8DJ10

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 82: “Three-position load-breakswitch” ON–OFF–EARTH

2/51

Secondary Distribution Switchgear Type 8DJ10

Examples out of 25 standard schemes With integrated HV HRC fuse assembly

Scheme 71

Scheme 81

800

1170

1630

800

800

800

1360

1360

1360

1760

1760

1760

Scheme 10

Dimensions [mm] Width Depth Height Version with low support frame Version with high support frame Without HV HRC fuses

Combinations

Scheme 70

Scheme 61

Scheme 64

Dimensions [mm] Width Depth Height Version with low support frame Version with high support frame

1450

1700

2070

800

800

800

1105

1360

1360

1505

1760

1760

Fig. 83: Schemes and dimensions

2/52

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear Type 8DJ20

Single panel for one transformer feeder, type 8DJ20, 7.2–24 kV nonextensible, SF6-insulated Typical use SF6-insulated, metal-enclosed, fixedmounted single panels type 8DJ20 are used for dead-end lines to feed one transformer, e.g. instead of pole-mounted equipment, installed in substation housings or any indoor rooms. Specific features ■ Minimal dimensions ■ Ease of operation ■ Proven components from the ■ ■ ■ ■

■ ■ ■ ■

8DJ10 range Metal-enclosed All-climate Maintenancefree Capacitive voltage taps for – incoming feeder cable – outgoing transformer feeder Optional double cable connection Optional surge arrester connection Transformer cable connected via straight or elbow plug Motor operating mechanism for auxiliary voltages of 24 V DC–230 V AC

Fig. 84: Nonextensible single panel for transformer feeder type 8DJ20

Technical data (rated values)1)

Transformer spur panel

Rated voltage and insulation level

[kV]

7.2

12

15

17.5

24

Rated frequency

[Hz]

50/60

50/60

50/60

50/60

50/60

Rated current of transformer feeders2)

[A]

200

200

200

200

200

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

Rated lightning-impulse withstand voltage

[kV]

60

75

95

95

125

Rated short-circuit making current of transformer switches

[kA]

25

25

25

25

25

Rated short-circuit current, 1s [kA]

10

10

10

10

10

Ambient temperature

Dimensions

[°C]

min. – 40 max. +70

1) Higher values on request 2) Depending on HV HRC fuse assembly

Fig. 85

Siemens Power Engineering Guide · Transmission & Distribution

min. – 40 min. – 40 min. – 40 min. – 40 max. +70 max. +70 max.+70 max.+70

Width

[mm]

575

Depth

[mm]

760

Height

[mm]

1400

Fig. 86

2/53

Secondary Distribution Switchgear Type 8DJ30

Ring-main unit type 8DJ30, 7.2–12 kV ultracompact, nonextensible SF6-insulated Typical use SF6-insulated, metal-enclosed, fixedmounted Ring-main units type 8DJ30 are designed as ultracompact transformer substations with extremly small dimensions. Specific features ■ Optimized compact design ■ Ease of cable testing by means

of bushings ■ Test bushing covers arranged and

■

■ ■ ■ ■

■

■

locked panel by panel, minimal effort logical interlocking Variable cable connection with cable plugs and conventional sealing ends Optional floor or wall mounting All-climate Maintenancefree Capacitive voltage taps for – incoming feeder cable – optional outgoing transformer feeder Optional motor operating mechanism for auxiliary voltages of 24 V DC–230 V AC Optional plug-in grounding links

Fig. 87: Nonextensible RMU, type 8DJ30

Technical data (rated values)1) Rated voltage and insulation level

[kV]

7.2

12

Rated frequency

[Hz]

50/60

50/60

Rated current of cable feeders

[A]

400/630

400/630

Rated current of transformer feeders2)

[A]

200

200

Rated power-frequency withstand voltage

[kV]

20

28

Rated lightning-impulse withstand voltage

[kV]

60

75

Rated short-circuit making current of cable feeder switches

[kA]

63

52

Rated short-circuit making current of transformer switches

[kA]

25

25

Rated short-circuit current, 1s

[kA]

25

21

Ambient temperature

[°C]

min. – 40 max. +70

min. – 40 max. +70

1) Higher values on request 2) Depending on HV HRC fuse assembly

Fig. 88

2/54

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear Type 8DJ30

Individual panels

Scheme 10

Scheme 32

Scheme 71

Dimensions [mm] Width

920

670

1140

Depth

540

540

540

Height Version wall-mounted without support frame

945

945

945

Version with low support frame

1200

1200

1200

Version with high support frame

1700

1700

1700

Fig. 89: Schemes and dimensions

Siemens Power Engineering Guide · Transmission & Distribution

2/55

Secondary Distribution Switchgear Type 8DJ40

Ring-main unit type 8DJ40, 7.2–24 kV nonextensible, SF6-insulated Typical use SF6-insulated, metal-enclosed, fixedmounted. Ring-main units type 8DJ40 are mainly used for transformer compact substations. The main advantages of this switchgear is the extremely high cable termination for easy cable connection and cable testing works. Specific features 8DJ40 units are type-tested, factoryfinished, metal-enclosed SF6-insulated switchgear installations and meet the following operational specifications: ■ High level of personnel safety and reliability ■ High availability ■ High-level cable connection ■ Minimum space requirement ■ Uncomplicated design ■ Separate operating mechanism actuation for switch disconnector and make-proof grounding switch, same switching direction in line with VDEW recommendation ■ Ease of installation ■ Motor operating mechanism retrofittable ■ Optional stored-energy release for ring cable feeders ■ Maintenancefree ■ All-climate

Fig. 90: Nonextensible RMU, type 8DJ40

Technical data (rated values)1) Rated voltage and insulation level

[kV]

12

24

Rated frequency

[Hz]

50

50

Rated current of cable feeders

[A] 400/630*

400/630*

Rated current of transformer feeders

[A]

≤ 200

≤ 200

Rated power-frequency withstand voltage

[kV]

28

50

Rated lightning-impulse withstand voltage

[kV]

75

125

Rated short-circuit making current of cable feeder switches

[kA] 50 (31.5)*

40 (31.5)*

Rated short-circuit making current of transformer switches2)

[kA]

25

25

Rated short-time current of cable feeder switches

[kA] 20 (12.5)*

16 (12.5)*

Rated short-circuit time

[s]

1

1

Rated filling pressure at 20 °C

[barg]

0.5

0.5

Ambient temperature

[°C]

min. – 40 max. +70

min. – 40 max. +70

1) Higher values on request * With snap-action/stored-energy operating mechanism up to 400 A/12.5 kA, 1s 2) Depending on HV HRC fuse assembly

Fig. 91

2/56

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear Type 8DJ40

Scheme 32

Scheme 10

Scheme 71

Dimensions [mm] Width

1140

909

1442

Depth

760

760

760

Height

1400/1250

1400/1250

1400/1250

Fig. 92: Schemes and dimensions

Siemens Power Engineering Guide · Transmission & Distribution

2/57

Secondary Distribution Switchgear Type 8DH10

Consumer substation modular switchgear type 8DH10 extensible, SF6-insulated Typical use SF6-insulated, metal-enclosed fixed-mounted switchgear units type 8DH10 are indoor installations and are mainly used for power distribution in customer substations or main substations. The units are particularly well suited for installation in industrial environments, damp river valleys, exposed dusty or sandy areas and in built-up urban areas. They can also be installed at high altitude or where the ambient temperature is very high. Specific features 8DH10 fixed-mounted switchgear units are type-tested, factory-assembled, SF6-insulated, metal-enclosed switchgear units comprising circuit-breaker panels, disconnector panels and metering panels. They meet the demands made on medium-voltage switchgear, such as ■ High degree of operator safety, reliability

and availability ■ No local SF 6 work ■ Simple to install and extend ■ Operation not affected by environmental ■ ■

■

■

■

■

factors Minimum space requirements Freedom from maintenance is met substantially better by these units than by earlier designs. Busbars from panel blocks are located within the SF6 gas compartment. Connections with individual panels and other blocks are provided by solid-insulated plug-in busbars Single-phase cast-resin enclosed insulated fuse mounting outside the switchgear housing ensures security against phase-to-phase faults All live components are protected against humidity, contamination, corrosive gases and vapours, dust and small animals All normal types of T-plugs for thermoplastic-insulated cables up to 300 m2 cross-section can be accommodated

Fig. 93: Extensible, modular switchgear type 8DH10 ■ The units have an grounded outer enclo-

■ ■

■

■

■ ■

2/58

sure and are thus shockproof. This also applies to the fuse assembly and the cable terminations. Plug-in cable sealing ends are housed in a shock-proof metalenclosed support frame Fuses and cable connections are only accessible when earthed All bushings for electrical and mechanical connections are welded gas-tight without gaskets Three-position switches are fitted for lead switching, disconnection and grounding, with the following switch positions: closed, open and grounded. Make-proof earthing is effected by the three-position switch (shown at page 2/51) Each switchgear unit can be composed as required from single panels and (preferably) panel blocks, which may comprise up to three combined single panels The 8DH10 switchgear is maintenancefree Integrated current transformer suitable for digital protection relays and protection systems for c.t. operation release

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear Type 8DH10

1 1

2 3 4

2

5 3

6 7

4

8

5

9 10

1 2 3 4 5

Fuse assembly Three-position switch Transformer/cable feeder connection Hermetically-welded gas tank Plug-in busbar up to 1250 A

Fig. 94: Cross section of transformer feeder panel

1 2 3 4 5

6 Three-position switch 7 Ring-main cable termination

Low-voltage compartment Circuit-breaker operating mechanism Metal bellow welded to the gas tank Pole-end kinematics Spring-assisted mechanism

(400/630 A T-plug system)

8 Hermetically-welded RMU housing 9 Busbar (up to 1250 A) 10 Overpressure release system

Fig. 95: Cross section of circuit-breaker feeder panel

LV cabinet 1 2

3 4

extensible

extensible

1 Plug bushing welded to the gas tank 2 Silicon adapter 3 Silicon-insulated busbar 4 Removable insulation cover to assemble the system at site

Fig. 96: Combination of single panels with plug-in type, silicon-insulated busbar. No local SF 6 gas work required during assembly or extension

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 97: Cross section of silicon-pluged busbar section.

2/59

Secondary Distribution Switchgear Type 8DH10

Technical data (rated values)1) Rated voltage and insulation level

[kV]

7.2

12

15

17.5

24

Rated frequency

[Hz]

50/60

50/60

50/60

50/60

50/60

Rated power-frequency withstand voltage

[kV]

20

28

36

38

50

Rated lightning-impulse withstand voltage

[kV]

60

75

95

95

125

Rated short-circuit breaking current of circuit-breakers

[kA]

25

25

20

20

16

Rated short-circuit current, 1s

[kA]

25

25

20

20

16

Rated short-circuit making current

[kA]

63

63

50

50

50

630 1250

630 1250

630 1250

630 1250

630 1250

[max. A] [max. A] [max. A]

400/630 400/630 200

400/630 400/630 200

400/630 400/630 200

400/630 400/630 200

400/630 400/630 200

[A] [A]

400/630 200

400/630 200

400/630 200

400/630 200

400/630 200

Busbar rated current Feeder rated current – Circuit-breaker panels – Ring-main panels – Transformer panels* Rated current of bus sectionalizer panels – without HV HRC fuses – with HV HRC fuses*

[A]

1) Higher values on request * Depending on HV HRC fuse assembly

Fig. 98

2/60

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear Type 8DH10

Individual panels

Ring-main panel

Transformer panel

Circuit-breaker panel

Billing metering panel

Busbar metering and grounding panel

Dimensions [mm] Width

500

500

350

600*/850

500

Depth

780

780

780

780

780

Height

1400

2000

1400

1400/2000**

1450

* Width for version with combined instrument transformer ** With low-voltage compartment

Blocks

2

Ring-main feeders

3 Ring-main feeders

2

Transformer feeders

3

Transformer feeders

Dimensions [mm] Width

700

1050

1000

1500

Depth

780

780

780

780

Height

1400

1400

1400

1400

Fig. 99: Schemes and dimensions

Siemens Power Engineering Guide · Transmission & Distribution

2/61

Secondary Distribution Switchgear Type 8AA20

Consumer substation modular switchgear type 8AA20, 7.2–24 kV extensible, air-insulated Typical use The air-insulated modular indoor switchgear is used as a flexible system with a lot of panel variations. Panels with fused and unfused load-break switches, with trucktype vacuum circuit breakers and metering panels can be combined with air-insulated busbars. The 8AA20 ring-main units are type-tested, factory-assembled metal-enclosed indoor switchgear installations. They meet operational requirements by virtue of the following features: Personnel safety

Fig. 100: Extensible modulares switchgear type 8AA20

■ Sheet-steel enclosure tested for resist-

ance to internal arcing ■ All switching operations with door

Technical data (rated values)1)

closed ■ Testing for dead state with door closed ■ Insertion of barrier with door closed

Rated voltage and insulation level

Safety, reliability/maintenance

Rated power-frequency withstand voltage

■ Complete mechanical interlocking ■ Preventive interlocking between barrier

Rated lightning-impulse withstand voltage

and switch disconnector ■ Door locking Excellent resistance to ambient conditions ■ High level of pollution protection by

virtue of sealed enclosure in all operating states ■ Insulators with high pollution-layer resistance

7.2

12

17.5

24

[kV]

20

28

38

50

[kV]

60

75

95

125

Rated short-time current 1s [kA]

20

20

16

16

40

40

Rated short-circuit making current

[kA]

50

50

Rated busbar current1)

[A]

630

630

630

630

Rated feeder current

[A]

630

630

630

630

1) Higher values on request

Fig. 101

Standards ■ The switchgear complies with the

following standards: IEC-Publ. 56, 129, 256-1, 298, 420, 694 VDE 0670 Part 2, 4 and 6 Part 101–107 Part 301, 303 Part 1000 In accordance with the harmonization agreement reached by the EC member states, their national specifications conform to IEC-Publ. No. 298.

2/62

Dimensions

Width

Height

Depth

12/24 kV [mm]

[mm]

12/24 kV [mm]

Load-breaker panels

600/750

2000

665/790 or 931/1131

Circuit-breaker panels

750/750

2000

931/1131

Metering panels

600/750

2000

665/790 or 931/1131

Fig. 102: Dimensions

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear Type 8AA20

Resistance to internal arcing – IEC-Publ. 298, Annex AA – VDE 0670, Part 6 and Part 601 Type of service location

1

Air-insulated ring-main units can be used in service locations and in closed electrical service locations in accordance with VDE 0101.

1 2 2

Specific features

central operating mechanism ■ Standard program includes numerous ■

■ ■ ■ ■ ■

circuit variants Operations enabled by protective interlocks; the insulating barrier is included in the interlocking Extensible by virtue of panel design Cubicles compartmentalized (option) Minimal cubicle dimensions without extensive use of plastics Lines up with earlier type 8AA10 Withdrawable circuit-breaker section can be moved into the service and disconnected position with the door closed

3

4

■ Switch disconnector fixed-mounted ■ Switch disconnector with integrated

1 Load-break switch 2 Grounding switch

1 2 3 4

Fig. 103a: Cross section of cable feeder panel

Fig. 103b: Cross section of withdrawable type vacuum circuit-breaker panel

Vacuum circuit breaker Current transformer Potential transformer Grounding switch

Individual panels Circuit-breaker panels Scheme 11/12

Scheme 13/14

Load-breaker panels Scheme 21/22

Scheme 23/24

Scheme 25/26

Metering and cable panels Scheme 33/34

Fig. 104: Schemes

Siemens Power Engineering Guide · Transmission & Distribution

2/63

Secondary Distribution Switchgear and Transformer Substations

Factory-assembled packaged substations type 8FB1 (example ) Factory-assembled transformer substations are available in different designs and dimensions. As an example of a typical substation program, type 8FB1 is shown here. Other types are available on request. The transformer substations type 8FB1 with up to 1000 kVA transformer ratings and 7.2–24 kV are prefabricated and factory-assembled, ready for connection of network cables on site. Special foundation not necessary. ■ Distribution substations for

public power supply ■ Nonwalk-in type ■ Switchgear operated with open substa-

tion doors General features/Applications ■ Power supply for LV systems, especially

in load centers for public supply ■ Power supply for small and medium

industrial plants with existing HV side cable terminations ■ Particularly suitable for installation at sites subject to high atmospheric humidity, hostile environment, and stringent demands regarding blending of the station with the surroundings ■ Extra reliability ensured by SF6-insulated ring-main units type 8DJ, which require no maintenance and are not affected by the climate Brief description The substation housing consists of a torsion-resistant bottom unit, with a concrete trough for the transformer, embedded in the ground, and a hot-dip galvanized steel structure mounted on it. It is subdivided into three sections: HV section, transformer section and LV section. The lateral section of the concrete trough serves as mounting surface for the HV and LV cubicles and also closes off the cable entry compartments at the sides. These compartments are closed off at the bottom and front by hot-dip galvanized bolted steel covers. Four threaded bushes for lifting the complete substation are located in the floor of the concrete trough. The substations are arc-fault-tested in order to ensure personnel safety during operation and for the pedestrians passing by the installed substation.

2/64

Fig. 105: Steel-clad outdoor substation 8FB1 for rated voltages up to 24 kV and transformers up to 1000 kVA

HV section (as an example):

LV section:

8DJ SF6-insulated ring-main unit (for details please refer to RMU‘s page 2/50–2/61)

The LV section can take various forms to suit the differing base configurations. The connection to the transformer is made by parallel cables instead of bare conductors. Incoming circuit: Circuit breaker, fused load disconnector, fuses or isolating links. Outgoing circuits: Tandem-type fuses, load-break switches, MCCB, or any other requested systems. Basic measuring and metering equipment to suit the individual requirements.

Technical data: ■ Rated voltages and insulation levels

■ ■ ■ ■

7.2 kV 12 kV 15 kV 17.5 kV 24 kV 60 75 95 95 125 kV (BIL) Rating of cable circuits: 400 / 630 A Rating of transformer circuits: 200 A Degree of protection for HV parts: IP 65 Ambient temperature range: –30°C/+55°C (other on request)

Transformer-section: Oil-cooled transformer with ratings up to max. 1000 kVA. The transformer is connected with the 8DJ10 ring-main unit by three single-core screened 35 mm2 plastic insulated cables. The connection is made by means of right-angle plugs or standard air-insulated sealing ends possible at the transformer side.

Siemens Power Engineering Guide · Transmission & Distribution

Secondary Distribution Switchgear and Transformer Substations

Substation housing type:

8FB10

8FB11

8FB12

8FB15

8FB16

8FB17

HV section: SF6 -insulated ring-main unit (RMU)

H High-voltage

H

T

L

section T Transformer section

H

T

T L L

H

T

L

H

T L

H

T

L

H

L Low-voltage section

Transformer rating

630 kVA

630 kVA

630 kVA

1000 kVA

1000 kVA

1000 kVA

3290 1300 1650

2570 2100 1650

2100 2100 1650

3860 1550 1700

3120 2300 1700

2350 2300 1700

2100 4.28 7.06 approx. 2280

2100 5.40 8.91 approx. 2530

2100 4.41 7.28 approx. 2400

2350 5.98 10.17 approx. 3400

2350 7.18 12.20 approx. 3800

2350 5.41 9.19 approx. 3600

Overall dimensions, weights: Length Width Height above ground Height overall Floor area Volume Weight without transformer

[mm] [mm] [mm] [mm] [mm2] [mm3] [kg]

Fig. 106: Technical data, dimensions and weights

Fig. 107: HV section: Compact substation 8FB with SF 6-insulated RMU (two loop switches, one transformer feeder switch with HRC fuses)

Fig. 108: Transformer section: Cable terminations to the transformer, as a example

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 109: LV section: Example of LV distribution board

2/65

Medium-Voltage Devices Product Range

Devices for medium-voltage switchgear With the equipment program for switchgear Siemens can deliver nearly every device which is required in the mediumvoltage range between 7.2 and 36 kV. Fig. 110 gives an overview about the available devices and their main characteristics. All components and devices conform to international and national standards, as there are:

Device

Type

Rated voltage

Shortcircuit current

Short-time current (3s)

[kV]

[kA]

[kA]

Indoor vacuum circuit breaker

3AH

7.2 … 36

13.1 … 63

13.1 … 63

Outdoor vacuum circuit breaker

3AF 3AG

12, 36

25

25

7.2 … 15

25 … 44

25 … 44

Vacuum circuit breakers IEC 56 IEC 694 BS5311 DIN VDE 0670

Modular assembly set with indoor VCB

Vacuum switches

Indoor vacuum switch

3CG

7.2 … 24

–

16 … 20

Indoor vacuum contactor

3TL

3.6 … 12

–

8 (1s)

Vacuum interrupter

VS

7.2 … 40.5

12.5 … 72

12.5 … 72

Indoor switch disconnector

3CJ

7.2 … 24

–

16 … 20 (1s)

Indoor disconnecting and grounding switch

3D

7.2 … 36

–

16 ... 63 (1s)

HV HRC fuses

3GD

7.2 … 36

31.5 … 80

–

Fuse bases

3GH

7.2 … 36

44 peak withstand current

–

Indoor post insulators, bushings

3FA

3.6 … 36

–

–

Indoor and outdoor current and voltage transformers

3M

12 … 36

–

–

■ ■ ■ ■

■ IEC 265-1 ■ DIN VDE 0670, Part 301

in combination with Siemens fuses: ■ IEC 420 ■ DIN VDE 0670, Part 303

Vacuum contactors ■ IEC 470 ■ DIN VDE 0660, Part 103 ■ UL 347

Switch disconnectors ■ ■ ■ ■

IEC 129 IEC 265-1 DIN VDE 0670, Part 2 DIN VDE 0670, Part 301

HV HRC fuses ■ IEC 282 ■ DIN VDE 0670, Part 4

Current and voltage transformers ■ ■ ■ ■

IEC 185, 186 DIN VDE 0414 BS 3938, 3941 ANSI C57.13

For further information please contact: Fax: ++ 49 - 91 31 - 73 46 54

Fig. 110: Equipment program for medium-voltage switchgear

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Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Product Range

Operating cycles

Rated current mechanical

with rated current

Applications/remarks

Page

with shortcircuit current

[A]

800 … 4000

10,000 … 120,000

10,000 … 30,000

25 … 100

All applications, e.g. overhead lines, cables, transformers, motors, generators, capacitors, filter circuits, arc furnaces

2/68

1600

10,000

10,000

30 … 50

All applications, e.g. overhead lines, cables, transformers, motors, generators, capacitors, filter circuits

2/72

1250 … 3150

–

–

–

Original equipment manufacturer (OEM) and retrofit

2/73

800

10,000

10,000

–

All applications, e.g. overhead lines, cables, transformers, motors, capacitors; high number of operations; fuses necessary for short-circuit protection

2/74

400 … 450

1x106 ... 3x106

0.25x105 ... 2x106

–

All applications, especially motors with very high number of operating cycles

2/76

800 … 4000

10,000 … 30,000

10,000 … 30,000

25 … 100

For circuit breakers, switches and gas-insulated switchgear

2/77

630

1000

20

–

Small number of operations, e.g. distribution transformers

2/78

400 … 2500

–

–

–

Protection of personnel working on equipment

2/79

6.3 … 250

–

–

–

Short-circuit protection; short-circuit current limitation

2/80

400

–

–

–

Accommodation of HV HRC fuse links

2/80

–

–

–

–

Insulation of live parts from another, carrying and supporting function

2/81

–

–

–

–

Measuring and protection

2/82

Siemens Power Engineering Guide · Transmission & Distribution

2/67

Medium-Voltage Devices Type 3AH

Indoor vacuum circuit breakers type 3AH

Rated voltage [kV] 36

The 3AH vacuum circuit breakers are three-phase medium-voltage circuit breakers for indoor installations. As standard circuit breakers they are available for the entire medium-voltage range. Circuit breakers with reduced pole center distances, circuit breakers for very high numbers of switching cycles and singlephase versions are part of the program. The following breaker types are available: ■ 3AH1 – the maintenancefree circuit

breaker which covers the range between 7.2 kV and 24 kV. It has a lifetime of 10,000 operating cycles ■ 3AH2 – the circuit breaker for 60,000 operating cycles in the range between 7.2 kV and 24 kV ■ 3AH3 – the maintenancefree circuit breaker for high breaking capacities in the range between 7.2 kV and 36 kV. It has a lifetime of 10,000 operating cycles ■ 3AH4 – the circuit breaker for up to 120,000 operating cycles ■ 3AH5 – the economical circuit breaker in the lower range for 10,000 maintenancefree operating cycle The 3AH circuit breakers are suitable for: ■ Rapid load transfer, synchronization

24

17.5 15

12

7.2 Rated shortcircuit breaking current [kA]

13.1

Rated current [A]

800

16

20

25

3AH1

3AH2

3AH3

Nonwearing material pairs at the bearing points and nonaging greases make relubrication superfluous on 3AH circuit breakers up to 10,000 operating cycles, even after long periods of standstill.

■ ■ ■

63

3AH4

3AH5

Properties of 3AH circuit breakers: No relubrication

■

50

Fig. 111: The complete 3AH program

■ Breaking short-circuit currents with

■

40

–- 1250 1250 1250 800 800 800 800 800 1250 -1250 -1250 -2500 -1250 -1250 -2500 2500 -3150 -3150 -4000

■ Automatic reclosing up to 31.5 kA

very high initial rates of rise of the recovery voltage Switching motors Switching transformers and reactors Switching overhead lines and cables Switching capacitors Switching arc furnaces

31.5

High availability Continuous tests have proven that the 3AHs are maintenancefree up to 10,000 operating cycles: accelerated temperature/ humidity change cycles between –25 and +60 °C prove that the 3AH functions reliably without maintenance. Assured quality Exemplary quality control with some hundred switching cycles per circuit breaker, certified to DIN/ISO 9001. No readjustment Narrow tolerances in the production of the 3AH permanently prevent impermissible play: even after frequent switching the 3AH circuit breaker does not need to be readjusted up to 10,000 operating cycles.

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Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Type 3AH

Advantages of the vacuum switching principle The most important advantages of the principle of arc extinction in a vacuum have made the circuit breakers a technically superior product and the principle on which they work the most economical extinction method available: ■ Constant dielectric: In a vacuum there are no decomposition products and because the vacuum interrupter is hermetically sealed there are no environmental influences on it. ■ Constant contact resistance: The absence of oxidization in a vacuum keeps the metal contact surface clean. For this reason, contact resistance can be guaranteed to remain low over the whole life of the equipment. ■ Large total current: Because there is little burning of contacts, the rated normal current can be interrupted up to 30,000 times, the short-circuit breaking current an average of 50 times ■ Small chopping current: The chopping current in the Siemens vacuum interrupter is only 4 to 5 A due to the use of a special contact material. ■ High reliability: The vacuum interrupters need no sealings as conventional circuit breakers. This and the small number of moving parts inside makes it extremely reliable.

Fig. 112: Vacuum circuit breakers type 3AH

Fig. 113: Front view of vacuum circuit breaker 3AH1 with 160-mm pole center distance. Available up to 17.5 kV

Siemens Power Engineering Guide · Transmission & Distribution

2/69

Medium-Voltage Devices Type 3AH

3AH1, 12 kV 20 kA, up to 1250 A 25 kA, up to 1250 A

604 532

520

210

190

210 105

473

437

60 Dimensions in mm

3AH1, 3AH2, 12 kV

604 538 210

550 190

210

31.5 kA, 2500 A, 40 kA, 2500 A

105

437

583

109 Dimensions in mm

565

3AH1, 24 kV 16 kA, up to 1250 A, 20 kA, up to 1250 A, 25 kA, up to 1250 A

708 662 275

565 190 275 105

535 437

60 Dimensions in mm Fig. 114a: Dimensions of typical vacuum circuit breakers type 3AH (Examples)

2/70

Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Type 3AH

708 670

3AH1, 3AH2, 24 kV 25 kA, 2500 A

275

595 190 275 105

648

437

109 Dimensions in mm

3AH3, 12 kV

610

750 275

211

483

275

63 kA, 4000 A

733

564

776

Dimensions in mm

3AH3, 3AH4, 36 kV

820 350

211

526

350

31.5 kA, 2500 A, 40 kA, 2500 A

791 1000

564

Dimensions in mm

853

612

Fig. 114b: Dimensions of typical vacuum circuit breakers type 3AH (Examples)

Siemens Power Engineering Guide · Transmission & Distribution

2/71

Medium-Voltage Devices Type 3AF/3AG

Outdoor vacuum circuit breakers type 3AF and 3AG

Technical data Vacuum circuit-breaker type

The Siemens outdoor vacuum circuit breakers are structure-mounted, easy-toinstall vacuum circuit breakers for use in systems up to 36 kV. The pole construction is a porcelain-clad construction similar to conventional outdoor high-voltage switchgear. The triple-pole circuit breaker is fitted with reliable and well proven vacuum interrupters. Adequate phase spacing and height have been provided to meet standards and safety requirements. It is suitable for direct connection to overhead lines. The type design incorporates a minimum of moving parts and a simplicity of assembly assuring a long mechanical and electrical life. All the fundamental advantages of using vacuum interrupters like low operating energy, lightweight construction, virtually shockfree performance leading to ease of erection and reduction in foundation requirements, etc. have been retained. The Siemens outdoor vacuum circuit breakers are designed and tested to meet the requirements of IEC 56/IS 13118.

High reliability Negligible maintenance Suitable for rapid autoreclosing duty Long electrical and mechanical life Completely environmental-friendly

Type 3AF

Rated voltage

[kV]

12

36

Rated frequency

[Hz]

50/60

50/60

Rated lightningimpulse withstand voltage

[kV]

75

170

Rated power-frequency withstand voltage (dry and wet)

[kV]

28

70

Rated short-circuit breaking current

[kA]

25

25

Rated short-circuit making current

[kA]

63

63

Rated current

[A]

1600

1600

Fig. 116: Ratings for outdoor vacuum circuit breakers

Front view

Side view

Advantages at a glance ■ ■ ■ ■ ■

Type 3AG

1830 190

725

285

285

725

3710 3748 3105 2510

1217

1730 1930

450 650

Dimensions in mm Fig. 115: Outdoor vacuum circuit breaker type 3AF for 36 kV

2/72

Fig. 117: Dimensions of outdoor circuit breaker type 3AF for 36 kV

Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Modular Assembly Sets

Modular assembly sets with indoor vacuum circuit breakers The modular assembly sets are especially suitable for retrofit applications and for the use by original equipment manufacturers (OEM). The withdrawable assembly sets consist of parts of type-tested, metal-clad, air-insulated medium-voltage primary distribution switchgear. The circuit-breaker compartment can be integrated in the complete bay as individually required. The centerpiece of the set is a mediumvoltage vacuum circuit breaker, incorporating all benefits of vacuum switchgear technology: High reliability Negligible maintenance Long electrical and mechanical life Completely environment-friendly Suitable for all switching duties Use of these parts allows the OEM to utilize Siemens know-how in the construction of air-insulated switchgear, with all the consequent advantages, such as:

■ ■ ■ ■ ■

■ Components type-tested to IEC, devel-

oped and manufactured to DIN/ISO 9001 ■ Maximum flexibility in the manufacturing

process ■ Wide product range

Fig. 118: Withdrawable truck with vacuum circuit breaker (Example)

Ratings for withdrawable truck shown in Fig. 118 7.2 kV to 15 kV 1250 A to 3150 A 25 kA to 44 kA

rated voltage rated current rated short-circuit breaking current

Siemens Power Engineering Guide · Transmission & Distribution

2/73

Medium-Voltage Devices Type 3CG

Indoor vacuum switches type 3CG The 3CG vacuum switches are multipurpose switches conforming to IEC 265-1 and DIN VDE 0670 Part 301. With these, all loads can be switched without any restriction and with a high degree of reliability. The electrical and mechanical data are greater than for conventional switches. A rated current of 800 A, for example, can be interrupted 10,000 times without maintenance. The operating mechanism needs to be lubricated only every 10 years. The vacuum switch is therefore extremely economical. Vacuum switches are suitable for the following switching duties: ■ ■ ■ ■ ■ ■

Overhead lines Cables Transformers Motors Capacitors Switching under ground-fault conditions

3CG switches can be combined with all Siemens fuses (250 A) and comply with the specifications of IEC 420 and DIN VDE 0670 Part 303.

Technical data Rated voltage U

[kV]

7.2

12

15

24

Rated lightning-impulse withstand voltage Ul,

[kV]

60

75

95

125

Rated short-circuit making current I ma

[kA]

50

50

50

40

Rated short-time current I m (3s)

[kA]

20

20

20

16

Rated normal current I n

[A]

800

800

800

800

Rated ring-main breaking current I c 1

[A]

800

800

800

800

Rated transformer breaking current

[A]

10

10

10

10

Rated capacitor breaking current

[A]

800

800

800

800

Rated cable-charging breaking current I c

[A]

63

63

63

63

Rated breaking current for stalled motors I d

[A]

2500

1600

1250

–

Inductive switching capacity (cos ϕ ≤ 0.15)

[A]

2500

1600

1250

1250

630 63

630 63

630 63

630 63

63+800

63+800

63+800

63+800

10,000

10,000

10,000

10,000

Switching capacity under ground fault conditions: – Rated ground fault breaking current I e [A] [A] – Rated cable-charging breaking current [A] – Rated cable charging breaking current with superimposed load current Number of switching cycles with I n Fig. 119: Ratings for vacuum switches type 3CG

Fig. 120: Vacuum switch type 3CG for 24 kV, 800 A

2/74

Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Type 3CG

7.2 and 12 kV switch 530 210

492 210

264

482

435

568

43

592

170

Dimensions in mm

24 kV switch 630 537 275

275

379

597 435

684 708

43 170

Dimensions in mm Fig. 121: Dimensions of vacuum switch type 3CG (Examples)

Siemens Power Engineering Guide · Transmission & Distribution

2/75

Medium-Voltage Devices Type 3TL

Vacuum contactors Type 3TL The three-pole vacuum contactors type 3TL are for medium-voltage systems between 3.6 kV and 12 kV and incorporate a solenoid-operated mechanism for high switching frequency and unlimited closing duration.They are suitable for the operational switching of AC devices in indoor systems and can perform, for example, the following switching duties: ■ Switching of three-phase motors in AC-3 and AC-4 operation ■ Switching of transformers ■ Switching of capacitors ■ Switching of ohmic loads (e.g. arc furnaces) 3TL vacuum contactors have the following features: ■ Small dimensions ■ Long electrical life (up to 10 6 operating cycles) ■ Maintenancefree ■ Vertical or horizontal mounting The vacuum contactors comply with the standards for high-voltage AC contactors between 1 kV and 12 kV according to IEC Publication 470-1970 and DIN VDE 0660 Part 103. 3TL contactors also comply with UL Standard 347. The vacuum contactors are available in different designs: ■ Type 3TL6 with compact dimensions and an electrical lifetime of 1x106 operating cycles ■ Type 3TL8 with slender design and an electrical lifetime of 0.25x106 operating cycles In the withdrawable unit, the 3TL6 vacuum contactor can be grouped together and electrically connected with fuse carriers for HV HRC fuse links according to DIN/BS and also with overvoltage limiters.

280 mm

1200 mm

780 mm 325 mm

605 mm

340 mm

Fig. 123: Vacuum contactor type 3TL6 mounted on withdrawable unit

Fig. 122: Vacuum contactor type 3TL6 for fixed mounting

Technical data Vacuum contactor type

3TL 60

3TL 61

3TL 65

3TL 81

7.2

12

7.2

Rated voltage U e

[kV]

3.6

Rated frequency

[Hz]

50/60

50/60

Rated normal current I e

[A]

450

400

4500 3600

4000 3200

Switching capacity according to [A] utilization category AC-4 (cos ϕ = 0.35) Rated making current Rated breaking current Mechanical life of the contactor switching cycles

3 x 106

3 x 106

1 x 106

1 x 106

Mechanical life of the vacuum interrupter – switching cycles

2 x 106

2 x 106

1 x 106

0.25 x 106

Electrical life of the vacuum interrupter (switching cycles with rated current)

1 x 106

1 x 106

1 x 106

0.25 x 106

Fig. 124: Ratings for vacuum contactors type 3TL

220 mm

375 mm

390 mm

Fig. 125: Vacuum contactor type 3TL8 for fixed mounting

2/76

Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Type VS

Vacuum interrupters Vacuum interrupters for the medium-voltage range are available from Siemens for all applications on the international market from 1 kV up to 40.5 kV. Applications ■ ■ ■ ■ ■ ■ ■

Vacuum circuit breakers Vacuum switches Vacuum contactors Transformer tap switches Circuit breakers for railway applications Autoreclosers Special applications, e.g. in nuclear fusion

Compact design Vacuum interrupters provide a very high switching capacity within very compact dimensions: e.g. vacuum interrupters for 15 kV/40 kA with housing dimensions of 125 mm diameter by 168 mm length or for 12 kV/12.5 kA with 68 mm diameter by 124 mm length. Consistant quality assurance Complete quality assurance (TQM and DIN/ISO 9001), rigorous material checking of every delivery and 100% tests of the interrupters for vacuum sealing guarantee reliable operation and the long life of Siemens vacuum interrupters. Environmental protection In the manufacture of our vacuum interrupters we only use environmentally compatible materials, such as copper, ceramics and high-grade steel. The manufacturing processes do not damage the environment. For example, no CFCs are used in production (fulfilling the Montreal agreement), the components are cleaned in a ultrasonic cleaning plant. During operation vacuum interrupters do not affect the environment and are themselves not affected by the environment. Know-how for special applications

Fig. 126: Vacuum interrupters from 1 kV to 40.5 kV

Interrupters for vacuum circuit breakers

Un

7.2 kV – 40.5 kV

In

800 A

Isc

12.5 kA – 72 kA

– 4000 A

Interrupters for vacuum contactors

If necessary, Siemens is prepared to supplement our wide standard program by way of tailored, customized concepts.

Un

1 kV – 12 kV

In

450 A

Fig. 127: Range of ratings for vacuum interrupters

Siemens Power Engineering Guide · Transmission & Distribution

2/77

Medium-Voltage Devices Type 3CJ1

Switch disconnectors type 3CJ1 Indoor switch disconnectors type 3CJ1 are multipurpose types and meet all the relevant standards both as the basic version and in combination with (make-proof) grounding switches. The 3CJ1 indoor switch-disconnectors have the following features: ■ A modular system with all important modules such as fuses, (make-proof) grounding switches, motor operating mechanism, shunt releases and auxiliary switches ■ Good dielectric properties even under difficult climatic conditions because of the exclusive use of standard post insulators for insulation against ground ■ No insulating partitions even with small phase spacings ■ Simple maintenance and inspection

Fig. 128: Switch disconnector type 3CJ1

Technical data Rated voltage

[kV]

7.2

12

15

24

Rated short-time current

[kA]

20

20

16

16

Rated short-circuit making current

[kA]

50

50

40

40

Rated normal current

[A]

630

630

630

630

Fig. 129: Ratings for switch disconnectors type 3CJ1

2/78

Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Type 3D

Disconnecting and grounding switches type 3D Disconnecting and grounding switches type 3D are suitable for indoor installations from 12 kV up to 36 kV. Disconnectors are mainly used to protect personnel working on equipment and must therefore be very reliable and safe. This is assured even under difficult climatic conditions. Disconnecting and grounding switches type 3D are supplied with a manual or motor drive operating mechanism.

Fig. 130: Disconnecting switch type 3DC

Technical data Rated voltage

[kV]

12

24

36

Rated short-time current

[kA]

16 to 63

16 to 31.5

20 to 31.5

Rated short-circuit making current

[kA]

40 to 160

40 to 80

50 to 80

Rated normal current

[A]

400 to 2500

630 to 2500

630 to 2500

Fig. 131: Ratings for disconnectors type 3DC

Technical data Rated voltage

[kV]

12

24

36

Rated short-time current

[kA]

20 to 63

20 to 31.5

20 to 31.5

Rated peak withstand current

[kA]

50 to 160

50 to 80

50 to 80

Fig. 132: Ratings for grounding switches type 3DE

Siemens Power Engineering Guide · Transmission & Distribution

2/79

Medium-Voltage Devices Type 3GD/3GH

HV HRC fuses type 3GD HV HRC (high-voltage high-rupturing-capacity) fuses are used as a short-circuit protection in high-voltage switchgear. They protect switchgear and components, such as transformers, motors, capacitors, voltage transformers and cable feeders, from the dynamic and thermal effects of high shortcircuit currents by breaking them as they occur. The HV HRC fuse links can only be used to a limited degree as overload protection because they only operate with certainty when their minimum breaking current has already been exceeded. Up to this current the integrated thermal striker prevents a thermal overload on the fuse when used in circuit breaker/fuse combinations. Siemens HV HRC fuse links have the following features: ■ Use in indoor and outdoor installations ■ Nonaging because the fuse element

is made of pure silver ■ Thermal tripping ■ Absolutely watertight ■ Low power loss With our 30 years of experience in the manufacture of HV HRC fuse links and with production and quality assurance that complies with DIN/ISO 9001, Siemens HV HRC fuse links meet the toughest demands for safety and reliability.

Fig. 133: HV HRC fuse type 3GD

Technical data Rated voltage

[kV]

7.2

12

24

36

Rated short-circuit breaking current

[kA]

63 to 80

40 to 63

31.5 to 40

31.5

Rated normal current

[A]

6.3 to 250

6.3 to 160

6.3 to 100

6.3 to 40

Fig. 134: Ratings for HV HRC fuse links type 3GD

Fuse-bases type 3GH 3GH fuse bases are used to accomodate HV HRC fuse links in switchgear. These fuse bases are suitable for: ■ Indoor installations ■ High air humidity ■ Occasional condensation

3GH HV HRC fuse bases are available as single-phase and three-phase versions. On request, a switching state indicator with an auxiliary switch can be installed.

Fig. 135: Fuse bases type 3GH with HV HRC fuse links

Technical data Rated voltage

[kV]

3.6/7.2

12

24

36

Peak withstand current

[kA]

44

44

44

44

Rated current

[A]

400

400

400

400

Fig. 136: Ratings for fuse bases type 3GH

2/80

Siemens Power Engineering Guide · Transmission & Distribution

Medium-Voltage Devices Insulators and Bushings

Insulators: Post insulators type 3FA and bushings type 3FH/3FM Insulators (post insulators and bushings) are used to insulate live parts from one another and also fulfill mechanical carrying and supporting functions. The materials for insulators are various cast resins and porcelains. The use of these materials, which have proved themselves over many years of exposure to the roughest operating and ambient conditions and the high quality standard to DIN/ISO 9001, assure the high degree of reliability of the insulators. Special ribbed forms ensure high electrical strength even when materials are deposited on the surface and occasional condensation is formed. Post insulators and bushings are manufactured in various designs for indoor and outdoor use depending on the application. Innovative solutions, such as the 3FA4 divider post insulator with an integrated expulsion-type arrester, provide optimum utility for the customer. Special designs are possible if requested by the customer.

Fig. 138: Post insulators type 3FA1/2

Technical data Normal voltage

[kV]

3.6

12

24

36

Lightning-impulse withstand voltage

[kV]

60 to 65

65 to 90

100 to 145

145 to 190

Rated power-frequency withstand voltage

[kV]

27 to 40

35 to 50

55 to 75

75 to 105

Minimum failing load

[kN]

3.75 to 16

3.75 to 25

3.75 to 25

3.75 to 16

Fig. 139: Ratings for post insulators type 3FA1/2

L

U1

C1

L Conductor U Operating voltage U1 Partial voltage across C1 U2 Partial voltage across C2 and indicator

M

U U2

V

C2

A

C1 Coupling capacitance C2 Undercapacitance V Arrester A Indicator M Measuring socket

Fig. 137: Draw-lead bushing type 3FH5/6

Fig. 140: The principle of capacitive voltage indication with the 3FA4 divider post insulator

Siemens Power Engineering Guide · Transmission & Distribution

2/81

Medium-Voltage Devices Type 4M

Current and voltage transformers type 4M Measuring transformers are electrical devices that transform primary electrical quantities (currents and voltages) to proportional and in-phase quantities which are safe for connected equipment and operating personnel. The indoor post insulator current and voltage transformers of the block type have DIN-conformant dimensions and are used in air-insulated switchgear. A maximum of operational safety is assured even under difficult climatic conditions by the use of cycloalyphatic resin systems and proven cast-resin technology. Special customized versions (e.g. up to 3 cores for current transformers, switchable windings, capacitance layer for voltage indication) can be supplied on request. The program also includes cast-resin insulated-bushing current transformers and outdoor current and voltage transformers.

Fig. 141: Block current transformer type 4MA

Fig. 142: Outdoor voltage transformer type 4MS4

Technical data Current transformers

Voltage transformers

Rated voltage

[kV]

12

24

36

Primary rated current

[A]

10 to 2500

10 to 2500

10 to 2500

80

80

80

Max. thermal rated [kA] short time current Sec. thermal limit current

[A]

12

24

36

5 to 10

5 to 13

8 to 17

Fig. 143: Ratings for current and voltage transformers

2/82

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards SIVACON

Contents

Page

Contents

Page

Introduction

3/2

Fixed-mounted design

Advantages

3/2

Frame and enclosure

3/15

Technical data

3/3

Forms of internal separation

3/16

Cubicle design

3/4

Installation details

Busbar system

3/5

Installation designs

3/6

Circuit-breaker design

3/6

Withdrawable-unit design

3/7–3/12

3/13–3/14

3/17–3/18

Low-Voltage Switchboards

Introduction Low-voltage switchboards form the link between equipment for generation, transmission (cables, overhead lines) and transformation of electrical energy on the one hand, and the loads, such as motors, solenoid valves, actuators and devices for heating, lighting and air conditioning on the other. As the majority of applications are supplied with low voltage, the low-voltage switchboard is of special significance in both public supply systems and industrial plants.

Reliable power supplies are conditional on good availability, flexibility for processrelated modifications and high operating safety on the part of the switchboard. Power distribution in a system usually comes via a main switchboard (power control center or main distribution board) and a number of subdistribution boards or motor control centers (Fig. 1).

up to 4 MVA up to 690 V

Cable or busbar system

up to 6300 A

Incoming circuit-breaker Main switchboard

LT

3-50 Hz

up to 5000 A

The SIVACON  low-voltage switchboard is an economical, practical and type-tested switchgear and controlgear assembly (Fig. 3), used for example in power engineering, in the chemical, oil and capital goods industries and in public and private building systems. It is notable for its good availability and high degree of personnel and system safety. It can be used on all power levels up to 6300 A: ■ As main switchboard (power control center or main distribution board) ■ As motor control centre ■ As subdistribution board. With the many combinations that the SIVACON modular design allows, a wide range of demands can be met both in fixed-mounted and in withdrawable-unit design. All modules used are type-tested (TTA), i.e they comply with the following standards: ■ IEC 439-1 ■ EN 60439-1 ■ DIN VDE 0660 Part 500

Circuit-breakers as feeders to the subdistribution boards

■ DIN VDE 0106 Part 100

Connecting cables

Advantages of a SIVACON switchboard

FT

ET

General

also Certification DIN EN ISO 9001

■ Type-tested standard modules ■ Space-saving base areas from

400 x 400 mm2 ■ Solid wall design for safe cubicle-

up to 630 A

up to 630 A

to-cubicle separation ■ High packing density with

up to 40 feeders per cubicle Subdistribution board e. g. services (Lighting, heating, air conditioning, etc.)

up to 630 A

M

M

M

M

Motor control center 1 in withdrawable-unit design for production/ manufacturing

M

M

M

withdrawable units ■ Test and disconnected position

with door closed ■ Visible isolating gaps and points

of contact

M

Motor control center 2 in withdrawable-unit design for production/ manufacturing

■ Standard operator interface for all

■ Alternative busbar positioning

up to 100 A

at top or rear ■ Cable/bar connection from above

Control

or below

LT = Circuit-breaker design ET = Withdrawable-unit design FT = Fixed-mounted design Fig. 1: Typical low-voltage network in an industrial plant

3/2

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Technical data at a glance

Rated insulation voltage (Ui)

1000 V

Rated operational voltage (Ue)

up to

690 V

up to up to up to

6300 A 220 kA 100 kA

up to up to up to

2000 A

up to up to up to

1000 A

up to up to up to

6300 A

Busbar currents (3- and 4-pole): Horizontal main busbars Rated current Rated impulse withstand current (Ipk) Rated short-time withstand current (Icw) Vertical busbars for circuit-breakers See horizontal busbars for fixed-mounted design Rated current Rated impulse withstand current (Ipk) Rated short-time withstand current (Icw)

110 kA 50 kA

for withdrawable-unit design Rated current Rated impulse withstand current (Ipk) Rated short-time withstand current (Icw) Device rated Circuit-breakers Cable feeders Motor feeders Power loss per cubicle with combination of various cubicles (Pv) Degree of protection to DIN VDE 40050, IEC 529

110 kA 50 kA

800 kA 630 kA

approx. 600 W* IP 20 up to IP 54

* Mean value at simultaneity factor of all feeders of 0.6 Fig. 2

1

2

3

1 Circuit-breaker-design cubicle with withdrawable circuit-breaker 3WN, 1600 A

2 Withdrawable-unit-design cubicle with 40 feeders ≤ 15 kW

3 Withdrawable-unit-design cubicle with miniature and normal withdrawable units up to 250 kW

Fig. 3: SIVACON low-voltage switchboard

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Low-Voltage Switchboards

Cubicle design The cubicle is structured in modular grid based on one modular spacing (1 M) corresponding to 175 mm. The effective device installation space with a height of 1750 mm therefore represents a height of 10 M. The top and bottom space each has a height of 1 x 1M + 50 mm, i.e. 225 mm (Fig. 5). A cubicle is subdivided into four function compartments: ■ Busbar compartment ■ Device compartment ■ Cable/busbar connection compartment ■ Cross-wiring compartment In 400 mm deep cubicles, the busbar compartment is at the top; in 600 mm deep cubicles it is at the rear. In double-front systems (1000 mm depth) and in a power control center (1200 mm depth), the busbar compartment is located centrally. The switching device compartment accommodates switchgear and auxiliary equipment. The cable/busbar connection compartment is located on the right-hand side of the cubicle. With circuit-breaker design, however, it is below the switching device compartment (Fig. 4). The cross-wiring compartment is located at the top front and is provided for leading control and loop lines from cubicle to cubicle.

400

600 400

Busbar compartment Device compartment

600

400 400 400

Cable/busbar connection compartment Cross-wiring compartment

Dimensions in mm

Fig. 4: Cubicle design

3/4

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Busbar system Together with the PEN or PE busbars, and if applicable the N busbars, the phase conductor busbars L1, L2 and L3 form the busbar system of a switchboard. One or more distribution buses and/or incoming and outgoing feeders can be connected to a horizontal main busbar. Depending on requirements, this main busbar passes through several cubicles and can be linked with another main busbar via a coupling. A vertical distribution busbar is connected with the main busbar and supplies outgoing feeders within a cubicle. In a 400 mm deep cubicle (Fig. 5a) the phase conductors of the main busbar are always at the top; the PEN or PE and N conductors are always at the bottom. The maximum rated current at 35 °C is 1965 A (non-ventilated), and 2250 A (ventilated); the maximum short-circuit strength is I pk = 110 kA or Icw = 50 kA, respectively. In single-front systems with 600 mm cubicle depth (Fig. 5b), the main busbars are behind the switching device compartment. In double-front systems of 1000 mm depth (Fig. 5c), they are between the two switching device compartments (central). The phase conductors can be arranged at the top or bottom; PEN, PE and N conductors are always at the bottom. The maximum rated current is at 35 °C 3250 A (non-ventilated) or 3500 A (ventilated); Ipk = 220 kA or I cw = 100 kA, respectively. In 1200 mm deep systems (power control center) (Fig. 5d) the conductors are arranged as for double-front systems, but in duplicate; the phase conductors are always at the top. The maximum rated current at 35 °C is 4850 A (non-ventilated) or 6000 A (ventilated); I pk = 220 kA, Icw = 100 kA.

Top space

50

50

175

175

10 x 175

10 x 175

2200

175

175 400

Switching device compartment

200 400 50

50

Bottom space a)

b)

50

50

175

10 x 175

2200

175

10 x 175

2200

175

175 400 200 400

50

c)

400

400

400

50

d)

Dimensions in mm

Fig. 5: Modular grid and location of main busbars

Siemens Power Engineering Guide · Transmission & Distribution

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Low-Voltage Switchboards

Installation designs The following designs are available for the duties specified: ■ Circuit-breaker design ■ Withdrawable-unit design ■ Fixed-mounted design

Circuit-breaker design Distribution boards for substantial energy requirements are generally followed by a number of subdistribution boards and loads. Particular demands are therefore made in terms of long-term reliability and safety. That is to say, ”supply“, ”coupling“ and ”feeder“ functions must be reliably available over long periods of time. Maintenance and testing must not involve long standstill times. The circuit-breaker design components meet these requirements. The circuit-breaker cubicles have separate function spaces for a switching device compartment, auxiliary equipment compartment and cable/busbar connection compartment (Fig. 7). The auxiliary equipment compartment is above the switching device compartment. The cable or busbar connection compartment is located below. With supply from above, the arrangement is a like a mirror image. The cubicle width is determined by the breaker rated current.

Breaker rated current [A]

Cubicle width

IN to 1600 IN to 2500 IN to 3200 IN to 6300

400 600 800 1000

[mm]

Fig. 6

Circuit-breaker design 3WN The 3WN circuit-breakers in withdrawableunit or fixed-mounted design are used for incoming supply, outgoing feeders and couplings (longitudinal and transverse). The operational current can be shown on an LCD display in the control panel; there is consequently no need for an ammeter or current transformer.

3/6

Fig. 7: Circuit-breaker cubicle with withdrawable circuit-breaker 3WN, 1600 A rated current

The high short-time current-carrying capacity for time-graded short-circuit protection (up to 500 ms) assures reliable operation of sections of the switchboard not affected by a short circuit. With the aid of short-time grading control for very brief delay times (50 ms), the stresses and damage suffered by a switchboard in the event of a short-circuit can be substantially minimized, regardless of the preset delay time of the switching device concerned. The withdrawable circuit-breaker has three positions between which it can be moved with the aid of a crank or spindle mechanism. In the connected position the main and auxiliary contacts are closed.

In the test position the auxiliary contacts are closed. In the disconnected position both main and auxiliary contacts are open. Mechanical interlocks ensure that, in the process of moving from one position to another, the circuit-breaker always reaches the OPEN state or that closing is not possible when the breaker is between two positions. The circuit-breaker is always moved with the door closed. The actual position in which it is can be telecommunicated via a signaling switch. A kit, switch or withdrawable unit can be used for grounding and short-circuiting.

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Withdrawable-unit design A major feature of withdrawable-unit design is removability and ease of replacement of equipment combinations under operating conditions, i.e. a switchboard can be adapted to process-related modifications without having to be shut down. Withdrawable-unit design is used therefore mainly for switching and control of motors (Fig. 8). Withdrawable units

A distinction is made between miniature (sizes 1/4 and 1/2) and normal withdrawable units (sizes 1, 2, 3 and 4) (Fig. 9). The normal withdrawable unit of size 1 has a height of one modular spacing (175 mm) and can, with the use of a miniature withdrawable unit adapter, be replaced by 4 withdrawable units of size 1/4 or 2 units of size 1/2. The withdrawable units of sizes 2, 3 and 4 have a height of 2, 3 and 4 modular spacings, respectively. The maximum complement of a cubicle is, for example, 10 full-size withdrawable units of size 1 or 40 miniature withdrawable units of size 1/4 .

The equipment of the main circuit of an outgoing feeder and the relevant auxiliary equipment are integrated as a function unit in a withdrawable unit, which can be easily accommodated in a cubicle. In basic state, all equipment and movable parts are within the withdrawable unit contours and thereby protected from damage. The facility for equipping the withdrawable units from the rear allows plenty of space for auxiliary devices. Measuring instruments, indicator lights, pushbuttons, etc. are located on a hinged instrument panel, such that settings (e.g. on the overload relay) can be easily performed during operation.

Fig. 8: High packing density with up to 40 feeders per cubicle

Fig. 9: Size 1 withdrawable unit, 18.5 kW with contactor-type star-delta starter

Siemens Power Engineering Guide · Transmission & Distribution

3/7

Low-Voltage Switchboards

Moving isolating contact system

Connected position

Disconnected position

For main and auxiliary circuits the withdrawable units are equipped with a moving isolating contact system. It has contacts on both the incoming and outgoing side; they can be moved by handcrank such that they come laterally out of the withdrawable unit and engage with the fixed contacts in the cubicle. On miniature withdrawable units the isolating contact system moves upwards into the miniature withdrawable unit adapter. A distinction is made between connected, disconnected and test position (Fig. 10) In the connected position both main and auxiliary contacts are closed; in the disconnected position they are open. The test position allows testing of the withdrawable unit for proper function in no-load (cold) state, in which the main contacts are open, but the auxiliary contacts are closed for the incoming control voltage. In all three positions the doors are closed and the withdrawable unit mechanically connected with the switchboard. This assures optimal safety for personnel and the degree of protection is upheld. Movement from the connected into the test position and vice-versa always passes through the disconnected position; this assures that all contactors drop out. Operating error protection

Test position

Integrated maloperation protection in each withdrawable unit reliably prevents moving of the isolating contacts with the main circuit-breaker ”CLOSED“ (handcrank cannot be attached) (Fig. 11).

Fig. 10: Withdrawable-unit principle

Fig. 11: Operating error protection prevents travel of the isolating contacts when the master switch is “ON”

3/8

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Indicating and signaling

AZNV

Test

AZNV/Test

- S21 - X19

- X19

- X19

- S21

- Q1

COM

- S21

- Q1 - S20

The current position of a withdrawable unit is clearly indicated on the instrument panel. Such signals as ”feeder not available“ (AZNV), ”test“ and ”AZNV and test“ can be given by additional alarm switches. The alarm switch in the compartment (S21) is a limit switch of NC design; that in the withdrawable unit (S20) is of NO design. Both are actuated by the main isolating contacts of the withdrawable unit (Fig. 12).

AZNV Test

WU

Compt.

Compt.

WU

WU

Compt.

X19 = Auxiliary isolating contact S20 = Alarm switch in withdrawable unit* S21 = Alarm switch in compartment* WU = Withdrawable unit Compt. = Compartment *actuated by main isolating contact

Main isolating contact

Aux. isolating contact

In withdrawable unit - S 20 1S

In compartment - S 21 1Ö

Connected

* Disconnected

Test

*No signal, as auxiliary isolating contact open Fig. 12: Circuitry and position of main and auxiliary contacts

Siemens Power Engineering Guide · Transmission & Distribution

3/9

Low-Voltage Switchboards

Vertical distribution bus (plug-on bus) The vertical plug-on bus with the phase conductors L1, L2 and L3 is located on the left-hand side of the cubicle and features safe-to-touch tap openings (Fig. 13). The vertical PE, PEN and N busbars are on the right-hand side of the cubicle in a separate, 400 mm wide cable connection compartment, equipped with variable cable brackets.

Fig. 13: Arcing fault-protected plug-on bar system embedded in the left of the cubicle

Rated currents – fused and withdrawable unit sizes of cable feeders

Rated currents – non-fused and withdrawable unit sizes of cable feeders

I

Fig. 14

3/10

Device

Rated current

Withdrawable unit size

Type

[A]

D306 3KL50 3KL52 3KL53 3KL55 3KL57 3KL61

35 63 125 160 250 400 630

1/4 / 1/2 1 1 2 2 2 3

Device

Rated current

Withdrawable unit size

Type

[A]

3VU13* 3VU16 3VU13 3VU16 3VF1 3VF3 3VF4 3VF5 3VF6

25 32 (25) 25 (6) 63 (32) 63 (32) 160 250 400 630

1/4 / 1/2 1/2 1 1 1 1 2 2 4

( ):Figures in brackets short-circuit-proof up to 100 kA *3VU13 with limiter short-circuit-proof up to 50 kA

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Power ratings – fused and withdrawable unit sizes of cable feeders

FVNR

FVR

Star-delta starters

Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage non-reversing (FVNR) motor starters Heavy-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

Star-delta starters [kW]

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

15 18.5 37 75 160 250 – –

15 22 45 90 200 355

22 22 37 90 160 500

– 5.5 15 75 90 160 – –

– 7.5 22 90 132 200

– 11 37 90 132 375

11 18.5 30 45 110 250 – –

11 22 37 55 132 315

11 22 37 55 160 375

– 18.5 37 55 132 – 250 355

– 22 30 55 160 – 355 –

– 22 45 90 160 – 400 500

Withdrawable unit size

1/4 1/2 1 2 3 4 3+3 4+4

Fig. 15

Siemens Power Engineering Guide · Transmission & Distribution

3/11

Low-Voltage Switchboards

Power ratings – non-fused with overload relay and withdrawable unit

FVNR

FVR

Star-delta starters

I

I

I

Coordination type 1

Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage non-reversing (FVNR) motor starters Heavy-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

Star-delta starters [kW]

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

11 11 30 75 160 250

3

– – – – – –

– 2.2 4 37 160 –

– – 5.5 45 200 –

– – – – – –

11

3 3 22 90 200 315

– – – – – –

– 11 15 55 110 200

– 1.1 37 75 132 250

– – – – – –

3 37 90 200 315

11 18.5 75 160 250

Withdrawable unit size

1/4 1/2 1 2 3 4

Coordination type 2

Full-voltage non-reversing (FVNR) motor starters Normal-duty start [kW]

Full-voltage non-reversing (FVNR) motor starters Heavy-duty start [kW]

Full-voltage reversing (FVR) motor starters Reversing circuit [kW]

Star-delta starters [kW]

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

400 V

500 V

690 V

11 11 18.5 75 160 250

3 3 15 90 200 315

– – – – –

– 2.2 4 37 160 –

– – 5.5 45 200

– – – – – –

4 11 18.5 55 160 250

1.1 3 15 75 200 315

– – – – – –

– 11 15 55 110 200

– 1.1 15 75 132 250

– – – – – –

Withdrawable unit size

1/4 1/2 1 2 3 4

Fig. 16

3/12

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Fixed-mounted design In certain applications, e.g. in building installation systems, either there is no need to replace components under operating conditions or short standstill times do not result in exceptional costs. In such cases the fixed-mounted design (Fig. 17) offers excellent economy, high reliability and flexibility by virtue of: ■ Any combination of modular function units ■ Easy replacement of function units after deenergizing the switchboard ■ Brief modification or standstill times by virtue of lateral vertical cubicle busbars ■ Add-on components for subdivision and even compartmentalization in accordance with requirements. Modular function units The modular function units enable versatile and efficient installation, above all whenever operationally required changes or adaptations to new load data are necessary (Fig. 18). The subracks can be equipped as required with switching devices or combinations thereof; the function units can be combined as required within one cubicle. When the function modules are fitted in the cubicle they are first attached in the openings provided and then bolted to the cubicle. This securing system enables uncomplicated ”one-man assembly“. Vertical distribution bus (cubicle busbar) The vertical cubicle busbar with the phase conductors L1, L2 and L3 is fastened to the left-hand side wall of the cubicle and offers many connection facilities (without the need for drilling or perforation) for cables and bars. It can be subdivided at the top or bottom once per cubicle (for group circuits or couplings). The connections are easily accessible and therefore equally easy to check. A transparent shock-hazard protection allows visual inspection and assures a very high degree of personnel safety. The vertical PE, PEN and N busbars are on the right-hand side of the cubicle in a separate, up to 400 mm wide cable connection compartment, equipped with variable cable brackets.

Fig. 17: Variable fixed-mounted design

Fig. 18: Fused modular function unit with direct protection, 45 kW

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Low-Voltage Switchboards

In-line-type switching devices In-line-type switching devices allow spacesaving installation of cable feeders in a cubicle and are particularly notable for their compact design (Fig. 19). The in-line-type switching devices feature plug-in contacts on the incoming side. They are alternatively available for cable feeders up to 630 A as: ■ Fuse module ■ Fuse-switch disconnectors

(single-break) ■ Fuse-switch disconnectors

(double-break) with or without solid-state fuse monitoring ■ Switch disconnectors The single- or double-break in-line-type switching devices allow fuse changing in dead state. The main switch is actuated by pulling a vertical handle to the side. The modular design allows quick reequipping and easy replacement of in-line-type switching devices under operating conditions. The in-line-type switching devices have a height of 50 mm, 100 mm or 200 mm. A cubicle can consequently be equipped with up to 35 in-line-type switching devices. Vertical distribution bus (plug-on bus) The vertical plug-on bus with the phase conductors L1, L2 and L3 is located at the back in the cubicle and can be additionally fitted with a shock-hazard protection. The vertical PE, PEN and N busbars are on the right-hand side of the cubicle in a separate, 400 mm wide cable connection compartment, equipped with variable cable brackets.

Fig. 19: Cubicle with in-line-type switching devices

Fuse-switch disconnector (single break)

Device

Rated current

In-linetype size

Type

[A]

Height [mm]

3NJ6110

160

50

3NJ6120

250

100

3NJ6140

400

200

3NJ6160

630

200

Fig. 20: Rated currents and installation data of in-line-type switching devices

3/14

Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Frame and enclosure The galvanized SIVACON cubicle frames are of solid wall design and ensure reliable cubicle-to-cubicle separation. The enclosure is made of powder-coated steel sheets (Fig. 21 and 22). A cubicle front features one or more doors, depending on requirements and cubicle type. These doors are of 2 mm thick, powder-coated sheet steel and are hinged on the right or left (attached to the frame). Spring-loaded door locks prevent the doors from flying open unintentionally, and also ensure safe pressure equalization in the event of an arcing fault. Degree of protection (against foreign bodies/water, and personnel safety) A distinction is made between ventilated and non-ventilated cubicles. Ventilated cubicles are provided with slits in the base space door and in the top plate and attain degree of protection in relation to the operating area of IP 20/21 or IP 40/41, respectively. Non-ventilated cubicles attain degree of protection IP 54. In relation to the cable compartment, degree of protection IP 00 or IP 40, is generally attained. Fig. 21: Frame for top busbar

Fig. 22: Frame for rear busbar

Cubicle dimensions and average weights

Height [mm]

Width [mm]

Depth [mm]

400 500 600 800 400 500 600 800 1000 1000

400

Rated current [A]

Approx. weight [kg]

up to 1600 up to 1600 up to 1600 up to 2000 up to 1600 up to 1600 up to 2500 up to 3150 up to 4000 up to 6300

300 310 320 440 315 335 440 540 700 1200

Circuit-breaker design 2200

600

1200

Withdrawable-unit design 2200

1000

400 600 1000

400 450 600

1000

400 600 1000

330 380 550

Fixed-mounted design 2200

Fig. 23: Cubicle dimensions and average weights

Siemens Power Engineering Guide · Transmission & Distribution

3/15

Low-Voltage Switchboards

Form of internal separation Form 1 in accordance to DIN VDE 0660 Part 500, 7.7 (Fig. 25) Depending on requirements, the function compartments can be subdivided as per the following table:

Functional unit

1

2

2

1 2 3 4

4 3

4

4

4 4

Form 1 2a 2b 3a 3b 4a 4b

Terminal for external conductors Main busbar Busbar Incoming circuit Outgoing circuit

4 4

Circuitbreaker design Withdrawableunit design Fixedmounted design – modular – in-line

Form 2a –

–

–

–

–

Form 2b

1

2

1

2

2

4 3

4

4

4

3

4

4

4

4 – –

–

– –

–

–

2 4 4

–

4

–

4

4

4

Fig. 24

Form 3a

Form 3b

1

2

1

2

2

4 3

4

2 4

4

4

3

4

4

4

4

4 4

4

4

4

Form 4a

Form 4b

1

2

1

2

2

4 3

4

4 4

4

2

3

4

4

4

4

4 4

4

4

4

Fig. 25: Forms of internal separation to DIN VDE 0660 Part 500/EN 60 439-1/IEC 439-1

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Siemens Power Engineering Guide · Transmission & Distribution

Low-Voltage Switchboards

Installation details

Floor penetrations

Transport units

The cubicles feature floor penetrations for leading in cables for connection, or for an incoming supply from below (Fig. 28).

For transport purposes, individual cubicles of a switchboard are combined to form a transport unit, up to a maximum length of 2400 mm. The transport base is 200 mm longer than the transport unit and is 190 mm high. The transport base depth is:

Cubicle depth 400 mm 75

Diameter 14.1

323

Cubicle depth

[mm]

Transport base depth [mm]

400

600 1000 1200

400

215

75

38.5 Cubicle width - 110

900 1050 1460 1660 Cubicle width

Fig. 26

Cubicle depth 600 mm If the busbar is at the top, the main busbars between two transport units are connected via lugs which are bolted to the busbar system. If the busbar is at the rear, the individual bars can be bolted together via connection elements, as the conductors of the right-hand transport unit are offset to the left and protrude beyond the cubicle edge. Mounting

75

Fastening for floor mounting

Diameter 14.1

Fastening for wall mounting 323

250 600 75

38.5

Cubicle depths 400 mm and 600 mm: ■ Wall- or ■ Floor-mounting Cubicle depths 1000 mm and 1200 mm: ■ Floor-mounting The following minimum clearances between the switchboard and any obstacles must be observed:

Cubicle width - 110 Cubicle width

Cubicle depth 1000 mm, 1200 mm 75

Diameter 14.1 75 250

Clearences

100 mm

523

75 mm

1000 or 1200

Cubicle depth - 77

100 mm

250

Switchboard

75

38.5 Cubicle width - 110 Fig. 27

Cubicle width

There must be a minimum clearance of 400 mm between the top and sides of the cubicle and any obstacles.

Free space for cables and bar penetrations Fig. 28: Floor penetrations

Siemens Power Engineering Guide · Transmission & Distribution

3/17

Low-Voltage Switchboards

Operating and maintenance gangways

20001)

600 7002)

700

600 7002)

All doors of a SIVACON switchboard can be fitted such that they close in the direction of an escape route or emergency exit. If they are fitted differently, care must be taken that when doors are open, there is a minimum gangway of 500 mm (Fig. 29). In general, the door width must be taken into account, i.e. a door must open through at least 90°. (In circuit-breaker and fixedmounted designs the maximum door width is 1000 mm.) Installation gangways behind closed rear walls call for a minimum width of 500 mm. If a lifting truck is used to install a circuitbreaker, the gangway widths must suit the dimensions of the lifting truck.

700

Dimensions of lifting truck [mm] 1)

Minimum gangway height under covers or enclosures 2) For installation gangways behind closed rear walls, a width of 500 mm is acceptable

Height Width Depth

2000 680 920

Minimum gangway width [mm] Approx.

1500

Fig. 30

Min. gangway width Escape route 600 or 700 mm

Free min. width 500 mm1)

2)

1) Where

switchboard fronts face each other, narrowing of the gangway as a result of open doors (i.e. doors that do not close in the direction of the escape route) is reckoned with only on one side 2) Note door widths, i.e. it must be possible to open the door through at least 90° Dimensions in mm For further information please contact: Fig. 29: Reduced gangways in area of open doors

3/18

Fax: ++ 49 - 3 41- 4 47 04 00

Siemens Power Engineering Guide · Transmission & Distribution

Transformers

Contents

Page

Introduction

4/2

Product Range

4/3

Contents

Page

Technical Data Distribution Transformers

4/13–4/17 4/18–4/23

Electrical Design

4/4–4/5

Technical Data Power Transformers

Transformer Loss Evaluation

4/6–4/7

On-load Tap Changers

4/24

4/8

Cast-resin Dry-type Transformers, GEAFOL

4/25–4/28

Technical Data GEAFOL Cast-resin Dry-type Transformers

4/29–4/32

Special Transformers and Reactors

4/33–4/34

Mechanical Design Connection Systems Accessories and Protective Devices

4/9– 4/10 4/11– 4/12

Introduction

Transformers are one of the primary components for the transmission and distribution of electrical energy. Their design results mainly from the range of application, the construction, the rated power and the voltage level. The scope of transformer types starts with generator transformers and ends with distribution transformers. Transformers which are directly connected to the generator of the power station are called generator transformers. Their power range goes up to far above 1000 MVA. Their voltage range extends to approx. 1500 kV. The connection between the different highvoltage system levels is made via network transformers (network interconnecting transformers). Their power range exceeds 1000 MVA. The voltage range exceeds 1500 kV. Distribution transformers are within the range from 50 to 2500 kVA and max. 36 kV. In the last step, they distribute the electrical energy to the consumers by feeding from the high-voltage into the low-voltage distribution network. These are designed either as liquid-filled or as dry-type transformers. Transformers with a rated power up to 2.5 MVA and a voltage up to 36 kV are referred to as distribution transformers; all transformers of higher ratings are classified as power transformers.

In addition, there are various specialpurpose transformers such as converter transformers, which can be both in the range of power transformers and in the range of distribution transformers as far as rated power and rated voltage are concerned. As special elements for network stabilization, arc-suppression coils and compensating reactors are available. Arc-suppression coils compensate the capacitive current flowing through a ground fault and thus guarantee uninterrupted energy supply. Compensating reactors compensate the capacitive power of the cable networks and reduce overvoltages in case of load rejection; the economic efficiency and stablility of the power transmission are improved. The general overview of our manufacturing/delivery program is shown in the table ”Product Range“.

Standards and specifications, general The transformers comply with the relevant VDE specifications, i.e. DIN VDE 0532 ”Transformers and reactors“ and the ”Technical conditions of supply for threephase transformers“ issued by VDEW and ZVEI. Therefore they also satisfy the requirements of IEC Publication 76, Parts 1 to 5 together with the standards and specifications (HD and EN) of the European Union (EU). Enquiries should be directed to the manufacturer where other standards and specifications are concerned. Only the US (ANSI/NEMA) and Canadian (CSA) standards differ from IEC by any substantial degree, however, a design according to these standards is also possible. Important additional standards ■ DIN 42 500, HD 428: oil-immersed

Rated power

Max. Figs. operating on voltage page

[MVA]

[kV]

■ ■ ■

Oil distribution transformers

0.05–2.5 ≤ 36

Power transformers

2.5–3000 36-1500

4/18– 4/23

GEAFOLcast-resin transformers

0.10–20 ≤ 36

4/29– 4/32

4/13– 4/17

■ ■ ■ ■ ■

three-phase distribution transformers 50– 2500 kVA DIN 42 504: oil-immersed three-phase transformers 2– 10 MVA DIN 42 508: oil-immersed three-phase transformers 12.5–80 MVA DIN 42 523, HD 538: three-phase dry-type transformers 100– 2500 kVA DIN 45 635 T30: noise level IEC 289: reactance coils and neutral grounding transformers IEC 551: measurement of noise level IEC 726: dry-type transformers RAL: coating/varnish

Fig. 1: Transformer types

4/2

Siemens Power Engineering Guide · Transmission & Distribution

Product Range

Oil-immersed distribution transformers, TUMETIC, TUNORMA

50 to 2 500 kVA, highest voltage for equipment up to 36 kV, with copper or aluminum windings, hermetically sealed (TUMETIC®) or with conservator (TUNORMA®) of three- or single-phase design

Generator and power transformers

Above 2.5 MVA up to more than 1000 MVA, above 30 kV up to 1500 kV (system and system interconnecting transformers, with separate windings or auto-connected), with on-load tap changers or off-circuit tap changers, of three- or single-phase design

Cast-resin distribution and power transformers GEAFOL

100 kVA to more than 20 MVA, highest voltage for equipment up to 36 kV, of three- or single-phase design GEAFOL®-SL substations

Special transformers for industry, traction and HVDC transmission systems

Furnace and converter transformers Traction transformers mounted on rolling stock and appropriate on-load tap-changers Substation transformers for traction systems Transformers for train heating and point heating Transformers for: Electrostatic precipitators, high-frequency generating plants, electrophoresis and graphite producing plants Transformers for HVDC transmission systems Starting transformers Transformers for audio frequencies in power supply systems Three-phase neutral electromagnetic couplers and grounding transformers Transformers for potentially explosive atmospheres Ignition transformers

Reactors

Liquid-immersed shunt and current-limiting reactors up to the highest rated powers Reactors for HVDC transmission systems Starting reactors, arc-suppression coils

Accessories

Buchholz relays, oil testing equipment, oil flow indicators and other monitoring devices Fan control cabinets, control cabinets for parallel operation and automatic voltage control Sensors (PTC, Pt 100)

Service

Advisory services for transformer specifications Organization, coordination and supervision of transportation Supervision of assembly and commissioning Service/inspection troubleshooting services Training of customer personnel Investigation and assessment of oil problems

Fig. 2

Siemens Power Engineering Guide · Transmission & Distribution

4/3

Electrical Design

Power ratings and type of cooling All power ratings in this guide are the product of rated voltage (times phase-factor for three-phase transformers) and rated current of the line side winding (at center tap, if several taps are provided), expressed in kVA or MVA, as defined in IEC 76-1. If only one power rating and no cooling method are shown, natural oil-air cooling (ONAN or OA) is implied for oil-immersed transformers. If two ratings are shown, forced-air cooling (ONAF or FA) in one or two steps is applicable. For cast resin transformers, natural air cooling (AN) is standard. Forced air cooling (AF) is also applicable.

I

Dy1

III

I

Dy5

III

11

Dy11

I

Yd11

I 11

i

i

ii III

iii

ii

II

III

iii

II

Fig. 3: Most commonly used vector groups

■ 2% increase for every 500 m altitude (or

part there of) in excess of 1000 m, or ■ 2% reduction of rated power for each 500 m altitude (or part there of) in excess of 1000 m. Transformer losses and efficiencies Losses and efficiencies stated in this guide are average values for guidance only. They are applicable if no loss evaluation figure is stated in the inquiry (see following chapter) and they are subject to the tolerances stated in IEC 76-1, namely +10% of the total losses, or +15% of each component loss, provided that the tolerance for the total losses is not exceeded. If optimized and/or guaranteed losses without tolerances are required, this must be stated in the inquiry.

Altitude of installation

4/4

II

i 5

(measured by the resistance method)

The transformers are suitable for operation at altitudes up to 1000 meters above sea level. Site altitudes above 1000 m necessitate the use of special designs and an increase/or a reduction of the transformer ratings as follows (approximate values):

iii

ii

II 5

■ 60 K top oil temperature

40 °C maximum temperature, 30 °C average on any one day, 20 °C average in any one year, –25 °C lowest temperature outdoors, –5 °C lowest temperature indoors. Higher ambient temperatures require a corresponding reduction in temperature rise, and thus affect price or rated power as follows: ■ 1.5% surcharge for each 1 K above standard temperature conditions, or ■ 1.0% reduction of rated power for each 1 K above standard temperature conditions. These adjustment factors are applicable up to 15 K above standard temperature conditions.

I

iii i

II

ii

Yd5

ii

■ 65 K average winding temperature

■ ■ ■ ■ ■

i

iii

II

Temperature rise

(measured by thermometer) The standard temperature rise for Siemens cast-resin transformers is ■ 100 K (insulation class F) at HV and LV winding. Whereby the standard ambient temperatures are defined as follows:

1

ii

III

I

i

iii

III

In accordance with IEC-76 the standard temperature rise for oil-immersed power and distribution transformers is:

Yd1

1

Connections and vector groups Distribution transformers The transformers listed in this guide are all three-phase transformers with one set of windings connected in star (wye) and the other one in delta, whereby the neutral of the star-connected winding is fully rated and brought to the outside.

The primary winding (HV) is normally connected in delta, the secondary winding (LV) in wye. The electrical offset of the windings in respect to each other is either 30, 150 or 330 degrees standard (Dy1, Dy5, Dy11). Other vector groups as well as single-phase transformers and autotransformers on request (Fig. 3). Power transformers Generator transformers and large power transformers are usually connected in Yd. For HV windings higher than 110 kV, the neutral has a reduced insulation level. For star/star-connected transformers and autotransformers normally a tertiary winding in delta, whose rating is a third of that of the transformer, has to be added. This stabilizes the phase-to phase voltages in the case of an unbalanced load and prevents the displacement of the neutral point. Single-phase transformers and autotransformers are used when the transportation possibilities are limited. They will be connected at site to three-phase transformer banks.

Siemens Power Engineering Guide · Transmission & Distribution

Electrical Design

Insulation level Power-frequency withstand voltages and lightning-impulse withstand voltages are in accordance with IEC 76-3, Para. 5, Table II, as follows:

Highest voltage for equipment Um (r. m. s.)

Rated shortduration powerfrequency withstand voltage (r. m. s.)

[kV]

[kV]

Rated lightningimpulse withstand voltage (peak)

List 2 [kV]

List 1 [kV]

≤ 1.1

3

3.6

10

20

40

7.2

20

40

60

12.0

28

60

75

17.5

38

75

95

24.0

50

95

125

36.0

70

145

170

52.0

95

250

72.5

140

325

123.0

185

450

230

550

275

650

325

750

360

850

395

950

–

Conversion to 60 Hz – possibilities All ratings in the selection tables of this guide are based on 50 Hz operation. For 60 Hz operation, the following options apply: ■ 1. Rated power and impedance voltage are increased by 10%, all other parameters remain identical. ■ 2. Rated power increases by 20%, but no-load losses increase by 30% and noise level increases by 3 dB, all other parameters remain identical (this layout is not possible for cast-resin transformers). ■ 3. All technical data remain identical, price is reduced by 5%. ■ 4. Temperature rise is reduced by 10 K, load losses are reduced by 15%, all other parameters remain identical.

Transformer cell (indoor installation) The transformer cell must have the necessary electrical clearances when an open air connection is used. The ventilation system must be large enough to fulfill the recommendations for the maximum temperatures according to IEC. For larger power transformers either an oil/water cooling system has to be used or the oil/air cooler (radiator bank) has to be installed outside the transformer cell. In these cases a ventilation system has to be installed also to remove the heat caused by the convection of the transformer tank.

– Overloading Overloading of Siemens transformers is guided by the relevant IEC-354 ”Loading guide for oil-immersed transformers“ and the (similar) ANSI C57.92 ”Guide for loading mineral-oil-immersed power transformers“. Overloading of GEAFOL cast-resin transformers on request. Routine and special tests

145.0

170.0

245.0

All transformers are subjected to the following routine tests in the factory: ■ Measurement of winding resistance ■ Measurement of voltage ratio and check of polarity or vector group ■ Measurement of impedance voltage ■ Measurement of load loss ■ Measurement of no-load loss and no-load current ■ Induced overvoltage withstand test ■ Seperate-source voltage withstand test ■ Partial discharge test (only GEAFOL cast-resin transformers). The following special tests are optional and must be specified in the inquiry: ■ Lightning-impulse voltage test (LI test), full-wave and chopped-wave (specify) ■ Partial discharge test ■ Heat-run test at natural or forced cooling (specify) ■ Noise level test ■ Short-circuit test. Test certificates are issued for all the above tests on request.

Higher test voltage withstand requirements must be stated in the inquiry and may result in a higher price.

Fig. 4: Insulation level

Siemens Power Engineering Guide · Transmission & Distribution

4/5

Transformer Loss Evaluation

The sharply increased cost of electrical energy has made it almost mandatory for buyers of electrical machinery to carefully evaluate the inherent losses of these items. In case of distribution and power transformers, which operate continuously and most frequently in loaded condition, this is especially important. As an example, the added cost of loss-optimized transformers can in most cases be recovered via savings in energy use in less than three years. Low-loss transformers use more and better materials for their construction and thus initially cost more. By stipulating loss evaluation figures in the transformer inquiry, the manufacturer receives the necessary incentive to provide a loss-optimized transformer rather than the lowcost model. Detailed loss evaluation methods for transformers have been developed and are described accurately in the literature, taking the project-specific evaluation factors of a given customer into account. The following simplified method for a quick evaluation of different quoted transformer losses is given, making the following assumptions:

A. Capital cost

Cc =

Cp · r 100

Cp

amount year

= purchase price n

p·q = depreciation factor qn – 1 p q= = interest factor 100

r=

p n

= interest rate in % p.a. = depreciation period in years

B. Cost of no-load loss

CP0 = Ce · 8760 h/year · P0

■ The transformers are operated con-

tinuously ■ The transformers operate at partial load, but this partial load is constant ■ Additional cost and inflation factors are not considered ■ Demand charges are based on 100% load. The total cost of owning and operating a transformer for one year is thus defined as follows:

Ce

= energy charges

P0

= no-load loss [kW]

amount year

amount kWh

C. Cost of load loss

CPk = Ce · 8760 h/year · α2 · Pk

■ A. Capital cost Cc

taking into account the purchase price Cp, the interest rate p, and the depreciation period n ■ B. Cost of no-load loss CP0, based on the no-load loss P0, and energy cost Ce ■ C. Cost of load loss Cpk, based on the copper loss P k, the equivalent annual load factor a, and energy cost Ce ■ D. Demand charges Cd, based in the amount set by the utility, and the total kW of connected load. These individual costs are calculated as follows:

amount year

constant operation load rated load

α

=

Pk

= copper loss [kW]

D. Cost resulting from demands charges

CD = Cd (P0 + Pk) Cd

amount year

= demand charges

amount kW · year

Fig. 5

4/6

Siemens Power Engineering Guide · Transmission & Distribution

Transformer Loss Evaluation

To demonstrate the usefulness of such calculations, the following arbitrary examples are shown, using factors that can be considered typical in Germany, and neglecting the effects of inflation on the rate assumed:

Example: 1600 kVA distribution transformer

Depreciation period Interest rate Energy charge

n = 20 years Depreciation factor p = 12% p. a. r = 13.39 Ce = 0.25 DM/kWh

Demand charge

Cd = 350

Equivalent annual load factor

α

A. Low-cost transformer

P0 = 2.6 kW Pk = 20 kW Cp = DM 25 000

DM kW · yr

= 0.8

B. Loss-optimized transformer

no-load loss load loss purchase price

Cc = 25000 · 13.39 100 = DM 3348/year

P0 = 1.7 kW Pk = 17 kW Cp = DM 28 000

no-load loss load loss purchase price

Cc = 28000 · 13.39 100 = DM 3 749/year

CP0 = 0.25 · 8760 · 2.6 = DM 5694/year

CP0 = 0.25 · 8760 · 1.7 = DM 3 723/year

CPk = 0.25 · 8760 · 0.64 · 20 = DM 28 032/year

CPk = 0.25 · 8760 · 0.64 · 17 = DM 23 827/year

CD = 350 · (2.6 + 20) = DM 7910/year

CD = 350 · (1.7 + 17) = DM 6 545/year

Total cost of owning and operating this transformer is thus:

Total cost of owning and operating this transformer is thus:

DM 44 984.–/year

DM 37 844.–/year

The energy saving of the optimized distribution transformer of DM 7140 per year pays for the increased purchase price in less than one year.

Fig. 6

Siemens Power Engineering Guide · Transmission & Distribution

4/7

Mechanical Design

General mechanical design for oil-immersed transformers: ■ Iron core made of grain-oriented

■

■ ■

■ ■

■

electrical sheet steel insulated on both sides, core-type. Windings consisting of copper section wire or copper strip. The insulation has a high disruptive strength and is temperature-resistant, thus guaranteeing a long service life. Designed to withstand short circuit for at least 2 seconds (IEC). Oil-filled tank designed as tank with strong corrugated walls or as radiator tank. Transformer base with plain or flanged wheels (skid base available). Cooling/insulation liquid: Mineral oil according to VDE 0370/IEC 296. Silicone oil or synthetic liquids are available. Standard coating for indoor installation. Coatings for outdoor installation and for special applications (e.g. aggressive atmosphere) are available.

Tank design and oil preservation system Sealed-tank distribution transformers, TUMETIC ® In ratings up to 2500 kVA and 170 kV LI this is the standard sealed-tank distribution transformer without conservator and gas cushion. The TUMETIC transformer is always completely filled with oil; oil expansion is taken up by the flexible corrugated steel tank (variable volume tank design), whereby the maximum operating pressure remains at only a fraction of the usual. These transformers are always shipped completely filled with oil and sealed for their lifetime. Bushings can be exchanged from the outside without draining the oil below the top of the active part. The hermetically sealed system prevents oxygen, nitrogen, or humidity from contact with the insulating oil. This improves the aging properties of the oil to the extent that no maintenance is required on these transformers for their lifetime. Generally the TUMETIC transformer is lower than the TUNORMA transformer. This design has been in successful service since 1973. A special TUMETIC-Protection device has been developed for this transformer.

4/8

Distribution transformers with conservator, TUNORMA® This is the standard distribution transformer design in all ratings. The oil level in the tank and the top-mounted bushings is kept constant by a conservator vessel or expansion tank mounted at the highest point of the transformer. Oil-level changes due to thermal cycling affect the conservator only. The ambient air is prevented from direct contact with the insulating oil through oiltraps and dehydrating breathers. Tanks from 50 to approximately 4000 kVA are preferably of the corrugated steel design, whereby the sidewalls are formed on automatic machines into integral cooling pockets. Suitable spot welds and braces render the required mechanical stability. Tank bottom and cover are fabricated from rolled and welded steel plate. Conventional radiators are available. Power transformers Power transformers of all ratings are equipped with conservators. Both the open and closed system are available. With the closed system ”TUPROTECT®“ the oil does not come into contact with the surrounding air. The oil expansion is compensated with an air bag. (This design is also available for greater distribution transformers on request). The sealing bag consists of strong nylon braid with a special double lining of ozon and oil-resistant nitrile rubber. The interior of this bag is in contact with the ambient air through a dehydrating breather; the outside of this bag is in direct contact with the oil. All tanks, radiators and conservators (incl. conservator with airbag) are designed for vacuum filling of the oil. For transformers with on-load tap changers a seperate smaller conservator is necessary for the diverter switch compartment. This seperate conservator (without air bag) is normally an integrated part of the main conservator with its own magnetic oil level indicator. Power transformers up to 10 MVA are fitted with weld-on radiators and are shipped extensively assembled; shipping conditions permitting. Ratings above 10 MVA require detachable radiators with individual butterfly valves, and partial dismantling of components for shipment. All the usual fittings and accessories for oil treatment, shipping and installation of these transformers are provided as standard. For monitoring and protective devices, see the listing on page 4/11.

Fig. 7: Cross section of a TUMETIC three-phase distribution transformer

Fig. 8: 630 kVA, three-phase, TUNORMA 20 kV ± 2.5 %/0.4 kV distribution transformer

Fig. 9: Practically maintenancefree: transformer with the TUPROTECT air-sealing system built into the conservator

Siemens Power Engineering Guide · Transmission & Distribution

Connection Systems

Distribution transformers All Siemens transformers have top-mounted HV and LV bushings according to DIN in their standard version. Besides the open bushing arrangement for direct connection of bare or insulated wires, three basic insulated termination systems are available: Fully enclosed terminal box for cables (Fig. 11) Available for either HV and LV side, or for both. Horizontally split design in degree of protection IP 44 or IP 54 (Totally enclosed and fully protected against contact with live parts, plus protection against drip, splash, or spray water). Cable installation through split cable glands and removable plates facing diagonally downwards. Optional conduit hubs. Suitable for single-core or three-phase cables with solid dielectric insulation, with or without stress cones. Multiple cables per phase are terminated on auxiliary bus structures attached to the bushings. Removal of transformer by simply bending back the cables.

Fig. 11: Fully enclosed cable connection box

Insulated plug connectors (Fig. 12) For substation installations, suitable HV can be attached via insulated elbow connectors in LI ratings up to 170 kV. Flange connection (Fig. 13) Air-insulated bus ducts, insulated busbars, or throat-connected switchgear cubicles are connected via standardized flanges on steel terminal enclosures. These can accommodate either HV, LV, or both bushings. Fiberglass-reinforced epoxy partitions are available between HV and LV bushings if flange/flange arrangements are chosen. The following combinations of connection systems are possible besides open bushing arrangements:

HV

LV

Cable box

Cable box

Cable box

Flange/throat

Flange

Cable box

Flange

Flange/throat

Elbow connector

Cable box

Elbow connector

Flange/throat

Fig. 10: Combination of connection systems

Fig. 12: Grounded metal-elbow plug connectors

Fig 13: Flange connection for switchgear and bus ducts

Siemens Power Engineering Guide · Transmission & Distribution

4/9

Connection Systems

Power transformers The most frequently used type of connection for transformers is the outdoor bushing. Depending on voltage, current, system conditions and transport requirements, the transformers will be supplied with bushings arranged vertically, horizontally or inclined. Up to about 110 kV it is usual to use oil-filled bushings according to DIN; condenser bushings are normally used for higher voltages. Limited space or other design considerations often make it necessary to connect cables directly to the transformer. For voltages up to 30 kV air-filled cable boxes are used. For higher voltages the boxes are oil-filled. They may be attached to the tank cover or to its walls (Fig. 14). The space-saving design of SF6-insulated switchgear is one of its major advantages. The substation transformer is connected directly to the SF6 switchgear. This eliminates the need for an intermediate link (cable, overhead line) between transformer and system (Fig. 15).

Fig. 14: Transformers with oil-filled HV cable boxes

Fig. 15: Direct SF6 -connection of the transformer to the switchgear

4/10

Siemens Power Engineering Guide · Transmission & Distribution

Accessories and Protective Devices Accessories not listed completely. Deviations are possible.

Double-float Buchholz relay (Fig. 16) For sudden pressure rise and gas detection in oil-immersed transformer tanks with conservator. Installed in the connecting pipe between tank and conservator and responding to internal arcing faults and slow decomposition of insulating materials. Additionally, backup function of oil alarm. The relay is actuated either by pressure waves or gas accumulation, or by loss of oil below the relay level. Seperate contacts are installed for alarm and tripping. In case of a gas accumulation alarm, gas samples can be drawn directly at the relay with a small chemical testing kit. Discoloring of two liquids indicates either arcing by products or insulation decomposition products in the oil. No change in color indicates an air bubble.

Fig. 16: Double-float Buchholz relay

Dial-type contact thermometer (Fig. 17) Indicates actual top-oil temperature via capillary tube. Sensor mounted in well in tank cover. Up to four seperately adjustable alarm contacts and one maximum pointer are available. Installed to be readable from the ground. With the addition of a CT-fed thermal replica circuit, the simulated hot-spot winding temperature of one or more phases can be indicated on identical thermometers. These instruments can also be used to control forced cooling equipment.

Fig. 17: Dial-type contact thermometer

Magnetic oil-level indicator (Fig. 18) The float position inside of the conservator is transmitted magnetically through the tank wall to the indicator to preserve the tank sealing standard device without contacts; devices supplied with limit (position) switches for high- and low-level alarm are available. Readable from the ground.

Fig. 18: Magnetic oil-level indicator

Siemens Power Engineering Guide · Transmission & Distribution

4/11

Accessories and Protective Devices

Protective device (Fig. 19) for hermetically sealed transformers (TUMETIC) For use on hermetically sealed TUMETIC distribution transformers. Gives alarm upon loss of oil and gas accumulation. Mounted directly at the (permanently sealed) filler pipe of these transformers. Pressure relief device (Fig. 20) Relieves abnormally high internal pressure shock waves. Easily visible operation pointer and alarm contact. Reseals positively after operation and continues to function without operator action. Dehydrating breather (Fig. 21, 22) A dehydrating breather removes most of the moisture from the air which is drawn into the conservator as the transformer cools down. The absence of moisture in the air largely eliminates any reduction in the breakdown strength of the insulation and prevents any buildup of condensation in the conservator. Therefore, the dehydrating breather contributes to safe and reliable operation of the transformer. Fig. 19: Protective device for hermetically sealed transformers (TUMETIC)

Fig. 20: Pressure relief device with alarm contact and automatic resetting

Bushing current transformer Up to three ring-type current transformers per phase can be installed in power transformers on the upper and lower voltage side. These multiratio CTs are supplied in all common accuracy and burden ratings for metering and protection. Their secondary terminals are brought out to shortcircuiting-type terminal blocks in watertight terminal boxes. Additional accessories Besides the standard accessories and protective devices there are additional items available, especially for large power transformers. They will be offered and installed on request. Examples are: ■ Fiber-optic temperature measurements ■ Permanent gas-in-oil analysis ■ Permanent water-content measurement ■ Sudden pressure rise relay, etc.

Fig. 21: Dehydrating breather A DIN 42 567 up to 5 MVA

4/12

Fig. 22: Dehydrating breather L DIN 42 562 over 5 MVA

Siemens Power Engineering Guide · Transmission & Distribution

Technical Data Distribution Transformers TUNORMA and TUMETIC

Oil-immersed TUMETIC and TUNORMA three-phase distribution transformers

12 11 10

3

8 2N 2U 2V 2W

■ ■ ■ ■ ■ ■

■

■

■ ■ ■

Standard: DIN 42500 Rated power: 50– 2500 kVA Rated frequency: 50 Hz HV rating: up to 36 kV Taps on ± 2.5 % or ± 2 x 2.5 % HV side: LV rating: 400– 720 V (special designs for up to 12 kV can be built) Connection: HV winding: delta LV winding: star (up to 100 kVA: zigzag) Impedance 4 % (only up to HV voltage at rated rating 24 kV and current: ≤ 630 kVA) or 6 % (with rated power ≥ 630 kVA or with HV rating > 24 kV) Cooling: ONAN Protection class: IP00 Final coating: RAL 7033 (other colours are available)

H1

1U 2U 1W

B1

7 9 E 2 3 6 7 8

6

8

2

Oil drain plug Thermometer pocket Adjustment for off-load tap changer Rating plate (relocatable) Grounding terminals

E

A1

9 10 11 12

Towing eye, 30 mm dia. Lashing lug Filler pipe Mounting facility for protective device

Fig. 24: TUMETIC distribution transformer (sealed tank)

5

4

1 10

3 8 2N 2U 2V 2W

H1

1U 2U 1W

B1

7

Um

LI

AC

[kV]

[kV]

[kV]

1.1

–

3

12

75

28

24

125

50

36

170

70

LI Lightning-impulse test voltage AC Power-frequency test voltage Fig. 23: Insulation level (IP00)

9 2 E 1 2 3 4 5

6

8

Oil level indicator Oil drain plug Thermometer pocket Buchholz relay (optional extra) Dehydrating breather (optional extra)

E 6 7 8 9 10

A1 Adjustment for off-load tap changer Rating plate (relocatable) Grounding terminals Towing eye, 30 mm dia. Lashing lug

Notes: Tank with strong corrugated walls shown in illustration is the preferred design. With HV ratings up to 24 kV and rated power up to 250 kVA (and with HV ratings > 24-36 kV and rated power up to 800 kVA), the conservator is fitted on the long side just above the LV bushings.

Fig. 25: TUNORMA distribution transformer (with conservator)

Losses The standard HD 428.1.S1 (= DIN 42500 Part 1) applies to three-phase oil-immersed distribution transformers 50 Hz, from 50 kVA to 2500 kVA, Um to 24 kV. For load losses (Pk), three different listings (A, B and C) were specified. There were also three listings (A’, B’ and C’) for no-load losses (P0) and corresponding sound levels. Due to the different requirements, pairs of values were proposed which, in the national standard, permit one or several combinations of losses. DIN 42500 specifies the combinations A-C’, C-C’ and B-A’ as being most suitable.

Siemens Power Engineering Guide · Transmission & Distribution

The combinations B-A’ (normal losses) and A-C’ (reduced losses) are approximately in line with previous standards. In addition there is the C-C’ combination. Transformers of this kind with additionally reduced losses are especially economical with energy (maximum efficiency > 99%). The higher costs of these transformers are counteracted by the energy savings which they make. Standard HD 428.3.S1 (= DIN 42500-3) specifies the losses for oil distribution transformers up to Um = 36 kV. For load losses the listings D and E, for no-load losses the listings D’ and E’ were specified. In order to find the most efficient transformer, please see part ”Transformer loss evaluation“.

4/13

Technical Data Distribution Transformers TUNORMA and TUMETIC

Dist. between wheel centers

TUMETIC

TUMETIC

TUNORMA

Height H1

Width B1 TUNORMA

TUMETIC

TUNORMA

TUMETIC

Length A1

LPA [dB]

LWA [dB]

[kg]

B-A'

190

1350

42

55

340 350

860

980 660

660 1210 1085 520

..4744-3RB

A-C'

125

1100

34

47

400 430

825 1045 660

660 1210 1085 520

4

..4744-3TB

C-C'

125

875

34

47

420 440

835

985 660

660 1220 1095 520

4

..4767-3LB

B-A'

190

1350

42

55

370 380

760

860 660

660 1315 1235 520

4

..4767-3RB

A-C'

125

1100

34

47

430 460

860

860 660

660 1300 1220 520

4

..4767-3TB

C-C'

125

875

33

47

480 510

880 1100 685

660 1385 1265 520

36

6

..4780-3CB

E-D´

230

1450

x

52

500

12

4

..5044-3LB

B-A'

320

2150

45

59

500 500

4

..5044-3RB

A-C'

210

1750

35

49

570 570

980

980 660

660 1315 1145 520

4

..5044-3TB

C-C'

210

1475

35

49

600 620

1030

930 660

660 1320 1150 520

4

..5067-3LB

B-A'

320

2150

45

59

520 530

1020 1140 685

660 1360 1245 520

4

..5067-3RB

A-C'

210

1750

35

49

600 610

1030 1030 690

660 1400 1280 520

4

..5067-3TB

C-C'

210

1475

35

49

640 680

960 1060 695

660 1425 1305 520

36

6

..5080-3CB

E-D´

380

2350

x

56

660

12

4

..5244 -3LA

B-A'

460

3100

47

62

620 610

1140 1140 710

710 1350 1185 520

4

..5244-3RA

A-C'

300

2350

37

52

700 690

1130 1010 660

660 1390 1220 520

4

..5244-3TA

C-C'

300

2000

38

52

760 780

985 1085 660

660 1380 1215 520

4

..5267-3LA

B-A'

460

3100

47

62

660 640

1150 1150 695

660 1440 1320 520

4

..5267-3RA

A-C'

300

2350

37

52

730 730

1030

930 695

660 1540 1420 520

4

..5267-3TA

C-C'

300

2000

37

52

800 820

1120 1120 710

660 1475 1355 520

36

6

..5280-3CA

E-D´

520

3350

x

59

900

1120

12

4

..5344-3LA

B-A'

550

3600

48

63

720 710

1190 1190 680

680 1450 1285 520

4

..5344-3RA

A-C'

360

2760

38

53

840 830

1070 1120 660

660 1470 1300 520

4

..5344-3TA

C-C'

360

2350

38

53

900 920

1130 1130 660

680 1450 1285 520

4

..5367-3LA

B-A'

550

3600

48

63

800 780

1290 1290 820

800 1595 1425 520

4

..5367-3RA

A-C'

360

2760

38

53

890 910

1110 1230 755

680 1630 1460 520

4

..5367-3TA

C-C'

360

2350

38

53

950 980

1080 1180 705

690 1595 1430 520

6

..5380-3CA

E-D´

600

3800

x

61

U2 [%]

4JB… 4HB…

50

12

4

..4744-3LB

4

24

24

24

(200)

Dimensions

Total weight

Pk 75* [W]

Um [kV]

160

Sound power level

P0 [W]

Sn [kVA]

100

CENELEC

Sound press. level 1m tolerance + 3 dB

TUNORMA

Combi- No-load Load nation of losses losses losses acc.

Type

TUMETIC

Max. Imperated dance volt. voltage HV side

TUNORMA

Rated power

24

36

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

1000

[mm]

x

x

x

x

1000

[mm]

x 710

1090 1020 660

1050

1250

x 780

x 800

x 800

[mm]

x 1530

E [mm]

x 520

660 1275 1110 520

x 1600

x 1700

x 1700

x 520

x 520

x 520

x: on request

* In case of short-circuits at 75 °C

Fig. 26: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

4/14

Siemens Power Engineering Guide · Transmission & Distribution

Technical Data Distribution Transformers TUNORMA and TUMETIC

P0 [W]

Height H1

Dist. between wheel centers

TUMETIC

TUNORMA

TUMETIC

TUMETIC

LWA [dB]

Width B1 TUNORMA

LPA [dB]

Length A1 TUMETIC

Pk 75* [W]

CENELEC

Dimensions

Total weight

TUNORMA

Sound power level

TUNORMA

Sound press. level 1m tolerance + 3 dB

Combi- No-load Load nation of losses losses losses acc.

Type

TUMETIC

Max. Imperated dance volt. voltage HV side

TUNORMA

Rated power

Sn [kVA]

Um [kV]

U2 [%]

250

12

4

..5444-3LA B-A'

650

4200

50

65

830 820 1300 1300

810 810 1450 1285 520

4

..5444-3RA A-C'

425

3250

40

55

940 920 1260 1260

670 820 1480 1415 520

4

..5444-3TA C-C'

425

2750

40

55

1050 1070 1220 1220

690 700 1530 1310 520

4

..5467-3LA B-A'

650

4200

49

65

920 900 1340 1340

800 760 1620 1450 520

4

..5467-3RA A-C'

425

3250

39

55

1010 1010 1140 1190

760 680 1675 1510 520

4

..5467-3TA C-C'

425

2750

40

55

1120 1140 1220 1340

715 710 1640 1475 520

36

6

..5480-3CA E-E´

650

4250

x

62

1100

800

12

4

..5544-3LA B-A'

780

5000

50

66

980 960 1440 1330

820 820 1655 1385 670

4

..5544-3RA A-C'

510

3850

40

56

1120 1100 1400 1250

820 820 1690 1415 670

4

..5544-3TA C-C'

510

3250

40

56

1240 1260 1380 1260

820 820 1665 1390 670

4

..5567-3LA B-A'

780

5000

50

66

1050 1030 1450 1350

840 840 1655 1510 670

4

..5567-3RA A-C'

510

3850

40

56

1170 1150 1410 1270

820 820 1755 1610 670

4

..5567-3TA C-C'

510

3250

40

56

1250 1280 1395 1290

820 820 1675 1540 670

36

6

..5580-3CA E-E´

760

5400

x

64

1220

960

12

4

..5644-3LA B-A'

930

6000

52

68

1180 1160 1470 1390

930 930 1700 1425 670

4

..5644-3RA A-C'

610

4600

42

58

1320 1310 1400 1360

820 820 1700 1430 670

4

..5644-3TA C-C'

610

3850

42

58

1470 1470 1410 1390

820 820 1695 1420 670

4

..5667-3LA B-A'

930

6000

52

68

1240 1220 1570 1570

940 940 1655 1510 670

4

..5667-3RA A-C'

610

4600

42

58

1370 1350 1475 1400

820 820 1760 1615 670

4

..5667-3TA C-C'

610

3850

42

58

1490 1520 1440 1400

820 820 1765 1540 670

36

6

..5580-3CA E-E´

930

6200

x

65

1480

990

12

4

..5744-3LA B-A'

1100

7100

53

69

1410 1380 1500 1430

840 840 1710 1440 670

4

..5744-3RA A-C'

720

5450

42

59

1650 1620 1560 1550

890 890 1745 1470 670

4

..5744-3TA C-C'

720

4550

43

59

1700 1710 1500 1470

820 820 1745 1470 670

4

..5767-3LA B-A'

1100

7100

53

69

1460 1440 1470 1530

835 850 1755 1610 670

4

..5767-3RA A-C'

720

5450

42

59

1650 1620 1495 1420

835 820 1815 1665 670

4

..5767-3TA C-C'

720

4550

43

59

1860 1910 1535 1500

820 820 1860 1645 670

6

..5780-3CA E-E´

1050

7800

x

66

1680

24

(315)

24

400

24

(500)

24

36

4JB… 4HB…

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

[kg]

[mm]

x 1350

x 1420

x 1470

x 1510

[mm]

x

x

x

x 1030

[mm]

x 1680

x 1700

x 1830

x 1900

E [mm]

x 520

x 670

x 670

x 670

x: on request

* In case of short-circuits at 75 °C

Fig. 27: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

Siemens Power Engineering Guide · Transmission & Distribution

4/15

Technical Data Distribution Transformers TUNORMA and TUMETIC

P0 [W]

Dist. between wheel centers

TUMETIC

TUMETIC

TUMETIC

TUNORMA

LWA [dB]

Height H1

Width B1 TUMETIC

LPA [dB]

Length A1

TUNORMA

Pk 75* [W]

CENELEC

Dimensions

Total weight

TUMETIC

Sound power level

TUNORMA

Sound press. level 1m tolerance + 3 dB

Combi- No-load Load nation of losses losses losses acc.

Type

TUNORMA

Max. Imperated dance volt. voltage HV side

TUNORMA

Rated power

Sn [kVA]

Um [kV]

U2 [%]

630

12

4

..5844-3LA B-A'

1300

8400

53

70

1660 1660 1680 1480

880 880 1755 1585 670

4

..5844-3RA A-C'

860

6500

43

60

1850 1810 1495 1420

835 820 1785 1510 670

4

..5844-3TA C-C'

860

5400

43

60

2000 1990 1535 1380

820 820 1860 1520 670

6

..5844-3PA B-A'

1200

8700

53

70

1750 1760 1720 1560

890 890 1920 1685 670

6

..5844-3SA A-C'

800

6750

43

60

1950 1920 1665 1600

870 870 1740 1400 670

6

..5844-3UA C-C'

800

5600

43

60

2160 2130 1670 1560

830 830 1840 1500 670

4

..5867-3LA B-A'

1300

8400

53

70

1690 1650 1665 1640

860 860 1810 1595 670

4

..5867-3RA A-C'

860

6500

43

60

1940 1920 1685 1680

870 870 1910 1695 670

4

..5867-3TA C-C'

860

5400

43

60

2100 2130 1600 1490

820 820 1940 1725 670

6

..5867-3PA B-A'

1200

8700

53

70

1730 1720 1780 1580

880 880 1760 1610 670

6

..5867-3SA A-C'

800

6750

43

60

1970 1960 1645 1640

830 830 1810 1595 670

6

..5867-3UA C-C'

800

5600

43

60

2240 2210 1740 1670

880 880 1840 1625 670

36

6

..5880-3CA E-E´

1300

8800

x

67

1950

12

6

..5944-3PA B-A'

1450

10700

55

72

1990 1960 1780 1540 1000 1000 1905 1660 670

6

..5944-3SA A-C'

950

8500

45

62

2210 2290 1720 1830

900 960 1935 1630 670

6

..5944-3UA C-C'

950

7400

44

62

2520 2490 1760 1710

920 920 1975 1730 670

6

..5967-3PA B-A'

1450

10700

55

72

2000 1950 1720 1710 1000 1000 1885 1670 670

6

..5967-3SA A-C'

950

8500

45

62

2390 2340 1760 1710

960 960 1945 1730 670

6

..5967-3UA C-C'

950

7400

44

62

2590 2550 1770 1700

930 930 1985 1780 670

36

6

..45980- E-E´

1520

11000

x

68

2400

12

6

3CA B-A'

1700

13000

55

73

2450 2640 1790 1630 1000 1000 2095 2070 820

6

..6044-3PA A-C'

1100

10500

45

63

2660 2610 1830 1830 1040 1040 2025 1770 820

6

..6044-3SA C-C'

1100

9500

45

63

2800 2750 1830 1830 1040 1040 2105 1840 820

6

..6044-3UA B-A'

1700

13000

55

73

2530 2720 1830 1670 1090 1010 2095 2120 820

6

..6067-3PA A-C'

1100

10500

45

63

2750 2690 1790 1740 1050 1050 2055 1840 820

6

..6067-3SA C-C'

1100

9500

45

63

2830 2810 1725 1770

6

..6067-3UA E-E´

1700

13000

x

68

2850

24

(800)

24

1000

24

36

4JB… 4HB…

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

[kg]

[mm]

x 1740

x 1800

x 2120

[mm]

x 1080

x 1100

[mm]

x 1940

x 2030

E [mm]

x 670

x 670

990 990 2065 1850 820

x 1160

x 2220

x 820

x: on request

* In case of short-circuits at 75 °C

Fig. 28: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

4/16

Siemens Power Engineering Guide · Transmission & Distribution

Technical Data Distribution Transformers TUNORMA and TUMETIC

Height H1

Dist. between wheel centers

TUMETIC

TUNORMA

TUMETIC

TUNORMA

Width B1

TUMETIC

TUNORMA

Length A1

TUMETIC

TUMETIC

Dimensions

Total weight

LPA [dB]

LWA [dB]

..6144 -3PA B-A'

2100

16000

56

74

2900 3080 1930 1850 1260 1100 2110 2070 820

6

..6144 -3SA A-C'

1300

13200

46

64

3100 3040 1810 1780

6

..6144-3UA C-C'

1300

11400

46

64

3340 3040 1755 1720 1015 1000 2235 1970 820

6

..6167 -3PA B-A'

2100

16000

56

74

2950 3200 2020 1780 1260 1100 2110 2220 820

6

..6167 -3SA A-C'

1300

13200

46

64

3190 3120 1840 1810 1060 1060 2115 1900 820

6

..6167 -3UA C-C'

1300

11400

46

64

3390 3330 1810 1780 1015

36

6

..6180 -3CA E-E´

2150

16400

x

70

3360

12

6

..6244 -3PA B-A'

2600

20000

57

76

3450 3590 1970 1870 1220 1140 2315 2095 820

6

..6244 -3SA A-C'

1700

17000

47

66

3640 3590 2030 1760 1080 1090 2315 2010 820

6

..6244 -3UA C-C'

1700

14000

47

66

3930 3880 2020 1900 1110 1100 2395 2070 820

6

..6267 -3PA B-A'

2600

20000

57

76

3470 3690 2070 1830 1280 1120 2335 2320 820

6

..6267 -3SA A-C'

1700

17000

47

66

3670 3850 2030 2000 1230 1070 2265 2120 820

6

..6267 -3UA C-C'

1700

14000

47

66

4010 3950 2000 1850 1030 1030 2305 2010 820

36

6

..6280 -3CA E-E´

2600

19200

x

71

3930

12

6

..6344 -3PA B-A'

2900

25300

58

78

4390 4450 2100 1890 1330 1330 2555 2540 1070

6

..6344 -3SA A-C'

2050

21200

49

68

4270 4430 2080 1840 1330 1330 2455 2250 1070

6

..6344 -3UA C-C'

2050

17500

49

68

4730 4710 2020 1730 1330 1330 2495 2170 1070

6

..6367 -3PA B-A'

2900

25300

58

78

4480 4500 2020 1860 1330 1330 2655 2660 1070

6

..6367 -3SA A-C'

2050

21200

49

68

4290 4490 2190 2030 1330 1330 2425 2280 1070

6

..6367 -3UA C-C'

2050

17500

49

68

4910 4840 2110 1980 1330 1330 2475 2180 1070

36

6

..63780- E-E´

3200

22000

x

75

5100

12

6

3CA B-A'

3500

29000

61

81

5200 5090 2115 2030 1345 1330 2685 2550 1070

6

..6444 -3PA A-C'

2500

26500

51

71

5150 5110 2195 1950 1345 1330 2535 2450 1070

6

..6444 -3SA C-C'

2500

22000

51

71

5790 5660 2190 2190 1330 1330 2565 2240 1070

6

..6444 -3UA B-A'

3500

29000

61

81

5420 5220 2115 2030 1335 1330 2785 2675 1070

6

..6467 -3PA A-C'

2500

26500

51

71

5260 5220 2195 2030 1335 1335 2585 2580 1070

6

..6467 -3SA C-C'

2500

22000

51

71

5640 5470 2160 2080 1330 1330 2605 2305 1070

6

..6467 -3UA E-E´

3800

29400

x

76

5900

U2 [%]

(1250)

12

6

24

24

24

2500

Sound power level

Pk 75* [W]

Um [kV]

(2000)

CENELEC

Sound press. level 1m tolerance + 3 dB

P0 [W]

Sn [kVA]

1600

Combi- No-load Load nation of losses losses losses acc.

Type

TUNORMA

Max. Imperated dance volt. voltage HV side

TUNORMA

Rated power

24

36

4JB… 4HB…

Dimensions and weights are approximate values. Rated power figures in parentheses are not standardized.

[kg]

[mm]

x 2150

x 2170

x 2260

x 2320

[mm]

990

x 1250

x 1340

x 1380

x 1390

[mm]

E [mm]

990 2145 1880 820

990 2245 2030 820 x 2350

x 2480

x 2560

x 2790

x 820

x 820

x 1070

x 1070

x: on request

* In case of short-circuits at 75 °C

Fig. 29: Selection table: oil-immersed distribution transformers 50 to 2500 kVA

Siemens Power Engineering Guide · Transmission & Distribution

4/17

Power Transformers – General

Oil-immersed three-phase power transformers with offand on-load tap changers

Rated power

HV range

Type of tap changer

Figure/ page

[MVA]

[kV]

3.15 to 10

25 to 123

off-load

Fig. 31, page 4/19

3.15 to 10

25 to 123

on-load

Fig. 33, page 4/20

10/16 to 20/31.5

up to 36

off-load

Fig. 35, page 4/21

10/16 to 20/31.5

up to 36

on-load

Fig. 38, page 4/22

10/16 to 63/100

72.5 to 145

on-load

Fig. 41, page 4/23

Cooling methods Transformers up to 10 MVA are designed for ONAN cooling. By adding fans to these transformers, the rating can be increased by 25%. However, in general it is more economical to select higher ONAN ratings rather than to add fans. Transformers larger than 10 MVA are designed with ONAN/ONAF cooling. Explanation of cooling methods: ■ ONAN: Oil-natural, air-natural cooling ■ ONAF: Oil-natural, air-forced cooling (in one or two steps) The arrangement with the attached radiators, as shown in the illustrations, is the preferred design. However, other arrangements of the cooling equipment are also possible. Depending on transportation possibilities the bushings, radiators and expansion tank have be removed. If necessary, the oil has to be drained and shipped separately.

4/18

Note: Off-load tap changers are designed to be operated de-energized only.

Fig. 30: Types of power transformers

Siemens Power Engineering Guide · Transmission & Distribution

Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformers with off-load tap changer 3 150–10000 kVA, HV rating: up to 123 kV ■ Taps on

HV side:

H

± 2 x 2.5 %

■ Rated frequency: 50 Hz ■ Impedance 6-10 %

voltage: ■ Connection:

HV winding: stardelta connection alternatively available up to 24 kV LV winding: star or delta

E

L

E W

Fig. 31

Rated power

HV rating

LV rating

No-load loss

Load loss Total at 75 °C weight

Oil weight

Dimensions L/W/H

E

[kVA] ONAN

[kV]

[kV]

[kW]

[kW]

[kg]

[mm]

[mm]

3150

6.1–36

3–24

4.6

28

7 200

1600

2800/1850/2870

1070

4000

7.8–36

3–24

5.5

33

8 400

1900

3200/2170/2940

1070

50–72.5

3–24

6.8

35

10 800

3100

3100/2300/3630

1070

9.5–36

4–24

6.5

38

9 800

2300

2550/2510/3020

1070

50–72.5

4–24

8.0

41

12 200

3300

3150/2490/3730

1070

90–123

5–36

9.8

46

17 500

6300

4560/2200/4540

1505

12.2–36

5–24

7.7

45

11 700

2500

2550/2840/3200

1505

50–72.5

5–24

9.3

48

13 600

3700

3200/2690/3080

1505

90–123

5–36

11.0

53

18 900

6600

4780/2600/4540

1505

12.2–36

5–24

9.4

54

14 000

3300

2580/2770/3530

1505

50–72.5

5–24

11.0

56

15 900

4200

3250/2850/4000

1505

90–123

5–36

12.5

62

21 500

7300

4880/2630/4590

1505

15.2–36

6–24

11.0

63

16 600

3900

2670/2900/3720

1505

50–72.5

6–24

12.5

65

18 200

4700

4060/2750/4170

1505

90–123

5–36

14.0

72

25 000

8600

4970/2900/4810

1505

5000

6300

8000

10000

[kg]

Fig. 32

Siemens Power Engineering Guide · Transmission & Distribution

4/19

Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformers with on-load tap changer 3 150–10 000 kVA, HV rating: up to 123 kV H

± 16 % in ± 8 steps HV side: of 2 % ■ Rated frequency: 50 Hz ■ Impedance 6–10 % voltage: ■ Connection: HV winding: star LV winding: star or delta ■ Taps on

E

E W

L

Fig. 33

Rated power

HV rating

LV rating

No-load loss

Load loss at 75 °C

Total weight

Oil weight

Dimensions L/W/H

E

[kVA] ONAN

[kV]

[kV]

kW

[kW]

[kg]

[kg]

[mm]

[mm]

3150

10.9–36

3–24

4.8

29

9100

2300

3400/2300/2900

1070

4000

9.2–36

3–24

5.8

35

10300

2600

3500/2700/3000

1070

50–72.5

4–24

7.1

37

13 700

4100

4150/2350/3600

1070

11.5–36

4–24

6.8

40

12300

3100

3600/2400/3200

1070

50–72.5

5–24

8.4

43

15 200

4500

4200/2700/3700

1070

90–123

5–36

9.8

49

21800

8000

5300/2700/4650

1505

14.4–36

5–24

8.1

47

14000

3600

3700/2700/3300

1505

50–72.5

5–24

9.8

50

17000

5000

4300/2900/3850

1505

90–123

5–36

11.5

56

23 000

8500

5600/2900/4650

1505

18.3–36

5–24

9.9

57

17 000

4500

3850/2500/3500

1505

50–72.5

5–24

11.5

59

19700

6000

4600/2800/4050

1505

90–123

5–36

13.1

65

25 500

9000

5650/2950/4650

1505

22.9–36

6–24

11.5

66

20 000

5200

4400/2600/3650

1505

50–72.5

6–24

13.1

68

22 500

6500

5200/2850/4100

1505

90–123

5–36

14.7

76

29 500

10 250

5750/2950/4700

1505

5000

6300

8000

10000

Fig. 34

4/20

Siemens Power Engineering Guide · Transmission & Distribution

Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformers with off-load tap changer 10/16 to 20/31.5 MVA HV rating: up to 36 kV

H Hs

■ Rated frequency: 50 Hz, tapping range ■ Connection of

± 2 x 2.5 % star

HV winding: ■ Connection of

star or delta LV winding: ■ Cooling method: ONAN/ONAF ■ LV range: 6 kV to 36 kV

L Ls

E W Ws

E

Fig. 35

Rated power at ONAF ONAN

No-load loss

Load loss at ONAN ONAF

Impedance voltage of ONAN ONAF

[MVA]

[MVA]

[kW]

[kW]

[kW]

[%]

[%]

10

16

12

31

80

6.3

10

12.5

20

14

37

95

6.3

10

16

25

16

45

110

6.4

10

20

31.5

19

52

130

6.4

10

Fig. 36

Rated power at ONAN ONAF [MVA]

[MVA]

10

16

12.5

Dimensions L x W x

H

Total weight

Oil weight

Shipping dimensions Ls x Ws

x Hs

Shipping weight incl. oil

[kg]

[kg]

[mm]

[kg]

3700 2350 3900

22

4200

3600 1550 2650

22000

20

3800 2350 4000

25

4500

3700 1600 2800

23000

16

25

3900 2400 4100

30

5000

3800 1600 2800

27000

20

31.5

4200 2450 4600

35

5700

3900 1650 3000

31500

[mm]

Fig. 37

Siemens Power Engineering Guide · Transmission & Distribution

4/21

Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformer with on-load tap changer 10/16 to 20/31.5 MVA, HV rating: up to 36 kV

H Hs

■ Rated frequency: 50 Hz, tapping range ■ Connection of

± 16 % in ± 9 steps star

HV winding: ■ Connection of

star or delta LV winding: ■ Cooling method: ONAN/ONAF ■ LV range: 6 kV to 36 kV

Ls

Ws W

L

Fig. 38

Rated power at ONAN ONAF

No-load loss

Load loss at ONAN ONAF

Impedance voltage of ONAN ONAF

[MVA]

[MVA]

[kW]

[kW]

[kW]

[%]

[%]

10

16

12

31

80

6.3

10

12.5

20

14

37

95

6.3

10

16

25

16

45

111

6.4

10

20

31.5

19

52

130

6.4

10

Fig. 39

Rated power at ONAN ONAF [MVA]

[MVA]

10

16

12.5

Dimensions L x W x

H

Total weight [kg]

Oil weight

Shipping dimensions Ls x Ws

x Hs

Shipping weight incl. oil

[kg]

[mm]

[kg]

4800 2450 3900 27 000

6200

4400 1550 2600

24000

20

4900 2500 4000 30 000

6700

4500 1600 2650

27000

16

25

5050 2500 4100 34 000

7000

4650 1650 2650

31000

20

31.5

5300 2550 4600 41 000

9000

5000 1700 3000

37000

[mm]

Fig. 40

4/22

Siemens Power Engineering Guide · Transmission & Distribution

Power Transformers – Selection Tables Technical Data, Dimensions and Weights

Oil-immersed three-phase power transformers with on-load tap changer 10/16 to 63/100 MVA, HV rating: from 72.5 to 145 kV ■ Rated frequency: 50 Hz, tapping range ■ Connection of

± 16 % in ± 9 steps star

HV winding: ■ Connection star or delta of LV winding: ■ Cooling method: ONAN/ONAF

Rated power at ONAN ONAF

No-load loss

Load loss at ONAN

ONAF

Impedance voltage of ONAN ONAF

[MVA] [MVA]

[kW]

[kW]

[kW]

[%]

[%]

10

16

13

42

108

9.6

15.4

12.5

20

15

45

115

9.4

15.0

16

25

17

51

125

9.6

15.0

20

31.5

20

56

140

9.6

15.1

25

40

24

63

160

9.5

15.2

31.5

50

28

71

180

9.5

15.0

40

63

35

86

214

9.8

15.5

50

80

41

91

232

10.0

16.0

63

100

49

113

285

10.5

16.7

Fig. 41

Rated power at Dimensions ONAN ONAF L x W x [MVA]

[MVA]

H

[mm]

Total weight

Oil weight

Shipping dimensions Ls x Ws x Hs

Shipping weight incl. oil

[kg]

[kg]

[mm]

[kg]

10

16

6600 2650 4700

39000

12000

5200 1900

3000

35000

12.5

20

6700 2700 4800

43000

12500

5300 1950

3100

39000

16

25

6750 2750 5300

48000

13500

5400 2000

3000

43000

20

31.5

6800 2800 5400

54000

14000

5500 2000

3100

49000

25

40

6900 2900 5400

61000

14500

5700 2100

3150

56000

31.5

50

7050 2950 5500

70000

17000

5850 2150

3350

65000

40

63

7100 3000 5700

82000

18000

6100 2200

3450

75000

50

80

7400 3100 5800

97000

20500

6250 2300

3700

90000

63

100

7800 3250 6100

118000

25500

6800 2450

4000

109000

Fig. 42

Siemens Power Engineering Guide · Transmission & Distribution

4/23

On-load Tap Changers

The on-load tap changers installed in Siemens power transformers are manufactured by Maschinenfabrik Reinhausen (MR). MR is a supplier of technically advanced on-load tap changers for oil-immersed power transformers covering an application range from 100 A to 4,500 A and up to 420 kV. About 90,000 MR high-speed resistor-type tap changers are succesfully in service worldwide. The great variety of tap changer models is based on a modular system which is capable of meeting the individual customers’ specifications for the respective operating conditions of the transformer. Depending on the required application range selector, switches or diverter switches with tap selectors can be used, both available for neutral, delta or single-pole connection. Up to 107 operating positions can be achieved by the use of a multiple course tap selector. In addition to the well-known on-load tapchanger for installation in oil-immersed transformers, MR offers also a standardized gas-insulated tap changer for indoor installation which will be mounted on drytype transformers up to approx. 30 MVA and 36 kV, or SF 6-type transformers up to 40 MVA and 123 kV. The main characteristics of MR products are: ■ Compact design ■ Optimum adaption and economic solutions offered by the great number of variants ■ High reliability ■ Long life ■ Reduced maintenance ■ Service friendliness The tap changers are mechanically driven – via the drive shafts and the bevel gear – by a motor drive attached to the transformer tank. It is controlled according to the step-by-step principle. Electrical and mechanical safety devices prevent overrunning of the end positions. Further safety measures, such as the automatic restart function, a safety circuit to prevent false phase sequence and running through positions, ensure the reliable operation of motor drives.

For operation under extremely onerous conditions an oil filter unit is available for filtering or filtering and drying of the switching oil. Voltage monitoring is effected by microprocessor-controlled operation control systems or voltage regulators which include a great variety of data input and output facilities. In combination with a parallel control unit, several transformers connected in parallel can be automatically controlled and monitored. Furthermore, Maschinenfabrik Reinhausen offers a worldwide technical service to maintain their high quality standard. Inspections at regular intervals with only small maintenance requirements guarantee the reliable operation expected with MR products.

Type VT Fig. 43: MR motor drive unit MA 7

Type V

Type H

Fig. 44: Gas-insulated on-load tap changer

Type M

Type G

Fig. 45: Selection of on-load tap changers from the MR product range

4/24

Siemens Power Engineering Guide · Transmission & Distribution

Cast-resin Dry-type Transformers, GEAFOL

Standards and regulations GEAFOL ® cast-resin dry-type transformers comply with IEC recommendation No. 726, CENELEC HD 464, HD 538 and DIN 42 523. Advantages and applications GEAFOL distribution and power transformers in ratings from 100 to more than 20 000 kVA and LI values up to 170 kV are full substitutes for oil-immersed transformers with comparable electrical and mechanical data. GEAFOL transformers are designed for indoor installation close to their point of use at the center of the major consumers.

They only make use of flame-retardent inorganic insulating materials which free these transformers from all restrictions that apply to oil-filled electrical equipment, such as oil-collecting pits, fire walls, fireextinguishing equipment, etc. GEAFOL transformers are installed wherever oil-filled units cannot be used: inside buildings, in tunnels, on ships, cranes and offshore platforms, in ground-water catchment areas, in food processing plants, etc. Often they are combined with their primary and secondary switchgear and distribution boards into compact substations that are installed directly at their point of use. As thyristor-converter transformers for variable speed drives they can be installed together with the converters at the drive

LV terminals

location. This reduces civil works, cable costs, transmission losses, and installation costs. GEAFOL transformers are fully LI-rated. They have similar noise levels as comparable oil-filled transformers. Taking the above indirect cost reductions into account, they are also frequently cost-competitive. By virtue of their design, GEAFOL transformers are completely maintenancefree for their lifetime. GEAFOL transformers have been in successful service since 1965. A lot of licenses have been granted to major manufactures throughout the world since.

Three-leg core

Normal arrangement: Top, rear Special version: Bottom, available on request at extra charge

Made of grain-oriented, low-loss electrolaminations insulated on both sides

HV terminals

To insulate core and windings from mechanical vibrations, resulting in low noise emissions

Variable arrangements, for optimal station design. HV tapping links on lowvoltage side for adjustment to system conditions, reconnectable in deenergized state

Cross-flow fans Permitting a 50% increase in the rated power

Resilient spacers

HV winding Consisting of vacuumpotted single foil-type aluminum coils. See enlarged detail in Fig. 47

LV winding Temperature monitoring By PTC thermistor detectors in the LV winding

Paint finish on steel parts Multiple coating, RAL 5009. On request: Two-component varnish or hot-dip galvanizing (for particularly aggressive environments)

Ambient class E2 Climatic category C2 (If the transformer is installed outdoors, degree of protection IP 23 must be assured)

Fire class F1

Made of aluminum strip. Turns firmly glued together by means of insulating sheet wrapper material

Insulation: Mixture of epoxy resin and quartz powder Makes the transformer maintenance-free, moisture-proof, tropicalized, flame-resistant and selfextinguishing

Clamping frame and truck Rollers can be swung around for lengthways or sideways travel * on-load tap changers on request.

Fig. 46: GEAFOL cast-resin dry-type transformer

Siemens Power Engineering Guide · Transmission & Distribution

4/25

Cast-resin Dry-type Transformers, GEAFOL

HV winding The high-voltage windings are wound from aluminum foil, interleaved with highgrade polypropylene insulating foil. The assembled and connected individual coils are placed in a heated mold, and are potted in a vaccum furnace with a mixture of pure silica (quartz sand) and specially blended epoxy resins. The only connections to the outside are copper bushings, which are internally bonded to the aluminum winding connections. The external star or delta connections are made of insulated copper connectors to guarantee an optimal installation design. The resulting high-voltage windings are fire-resistant, moistureproof, corrosionproof, and show excellent aging properties under all indoor operating conditions. (For outdoor use, specially designed sheetmetal enclosures are available). The foil windings combine a simple winding technique with a high degree of electrical safety. The insulation is subjected to less electrical stress than in other types of windings. In a conventional round-wire winding, the interturn voltage can add up to twice the interlayer voltage, while in a foil winding it never exeeds the simple voltage per turn because a layer consists of only one winding turn. Result: a high AC voltage and impulse-voltage withstand capacity. Why aluminum? The thermal expansion coefficients of aluminum and cast resin are so similar that thermal stresses resulting from load changes are kept to a minimum (see Fig. 47).

8 8

U

7

1

7 6 5

LV winding The standard low-voltage winding with its considerably reduced dielectric stresses is wound from single aluminum sheets with interleaved cast-resin impregnated fiberglass fabric. The assembled coils are then oven-cured to form uniformly bonded solid cylinders that are impervious to moisture. Through the single-sheet winding design, excellent dynamic stability under short-circuit conditions is achieved. Connections are submerged-arc-welded to the aluminum sheets and are extended either as aluminum or copper busbars to the secondary terminals.

Round-wire winding

4

6 4

3

3

2

2

2

8

3

7

4

6 5

1

Strip winding

U

2 4 6 8

2

3

4

5

6

7

8 1 3 5 7

1

2

3

4

5

6

7

Fig. 47: High-voltage encapsulated winding design of GEAFOL cast-resin transformer and voltage stress of a conventional round-wire winding (above) and the foil winding (below)

4/26

Siemens Power Engineering Guide · Transmission & Distribution

Cast-resin Dry-type Transformers, GEAFOL

Fire safety GEAFOL transformers use only flameretardent and self-extinguishing materials in their construction. No additional substances, such as aluminum oxide trihydrate, which could negatively influence the mechanical stability of the cast-resin molding material, is used. Internal arcing from electrical faults and externally applied flames do not cause the transformers to burst or burn. After the source of ignition is removed, the transformer is self-extinguishing. This design has been approved by fire officials in many countries for installation in populated buildings and other structures. The environmental safety of the combustion residues has been proven in many tests. Categorization of cast-resin transformers Dry-type transformers have to be categorized under the sections listed below: ■ Environmental category ■ Climatic category ■ Fire category These categories have to be shown on the rating plate of each dry-type transformer.

The properties laid down in the standards for ratings within the approximate category relating to environment (humidity), climate and fire behavior have to be demonstrated by means of tests. These tests are described for the environmental category (code number E0, E1 and E2) and for the climatic category (code number C1, C2) in DIN VDE 0532 Part 6 (corresponding to HD 464). According to this standard, they are to be carried out on complete transformers. The tests of fire behavior (fire category code numbers F0 and F1) are limited to tests on a duplication of a complete transformer. It consists of a core leg, a low-voltage winding and a high-voltage winding. The specifications for fire category F2 are determined by agreement between the manufacturer and the customer. Siemens have carried out a lot of tests. The results for our GEAFOL transformers are something to be proud of: ■ Environmental category E2 ■ Climatic category C2 ■ Fire category F1

This good behavior is solely due to the GEAFOL cast-resin mix which has been used successfully for decades.

Insulation class and temperature rise The high-voltage winding and the lowvoltage winding utilize class F insulating materials with a mean temperature rise of 100 K (standard design). Overload capability GEAFOL transformers can be overloaded permanently up to 50% (with a corresponding increase in impedance voltage) if additional radial cooling fans are installed. (Dimensions increase by approximately 200 mm in length and width.) Short-time overloads are uncritical as long as the maximum winding temperatures are not exceeded for extended periods of time. Temperature monitoring Each GEAFOL transformer is fitted with three temperature sensors installed in the LV winding, and a solid-state tripping device with relay output. The PTC thermistors used for sensing are selected for the applicable maximum hot-spot winding temperature. Additional sets of sensors with lower temperature points can be installed for them and for fan control purposes. Additional dial-type thermometers and Pt100 are available, too. For operating voltages of the LV winding of 3.6 kV and higher, special temperature measuring equipment can be provided. Auxiliary wiring is run in protective conduit and terminated in a central LV terminal box (optional). Each wire and terminal is identified, and a wiring diagram is permanently attached to the inside cover of this terminal box. Installation and enclosures Indoor installation in electrical operating rooms or in various sheet-metal enclosures is the preferred method of installation. The transformers need only be protected against access to the terminals or the winding surfaces, against direct sunlight, and against water. Sufficient ventilation must be provided by the installation location or the enclosure. Otherwise forced-air cooling must be specified or provided by others.

Fig. 48: Flammability test of cast-resin transformer

Siemens Power Engineering Guide · Transmission & Distribution

4/27

Cast-resin Dry-type Transformers, GEAFOL

Instead of the standard open terminals, insulated plug-type elbow connectors can be supplied for the high-voltage side with LI ratings up to 170 kV. Primary cables are usually fed to the transformer from trenches below, but can also be connected from above. Secondary connections can be made by multiple insulated cables, or by busbars, from either below or above. Secondary terminals are either aluminum or copper busbar stubs, drilled to specification. A variety of indoor and outdoor enclosures in different protection classes are available for the transformers alone, or for indoor compact substations in conjunction with high- and low-voltage switchgear cubicles. Recycling of GEAFOL transformers Of all the GEAFOL transformers manufactured since 1965, even the oldest units are not about to reach the end of their service life expectancy. In spite of this, a lot of experiences have been made over the years with the recycling of coils that have become unusable due to faulty manufacture or damage. These experiences show that all the metallic components, i.e. approx. 90% of all materials, can be fully recovered economically. The recycling method used by Siemens does not pollute the environment. In view of the value of the secondary raw materials, the procedure can be economical even considering the currently small amounts.

Fig. 49: GEAFOL transformer with plug-type cable connections

Fig. 50: Radial cooling fans on GEAFOL transformer for AF cooling

4/28

Fig. 51: GEAFOL transformer in protective housing to IP 20/40

Siemens Power Engineering Guide · Transmission & Distribution

GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

■ ■ ■ ■ ■

■ ■ ■

■ ■ ■

Standard: DIN 42523 Rated power: 100–20000 kVA* Rated frequency: 50 Hz HV rating: up to 36 kV LV rating: up to 780 V; special designs for up to 12 kV are possible Tappings on ± 2.5 % or ± 2 x 2.5 % HV side: Connection: HV winding: delta LV winding: star Impedance 4– 8% voltage at rated current: Insulation class: HV/LV = F/F Temperature HV/LV = 100/100 K rise: Color of metal RAL 5009 (other parts: colors are available)

Um [kV]

LJ [kV]

AC [kV]

1.1

–

3

12

75

28

24

95**

50

36

145**

70

* power rating > 2.5 MVA uopn request ** other levels upon request

Fig. 52: Insulation level

2U

2V

2N

2W

H1

E B1

E A1 Fig. 53: GEAFOL cast-resin transformer

Sound power level

Total weight

Pk 75* [W]

Sound Load losses press. level 1m tolerance + 3 dB Pk 120** LPA [W] [dB]

LWA [dB]

440

1600

1900

45

.5044-3GA

320

1600

1900

.5044-3DA

360

2000

2300

6

.5044-3HA

300

2000

4

.5064-3CA

600

4

.5064-3GA

6

.5064-3DA

6

Rated power

Rated Impevoltage dance voltage

Sn [kVA]

Um [kV]

U2 [%]

4GB…

100

12

4

.5044-3CA

4 6 24

160

12

24

Type

No-load Load losses losses

Dimensions Length

Width

Height

Distance between wheel centers

GGES [kg]

A1 [mm]

B1 [mm]

H1 [mm]

E [mm]

59

630

1210

705

835

without wheels

37

51

760

1230

710

890

without wheels

45

59

590

1190

705

860

without wheels

2300

37

51

660

1230

710

855

without wheels

1500

1750

45

59

750

1310

755

935

without wheels

400

1500

1750

37

51

830

1300

755

940

without wheels

420

1800

2050

45

59

660

1250

750

915

without wheels

.5064-3HA

330

1800

2050

37

51

770

1300

755

930

without wheels

4

.5244-3CA

610

2300

2600

47

62

770

1220

710

1040

520

4

.5244-3GA

440

2300

2600

39

54

920

1290

720

1050

520

6

.5244-3DA

500

2300

2700

47

62

750

1270

720

990

520

6

.5244-3HA

400

2300

2700

39

54

850

1300

725

985

520

4

.5264-3CA

800

2200

2500

47

62

910

1330

725

1090

520

4

.5264-3GA

580

2200

2500

39

54

940

1310

720

1095

520

6

.5264-3DA

600

2500

2900

47

62

820

1310

725

1075

520

6

.5264-3HA

480

2500

2900

39

54

900

1350

765

1060

520

P0 [W]

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11.

Rated power figures in parentheses are not standardized.

* In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C

Fig. 54: GEAFOL cast-resin transformers 50 to 2500 kVA

Siemens Power Engineering Guide · Transmission & Distribution

4/29

GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

Rated power

Rated Impevoltage dance voltage

Sn [kVA]

Um [kV]

U2 [%]

250

12

4

.5444-3CA

4

.5444-3GA

6

Sound power level

Total weight

Pk 75* [W]

LWA [dB]

GGES [kg]

820

3000

3500

50

65

600

3000

3400

42

57

.5444-3DA

700

2900

3300

50

6

.5444-3HA

570

2900

3300

4

.5464-3CA

1050

2900

4

.5464-3GA

800

6

.5464-3DA

880

6

.5464-3HA

36

6

12

Length

Width

Height

A1 [mm]

B1 [mm]

H1 [mm]

E [mm]

1040

1330

730

1110

520

1170

1330

730

1135

520

65

990

1350

740

1065

520

42

57

1120

1390

745

1090

520

3300

50

65

1190

1390

735

1120

520

2900

3300

41

57

1230

1400

735

1150

520

3100

3600

50

65

990

1360

735

1140

520

650

3100

3600

41

57

1180

1430

745

1160

520

.5475-3CA

1300

3800

4370

50

65

1700

1900

900

1350

520

4

.5544-3CA

980

3300

3800

52

67

1160

1370

820

1125

670

4

.5544-3GA

720

3300

3800

43

59

1320

1380

820

1195

670

6

.5544-3DA

850

3400

3900

51

67

1150

1380

830

1140

670

6

.5544-3HA

680

3400

3900

43

59

1290

1410

830

1165

670

4

.5564-3CA

1250

3400

3900

51

67

1250

1410

820

1195

670

4

.5564-3GA

930

3400

3900

43

59

1400

1440

825

1205

670

6

.5564-3DA

1000

3600

4100

51

67

1190

1410

825

1185

670

6

.5564-3HA

780

3600

4100

43

59

1300

1460

830

1195

670

36

6

.5575-3CA

1450

4500

5170

51

67

1900

1950

920

1400

670

12

4

.5644-3CA

1150

4300

4900 52

68

1310

1380

820

1265

670

4

.5644-3GA

880

4300

4900 44

60

1430

1380

820

1290

670

6

.5644-3DA

1000

4300

4900 52

68

1250

1410

825

1195

670

6

.5644-3HA

820

4300

4900 44

60

1350

1430

830

1195

670

4

.5664-3CA

1450

3900

4500 52

68

1410

1440

825

1280

670

4

.5664-3GA

1100

3900

4500 44

60

1570

1460

830

1280

670

6

.5664-3DA

1200

4100

4700 52

68

1350

1480

835

1275

670

6

.5664-3HA

940

4100

4700 44

60

1460

1480

835

1280

670

36

6

.5675-3CA

1700

5100

5860 52

68

2100

2000

920

1440

670

12

4

.5744-3CA

1350

4900

5600 53

69

1520

1410

830

1320

670

4

.5744-3GA

1000

4900

5600 45

61

1740

1450

835

1345

670

6

.5744-3DA

1200

5600

6400 53

69

1470

1460

845

1275

670

6

.5744-3HA

980

5600

6400 45

61

1620

1490

845

1290

670

4

.5764-3CA

1700

4800

5500 53

69

1620

1500

835

1330

670

4

.5764-3GA

1270

4800

5500 44

61

1830

1540

840

1350

670

6

.5764-3DA

1400

5000

5700 53

69

1580

1540

850

1305

670

6

.5764-3HA

1100

5000

5700 45

61

1720

1560

850

1320

670

6

.5775-3CA

1900

6000

6900 53

69

2600

2050

940

1500

670

24

(500)

Dimensions

Distance between wheel centers

24

400

No-load Load losses losses

Sound press. level 1m tolerance + 3 dB Pk 120** LPA [W] [dB]

24

(315)

Type

24

36

4GB…

P0 [W]

Load losses

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11.

Rated power figures in parentheses are not standardized.

* In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C

Fig. 55: GEAFOL cast-resin transformers 50 to 2500 kVA

4/30

Siemens Power Engineering Guide · Transmission & Distribution

GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

Rated power

Rated Impevoltage dance voltage

Sound power level

Total weight

Sn [kVA]

Um [kV]

U2 [%]

4GB…

P0 [W]

Pk 75* [W]

LWA [dB]

630

12

4

.5844-3CA

1500

6400

7300

54

4

.5844-3GA

1150

6400

6

.5844-3DA

1370

6400

7300 7400

6

.5844-3HA

1150

6400

4

.5864-3CA

1950

4 6

.5864-3GA .5864-3DA

6 36

6

12

24

(800)

24

1000

No-load Load losses losses

Length

Width

Height

Distance between wheel centers

GGES [kg]

A1 [mm]

B1 [mm]

H1 [mm]

E [mm]

70

1830

1510

840

1345

670

45

62

2070

1470

835

1505

670

54

70

1770

1550

860

1295

670

7400

45

62

1990

1590

865

1310

670

6000

6900

53

70

1860

1550

845

1380

670

1500

6000

6900

45

62

2100

1600

850

1400

670

1650

6400

7300

53

70

1810

1580

855

1345

670

.5864-3HA

1250

6400

7300

45

62

2050

1620

860

1370

670

.5875-3CA

2200

7000

8000

53

70

2900

2070

940

1650

670

4

.5944-3CA

1850

7800

9000

55

72

2080

1570

850

1560

670

4

.5944-3GA

1450

7800

9000

47

64

2430

1590

855

1640

670

6

.5944-3DA

1700

7600

8700

55

72

2060

1560

865

1490

670

6

.5944-3HA

1350

7600

8700

47

64

2330

1600

870

1530

670

4

.5964-3CA

2100

7500

8600

55

72

2150

1610

845

1580

670

4

.5964-3GA

1600

7500

8600

47

64

2550

1650

855

1620

670

6

.5964-3DA

1900

7900

9100

55

71

2110

1610

860

1590

670

6

.5964-3HA

1450

7900

9100

47

64

2390

1630

865

1595

670

Sound Load losses press. level 1m tolerance + 3 dB Pk 120** LPA [W] [dB]

Dimensions

36

6

.5975-3CA

2600

8200

9400

55

72

3300

2140

950

1850

670

12

4

.6044-3CA

2200

8900 10200

55

73

2480

1590

990

1775

820

4

.6044-3GA

1650

8900 10200

47

65

2850

1620

990

1795

820

6

.6044-3DA

2000

8500

9700

56

73

2420

1620

990

1560

820

6

.6044-3HA

1500

8500

9700

47

65

2750

1660

990

1560

820

4

.6064-3CA

2400

8700 10000

55

73

2570

1660

990

1730

820

4

..6064-3GA

1850

8700 10000

47

65

3060

1680

990

1815

820

6

.6064-3DA

2300

9200 10500

55

73

2510

1680

990

1620

820

24

(1250)

Type

6

.6064-3HA

1750

9600 11000

47

65

2910

1730

990

1645

820

36

6

.6075-3CA

3000

9500 10900

55

73

3900

2200

1050

1900

820

12

6

.6144-3DA

2400

9600 11000

57

75

2900

1780

990

1605

820

6

.6144-3HA

1850

10500 12000

49

67

3370

1790

990

1705

820

6

.6164-3DA

2700

10000 11500

57

75

3020

1820

990

1635

820

6

.6164-3HA

2100

10500 12000

49

67

3490

1850

990

1675

820

6

.6175-3CA

3500

11000 12600

57

75

4500

2300

1060

2000

520

24 36

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11.

Rated power figures in parentheses are not standardized.

* In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C

Fig. 56: GEAFOL cast-resin transformers 50 to 2500 kVA Siemens Power Engineering Guide · Transmission & Distribution

4/31

GEAFOL Cast-resin Selection Tables, Technical Data, Dimensions and Weights

Sound power level

Total weight

LWA [dB]

58 50

11800 13500

2400

Rated Impevoltage dance voltage

Sn [kVA]

Um [kV]

U2 [%]

4GB…

P0 [W]

Pk 75* Pk 120** LPA [W] [W] [dB]

1600

12

6

.6244-3DA

2800

11000 12500

6

.6244-3HA

2100

11400 13000

6

.6264-3DA

3100

6

.6264-3HA

24

(2000)

No-load Load losses losses

Dimensions Length

Width

Height

Distance between wheel centers

GGES [kg]

A1 [mm]

B1 [mm]

H1 [mm]

E [mm]

76

3550

1840

995

2025

1070

68

4170

1880

1005

2065

1070

58

76

3640

1880

995

2035

1070

12300 14000

49

68

4080

1900

1005

2035

1070

36

6

.6275-3CA

4300

12700 14600

58

76

5600

2500

1100

2400

1070

12

6

.6344-3DA

3600

14000 16000

59

78

4380

1950

1280

2150

1070

6

.6344-3HA

2650

14500 16500

51

70

5140

1990

1280

2205

1070

6

.6364-3DA

4000

14500 16500

59

78

4410

2020

1280

2160

1070

24

2500

Type

Sound Load losses press. level 1m tolerance + 3 dB

Rated power

6

.6364-3HA

3000

14900 17000

51

70

4920

2040

1280

2180

1070

36

6

.6375-3CA

5100

15400 17700

59

78

6300

2500

1280

2400

1070

12

6

.6444-3DA

4300

17600 20000

62

81

5130

2110

1280

2150

1070

6

.6444-3HA

3000

18400 21000

51

71

6230

2170

1280

2205

1070

6

.6464-3DA

5000

17600 20000

61

81

5280

2170

1280

2160

1070

6

.6464-3HA

3600

18000 20500

51

71

6220

2220

1280

2180

1070

6

.6475-3CA

6400

18700 21500

61

81

7900

2700

1280

2400

1070

24 36

Dimensions and weights are approximate values and valid for 400 V on the secondary side, vector-group can be Dyn 5 or Dyn 11.

Rated power figures in parentheses are not standardized.

* In case of short-circuits at 75 °C ** In case of short-circuits at 120 °C Rated power >2500 kVA to 20 MVA on request.

Fig. 57: GEAFOL cast-resin transformers 50 to 2500 kVA

4/32

Siemens Power Engineering Guide · Transmission & Distribution

Special Transformers and Reactors

Rectifier transformer for electrostatic precipitators DC voltages up to 148 kV are used to remove solid pollutants from smokestack emissions in industrial and power generating plants. Siemens has developed special transformers with built-in silicon rectifier diodes, so-called rectiformers, for this purpose. These units are constructed based on the TUMETIC hermetically sealed transformer principle. In addition to the transformer windings, the following components are contained in this variable-volume sealed oil tank: LV current-attenuating reactor HV rectifier bridge HV measuring resistor HF reactor The DC voltage is fed through the tank top by means of a single bushing. The separate LV terminal 60x, mounted on the transformer side, contains the LV terminal, HV flashover detection with amplifier for kV measurement, shunt for precipitator current measurement, 2 surge-voltage protectors. To adjust the DC output voltage, the LV windings of the transformer are supplied via a thyristor AC power controller. This controller is mounted inside a separate weatherproof control cabinet. For technical data please inquire.

■ ■ ■ ■

Fig. 58: Rectifier-transformer for electrostatic precipitator

Flameproof transformers for coal mines In deep-shaft coal mines the release of methane must be taken into account in the design of electrical systems. Siemens has developed flameproof distribution transformers that comply with the relevant German mine safety codes, which apply in various other countries as well. The flameproof units are dry-type threephase distribution transformers inside corrugated steel enclosures with integral highand low-voltage terminal boxes. The enclosures are designed to withstand internal explosions of combustible gas without igniting the surrounding explosive atmosphere. The transformers are supplied for primary voltages of up to 10 kV, secondary voltages of 525 and 1050 V at 50/60 Hz, and power ratings up to 1000 kVA.

Fig. 59: Flameproof distribution transformer 630 kVA for coal mines

Siemens Power Engineering Guide · Transmission & Distribution

4/33

Special Transformers and Reactors

Transformers for thyristor converters These are special oil-immersed or castresin power transformers that are designed for the special demands of thyristor converter or diode rectifier operation. The effects of such conversion equipment on transformers and additional construction requirements are as follows: ■ Increased load by harmonic currents ■ Continuous short-circuit-like stresses by current communication and communication faults ■ Balancing of phase currents in multiple winding systems (e.g. 12-pulse systems) ■ Overload factor up to 2.5 ■ Types for 12-pulse systems, if required. Siemens supplies oil-filled converter transformers of all ratings and configurations known today, and dry-type cast-resin converter transformers up to more than 20 MVA and 200 kV LI. To define and quote for such transformers, it is necessary to know considerable details on the converter to be supplied and on the line feeding it. These transformers are almost exclusively inquired together with the respective drive or rectifier system and are always custom-engineered for the given application.

Arc-suppression coils for distribution networks (Neutral reactors or Petersen coils) Arc-suppression coils or Petersen coils are used in distribution networks up to 150 kV to neutralize the prospective capacitive ground-fault current by inserting a corresponding reactance into the starpointto-ground connection of the network. Through this method, damages due to arcing ground faults can be limited or avoided entirely. System operation can often be maintained under ground-fault conditions until corrective switching actions have been taken; temporary ground faults require no action at all. Since the prospective capacitive groundfault current depends on the varying system condition, the neutralizing reactor must be adjustable – either in steps, or continuously. Siemens builds Petersen coils with fixed and variable reactance in sizes from 50 kVA to 30 MVA, and line-to-neutral voltages of 5 to 150 kV. Adjustment in steps is realized with off-load tapping switches, resulting in an adjustment ratio of about 1:2.5. Continuous adjustment results in tuning ratios of better than 1:10 and is done via electric motor or electrohydraulically operated moving-core mechanisms. Current transformers for measuring and recording purposes, as well as ground-fault locating devices are optionally available.

Fig. 60: Dry-type converter transformer GEAFOL for rolling mill

4/34

Neutral grounding transformers When a neutral grounding reactor or ground-fault neutralizer is required in a three-phase system and no suitable neutral is available, a neutral must be provided by using a neutral grounding transformer. Neutral grounding transformers are available for continuous operation or short-time operation. The zero impedance is normally low. The standard vector groups are zigzag or wye/delta. Some other vector groups are also possible. Neutral grounding transformers can be built by Siemens in all common power ratings. Normally, the neutral grounding transformers are built in oil-immersed design, however, they can also be built in cast-resin design. For further information please contact: Distribution transformers: Fax: ++ 49-70 21- 50 85 48 Power transformers: Fax: ++ 49 -9 11-4 34 2147

Fig. 61: Arc-suppression coil with electrically controlled reactance adjustment

Siemens Power Engineering Guide · Transmission & Distribution

Power Cables

Contents Power Cables – General

Page 5/2–5/6

Medium- and Low-Voltage Cables up to 45 kV 5/7–5/12 Accessories for Lowand Medium-Voltage Cables

5/13–5/20

High-Voltage Cables up to 290/500 kV

5/21–5/22

Accessories for High-Voltage Cables up to 290/500 kV 5/23–5/24

Power Cables – General

Application Cables intended for the transmission and distribution of electrical energy are mainly used in power plants, in distribution systems and substations of power supply utilities, and in industry. They are preferably used where overhead lines are not suitable, e.g. in densely builtup areas, in cities (pedestrian zones), industrial installations and buildings. For power supply cables there are two main fields of application with different stresses (Fig. 1):

Laying in the ground

In view of the possible external stresses for power cables, cables are be divided into two standard cable types, i. e. one for laying in the ground (distribution cables) and one for installation in air (installation cables) (Fig. 3). High-voltage cables are often designed according to the specific stresses of each special case of application. The Siemens instructions AR 320-220 and AR 320-1-220 contain detailed information on the application of cables, e. g. permissible pulling forces, limit temperatures, bending radii, cable fixing, storage and transport, etc.

Installation in air

Directly in the ground

Outdoors

In ducts

Indoors

In concrete

In channels

Voltages ■ Rated voltage

– Power cables are classified according to the rated voltages U0 /U and Um . – U0 is the rms value between conductor and ground or grounded metallic covering (concentric conductor, screen, armor, metal sheath). – U is the rms value between phase conductors. – Um is the maximum rms value between phase conductors. In an a. c. system, the rated voltage Um must be at least equal to the highest voltage of the system Ub max for which it is intended. U0 = U/ 3 – For application in three-phase and single-phase systems the main standard rated voltages (rounded values) in compliance with IEC 183 are given in Fig. 4. The maximum continuous operating-voltage at normal operation for low voltage cables with rated voltage of 0.6/1kV ( Um = 1.2 kV) is – 1.8 kV in d.c. systems – 3.6 kV in a.c. systems for PVC-insulated cables having a concentric conductor or armor and conductor cross-sectional areas from 240 mm 2 and above.

In water

Fig. 1: Fields of application

Stresses determined by the function: Stresses and requirements These cables, especially the insulation (electrical strength) of buried cables, must be reliable and have a long service life. In order to fulfil this requirement for Siemens cables, the cable construction as well as the materials and manufacturing processes are permanently improved with a lot of development work. The different stresses determined by the function form the basis for the definition of the cable requirements (Fig. 2).

Normal operation

Operation under fault conditions

Current

Thermal stress

Voltage

Electrical stress

Short-circuit

Thermal/ mechanical stress

Ground fault

Thermal stress

Transient waves

Electrical stress

Fig. 2: Stresses determined by the function

5/2

Siemens Power Engineering Guide · Transmission & Distribution

Power Cables – General

Current ratings For safe project planning of cable installations, the cross-sectional area of conductor shall be determined such that the requirement current-carrying capacity I z ≥ loading Ib is fulfilled for all operating conditions which can occur. A distinction is made between the current-carrying capacity ■ for normal operation ■ and for short-circuit (operation under fault conditions) Especially in low-voltage systems, the cross-sectional area of the conductor must be additionally determined in respect of the permitted voltage drop ∆U. In order to avoid thermal overloading of the cable a suitable protective device also has to be selected. Besides that, the relevant installation rules shall be observed. With regard to these criteria, brief instructions for project planning are given in Part 2 of the book “Power Cables and their Application”. They are sufficient for most cases when using the values listed in this book. The procedure is shown by examples. More comprehensive calculation methods with detailed project planning data can be taken from Part 1 of the book “Power Cables and their Application”. Order-Nr.: Part 1: A19100-L531-F159-X-7600 Part 2: A19100-L531-F506-X-7600. For high-voltage cables, the current-carrying capacity is to be examined for each special case of application. It depends on a lot of special laying and installation conditions so that it is not possible to give standard values.

Laying in the ground

Installation in air

Mechanical

Tensile strength (laying) Impact strength (civil works) Abrasion Termites, rodents, etc.

Tensile strength (laying) Pressure force (cleats) Vibrations

Chemical

Chemicals (permanent influence), oil, acids

Chemicals (short-term influence) Ozone

Climatic

Moisture (water) Temperature

Moisture (rain, humidity) UV radiation Temperature (cold, heat)

Fire behavior

Fire propagation

Fire propagation Corrosive combustion gases Smoke density Circuit integrity of cable installation

Fig. 3: Stresses determined by the installation method

Uo

Standards To ensure the operational properties and the high quality of all types of Siemens cables, short-term and long-term tests are carried out. They are based on national and international standards such as VDE and IEC. A perfect quality system according to ISO 9001 ensures a maximum of reliability of Siemens cables.

Um in three-phase systems

Um in single-phase a.c. systems Both phase conductors insulated

One phase conductor grounded

[kV]

[kV]

[kV]

[kV]

0.6

1.2

1.4

0.7

3.6

7.2

8.3

4.1

6

12

14

7

12

24

28

14

18

36

42

21

64

123

142

71

76

145

168

84

87

170

196

98

127

245

284

142

160

300

346

173

290

525

606

303

Fig. 4

Siemens Power Engineering Guide · Transmission & Distribution

5/3

Power Cables – General

Constructional elements of cables Conductors The conductors comply with IEC 228. The type and construction of conductor – whether circular solid (RE) or circular stranded (RM), sector-shaped solid (SE) or sector-shaped stranded (SM) – can be taken from the relevant tables in the book “Power Cables and their Application”, Part 2. The smallest permissible nominal cross-sectional areas for circular and sector-shaped conductors are specified in the relevant standard. Especially for high-voltage low-pressure oil-filled cables, circular stranded hollow conductors (RM...H) are used. For crosssectional areas of 1000 mm 2 and above, special segmental conductors, also known as Milliken conductors, are used in order to reduce current losses occurring due to skin and proximity effects. Insulation In the field of cables with extruded insulation, there are two dominating insulation materials which have proved to be reliable. One of these two materials is XLPE which is used for Siemens PROTOTHEN X cables. These cables have a high-grade insulating compound of high-molecular pure polyethylene with a cross-linked structure which is distinguished by excellent properties. Cables up to 500 kV are designed with this insulation material because of the very low and almost constant dielectric loss factor at all operating temperatures. The permittivity is also relatively low and unaffected by fluctuations in temperature so that total dielectric losses of Siemens PROTOTHEN X cables are extremely low. The conductor screen and insulation screen of these cables are extruded together with the insulation (triple extrusion) in special manufacturing processes. So the insulation screen is generally solidly bonded to the insulation. To remove this insulation screen during installation of accessories, a special peeling tool is required. Designs with easy-strip semiconductive layers are also available for medium-voltage cables. The second dominating material for extruded insulations is PVC, but it is mainly used for cables designed for voltages from 1 kV up to and including 6 kV. Siemens PROTODUR cables have an insulation based on that material. Compared to XLPE, these cables have a significantly higher permittivity.

5/4

Oil-impregnated paper, a classic insulation material, is still used especially for extrahigh-voltage low-pressure oil-filled cables. Two advantages of this type of insulation are the vast experience that stands behind it and the high degree of reliability so impressively demonstrated by the faultfree service of these cables decade after decade. Identification of cores for low-voltage cables Cables with more than 5 cores (control cables) have black cores with white imprinted numbers. The green-yellow core is to be used solely as a PE (protective earth) or PEN (protective earth and neutral) conductor. The blue core is provided for use as a neutral conductor. The blue core may be used as a phase conductor if the cable has a concentric conductor or if a neutral conductor is not required.

Concentric conductors, screens, armor and metal sheaths Low-voltage cables are provided with concentric conductors as protection from contact if there is a possibility of the cables being exposed to mechanical damage. Concentric conductors are made of copper. The data on the cross-sectional area in the type designation code always refer to the material of the phase conductors. For cables with concentric conductors in distribution systems, the wires of the concentric conductors are laid in waveform (CEANDER conductor) on the inner covering. These conductors facilitate the installation of the branch joints because the concentric conductor can easily be lifted up and bundled at one side. It also ensures that there is sufficient space for connecting branches to the underlying phase conductors without having to cut the CEANDER conductor. Screens are compulsory for all cable types above 0.6/1 kV. Screens shall consist of copper. In case of single-core cables multicore cables may have individual screened cores or a common screen. In multi-core cables a steel wire armor may also be used as a common screen. The screens which are always grounded ensure protection from contact and carry the leakage and ground-fault currents. According to DIN VDE 0276-620 the nominal crosssectional area of the screens (geometrical cross-sectional area) may not fall below the values in the following table (Fig. 5).

Nominal crosssectional area of phase conductor

Nominal crosssectional of the screen*

mm 2

mm 2

25 to 120

16

150 to 300

25

400, 500

35

* A nominal cross-sectional area of the screen of 16 mm2 is permissible for multi-core cables laid in the ground and single-core cables with a phase conductor cross-sectional area of up to 185 mm2 and 240 mm2 respectively, provided that these values are compatible with ground-fault or double ground-fault currents.

Fig. 5

To protect the insulation of PROTODUR or PROTOTHEN X cables against permanent, intensive ingress of fuels, oils or solvents, a lead sheath can be provided under the PVC sheath. For high-voltage cables a lead sheath is normally used for low-pressure oil-filled cables, but it is also available for cables with XLPE insulation. For these high-voltage PROTOTHEN X cables, however, normally a screen of round copper wires with a cross-sectional area of 35 mm2 or 50 mm2 is used together with an aluminum laminated PE sheath. For all types of insulation used for highvoltage cables, a metal sheath of aluminum is available as well. The advantage of such a cable design with a corrugated aluminum sheath is the very high mechanical protection and, under fault conditions, the very high ground-fault current-carrying capacity. Outer coverings For low-voltage PROTODUR cables with PVC insulation and PROTOTHEN X cables with XLPE insulation, a PVC sheath is normally applied. Medium-voltage XLPE-insulated cables normally have a sheath of polyethylene which is more resistant with respect to the mechanical properties. PVC sheaths can also be provided, especially for underground mining or indoor installation (flame retardance according to IEC 332-2). As already mentioned, high-voltage cables having a screen of round copper wires are provided with an aluminum laminated PE sheath consisting of an aluminum tape coated with PE copolymer on the outer

Siemens Power Engineering Guide · Transmission & Distribution

Power Cables – General

side and bonded to a black PE sheath. All other high-voltage cable types are usually also combined with a PE sheath because of its high mechanical stability. Only if there are requirements for flame retardance according to IEC 332-2 should a PVC sheath be applied instead of or in addition to the commonly used PE sheath.

Products Low- and medium-voltage cables Information on low-voltage and mediumvoltage cables with voltages or constructions not listed in this Engineering Guide, for example paper-insulated cables, can be obtained from Dept. EV SK2. For further information please contact: Fax: ++49 - 91 31-73 24 55 SIENOPYR cables have the following excellent characteristics: ■ Reduced fire propagation performance: Even in the case of large grouping and vertical installation of cables, the spread of fire by cables is prevented (tests according to IEC 332-3). ■ Corrosivity: No subsequential fire damage because the materials of these cables are halogen-free and the gas emission is noncorrosive (tests according to IEC 754-2). ■ Low smoke density: Fire-fighting and rescue operations are decisively facilitated (tests according to IEC 1034). Flexible cables which are used for installations in high-rise and industrial high-rise buildings, for connecting mobile equipment as well as for internal wiring of equipment can be obtained from Dept. EV SK 3. For further information please contact: Fax: ++ 49-9131-73 10 92

Application The cables and accessories shown on the following pages are designed for all kinds of high-voltage transmission of electrical energy. The main requirements for these applications are as follows: ■ Low loss factor tan delta: This is for low dielectric losses to minimize heating. ■ Thermal stability of insulation: This is for a uniform loss factor at all load fluctuations and overvoltages occurring in operation. ■ Electrical stability of insulation: This is for freedom from partial discharge through effective prevention of ionization in voids. All these main requirements are fulfilled by XLPE-insulated PROTOTHEN X cables and low-pressure oil-filled cables, together with Siemens accessories for high-voltage cables shown in Fig. 37 to 44 by examples to demonstrate their typical constructional elements.

Fig. 8: Low-pressure oil-filled cables to switchgear by GIS-type sealing ends

Fig. 6: Installation of low- and medium-voltage cables in an industrial area

High- and Extra-High-Voltage Cables up to 290/500 kV and Accessories Information on high-voltage cables and accessories is available from Siemens Dept. EV SK1 V. For further information please contact: Fax: ++ 49-9131-73 47 44 High-voltage cables are laid and installed by Siemens on a contractual basis. This covers all tasks from route planning up to the final voltage test to be carried out. This is due to the very special requirements each customer has for a high-voltage cable circuit and the specific solutions Siemens can offer to fulfil these requirements.

Fig. 7: Laying of a 20 kV single-core PROTOTHEN X Cable

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 9: 110 kV single-core PROTOTHEN X cables with outdoor sealing ends

5/5

Power Cables – General

Product Overview – Selection Guide Overview of main cable types and a guide for the selection of cable according to voltage, insulation and metallic coverings.

Lowand mediumvoltage Power cables

0.6/1 kV

Multi- core

PVC insulation

PVC sheath

Concentric conductor XLPE insulation

3.6/6 kV

Three- core

6/10 kV

6/10 kV 12/20 kV 18/30 kV

0.6/1 kV

Steel armor

64/110 kV

2XFY

Page 8

PVC insulation

Steel armor

PVC sheath

NYFGY

Page 9

XLPE insulation

Screen

N2XSEY

Page 9

2XSEYFY

Page 10

N2XSY

Page 10

PEsheath

N2XS2Y

Page 11

PVC sheath

NYY

Page 12

NYCY

Page 12

YKYRY

Page 8

2XS(FL)2Y

Page 21

2XK2Y

Page 21

2XKLDE2Y

Page 22

NÖKLDE2Y

Page 22

Screen

PVC insulation

No screen

XLPE insulation

No screen

Lead + PVC

Screen

Laminated PEsheath

Lead sheath 160/275 kV

290/500 kV

Page 7

Page 11

Single- core

Single- core

NYCWY

N2XH

Screen

Highvoltage cable

Page 7

EVAsheath

Steel armor

Multi- core

NYY

No screen

12/20 kV

Control cables

No screen

Oil-impregnated paper insulation

Corrugated aluminumsheath

Fig. 10: Overview of main cable types

5/6

Siemens Power Engineering Guide · Transmission & Distribution

Medium- and Low-Voltage Cables up to 45 kV

Multi-Core PROTODUR Power Cables

0.6/1 kV

Mainly for power stations, industrial plants and substations. Usually laid indoors, in ducts and outdoors. May also be laid in the ground where damage (e. g. from pickaxes) is unlikely.

NYY U0/U = 0.6/1 kV (U m = 1.2 kV) acc. to DIN VDE 0276-603, HD 603, IEC 502

Application

Design Current-Carrying Capacity

Power cables with ■ copper conductor, ■ PVC insulation and ■ PVC sheath.

acc. to DIN VDE 0276-603, based on IEC 287 Permissible operating temp. 70 °C Permissible short-circuit temp. 160 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A58-X-7600 Four-core PROTODUR cables, type NYY for 0.6/1 kV 2. Cable book: Power Cables and their Application, Part 2, pp. 226, 227

Fig. 11

Multi-Core PROTODUR Power Cables with concentric waveform conductor NYCWY U 0/U = 0.6/1 kV ( Um = 1.2 kV) acc. to DIN VDE 0276-603, HD 603, IEC 502

Design Power cables with ■ copper conductor, ■ PVC insulation, ■ concentric copper conductor laid in waveform and ■ PVC sheath.

0.6/1 kV

Application Mainly for distribution systems. Also for power stations, industrial plants and substations. Current-Carrying capacity acc. to DIN VDE 0276-603, HD 603, based on IEC 287 Permissible operating temp. 70 °C Permissible short-circuit temp. 160 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A28-X-7600 PROTODUR cables, type NYCY/NYCWY for 0.6/1 kV 2. Cable book: Power Cables and their Application, Part 2, pp. 232, 233

Fig. 12

Siemens Power Engineering Guide · Transmission & Distribution

5/7

Medium- and Low-Voltage Cables up to 45 kV

Multi-Core PROTOTHEN X Power Cables with flat steel wire armor

0.6/1 kV

For very severe operating, laying and installation conditions. The armor withstands tensile stresses such as those occurring on step gradients and in mining subsidence areas. Suitable as river and submarine cables.

2XFY U 0/U = 0.6/1 kV ( Um = 1.2 kV) acc. to IEC 502

Application

Design Current-Carrying Capacity

Power cable with ■ copper conductor, ■ XLPE insulation, with ■ flat steel-wire armor and ■ PVC sheath.

on request Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short circuit durations up to 5 s)

Fig. 13

Multi-Core PROTODUR Control Cables with round steel wire armor YKYRY U 0/U = 0.6/1 kV ( Um = 1.2 kV) acc. to IEC 502

0.6/1 kV

Application For filling stations, refineries and other installations where the effects of oil, solvents, etc. are to be expected. The lead sheath protects the installation from such effects.

Design

Current-Carrying Capacity

Control cable with ■ copper conductor, ■ PVC insulation, with ■ lead sheath, ■ round wire armoring and ■ PVC sheath.

on request Permissible operating temp. 70 °C Permissible short-circuit temp. 160 °C (for short-circuit durations up to 5 s)

Fig. 14

5/8

Siemens Power Engineering Guide · Transmission & Distribution

Medium- and Low-Voltage Cables up to 45 kV

3-Core PROTODUR Cables with flat steel wire armor

3.6/6 kV

Mainly in power stations, industrial plants and substation stations. For laying outdoors, in ducts and indoors, resistant to tensile stress, suitable as river and submarine cables.

NYFGY U 0/U = 3.6/6 kV ( Um = 7.2 kV) acc. to DIN VDE 0271, IEC 502

Application

Design

Current-Carrying Capacity

Power cable with ■ copper conductor, ■ PVC insulation, ■ flat steel-wire armor and ■ PVC sheath.

on request Permissible operating temp. 70 °C Permissible short-circuit temp. 160 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A50-X-7600 3-core PROTODUR cables, type NYFGY for 3.6/6 kV 2. Cable book: Power Cables and their Application, Part 2, pp. 248, 249

Fig. 15

3-Core PROTOTHEN X Cables with copper wire screen on each core

6/10 kV

Application Mainly in power stations, industrial plants and substations and in distribution systems where high thermal stresses occur. For laying outdoors, in ducts and indoors.

N2XSEY Current-Carrying Capacity

U 0/U = 6/10 kV (U m = 12 kV) acc. to DIN VDE 0276-620, HD 620, IEC 502

Design Power cables with ■ copper conductor, ■ extruded firmly bonded semiconductive layers under and over the XLPE insulation, with ■ individually screened cores and ■ PVC sheath.

acc. to DIN VDE 0276-620, HD 620, based on IEC 287 Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A1-X-7600 3-core PROTOTHEN X cables, type N2XSEY for 6/10 kV

Fig. 16

Siemens Power Engineering Guide · Transmission & Distribution

5/9

Medium- and Low-Voltage Cables up to 45 kV

3-Core PROTOTHEN X Cables with copper wire screen and flat steel wire armoring

12/20 kV

2XSEYFY U 0/ U = 12/20 kV (Um = 24 kV) acc. to IEC 502

Design Power cable with ■ copper conductor, ■ extruded firmly bonded semiconductive layers under and over the XLPE insulation, with ■ individually screened cores, PVC separation sheath with ■ flat steel wire armor and ■ PVC sheath.

Application Mainly in industrial plants, power stations and public distribution systems, where high thermal and mechanical stresses occur. Note: This type is available on request for the full range af cable types incorporating aluminum conductors, screens of copper tapes, armor of galvanized round steel wires or steel tapes, outer sheath of PE or any combination of these. Current-Carrying Capacity on request Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A43-X-7600 3-core PROTOTHEN X cables with wire screen and galvanized flat steel-wire armor, type 2XSEYFY for 12/20 kV

Fig. 17

Application Mainly in power stations, industrial plants and substations. For laying outdoors, in ducts and indoors.

Single-Core PROTOTHEN X Cables with copper wire screen N2XSY U 0/U = 6/10 kV (U m = 12 kV) U 0/U = 12/20 kV (U m = 24 kV) U 0/U = 18/30 kV (U m = 36 kV) acc. to DIN VDE 0276-620, HD 620, IEC 502

Design Power cable with ■ copper conductor, ■ extruded firmly bonded semiconductive layers under and over the XLPE insulation, ■ copper wire screen and ■ PVC sheath.

Current-Carrying Capacity acc. to DIN VDE 0276-620, HD 620, based on IEC 287 Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A2-X-7600 1-Core PROTOTHEN X Cables 6/10 kV Order No. E50001-U511-A48-X-7600 1-Core PROTOTHEN X Cables 12/20 kV Order No. I115/111I8-101-02 1-Core PROTOTHEN X Cables 18/30 kV 2. Cable book: Power Cables and their Application, Part 2, pp. 258–265

Fig. 18

5/10

Siemens Power Engineering Guide · Transmission & Distribution

Medium- and Low-Voltage Cables up to 45 kV

Application Mainly for industrial and distribution systems, for laying in the ground. When these cables are laid indoors or in ducts, it must be noted that polyethylene-sheathed cables are not flame-retardant according to DIN VDE 0472, Part 804, Test method B

Single-Core PROTOTHEN X Cables with copper wire screen N2XS2Y U 0/U = 6/10 kV (U m = 12 kV) U 0/U = 12/20 kV (U m = 24 kV) U 0/U = 18/30 kV (U m = 36 kV) acc. to DIN VDE 0276-620, HD 620, IEC 502

Design Power cables with ■ copper conductor, ■ extruded firmly bonded semiconductive layers under and over the XLPE insulation, with ■ copper wire screen and ■ PE sheath.

Current-Carrying Capacity To DIN VDE 0276-620, HD 620, based on IEC 287 Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A65-X-7600 1-Core PROTOTHEN X Cables 6/10 kV Order No. A19100-I11-A41-X-7600 1-Core PROTOTHEN X Cables 12/20 kV Order No. A19100-I11-A42-V1-7600 1-Core PROTOTHEN X Cables 18/30 kV 2. Cable book: Power Cables and their Application, Part 2, pp. 258–265

Fig. 19

SIENOPYR Power Cables Halogen-Free Cables with Improved Characteristics in Case of Fire N2XH U0/U = 0.6/1 kV (U m = 1.2 kV) acc. to DIN VDE 0266 Part 2 (HD 604.5G)

Design Power cables with ■ copper conductor, ■ XLPE insulation, ■ inner covering and ■ EVA sheath.

Application SIENOPYR cables with improved characteristics in the case of fire are mainly used in buildings and installations with increased safety risks and high concentration of people or valuable contents. The application of these cables should be regarded as a measure for preventive fire protection in: ■ Hospitals ■ Hotels ■ Underground and local rapid transit rail systems ■ Schools SIENOPYR cables are intended for installation indoors and outdoors. Current-Carrying Capacity on request Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A56 SIENOPYR Cables N2XH for 0.6/1 kV 2. Cable book: Power Cables and their Application, Part 2, pp. 271–277

Fig. 20

Siemens Power Engineering Guide · Transmission & Distribution

5/11

Medium- and Low-Voltage Cables up to 45 kV

Multi-Core PROTODUR Control Cables

0.6/1 kV

NYY U0/U = 0.6/1 kV (U m = 1.2 kV) acc. to DIN VDE 0276-627, HD 627, IEC 502

Design Control cable with ■ copper conductor, ■ PVC insulation (numbered cores) and ■ PVC sheath.

Application Transmission of control pulses, measured values, etc. in power stations, industrial plants, installation indoors, etc., in ducts in the ground and outdoors. The printed numbers on the cores simplify identification and speed up installation, as ringing out is not necessary. When long runs are laid in the ground, inductive effects are to be taken into account. Current-Carrying Capacity acc. to DIN VDE 0276-627, HD 627, based on IEC 287 Permissible operating temp. 70 °C Permissible short-circuit temp. 160 °C (for short-circuit durations up to 5 s) Publications:

Fig. 21a

NYCY U0/U = 0.6/1 kV (U m = 1.2 kV) acc. to DIN VDE 0276-627, HD 627, IEC 502

Design

1. Leaflets: Order No. E50001-U511-A63-X-7600 PROTODUR control cables, type NYY for 0.6/1 kV 2. Cable book: Power Cables and their Application, Part 2, pp. 246, 247

Control cable with ■ copper conductor, ■ PVC insulation (numbered cores), ■ concentric copper conductor and ■ PVC sheath.

Fig. 21b

5/12

Siemens Power Engineering Guide · Transmission & Distribution

Accessories for Low- and Medium-Voltage Cables

The service reliability of a cable installation depends, among other things, on the application of suitable accessories and the careful installation of accessories. Due to our extensive manufacturing program, suitable accessories can be supplied for each cable and each application.

General Voltage classes: ■ Low voltage up to 1.2 kV; ■ Medium voltage > 1.2 kV up to 36 kV

Cable joints ... ... connect lengths of cable in long transmission routes as straight joints for connection and branch joints for connecting service cable and must fulfill the following functions: ■ Connection of the conductors ■ Insulation of the conductors and, especially in medium-voltage cables, re-establishment of the elements of the cable ■ Protection against all ambient conditions of the ground ■ Establishment of branch points for service cables in low-voltage networks

... form the termination points of cable and serve as a connection to electric apparatus or machines or switchgear. Depending on the system rated voltage and the cable construction, the following objectives must be met:

3-core

Power cable

Single-core

Control cables

Multi-core

influences. ■ Protection of core insulation

(e.g. against UV radiation). ■ Controlled reduction of the electric field

strength on medium-voltage cable. ■ Insulation from grounding parts.

Conductor Connection: Hexagonal compression crimping is recommended. Other kinds of compression crimping are possible. Outer conductive layer ...

Terminations ...

Multi-core

■ Connection of the conductors. ■ Sealing of the cable against ambient

... will be removed in an approved manner with a suitable stripping tool.

Branch joint

PA, PAK GNKA2

Fig. 23 Fig. 23

Page 5/14 Page 5/14

Voltage-proof end joint

SKEM

Fig. 24

Page 5/14

Straight joint

SKSM, SKSM-C, GNKV PV

Fig. 25 Fig. 27

Page 5/15 Page 5/16

Termination

SKSA, SKSE, GNKI

Fig. 26

Page 5/15

3.6/6 kV NYFGY

Straight joint

PV

Fig. 27

Page 5/16

Termination

GHKI/GHKF 7.2

Fig. 28

Page 5/16

6/10 kV N2XSEY 12/20 kV 2XSEYFY

Straight joint

WP 10/20/30

Fig. 29

Page 5/17

Termination

GHKI/GHKF 12/24 IAES

Fig. 28 Fig. 32

Page 5/16 Page 5/18

6/10 kV 12/20 kV 18/30 kV N2XSY N2XS2Y

Straight joint

WP 10/20/30 WPS 10/20/30 GHSV 12/24/36

Fig. 29 Fig. 30 Fig. 31

Page 5/17 Page 5/17 Page 5/18

Termination

GHKI/GHKF 12/24/36 IAES 10/20/30 FAE 10/20

Fig. 33 Fig. 34 Fig. 35

Page 5/19 Page 5/19 Page 5/20

Boots

FHKG/FHKW

Fig. 36

Page 5/20

Straight joint

SKSM-ST PV

Fig. 25 Fig. 27

Page 5/15 Page 5/16

0.6/1 kV NYY NYCWY 2XFY

0.6/1 kV NYY NYGY YKYRY

Fig. 22: Overview of Acessories for Low- and Medium-Voltage Cable

Siemens Power Engineering Guide · Transmission & Distribution

5/13

Accessories for Low- and Medium-Voltage Cables

Branch Joint for multi-core cable

0.6/1 kV

PA/PAK + GNKA 2

Design ■ PROTOLIN cast-resin-filled plastic mold. ■ PA joint: using single clamps. ■ PAK joint: Cores connected by compact locking collar without removing the insulation. Application In ground, ducts and in air. Installation Without special tools. Design GNKA 2 consists of sealant mats placed around the compact locking collar. A fiberreinforced sleeve with coating of sealant is used as outer protection. Cores connected by compact locking collar without removing the insulation. Application In ground, ducts and in air. Installation With gas torch or hot air blower.

Fig. 23

Voltage-Proof End Joint for multi-core cable SKEM

0.6/1 kV

Design Heatshrinkable cross-linked polyolefin end caps inside coated with a hot melt adhesive. Application ■ To sealing cables ends, where the cable

is connected to voltage. ■ In ground, ducts and in air.

Installation With gas torch or hot air blower.

Fig. 24

5/14

Siemens Power Engineering Guide · Transmission & Distribution

Accessories for Low- and Medium-Voltage Cables

Straight Joint for multi-core cable

0.6/1 kV

Design Heatshrinkable cross-linked polyolefin tubes coated with a special hot melt adhesive on the inside. The number of inner tubes depends on the number of cable cores.

SKSM/SKSM-C/SKSM-ST/GNKV

Application ■ In ground, ducts and in air. ■ SKSM for multi-core power cables, ■ SKSM-C for power cables with

concentric neutral, ■ SKSM-ST for control cables.

Installation With gas torch or hot air blower.

Fig. 25

Termination for multi-core cable

0.6/1 kV

Design ■ SKSA: breakout consist of heat shrink-

SKSA, SKSE, GNKI

able cross-linked polyolefin hot melt coated and serves to protect the cable spreader area against moisture. ■ SKSE and GNKI: additional with heat-

shrinkable tubes for protection and sealing the cable cores. In case of metal shielded cables, the connection material are included in the kit. Application Outdoor and indoor. Installation With gas torch or hot air blower.

Fig. 26

Siemens Power Engineering Guide · Transmission & Distribution

5/15

Accessories for Low- and Medium-Voltage Cables

Straight Joint for 3-core and multi-core cable

0.6/1 up to 3.6/6 kV

Design PROTOLIN cast-resin-filled plastic. The size of joint depends on the number of cable cores.

PV

Application All areas.

Fig. 27

Termination for 3-core polymeric cable GHKI/GHKF 7.2/12/24

3.6/6 up to 18/30 kV

Design Heatshrinkable, track-resistant, cross-linked polyolefin tubes and breakout, coated with sealing adhesive. Application GHKI-Indoor and GHKF-Outdoor terminations can be used in all applications. Installation With gas torch or hot air blower.

Fig. 28

5/16

Siemens Power Engineering Guide · Transmission & Distribution

Accessories for Low- and Medium-Voltage Cables

Straight Joint for 1- and 3-core polymeric cable

10/12 – 18/30 kV

Design Shielded joint wrapping which is mechanically protected by a plastic tube filled with PROTOLIN cast resin.

WP 10/20/30

Application In ground, ducts and in air.

Fig. 29

Straight Joint for 1-core polymeric cable WPS 10/20/30

10/12 up to 18/30 kV

Design Shielded joint wrapping which is mechanically protected by a thick-walled heatshrinkable tube. Application In ground, ducts and in air. Installation Without special tools.

Fig. 30

Siemens Power Engineering Guide · Transmission & Distribution

5/17

Accessories for Low- and Medium-Voltage Cables

Straight Joint for 1- and 3-core polymeric cable GHSV 12/24/36

10/12 – 18/30 kV

Design Heatshrinkable insulation tubes combined with stress control components and sealing tapes or coatings protected by a thickwalled heatshrinkable tube. Application In ground, ducts and in air.

Fig. 31

Termination IAES 10

Design Track-resistant, silicon rubber insulator with an integrated control deflector for controlling the electrical field. Application IAES indoor terminations can be used in switchgear and transformer stations. Installation Without special tools.

Fig. 32

5/18

Siemens Power Engineering Guide · Transmission & Distribution

Accessories for Low- and Medium-Voltage Cables

Terminations GHKI/GHKF 12/24/36

Design Heatshrinkable, track-resistant, cross-linked polyolefin tubes and breakout, coated with sealing adhesive. Application GHKI-Indoor, GHKF-Outdoor used in switchgear and transformer stations. Installation Gas torch or hot air blower.

Fig. 33

Termination IAES 10/20/30

Design Track-resistant, silicon rubber insulator with an integrated control deflector for controlling the electrical field. Application IAES indoor terminations can be used in switchgear and transformer boxes. Installation Without special tools.

Fig. 34

Siemens Power Engineering Guide · Transmission & Distribution

5/19

Accessories for Low- and Medium-Voltage Cables

Termination FAE 10/20

Design Track-resistant, silicon rubber insulator with an integrated control deflector for controlling the electrical field. Application FAE outdoor terminations can be used in switchgear and transformer stations. Installation Without special tools.

Fig. 35

Seperable connectors FHKG, FHKW

Design Heatshrinkable, track-resistant, insulation molded parts sealed with track-resistant adhesive. Application The boots can protect the connection bushings into transformer and motor connection boxes.

All the accessories are listed in the RXS catalog Order No.: A 45050-W2165-D7-X-7600 For further information please contact: Fax: ++49 - 23 31- 35 7118 Fig. 36

5/20

Siemens Power Engineering Guide · Transmission & Distribution

High-Voltage Cables up to 290/500 kV

Single-core XLPE-insulated cable with laminated sheath

64/110 kV

Design Cable with ■ Conductor ■ Conductor screen ■ XLPE insulation ■ Insulation screen ■ Semiconductive nonwoven swelling tape ■ Screen of copper wires ■ Copper contact helix ■ PE-coated Al tape and PE sheath (laminated sheath)

2XS(FL)2Y 64/110 kV (U m = 123 kV) according to IEC 840

Current-Carrying Capacity on request Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A5-X-7600 Cables and Accessories for High- and Extra-High-Voltages Fig. 37

Single-core XLPE-insulated cable with lead sheath 2XK2Y 160/275 kV (Um = 300 kV) based on IEC 840

160/275 kV

Design Cable with Conductor Conductor screen XLPE insulation Insulation screen Semiconductive nonwoven swelling tape ■ Lead sheath ■ Compound ■ PE sheath ■ ■ ■ ■ ■

Current-Carrying Capacity on request Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short-circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A5-X-7600 Cables and Accessories for High- and Extra-High-Voltages

Fig. 38

Siemens Power Engineering Guide · Transmission & Distribution

5/21

High-Voltage Cables up to 290/500 kV

Single-core XLPE-insulated cable 290/500kV with Milliken conductor and corrugated aluminum sheath 2XKLDE2Y 290/500 kV (U m = 525 kV) based on IEC 840

Design Cable with ■ Milliken conductor ■ Conductor screen ■ XLPE insulation ■ Insulation screen ■ Semiconductive bedding layer ■ Fabric tape with interwoven copper wires ■ Corrugated aluminum sheath ■ Plastic tape in compound and PE sheath Current-Carrying Capacity on request Permissible operating temp. 90 °C Permissible short-circuit temp. 250 °C (for short circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A5-X-7600 Cables and Accessories for High- and Extra-High-Voltages

Fig. 39

Single-core low pressure oil filled cable with corrugated aluminum sheath NÖKLDE2Y 290/500 kV (Um = 525 kV) according to IEC 141

290/500 kV

Design Cable with ■ Hollow conductor ■ Carbon black paper ■ Paper insulation ■ Carbon black paper and metallized black paper ■ Fabric tape with interwoven copper wires ■ Corrugated aluminum sheath ■ Plastic tape in compound and PE sheath Current-Carrying Capacity on request Permissible operating temp. 85 °C Permissible short-circuit temp. 160 °C (for short circuit durations up to 5 s) Publications: 1. Leaflets: Order No. E50001-U511-A5-X-7600 Cables and Accessories for High- and Extra-High-Voltages

Fig. 40

5/22

Siemens Power Engineering Guide · Transmission & Distribution

Accessories for High-Voltage Cables up to 290/500 kV

Typical design of outdoor-type sealing end

Connector stalk Corona shield

Typical design of transformer-type sealing end

Connecting tube

Corona shield

Porcelain insulator

Arcing horn

Filling compound

Filling compound Slip-on stress cone Insulator

Slip-on stress cone Outlet screw or valve connection

Support base

Outlet screw or valve connection

Aluminumbaseplate

Copper entrance bell

Insulating ring Copper entrance bell

Mechanical protection

Mechanical protection

Fig. 41

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 42

5/23

Accessories for High-Voltage Cables up to 290/500 kV

Single-core sectionalized joint Coaxial cable for cross-bonding

Deflector

Conductor shield

Housing

Insulation

Deflector

Fig. 43

All the accessories are listed in the RXS catalog Order No.: A 45050-W2165-D7-X-7600

Typical design of GIS-type sealing end Connection interface according to IEC 859

For further information please contact: Fax: ++49 - 23 31- 35 71 18

Cast-resin insulator

Filling compound

Slip-on stress cone

Copper entrance bell

Outlet screw or valve connection

Mechanical protection

Fig. 44

5/24

Siemens Power Engineering Guide · Transmission & Distribution

Protection and Substation Control

General overview Three trends have emerged in the sphere of substation secondary equipment: intelligent electronic devices (IEDs), open communication and operation with a PC. Numerical relays and cumputerized substation control are now state-of-the-art. The multitude of conventional, individual devices prevalent in the past as well as comprehensive parallel wiring are being replaced by a small number of multifunctional devices with serial connections. One design for all applications In this respect, Siemens offers a uniform, universal technology for the entire functional scope of secondary equipment, both in the construction and connection of the devices and in their operation and communication. This results in uniformity of design, coordinated interfaces and the same operating concept being established throughout, whether in power system and generator protection, in measurement and recording systems, in substation control and protection or in telecontrol. All devices are highly compact and immune to interference, and are therefore also suitable for direct installation in switchgear cells. Furthermore, all devices and systems are largely self-monitoring, which means that previously costly maintenance can be reduced considerably.

Substation

Fig. 1: The digital substation control system SINAUT LSA implements all of the control, measurement and automation functions of a substation. Protection relays are connected serially

“Complete technology from one partner“ The Substation Secondary Equipment Division of the Siemens Power Transmission and Distribution Group supplies devices and systems for: Power System Protection Substation Control Remote Control (RTUs) Measurement and Recording This covers all of the measurement, control and protection functions for substations*. Furthermore, our activities cover:

■ ■ ■ ■

Consulting Planning Design Commissioning and Service This uniform technology ”all from one source“ saves the user time and money in the planning, assembly and operation of his substations.

■ ■ ■ ■

*An exception is revenue-metering. Meters are separate products of our Energy Metering Division.

6/2

Fig. 2a: Protection and control in HV GIS switchgear

Fig. 2b: Protection and control in bay dedicated kiosks of an EHV-switchyard

Rationalisation of operation

by means of SCADA-like operation control and high-performance, uniformly operable PC tools

Savings in terms of space and costs

by means of integrationof many functions into one unit and compact equipment design

Simple planning and operational reliability

by means of uniform design, coordinated interfaces and universally identical EMC

Efficient parameterization and operation

by means of PC tools with uniform operator interface

High levels of reliability and availability

by means of type-tested system technology, complete self-monitoring and the use of poven technology – 20 years of practical experience with digital protection, 50,000 devices in operation (1996) – 10 years of practical LSA678 experience, 400 substations in operation (1996)

Fig. 3: For the user, “complete technology from one source” has many advantages

Siemens Power Engineering Guide · Transmission & Distribution

Protection and Substation Control

Protection and substation control

Local and remote control SINAUT LSA/SINAUT RTU

SINAUT LSA

SINAUT LSA

Local and remote control, centralized version

Local and remote control, decentralized version

6MB551

6MB51/52

Remote terminal units

Central units

Protection 7**5

Measurement and recording

Feeder protection overcurrent/overload relays

Fault recorders (Oscillostores)

7SJ5

P5**

Line protection distance relays

SIMEAS

7SA5

7KG60

Measuring transducers

6MB51* Line protection Unit protection (PW and OF)

SINAUT LSA

Bay units

Compact unit

6MB52*

7SD5

6MB552 Minicompact unit

6MB553

Transformer protection

Switchgear interlocking 8TK

7UT5

Generator/motor protection

SINAUT RTU 6MD2010

7UM5

Busbar protection 7SS5 and 7VH8

Fig. 4: Siemens Protection and Substation Control comprises these systems and product ranges

System Protection Siemens offers a complete spectrum of multifunctional, numerical relays for all applications in the field of network and machine protection. Uniform design and electromagnetic-interferencefree construction in metal housings with conventional connection terminals in accordance with public utility requirements guarantee simple system design and usage just as with conventional relays. Numerical measurement techniques ensure precise operation and necessitate less maintenance thanks to their continuous self-monitoring capability.

The integration of additional protection and other functions, such as real-time operational measurements, event and fault recording, all in one unit economizes on space, design and wiring costs. Setting and programming of the devices can be through the integral, plaintext, menu-guided operator display or by using the comfortable PC program DIGSI for Windows*. Open serial interfaces, IEC 870-5-103 compliant allow free communication with higher level control systems, including those from other manufacturers.

Thus the on-line measurements and fault data registered in the protective relays can be used for local and remote control or can be transmitted via telephone modem connections to the workplace of the service engineer. Siemens supplies individual devices as well as complete protection systems in factory finished cubicles. For complex applications, for example, in the field of extrahigh-voltage transmission, type and design test facilities are available together with an extensive and comprehensive network model using the most modern simulation and evaluation techniques.

* Windows is a registered product of Microsoft

Siemens Power Engineering Guide · Transmission & Distribution

6/3

Protection and Substation Control

Substation control

Switchgear interlocking

■ Rationalized programming and handling

The digital substation control systems 6MB51/52 (decentralized version) and 6MB551 (centralized version) provide all control, measurement and automation functions (e.g. transformer tap changing) required by a switching station. They operate with distributed intelligence. Communication between feeder-located devices and central unit is made via interferencefree fiber optic connections. Devices are extremely compact and can be built directly into medium- and high-voltage switchgear. To input data, set and program the system, the unique PC program LSA-TOOLS is available. Parameters and values are input at the central unit and downloaded to the field devices, thus ensuring error-free and consistent data transfer. The operator interface is menu-guided, with SCADA comparable functions, that is, with a level of comfort which was previously only available in a network control center. Optional telecontrol functions can be added to allow coupling of the system to one or more network control centers. In contrast to conventional controls, digital technology saves enormously on space and wiring. LSA systems are subjected to full factory tests and are delivered in fully functional condition.

The digital interlocking system 8TK is used for important substations in particular with multiple busbar arrangements. It prevents false switching and provides an additional local bay control function which allows failsafe switching, even when the substation control system is not available. Therefore the safety of operating personnel and equipment is considerabely enhanced. The 8TK system can be used as a standalone interlocked control, or as back-up system together with the digital 6MB substation control.

– through menu-guided PC Tools and unified keypads and displays ■ High-level operational security and availability – through continuous self-monitoring and proven technology: – 20 years digital relay experience (approximately 50,000 units in operation) – 10 years of SINAUT LSA substation control (400 systems in operation) ■ Rapid problem solving – through comprehensive advice and fast response from local sales and workshop facilities worldwide.

Remote control Siemens remote control equipment 6MB55* and 6MD2010 fulfills all the classic functions of remote measurement and control. Furthermore, because of the powerful microprocessors with 32-bit technology, they provide comprehensive data preprocessing, automation functions and bulk storage of operational and fault information. In the classic case, connections to the switchgear are made through coupling relays and transducers. This method allows an economically favorable solution when modernizing or renewing the secondary systems in older installations. Alternatively, especially for new installations, direct connection is also possible. Digital protection devices can be connected by serial links through fiber-optic conductors. In addition, the functions ”operating and monitoring“ can be provided by the connection of a PC, thus raising the telecontrol unit to the level of a central station control system. Using the facility of nodal functions, it is also possible to build regional control points so that several substations can be controlled from one location.

6/4

Measurement and recording This segment of our business division offers equipment for the superversion of power supply quality (harmonic content, distortion factor, peak loads, power factor, etc.), fault recorders (Oscillostore), data logging printers and measurement transducers. Stored data can be transmitted manually or automatically to PC evaluation systems where it can be analysed by intelligent programs. Expert systems are also applied here. This leads to rapid fault analysis and valuable indicators for the improvement of network reliability. For local bulk data storage and transmission, the central processor DAKON can be installed at substation level. Data transmission circuits for analog telephone or digital ISDN networks are incorporated as standard. Connection to local- or wide-area networks (LAN, WAN) is equally possible. To complete the spectrum, we have the SIMEAS series of compact and powerful measurement transducers with analog and digital outputs. Advantages for the user The concept of ”Complete technology from one partner“ offers the user many advantages: ■ High-level security for his systems and operational rationalization possibilities – through powerful system solutions with the most modern technology ■ Space and cost savings – through integration of many functions into one unit and compact equipment packaging ■ Simple planning and secure operation – through unified design, matched interfaces and EMI security throughout

Siemens Power Engineering Guide · Transmission & Distribution

Protection and Substation Control

Electromagnetic compatibility

Application hints

EC Conformity declaration (CE mark): All named devices and systems for protection, metering and control are designed to be used in the harsh environment of electrical substations, power plants and the various industrial application areas. When the devices were developed, special emphasis was placed on EMI. The devices are in accordance with IEC255 standards. Detailed information is contained in the device manuals. Reliable operation of the devices is not affected by the usual interference from the switchgear, even when the device is mounted directly in a low-voltage compartment of a medium-voltage cubicle. It must, however, be ensured that the coils of auxiliary relays located on the same panel, or in the same cubicle, are fitted with suitable spike quenching elements (e.g. free-wheeling diodes). When used in conjunction with switchgear for 100 kV or above, all external connection cables should be fitted with a screen grounded at both ends and capable of carrying currents. That means that the cross section of the screen should be at least 4 mm 2 for a single cable and 2.5 mm2 for multiple cables in one cable duct. All equipment proposed in this guide is built-up either in closed housings (type 7XP20) or cubicles with protection degree IP51 according to IEC 529: ■ Protected against access to dangerous parts with a wire ■ Sealed against dust ■ Protected against dripping water Climatic conditions: ■ Permissible temperature during

service –5 °C to +55 °C permissible temperature during storage –25 °C to +55 °C permissible temperature during transport –25 °C to +70 °C Storage and transport with standard works packaging! ■ Permissible humidity Mean value per year ≤ 75% relative humidity; on 30 days per year 95% relative humidity; Condensation not permissible! We recommend that units be installed such that they are not subjected to direct sunlight, nor to large temperature fluctuations which may give rise to condensation.

All Siemens protection and control products, recommended in this guide, comply with the EMC Directive 99/336/EEC of the Council of the European Community and further relevant IEC 255 standards on electromagnetic compatibility. All products carry the CE mark. EMC tests; immunity (type tests) ■ Standards:

Fig. 5: Installation of the numerical protection in the door of the low-voltage section of medium-voltage cells

■

Mechanical stress Vibration and shock during operation ■ Standards:

■

IEC 255-21 and IEC 68-2 ■ Vibration

– sinusoidal IEC 255-21-1, class 1 – 10 Hz to 60 Hz: ± 0.035 mm amplitude; IEC 68-2-6 – 60 Hz to 150 Hz: 0.5 g acceleration sweep rate 10 octaves/min 20 cycles in 3 orthogonal axes

■

■

Vibration and shock during transport ■ Standards:

IEC 255-21and IEC 68-2 ■ Vibration

– sinusoidal IEC 255-21-1, class 2 – 5 Hz to 8 Hz: ± 7.5 mm amplitude; IEC 68-2-6 – 8 Hz to 150 Hz: 2 g acceleration sweep rate 1 octave/min 20 cycles in 3 orthogonal axes ■ Shock IEC 255 -21-2, class 1 IEC 68 -2-27

■

■

■

Insulation tests ■ Standards:

Siemens Power Engineering Guide · Transmission & Distribution

IEC 255-5 – High-voltage test (routine test) 2 kV (rms), 50 Hz – Impulse voltage test (type test) all circuits, class III 5 kV (peak); 1,2/50 µs; 0,5 J; 3 positive and 3 negative shots at intervals of 5 s

■

IEC 255-22 (product standard) EN 50082-2 (generic standard) High frequency IEC 255-22-1 class III – 2.5 kV (peak); 1 MHz; γ = 15 µs; 400 shots/s; duration 2 s Electrostatic discharge IEC 255-22-2 class III and EN 61000-4-2 class III – 4 kV contact discharge; 8 kV air discharge; both polarities; 150 pF; Ri = 330 Ohm Radio-frequency electromagnetic field, nonmodulated; IEC 255-22-3 (report) class III – 10 V/m; 27 MHz to 500 MHz Radio-frequency electromagnetic field, amplitude-modulated; ENV 50140, class III – 10 V/m; 80 MHz to 1000 MHz, 80%; 1 kHz; AM Radio-frequency electromagnetic field, pulse-modulated; ENV 50140/ENV 50204, class III – 10 V/m; 900 MHz; repetition frequency 200 Hz; duty cycle 50% Fast transients IEC 255-22-4 and EN 61000-4-4, class III – 2 kV; 5/50 ns; 5 kHz; burst length 15 ms; repetition rate 300 ms; both polarities; Ri = 50 Ohm; duration 1 min Conducted disturbances induced by radio-frequency fields HF, amplitude-modulated ENV 50141, class III – 10 V; 150 kHz to 80 MHz; 80%; 1kHz; AM Power-frequency magnetic field EN 61000-4-8, class IV – 30 A/m continuous; 300 A/m for 3 s; 50 Hz

6/5

Protection and Substation Control

EMC tests; emission (type tests)

Cores for revenue metering

■ Standard:

In this case, class 0.2 M is normally required.

EN 50081-2 (generic standard) ■ Interference field strength CISPR 11,

EN 55011, class A – 30 MHz to 1000 MHz ■ Conducted interference voltage, aux voltage CISPR 22, EN 55022, class B – 150 kHz to 30 MHz Instrument transformers Instrument transformers must comply with the applicable IEC recommendations IEC 185 (c.t.) and 186 (p.t.), ANSI/IEEE C57.13 or other comparable standards. Potential transformers Potential transformers (p.t.) in single- or double-pole design for all primary voltages have single or dual secondary windings of 100, 110 or 120 V/ 3, with output ratings between 10 and 300 VA, and accuracies of 0.2, 0.5 or 1% to suit the particular application. Primary BIL values are selected to match those of the associated switchgear. Current transformers Current transformers (c.t.) are usually of the single-ratio type with wound or bartype primaries of adequate thermal rating. Single, dual or triple secondary windings of 1 or 5 A are standard. 1 A rating however should be preferred, particularly in HV and EHV stations, to reduce the burden of the connecting leads. Output power (rated burden in VA), accuracy, and saturation characteristics (accuracy limiting factor) of the cores and secondary windings must meet the particular application. The c.t. classification code of IEC is used in the following: Measuring cores They are normally specified with 0.5% or 1.0% accuracy (class 0.5 M or 1.0 M), and an accuracy limiting factor of 5 or 10. The required output power (rated burden) must be higher than the actually connected burden. Typical values are 5, 10, 15 VA. Higher values are normally not necessary when only electronic meters and recorders are connected. A typical specification could be: 0.5 M 10, 15 VA.

Protection cores: The size of the protection core depends mainly on the maximum short-circuit current and the total burden (internal c.t. burden, plus burden of connecting leads, plus relay burden). Further, an overdimensioning factor has to be considered to cover the influence of the d.c. component in the short-circuit current. In general, an accuracy of 1% (class 5 P) is specified. The accuracy limiting factor KALF should normally be designed so that at least the maximum short-circuit current can be transmitted without saturation. (d.c. component not considered). This results, as a rule, in rated accuracy limiting factors of 10 or 20 dependent on the rated burden of the c.t. in relation to the connected burden. A typical specification for protection cores for distribution feeders is 5P10, 15 VA or 5P20, 10 VA. The requirements for protective current transformers for transient performance are specified in IEC 44-6. The recommended calculation procedure for saturationfree design, however, leads to very high c.t. dimensions. In many practical cases, the c.t.s cannot be designed to avoid saturation under all circumstances because of cost and space reasons, particularly with metal-enclosed switchgear. The Siemens relays are therefore designed to tolerate c.t. saturation to a large extent. The numerical relays, proposed in this guide, are particularly stable in this case due to their integral saturation detection function.

RBC + Ri KALF > RBN + Ri

K*ALF

KALF : Rated c.t. accuracy limiting factor K*ALF : Effective c.t. accuracy limiting factor RBN : Rated burden resistance RBC : Connected burden Ri : Internal c.t. burden (resistance of the c.t. secondary winding) with: K*ALF > KOF

Iscc.max. IN

Iscc.max. = Maximum short-circuit current IN = Rated primary c.t. current KOF = Overdimensioning factor Fig. 6: C.t. dimensioning formulas

6/6

The required c.t. accuracy-limiting factor KALF can be determined by calculation, as shown in Fig. 6. The overdimensioning factor KOF depends on the type of relay and the primary d.c. time constant. For the normal case, with short-circuit time constants lower than 100 ms, the necessary value for K*ALF can be taken from the table in Fig. 9. The recommended values are based on extensive type tests. C.t. design according to BS 3938 In this case the c.t. is defined by the kneepoint voltage UKN and the internal secondary resistance Ri. The design values according to IEC 185 can be approximately transferred into the BS standard definition by the following formula:

UKN =

(RNC + Ri) • I2N • KALF 1.3

I2N = Nominal secondary current Example: IEC 185 : 600/1, 15 VA, 5P10, Ri = 4 Ohm (15 + 4) • 1 • 10 = 146 V BS : UKN = 1.3 Ri = 4 Ohm Fig. 7: BS c.t. definition

C.t. design according to ANSI/IEEE C 57.13 Class C of this standard defines the c.t. by its secondary terminal voltage at 20 times nominal current, for which the ratio error shall not exceed 10%. Standard classes are C100, C200, C400 and C800 for 5 A nominal secondary current. This terminal voltage can be approximately calculated from the IEC data as follows:

Vs.t. max = 20 x 5 A x RBN •

KALF 20

with:

RBN = PBN and INsec = 5 A , we get INsec2 Vs.t. max =

PBN • KALF 5

Example: IEC 185 : 600/5, 25 VA, 5P20, 25 • 20 = ANSI C57.13: Vs.t. max = 5 = 100, i.e. class C100 Fig. 8: ANSI c.t. definition

Siemens Power Engineering Guide · Transmission & Distribution

Protection and Substation Control

Relay type

Example: Stability-verification of the numerical busbar protection 7SS5

Minimum K*ALF

o/c protection 7SJ511, 512, 551, 7SJ60

=

Transformer differential protection 7UT512/513

=4.

IHigh set point

Line differential (fiber-optic) protection 7SD511/12

=4.

Line differential (pilot wire) protection 7SD502/503

=4.

Given case:

, at least 20

IN

Iscc. max. (internal fault) IN

[K*ALF . UN . IN](High voltage) and 1 <

1.8 + 4 15 + 4

= 1.8 Ohm

25 = 7.6

l

Fig. 10

Siemens Power Engineering Guide · Transmission & Distribution

Result: The rated KALF-factor (10) is higher than the calculated value (7.6). Therefore, the stability criterium is fulfilled. Fig. 11

6/7

Power System Protection

Introduction Siemens is one of the world’s leading suppliers of protective equipment for power systems. Thousands of our relays ensure first-class performance in transmission and distribution networks of all voltage levels, all over the world, in countries of tropical heat or arctic frost. For many years, Siemens has also significantly influenced the development of protection technology. ■ In 1976, the first minicomputer (process

computer) based protection system was commissioned: A total of 10 systems for 110/20 kV substations were supplied and are still operating satisfactorily today. ■ Since 1985 we have been the first to manufacture a range of fully numerical relays with standardized communication interfaces. Today, Siemens offers a complete program of protective relays for all applications including numerical busbar protection. To date (1996), more than 50,000 numerical protection relays from Siemens are providing successful service, as standalone devices in traditional systems or as components of coordinated protection and substation control. Meanwhile, a second-generation innovative series has been launched, incorporating the many years of operational experience with thousands of relays, together with users’ requirements, (power authority reommendations). State of the art Mechanical and solid-state (static) relays have been almost completely phased out of our production because numerical relays are now preferred by the users due to their decisive advantages: ■ Compact design and lower cost due to integration of many functions into one relay ■ High availability even with less maintenance due to integral self-monitoring ■ No drift (aging) of measuring characteristics due to fully numerical processing ■ High measuring accuracy due to digital filtering and optimized measuring algorithms

6/8

Fig. 12: Numerical relay range of Siemens ■ Many integrated add-on functions,

for example, for load-monitoring and event/fault recording ■ Easy and secure read-out of information via serial interfaces with a PC, locally or remotely ■ Possibility to communicate with higherlevel control systems

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

21

67N

FL

79

25

SM

ER

FR

BM

85

Serial link to station – or personal computer to remote line end

21 67N FL 79 25 85 SM ER FR BM

Distance protection Directional ground-fault protection Distance-to-fault locator Autoreclosure Synchro-check Carrier interface (teleprotection) Self-monitoring Event recording Fault recording Breaker monitor

kA, kV, Hz, MW, MVAr, Load monitor MVA,

01.10.93

Fault report Fault record Relay monitor Breaker monitor Supervisory control

Fig. 13: Numerical relays, increased information availability

Modern protection management All the functions, for example, of a line protection scheme can be incorporated in one unit:

All relays can stand fully alone. Thus the traditional protection concept of separate main and alternate protection as well as the external connection to the switchyard remain unchanged.

■ Distance protection with associated

add-on and monitoring functions ■ Universal teleprotection interface ■ Autoreclose and synchronism check

Protection-related information, can be called up on-line or off-line such as: ■ Distance to fault ■ Fault currents and voltages ■ Relay operation data (fault detector pickup, operating times etc.) ■ Set values ■ Line load data (kV, A, MW, kVAr) To fulfill vital protection redundancy requirements, only those functions which are interdependent and directly associated with each other are integrated in the same unit. For back-up protection, one or more additional units have to be provided.

”One feeder, one relay“ concept Analog protection schemes have been engineered and assembled from individual relays. Interwiring between these relays and scheme testing has been carried out manually in the workshop. Data sharing now allows for the integration of several protection and protection related tasks into one single numerical relay. Only a few external devices may be required for completion of the total scheme. This has significantly lowered the costs of engineering, assembly, panel wiring, testing and commissioning. Scheme failure probability has also been lowered. Engineering has moved from schematic diagrams towards a parameter definition procedure. The documentation is provided by the relay itself. Free allocation of LED operation indicators and output contacts provides more application design flexibility.

Siemens Power Engineering Guide · Transmission & Distribution

Metering included For many applications, the protective-current transformer accuracy is sufficient for operational metering. The additional metering c.t. was more for protection of meters under system fault conditions. Due to the low thermal withstand ability of the meters, they could not be connected to the protection c.t.. Consequently, additional metering c.t.s and meters are now only necessary where high accuracy is required, e.g. for revenue metering.

6/9

Power System Protection

On-line remote data exchange A powerful serial data link provides for interrogation of digitized measured values and other information, stored in the protection units, for printout and further processing at the substation or system control level. In the opposite direction, settings may be altered or test routines initiated from a remote control center. For greater distances, especially in outdoor switchyards, fiber-optic cables are preferably used. This technique has the advantage that it is totally unaffected by electromagnetic interference.

Recording

Personal computer

Assigning

Protection

Laptop

Off-line dialog with numerical relays A simple built-in operator panel which requires no special software knowledge or codeword tables is used for parameter input and readout. This allows operator dialog with the protection relay. Answers appear largely in plaintext on the display of the operator panel. Dialog is divided into three main phases:

Recording and confirmation

Fig. 14: PC-aided setting procedure

■ Input, alternation and readout of settings ■ Testing the functions of the protection

device and

to remote control

System level

■ Readout of relay operation data for the

three last system faults and the autoreclose counter.

Substation level

Modern system protection management A more versatile notebook computer may be used for upgraded protection management. The relays may be set in 2 steps. First, all relay settings are prepared in the office with the aid of a PC and stored on a floppy or the hard disk. At site, the settings can then be transferred from a portable PC into the relay. The relay confirms the settings and thus provides an unquestionable record. Vice versa, after a system fault, the relay memory can be uploaded to a PC and comprehensive fault analysis can then take place in the engineer’s office.

Coordinated protection & control

Modem (option)

ERTU

RTU

Data concentrator

Bay level

Relay

Control

Fig. 15: Communication options

6/10

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

Relay data management Analog-distribution-type relays have some 20–30 setpoints. If we consider a power system with about 500 relays, then the number adds up to 10,000 settings. This required considerable expenditure in setting the relays and filing retrieval setpoints. A personal computer-aided man-machine dialog and archiving program assists the relay engineer in data filing and retrieval. The program files all settings systematically in substation-feeder-relay order.

Setpoints

Relay operations

10 000 setpoints 1 system ca. 500 relays

20 setpoints

system

1 sub

4 flags

1 bay

bay OH-Line

Fig. 16: System-wide setting and relay operation library

1000 Adaptive relaying Numerical relays now offer secure, convenient and comprehensive matching to changing conditions. Matching may be initiated either by the relay’s own intelligence or from the outside world via contacts or serial telegrams. Modern numerical relays contain a number of parameter sets that can be pretested during commissioning of the scheme (Fig. 17). One set is normally operative. Transfer to the other sets can be controlled via binary inputs or serial data link. There are a number of applications for which multiple setting groups can upgrade the scheme performance, e.g. a) for use as a voltage-dependent control of o/c relay pick-up values to overcome alternator fault current decrement to below normal load current when the AVR is not in automatic operation. b) for maintaining short operation times with lower fault currents, e.g. automatic change of settings if one supply transformer is taken out of service. c) for “switch-onto-fault” protection to provide shorter time settings when energizing a circuit after maintenance. The normal settings can be restored automatically after a time delay.

300 faults p. a. ca. 6,000 km OHL (fault rate: 5 p. a. and 100 km)

200 setpoints

Corrective rather than preventive maintenance Numerical relays monitor their own hardware and software. Exhaustive self-monitoring and failure diagnostic routines are not restricted to the protective relay inself, but are methodically carried through from current transformer circuits to tripping relay coils. Equipment failures and faults in the c.t. circuits are immediately reported and the protective relay blocked. Thus the service personnel is now able to correct the failure upon occurrence, resulting in a significantly upgraded availability of the protection system.

1200 flags p. a.

1000 1000 1000 1100 1200 1500 2800 3900

Parameter

1100 ParameterLine data

D

C

1100 Line data O/C Phase settings 1200 Parameter

B

1100 Line data O/C Phase settings 1200 Parameter 1500 O/C Earth settings A Line data 1200 O/C PhaseO/C settings settings 1500 2800 EarthFault Recording O/C Phase settings 1500 O/C EarthFault settings 2800 3900 Recording Breaker Fall O/C Ground settings 2800 Fault Recording 3900 Breaker Fall Fault recording 3900 Breaker Fall Breaker fail

Fig. 17: Alternate parameter groups

d) for autoreclose programs, i.e. instantaneous operation for first trip and delayed operation after unsuccessful reclosure. e) for cold load pick-up problems where high starting currents may cause relay operation. f) for ”ring open“ or ”ring closed“ operation.

Siemens Power Engineering Guide · Transmission & Distribution

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Power System Protection

PC interface LSA interface

Meas. inputs

Input filter

Current inputs (100 x /N, 1 s)

Amplifier

Input/output ports

V24 O. F. Serial interface

Binary inputs

Alarm relay

Command relay Voltage inputs (140 V continuous)

100 V/1 A, 5 A analog

Processor system

A/D converter 0001 0101 0011

10 V analog

Memory: RAM EEPROM EPROM

Input/ output units

digital

LED displays

Input/output contacts

Fig. 18: Block diagram of numerical protection

Mode of operation Numerical protection relays operate on the basis of numerical measuring principles. The analog measured values of current and voltage are decoupled galvanically from the plant secondary circuits via input transducers (Fig. 18). After analog filtering, the sampling and the analog-to-digital conversion take place. The sampling rate is, depending on the different protection principles, between 12 and 20 samples per period. With certain devices (e.g. generator protection) a continuous adjustment of the sampling rate takes place depending on the actual system frequency. The protection principle is based on a cyclic calculation algorithm, utilizing the sampled current and voltage analog measured values. The fault detections determined by this process must be established in several sequential calculations before protection reactions can follow. A trip command is transferred to the command relay by the processor, utilizing a dual channel control. The numerical protection concept offers a variety of advantages, especially with regard to higher security, reliability and user friendliness, such as:

6/12

■ High measurement accuracy:

The high ultilization of adaptive algorithms produce accurate results even during, problematic conditions ■ Good long-term stability: Due to the digital mode of operation, drift phenomena at components due to ageing do not lead to changes in accuracy of measurement or time delays ■ Security against over- and underfunction With this concept the danger of an undetected error in the device causing protection failure in the case of a network fault is clearly reduced when compared to conventional protection technology. Cyclical and preventive maintenance services have therefore become largely obsolete. The integrated self-monitoring system (Fig. 19) encompasses the following areas: – Analog inputs – Microprocessor system – Command relays. Setting of protection relays Numerical protection devices are able to handle a number of additional protection related functions, for which additional devices were required in the past.

A compact numerical protection device can replace a number of complicated conventional single devices.

Protection functions, configurations and marshalling data are selected by parameter setting. Functions can be activated or deactivated by configuration. By marshalling internal logic alarms (which are produced by certain device functions on the software side) to light-emitting diodes or to alarm relays, an allocation between these can be made (Fig. 20). The same also applies to the input contacts. A flexible application according to the specific requirements of the plant configuration is possible thanks to the extensive marshalling and configuration options. All set values are stored in E2PROMS. In this way the settings cannot be lost as a result of supply failure. The setting values are accessed via 4-digit addresses. Each parameter can be accessed and altered via the integrated operator panel or an externally connected operator terminal.

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

The display appears on an alphanumeric LCD display with 2 lines with 16 characters per line. A code word prevents unintentional changes of setting values. Some relays allow for the storage of 4 different sets of protection settings. Via binary inputs or via the operator panel a particular set of setting values can be activated (switching of settings groups).

Plausibility check of input quantities e.g. iL1 + iL2 + iL3 = iE uL1 + uL2 + uL3 = uE

Check of analog-to-digital conversion by comparison with converted reference quantities

A

Fault analysis

D

Microprocessor system

Hardware and software monitoring of the microprocessor system incl. memory, e.g. by watchdog and cyclic memory checks

Relay

Monitoring of the tripping relays operated via dual channels

■ 1 operational event memory

Tripping check or test reclosure by local or remote operation (not automatic)

Fig. 19: Self-monitoring system

Logical signal Start L1 Start L2 Start L3 Start E Trip Autoreclosure . . . LED No.

...

LED 7

LED 6

LED 5

LED 4

LED 3

LED 2

The evaluation of faults is simplified by numerical protection technology. In the event of a fault in the network, all events as well as the analog traces of the measured voltages and currents are recorded. The following types of memory are available:

LED 1

Alarms that are not directly assigned to a fault in the network (e.g. monitoring alarms, alternation of a set value, blocking of the automatic reclose function). ■ 3 fault-event histories Alarms that occurred during the last 3 faults on the network (e.g. type of fault detection, trip commands, fault location, autoreclose commands). A reclose cycle with one or more reclosures is treated as one fault history. Each new fault in the network overrides the oldest fault history. ■ A memory for the fault recordings for voltage and current. Up to 8 fault recordings are stored. The fault recording memory is organized as a ring buffer, i.e. a new fault entry overrides the oldest fault record. ■ 1 earth-fault event memory (optional for isolated or resonant grounded networks) Event record of the sensitive earth fault detector (e.g. faulted phase, real component of residual current). The time tag attached to the fault-record events is a relative time from fault detection with a resolution of 1 ms. In the case of devices with integrated, battery back-up clock the operational events as well as the fault detection are assigned the internal clock time and date stamp. The memory for operational events and fault record events is protected against failure of auxiliary supply with battery back-up supply. The integrated operator interface or a PC supported by the programming tool DIGSI is used to retrieve fault reports as well as for the input of settings and marshalling.

Fig. 20: Marshalling matrix, LED control as an example

Siemens Power Engineering Guide · Transmission & Distribution

6/13

Power System Protection

A further source of information is the indication via LEDs and alarm relays, as was the case with traditional relays. The LEDs can be selected on an individual basis to provide the indication stored or unstored, depending on what information they represent. In the case of devices with internal battery back-up, the LED indications are restored following an auxiliary power supply failure. The alarm relays in these devices provide N0-type contacts, some of them changeover contacts. Operation of numerical protection devices The DIGSI operation software enables convenient and transparent operation of the numerical protection devices using a PC. The new DIGSI V3 version operates under WINDOWS and can therefore make use of all advantages of this internationally accepted user interface. DIGSI V3 uses protocol-secured data exchange between PC and protection device. This data exchange also meets the standard recommendations for the interface between protection equipment and station control equipment (IEC 870-5-103).

Fig. 21: Operation of the protection relays using PC and DIGSI V3 software program

Application DIGSI V3 is a WINDOWS PC program, with which numeric protection relays can be conveniently operated under menu guidance using the serial interface of a PC (see Fig. 21). The PC can thus be directly connected with the protection device via a V24 (RS232) interface cable. The isolated connection version using optoelectrical converter and fiber-optic cable is recommended, particularly if the protection device is in operation in the substation. Hardware and software platform ■ PC 386 SX or above, with at least

4 Mbytes RAM ■ DIGSI V3 requires about 10 Mbytes ■ ■ ■

■ ■

Fig. 22: Parameterization using DIGSI V3

harddisk space Additional hard-disk space per installed protection device 2 to 3 Mbytes One free serial interface to the protection device (COM 1 to COM 4) One floppy disk drive 3.5", high density with 1.44 Mbytes (required for installation) MS DOS 5.0 or higher WINDOWS version 3.1 or higher

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Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

Operation features The DIGSI V3 user interface is structured in accordance with the SAA/CUA standard used for WINDOWS programs (see Fig. 22). The selection of a system, a feeder and a protection device is implemented in DIGSI V3, using system, bay and protection unit addresses. Consistent use of this principle, which will be supported in future both in protection devices and DIGSI file management, prevents incorrect allocation of protection units within a system. DIGSI V3 supports the complete parameterization and marshalling functionality of the numeric Siemens protection relays. Parameterization and routing of a protection device can be done in file mode. All advanced storage media for management and archiving of this data (e.g. memory cards, exchangeable hard disks, optodisks, etc.) are provided. Device files of a protection unit created in the office can be transferred subsequently with protocolsecurity into the protection unit. Data consistency is ensured, for example, by automatic comparison of data stored on a file and in the device. DIGSI V3 permits the readout of operational and fault events from a protection device which are stored with a 1 millisecond realtime resolution. This enables effective and rapid fault analysis, which contributes to optimization of protection in network operation. Archiving and printout are conveniently supported. The polling procedure is defined as a standard. Likewise, measured load values of a protection device can be read out on-line and recorded. Integration of extensive test functions facilitate the PC-guided commissioning and testing of a protection device. Printer, plotter, networks DIGSI V3 uses the full WINDOWS interface functionality. All common printers and plotters for which WINDOWS drivers are available can be used with DIGSI V3. The user is therefore not faced with any restrictions when purchasing printers or plotters as long as WINDOWS drivers are available. Even transmission of information via fax from DIGSI V3 can be implemented. Linking into the PC network and remote access to DIGSI V3 via communication networks (e.g. ISDN) are part of the framework as supported by the WINDOWS operating system.

Fig. 23: Display and evaluation of a fault record using DIGSI V3

Evaluation of the fault recording

Data security, data interfaces

Readout of the fault record from the protection device by DIGSI V3 is done by fault-proof scanning procedures in accordance with the standard recommendation for transmission of fault records. A fault record can also be read out repeatedly. In addition to analog values, such as voltage and current, binary tracks can also be transferred and presented. DIGSI V3 is supplied together with the DIGRA (Digsi Graphic) program, which provides the customer with full graphical operating and evaluation functionality like that of the digital fault recorders (Oscillostores) from Siemens (see Fig. 23). Real-time presentation of analog disturbance records, overlaying and zooming of curves, visualization of binary tracks (e.g. trip command, reclose command, etc.) are also part of the extensive graphical functionality as are setting of measurement cursors, spectrum analysis and R/X derivation.

DIGSI V3 is a closed system as far as protection parameter security is concerned. The security of the stored data of the operating PC is ensured by checksums. This means that it is only possible to change data with DIGSI V3, which subsequently calculates a checksum for the changed data and stores it with the data. Changes in the data and thus in safety-related protection data are thus reliably detected. DIGSI V3 is, however, also an open system. The data export function supports export of parameterization and marshalling data in standard ASCII format. This permits simple access to these data by other programs, such as test programs without endangering the security of data within the DIGSI program system. With the import and export of fault records in IEEE standard format COMTRADE (ANSI) a high performance data interface is produced which supports import and export of fault records into the DIGSI V3 partner program DIGRA. This enables the export of fault records from Siemens protection units to customer-specific programs via the COMTRADE format.

Siemens Power Engineering Guide · Transmission & Distribution

6/15

Power System Protection

Remote relay interrogation The numerical relay range 7**5 of Siemens can also be operated from a remotely located PC via modem-telephone connection. Up to 254 relays can be addressed via one modem connection if the star coupler 7XV53 is used as a communication node (Fig. 24). The relays are connected to the star coupler via optical fiber links. Every protection device which belongs to a DIGSI V3 substation structure has a unique address. The attached relays are always listening, but only the addressed one answers to the operator command which comes from the central PC. If the relay which is located in a station is to be operated from a remote office, then a device file is opened in DIGSI (V3.2 or higher) and protection dialog is chosen via modem. After password input, DIGSI establishes a connection to the protection device after receiving a call-back from the system. In this way secure and timesaving remote setting and readout of data are possible. Diagnostics and control of test routines are also possible without the need for visiting the substation.

Office Analog ISDN DIGSI V3 PC, remotely located

Modem

Substation Star coupler DIGSI V3 PC,centrally located in the substation (option)

7XV53

Modem, optionally with call-back function

Signal converter opt. RS485 Bus

RS485

7SJ60

7SJ60

7**5

7**5

7SJ60

Housing and terminal system The protection devices and the corresponding supplementary devices are available mainly in 7XP20 housings (Fig. 26). The dimension drawings are to be found on 6/24 and following pages. Installing of the modules in a cubicle without the housing is not permissible. The width of the housing conforms to the 19" system with the divisions 1/6, 1/3, 1/2 or 1/1 of a 19" rack. The termination module is located at the rear of devices for panel flush mounting or cubicle mounting (Fig. 26 left). Each termination may be made via a screw terminal or crimp contact. The termination modules used each contain: ■ 4 termination points for measured voltages, binary inputs or relay outputs (max. 1.5 mm2) or ■ 2 termination points for measured currents (screw termination max. 4 mm, crimp contact max. 2.5 mm 2) or ■ 2 FSMA plugs for fiber-optic termination. For mounting of devices into cubicles, the 8MC cubicle system is recommended. It is described in Siemens Catalog NV21.

6/16

Fig. 24: Remote relay communication

The standard cubicle has the following dimensions: 2200 mm x 900 mm x 600 mm (HxWxD). These cubicles are provided with a 44 U high mounting rack (standard height unit U = 44.45 mm). It can swivel as much as 180° in a swing frame. The rack provides for a mounting width of 19", allowing, for example, 2 devices with a width of 1/2 x 19" to be mounted. The devices in the 7XP20 housing are secured to rails by screws. Module racks are not required. To withdraw crimp contact terminations, the following tool is recommended: extraction tool No. 135900 (from Messrs. Weidmüller, Paderbornstrasse 157, D-32760 Detmold). In the housing version for surface mounting, the terminations are wired up on terminal strips on the top and bottom side of the device (max. terminated wire cross section 7 mm 2). For this purpose two-tier terminal blocks are used to attain the required number of terminals (Fig. 26 right).

According to IEC 529 the degree of protection is indicated by the identifying IP, followed by a number for the degree of protection. The first digit indicates the protection against accidental contact and ingress of solid foreign bodies, the second digit indicates the protection against water. 7XP20 housings are protected against access to dangerous parts with a wire, dust and dripping water (IP 51).

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

1/6

1/3

1/2

1/1 of 19" width

Fig. 25: Numerical protection relays in 7XP20 standard housings

Fig. 26 left: Connection method for panel flash mounting including fiber-optic interfaces; right: Connection method for panel surface mounting

Siemens Power Engineering Guide · Transmission & Distribution

6/17

Power System Protection

Autoreclose + Synchrocheck

Synchronizing

7VK512

7VE51

7SV512

7RW600

–

–

–

–

–

–

–

–

–

–

– ■

■ –

–

–

–

–

– –

–

– –

21

Distance protection, phase

■ ■ –

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

– –

–

– ■

–

–

–

–

21N

Distance protection, ground

■ ■ –

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

– –

–

– –

–

–

–

–

24

Overfluxing

– – –

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

– –

– ■ –

–

–

–

■

25

Synchronism check

■ ■ –

–

–

–

–

–

–

–

– –

– –

–

–

–

–

–

– –

– –

■

–

–

–

Synchronizing

–

– –

–

–

–

–

–

–

–

– –

– –

–

–

–

–

–

– –

– –

–

■ –

–

7SJ60 7SJ511 7SJ512 7SJ55 7SJ531

7SA511 7SA513 7SD24 7SD502 7SD503 7SD511 7SD512

Protection functions

Breaker failure

Differential 7VH80 7UT512 7UT513 7SS50/51 7VH83

Zero speed and underspeed dev. – – –

Type

Overcurrent

14

Distance

Motor protection

Voltage, Frequency

Generator protection 7UM511 7UM512 7UM515 7UM516

–

7SJ551 7SJ60

Fiber-optic current comparison

Pilot wire differential

Relay Selection Guide

ANSI Description No.*

Undervoltage

–

– –

–

–

–

–

–

–

–

– ■

■ –

–

–

–

–

–

■ ■ ■ –

–

–

–

■

27/59/ U/f protection 81

–

– –

–

–

–

–

–

–

–

– –

– –

–

–

–

–

–

– – ■ –

–

–

–

■

32

Directional power

–

– –

–

–

–

–

–

–

– –

–

– –

– –

–

– –

■ –

– ■

–

–

–

–

32F

Forward power

–

– –

–

–

–

–

–

–

– –

–

– –

– –

–

– –

■ ■ – ■

–

–

–

–

32R

Reverse power

–

– –

–

–

–

–

–

–

– –

–

– –

– –

–

– –

■ ■ – ■

–

–

–

–

37

Undercurrent or underpower

–

– –

–

–

–

–

–

–

– – ■

■ –

– –

–

– –

– ■ – –

–

–

–

–

40

Field failure

–

– –

–

–

–

–

–

–

– –

–

– –

– –

–

– –

■ –

– –

–

–

–

–

46

Load unbalance, negative phase sequence overcurrent

–

– –

–

–

–

–

–

–

– – ■

■ ■

– –

–

– –

■ ■ – ■

–

–

–

–

47

Phase sequence voltage

■ ■ –

–

–

–

–

–

–

–

– –

– –

–

–

–

– –

–

–

– –

–

–

–

–

48

Incomplete sequence, locked rotor, failure to accelerate

–

–

–

–

–

–

–

–

– ■

■ ■

–

–

–

– –

–

–

– –

–

–

–

–

49

Thermal overload

■ – –

■ ■ ■ ■

■ ■ ■ – ■

■ ■

– ■ ■

– –

■ –

–

–

–

–

–

–

49R

Rotor thermal protection

–

– –

–

–

–

–

–

–

–

– ■

■ ■

– –

–

– –

– –

–

–

–

–

–

–

49S

Stator thermal protection

–

– –

–

–

–

–

–

–

–

– ■

■ ■

– –

–

– –

■ –

–

–

–

–

–

–

50

Instantaneous overcurrent

–

– –

–

–

–

–

■ ■ ■ ■ ■

■ ■

– ■ ■

– –

■ –

–

–

–

–

–

–

50N

Instantaneous ground fault overcurrent

–

– –

–

–

–

–

■ ■ ■ – ■

■ ■

– –

–

– –

– –

–

–

–

–

–

–

51G

Ground overcurrent relay

–

– –

–

–

–

–

■

■ ■

– ■

–

– –

– ■ ■ –

–

–

–

–

27

– –

–

– – ■

* ANSI/IEEE C 37.2: IEEE Standard Electrical Power System Device Function Numbers

Fig. 27a

6/18

Siemens Power Engineering Guide · Transmission & Distribution

Overcurrent

Motor protection

Differential

Generator protection

Autoreclose + Synchrocheck

Synchronizing

Breaker failure

Voltage, Frequency

7SJ60 7SJ511 7SJ512 7SJ55 7SJ531

7SJ551 7SJ60

7VH80 7UT512 7UT513 7SS50/51 7VH83

7UM511 7UM512 7UM515 7UM516

7VK512

7VE51

7SV512

7RW600

– – –

– –

–

–

– – ■

■ –

–

–

– –

■ ■ ■ –

–

–

–

–

51

Overcurrent with time delay

– – –

■ ■ ■ ■ ■ ■

■ – ■

■ –

–

■ ■ – –

■ ■ – ■

–

–

–

–

51N

Ground-fault overcurrent with time delay

■ ■ –

– – ■ ■ ■ ■

– – ■

■ –

–

–

–

– –

■ ■ – –

–

–

–

–

59

Overvoltage

– ■ –

–

–

–

–

–

–

– – ■

■ –

–

–

–

– –

■ ■ ■ –

–

–

–

■

59N

Residual voltage ground-fault protection

–

–

–

–

–

–

–

■ – ■

–

–

–

–

–

– –

■ – ■ ■

–

–

–

–

64R

Rotor ground fault

– – –

– –

–

–

–

–

– – –

– –

–

–

–

– –

■ ■ ■ –

–

–

–

–

67

Directional overcurrent

– – –

– –

–

–

–

–

■ – ■

– –

–

–

–

– –

–

–

– –

–

–

–

–

67N

Directional ground-fault overcurrent

■ ■ –

– –

–

–

–

–

■ – ■

■ –

–

–

–

– –

–

–

– –

–

–

–

–

67G

Stator ground-fault, directional overcurrent

–

– –

–

– –

–

–

–

– – –

– –

–

–

–

– –

– ■ – –

–

–

–

–

68/78 Out-of-step protection

■ ■ –

–

– –

–

–

–

– – –

– –

–

–

–

– –

–

–

–

–

–

–

79

Autoreclose

■ ■ –

–

–

– ■

■ –

■ ■ ■

–

–

– –

–

– –

–

– –

–

■

–

–

–

81

Frequency relay

–

– –

–

–

–

–

–

–

– – –

–

–

– –

–

– – ■ ■ ■ –

–

–

–

■

85

Carrier interface

■ ■ –

–

–

–

–

–

–

– – –

–

–

– –

–

– –

–

– –

–

–

–

–

–

86

Lockout relay, start inhibit

–

– –

–

–

–

–

–

–

– – ■

■

–

– –

–

– –

–

– –

–

–

–

–

–

87G

Differential protection, generator –

– –

–

–

–

–

–

–

– – –

–

–

– ■ ■

– –

–

– –

–

–

–

–

–

87T

Differential protection, transf.

–

– –

–

–

–

–

–

–

– – –

–

–

– ■ ■

– –

–

– –

–

–

–

–

–

87B

Differential protection, bus-bar

–

– –

–

–

–

–

–

–

– – –

–

–

– –

–

■ ■

– – – –

–

–

–

–

87M

Differential protection, motor

–

– –

–

–

–

–

–

–

– – –

–

–

– ■ ■

– ■

– – – –

–

–

–

–

87L

Differential protection, line

–

– ■ ■ ■ ■ ■

–

–

– – –

–

–

– –

–

– –

– – – –

–

–

–

–

87N

Restricted earth-fault protection

–

– –

–

–

–

–

–

–

– – –

–

–

■ –

■

– –

– – – –

–

–

–

–

92

Voltage and power directional rel. –

– –

–

–

–

–

–

–

– – –

–

–

– –

–

– –

– – – –

–

–

–

–

BF

Breaker failure

– ■ –

–

–

–

–

– ■ ■ – ■

–

–

– –

–

■ –

– – – –

–

–

■

–

Type Protection functions

Fiber-optic current comparison

51GN Stator ground-fault overcurrent

Distance

7SA511 7SA513 7SD24 7SD502 7SD503 7SD511 7SD512

Pilot wire differential

Power System Protection

ANSI Description No.*

– –

–

–

–

– ■

* ANSI/IEEE C 37.2: IEEE Standard Electrical Power System Device Function Numbers

Fig. 27b

Siemens Power Engineering Guide · Transmission & Distribution

6/19

Power System Protection

Protection relays Siemens manufactures a complete series of numerical relays for all kinds of protection application. The series is briefly portrayed on the following pages. 7SJ60 Universal overcurrent and overload protection ■ Phase-segregated measurement and

indication (Input 3 ph, IE calculated) ■ All instantaneous, i.d.m.t. and d.t.

■ ■ ■ ■ ■

characteristics can be set individually for phase and ground faults Selectable setting groups Integral autoreclose function (option) Thermal overload, unbalanced load and locked rotor protection Suitable for busbar protection with reverse interlocking With load monitoring, event and fault memory

* only with 7SJ512 50

50N

49

48

50

50N

BF

51

51N

46

79

51

51N

67

67N *

79

* *

7SJ511 Fig. 28: 7SJ60

Fig. 29: 7SJ511/512

Universal overcurrent protection ■ Phase-segregated measurement and ■ ■ ■ ■

indication (3 ph and E) I.d.m.t and d.t. characteristics can be set individually for phase and ground faults Suitable for busbar protection with reverse interlocking With integral breaker failure protection With load monitoring, event and fault memory

7SJ512 Digital overcurrent-time protection with additional functions the same features as 7SJ511, plus: ■ Autoreclose ■ Sensitive directional ground-fault protection for isolated, resonant or high-resistance grounded networks ■ Directional module when used as directional overcurrent relay (optional) ■ Selectable setting groups ■ Inrush stabilization

7SA511 Subtransmission line protection with distance-to-fault locator Universal distance relay for all networks, with many additional functions, amongst others ■ Universal carrier interface (permissive

and blocking procedures programmable) ■ Power swing blocking or tripping ■ Selectable setting groups ■ Sensitive directional ground-fault deter-

■ ■ ■ ■ ■ ■

mination for isolated and compensated networks Ground-fault protection for earthed networks Single and three-pole autoreclose Synchrocheck Free marshalling of optocoupler inputs and relay outputs Line load monitoring, event and fault recording Thermal overload protection

21

25

67N

68

49

21N

85

51N

78

79 47

Fig. 30: 7SA511

6/20

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

7SA513 Transmission line protection with distance-to-fault locator ■ Fast distance protection, with operating

■ ■ ■ ■

■ ■ ■ ■ ■ ■ ■

■ ■ ■ ■

times less than one cycle (20 ms at 50 Hz), with a package of extra functions which cover all the demands of extrahigh-voltage applications Universal carrier interface (permissive and blocking procedures programmable) Power swing blocking or tripping Parallel line compensation Load compensation that ensures high accuracy even for high-resistance faults and double-end infeed High-resistance ground-fault protection Back-up ground-fault protection Overvoltage protection Single- and three-pole autoreclose Synchrocheck option Breaker failure protection Free marshalling of a comprehensive range of optocoupler inputs and relay outputs Selectable setting groups Line load monitoring, event and fault recording High-performance measurement using digital signal processors Flash EPROM memories

21

25

67N

BF

79

21N

59

85

68

78

Fig. 31: 7SA513

7SD511 Current-comparison protection for overhead lines and cables ■ With phase-segregated measurement ■ For serial data transmission

■ ■ ■

■

(19.2 kbits/sec) – with integrated optical transmitter/ receiver for direct fiber-optic link up to approx. 15 km distance – or with the additional digital signal transmission device 7VR5012 up to 150 km fiber-optic length – or through a 64 kbit/s channel of available multipurpose PCM devices, via fiber-optic or microwave link Integral overload and breaker failure protection Emergency operation as overcurrent back-up protection on failure of data link Automatic measurement and correction of signal transmission time, i.e. channelswapping is permissible Line load monitoring, event and fault recording

87L

51

49

BF

50

Fig. 32: 7SD511

87L

51

60

49

BF

79

Fig. 33: 7SD512

7SD512 Current-comparison protection for overhead lines and cables with functions as 7SD511, but additionally with autoreclose function for single- and three-pole fast and delayed autoreclosure.

Siemens Power Engineering Guide · Transmission & Distribution

6/21

Power System Protection

7UT512 Differential protection for machines and power transformers with additional functions, such as: ■ Numerical matching to transformer ratio and connection group (no matching transformers necessary) ■ Thermal overload protection ■ Back-up overcurrent protection ■ Measured-value indication for commissioning (no separate instruments necessary) ■ Load monitor, event and fault recording 7UT513 Differential protection for three-winding transformers with the same functions as 7UT512, plus: ■ Sensitive restricted ground-fault protection ■ Sensitive d.t. or i.d.m.t. ground-fault – o/c-protection 7SS5 Numerical busbar protection

*

87 T

49

Fig. 34: 7UT512

50/51

87T

50G

49

50/51

87 * REF

* 87REF or 50G

Fig. 35: 7UT513

■ With absolutely secure 2-out-of-2 meas-

■ ■ ■ ■ ■

■ ■

urement and additional check zone, each processed on separate microprocessor hardware With fast operating time (< 15 ms) Extreme stability against c.t. saturation Completely self-monitoring, including c.t. circuits, isolator positions and run time With integrated circuit-breaker failure protection With commissioning-friendly aids (indication of all feeder, operating and stabilizing currents) With event and fault recording Designed for single and multiple busbars, up to 8 busbar sections and 32 bays

7UM511/12/15/16 Multifunctional devices for machine protection ■ With 10 protection functions on average,

with flexible combination to complete protection systems from the smallest to the largest motor generator units ■ With improved measurement methods based on Fourier filters and the evaluation of symmetrical components (fully numeric, frequency compensated) ■ With load monitoring, event and fault recording

6/22

Fig. 37: Protection operation with the PC operator program DIGSI

87 BB Fig. 36: 7SS5

BF See separate reference list for machine protection. Order No. E50001-U321-A39-X-7600

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

7VE51 Paralleling device for synchronization of generators and networks ■ Absolutely secure against faulty switching due to duplicate measurement with different procedures ■ With numerical measurand filtering that ensures exact synchronization even in networks suffering transients ■ With synchrocheck option ■ Available in two versions: 7VE511 without, 7VE512 with voltage and frequency balancing Combined bay protection and control unit 7SJ531

50

50N

79

49

59

27

49R

51N

51

51N

67N

49LR

27

37

50

59

48

51

64

BF

46

37

46

50G

86

49

51G

Line protection ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

Non directional time overcurrent Directional time overcurrent IEC/ANSI and user definable TOC curves Overload protection Sensitive directional ground fault Negative sequence overcurrent Under/Overvoltage Breaker failure Autoreclosure Fault locator

Motor protection ■ ■ ■ ■

Thermal overload Locked rotor Start inhibit Undercurrent

Control functions Measured-value acquisition Signal and command indications P, Q, cos ϕ and meter-reading calculation Measured-value recording Event logging Switching statistics Feeder control diagram with load indication ■ Switchgear interlocking ■ ■ ■ ■ ■ ■ ■

Fig. 38: 7SJ531

Fig. 39: 7SJ551

– up to 2 heating time constants for the stator thermal replica – separate cooling time constants for stator and rotor thermal replica – ambient temperature biasing of thermal replica ■ Connection of up to 8 RTD sensors ■ Multi-curve overcurrent and ground-fault protection: – four selectable i.d.m.t. and d.t. curves for phase faults, two for ground-faults – customized curves instead of standard curves can be programmed to offer optimal flexibility for both phase and ground elements ■ Real-Time Clock: last 3 events are stored with real-time stamps of alarm and trip data

87L

50

7SD502

49

51

■ Pilot-wire differential protection for

7SJ551 Universal motor protection and overcurrent relay ■ Thermal overload protection

– separate thermal replica for stator and rotor based on true RMS current measurement

lines and cables (2 pilot wires)

Fig. 40: 7SD502/503

■ Up to about 25 km telephone-type pilot

length ■ With integrated overcurrent back-up

7SD503

and overload protection ■ Also applicable to 3-terminal lines (2 devices at each end)

■ Pilot-wire differential protection for lines

and cables (3 pilot wires) ■ Up to about 15 km pilot length ■ With integrated overcurrent back-up

and overload protection ■ Also applicable to 3-terminal lines

(2 devices at each end)

Siemens Power Engineering Guide · Transmission & Distribution

6/23

Power System Protection

Cutout and drilling dimensions Case 7XP20 for relays 7SJ600, 7RW600 Back view

Panel cutout

Side view

70

7.3

71+2

56.5±0.3

ø5 or M4 244

266

255±0.3

245+1

ø6 75

37

29.5

172

Fig. 41

Case 7XP2030-2 for relays 7SD511, 7SJ511/12, 7SJ531, 7UT512, 7VE51 Panel cutout

Side view

Front view 145

30

172

29.5

7.3 13.2

244

245

266

or M4

255.8

ø6

1.5

231.5

150

5.4

ø5

10 Optical fibre interface

131.5 105

146

Fig. 42

Case 7XP2040-2 for relays 7SA511, 7UT513, 7SD512, 7UM5**, 7VE512, 7SD502/503 Front view 220

Side view Optical fiber interface 30 172

Panel cutout 29.5

7.3 13.6

206.5 180

5.4

ø5 266 245 1,5

10

225

231.5

or M4 ø6

221

255.8

All dimensions in mm.

Fig. 43

6/24

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

Case 7XP2020-2 Front view 75

30

Side view 172

Back view 70

29.5

7.3 13.2

Panel cutout 56.3 30 5.4

ø5 24

or M4

266

245

255.8

ø6 71 Fig. 44

7XR9672 Core-balance current transformer (zero sequence c.t.) M6 14 K

L

120

96 104

55

102

k l 14.5 x 6.5 200

K 120

2

Fig. 45

7XR9600 Core-balance current transformer (zero sequence c.t.) 94

12

Diam. 149

80

81 Diam. 6.4 143

54

170 All dimensions in mm. Fig. 46

Siemens Power Engineering Guide · Transmission & Distribution

6/25

Power System Protection

Case for relay 7SJ551 Back view

Side view

Front view 105

30

172

29.5

244

266

100 86.4

255.9

115 Fig. 47

Case 7XP2060-2 for relay 7SA513 Side view

Front view 450

30

172

29.5

445

266 1.5

266 10

Optical fiber interface

Panel cutout 7.3

431.5

13.2

405

5.4

ø 5 or M4 245

255.8

ø6 446

All dimensions in mm.

Fig. 48

6/26

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

Typical protection schemes Application group

Cables and overhead lines

Transformers

Motors

Generators

Busbars

Circuit number

Circuit equipment protected

Page

1

Radial feeder circuit

6/28

2

Ring main circuit

6/28

3

Distribution feeder with reclosers

6/29

4

Parallel feeder circuit

6/29

5

Cable or short overhead line with infeed from both ends

6/30

6

Overhead lines or longer cables with infeed from both ends

6/30

7

Small transformer infeed

6/31

8

Large or important transformer infeed

6/31

9

Dual infeed with single transformer

6/32

10

Parallel incoming transformer feeder

6/32

11

Parallel incoming transformer feeder with bus tie

6/33

12

Small- and medium-sized motors

6/33

13

Large HV motors

6/34

14

Smallest generator < 500 kW

6/34

15

Small generator, around 1 MW

6/35

16

Large generator > 1 MW

6/35

17

Generator-transformer unit

6/36

18

Busbar protection by o/c relays with reverse interlocking

6/37

19

High-impedance differential busbar protection

6/38

20

Low-impedance differential busbar protection

6/38

Fig. 49

Siemens Power Engineering Guide · Transmission & Distribution

6/27

Power System Protection

1. Radial feeder circuit Infeed

Notes:

Transformer protection, see Fig. 56

1) Autoreclosure 79 only with O.H. lines. 2) Negative sequence o/c protection 46 as sensitive back-up protection against unsymmetrical faults.

A

General hints: – The relay at the far end (D) gets the shortest operating time. Relays further upstream have to be time-graded against the next downstream relay in steps of about 0.3 seconds. – Inverse-time curves can be selected according to the following criteria: – Definite time: source impedance large compared to the line impedance, i.e. small current variation between near and far end faults – Inverse time: Longer lines, where the fault current is much less at the end of the line than at the local end. – Very or extremely inverse time: Lines, where the line impedance is large compared to the source impedance (high difference for close-in and remote faults), or lines, where coordination with fuses or reclosers is necessary. Steeper characteristics provide also higher stability on service restoration (cold load pick-up and transformer in rush currents)

I>, t IE>, t I2>, t

B Further feeders

51

51N

46 2)

ARC

7SJ60

79 1)

I>, t IE>, t I2>, t

C

51

51N

7SJ60

46

Load I>, t IE>, t I2>, t

D

51

51N

7SJ60

46

Load

Load Fig. 50

Infeed Transformer protection, see Fig. 56 52

52

2. Ring main circuit General hints: – Operating time of overcurrent relays to be coordinated with downstream fuses of load transformers. (Preferably very inverse time characteristic with about 0.2 s grading-time delay – Thermal overload protection for the cables (option) – Negative sequence o/c protection 46 as sensitive protection against unsymmetrical faults (option)

7SJ60 52

7SJ60

I>, t IE>, t I2>, t 51

51N

46

ϑ> 49

52

I>, t IE>, t I2>, t 51

51N

46

ϑ> 49

Fig. 51

6/28

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

3. Distribution feeder with reclosers

Infeed

General hints:

52

I>>, I>, t

52

IE>>, I2>, t IE>, t

50/ 51

50N/ 51N

7SJ60

46 79

Autoreclose

Further feeders

Recloser

Sectionalizers

Fuses

– The feeder relay operating characteristics, delay times and autoreclosure cycles must be carefully coordinated with downstream reclosers, sectionalizers and fuses. The instantaneous zone 50/50N is normally set to reach out to the first main feeder sectionalizing point. It shall ensure fast clearing of close-in faults and prevent blowing of fuses in this area (“fuse saving”). Fast autoreclosure is iniciated in this case. Further time delayed tripping and reclosure steps (normally 2 or 3) have to be graded against the recloser. – The o/c relay should automatically switch over to less sensitive characteristics after longer breaker interruption times to enable overriding of subsequent cold load pick-up and transformer inrush currents.

Fig. 52

4. Parallel feeder circuit General hints:

Infeed 52 52

I>, t IE>, t 51

51N

ϑ>

I2>, t

49

46

52

7SJ60

67

67N

Protection same as line or cable 1

O.H. line or cable 2

O.H. line or cable 1

51

51N

– This circuit is preferably used for the interruptionfree supply of important consumers without significant back-feed. – The directional o/c protection 67/67N trips instantaneously for faults on the protected line. This allows the saving of one time-grading interval for the o/crelays at the infeed. – The o/c relay functions 51/51N have each to be time-graded against the upstream located relays.

7SJ512

52 52 52 52

52

Load

Load

Fig. 53

Siemens Power Engineering Guide · Transmission & Distribution

6/29

Power System Protection

5. Cables or short overhead lines with infeed from both sides

Infeed

Notes:

52 52

1) Autoreclosure only with overhead lines 2) Overload protection only with cables 3) Differential protection options: – Type 7SD511/12 with direct fiber-optic connection up to about 20 km or via a 64 kbit/s channel of a general purpose PCM connection (optical fiber, microwave) – Type 7SD502 with 2-wire pilot cables up to about 20 km – Type 7SD503 with 3-wire pilot cables up to about 10 km.

52

7SJ60

79

1)

52 2)

51N/ 51N Line or cable

49

87L

7SJ60

7SD5** Same protection for parallel line, if applicable

3)

51N/ 51N

49

87L

7SD5** 2)

79

52

52

1)

52 52

52

52

Load

Backfeed

52

Fig. 54

6. Overhead lines or longer cables with infeed from both sides

Infeed

Notes:

52

1) Teleprotection logic 85 for transfer trip or blocking schemes. Signal transmission via pilot wire, power-line carrier, microwave or optical fiber (to be provided seperately). The teleprotection supplement is only necessary if fast fault clearance on 100% line length is required, i.e. second zone tripping (about 0.3 s delay) cannot be accepted for far end faults. 2) Directional ground-fault protection 67N with inverse-time delay against highresistance faults 3) Single- or multishot autoreclosure 79 only with overhead lines.

52 52

52 21/ 21N

67N

85

79

2)

7SA511

3) Line or cable

Same protection for parallel line, if applicable

1) 85 21/ 21N

79

3)

7SA511

2) 67N

52

52 52

52

52

Load

Backfeed

52

52

Fig. 55

6/30

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

7. Small transformer infeed HV infeed 52

General hints: I>>

I>, t

IE>

ϑ> I2>, t

50

51

50N

49

63

– Ground-faults on the secondary side are detected by current relay 51G which, however, has to be time graded against downstream feeder protection relays. The restricted ground-fault relay 87N can optionally be provided to achieve fast clearance of ground-faults in the transformer secondary winding. Relay 7VH80 is high-impedance type and requires class X c.t.s with equal transformation ratio. – Primary breaker and relay may be replaced by fuses.

7SJ60

46

Optional resistor or reactor

RN

I>> 87N 51G 52

7VH80

7SJ60

IE> Distribution bus

52 Fuse

o/crelay

Load

Load Fig. 56

8. Large or important transformer infeed HV infeed

High voltage, e.g. 115 kV 52

I>>

I>, t

I E>

ϑ>

I2>, t

50

51

51N

49

46

Notes:

7SJ60

2) 51G

7SJ60

63 1) 87N

52

I>, t

IE>, t

51

51N

87T

7UT513

1) Three winding transformer relay type 7UT513 may be replaced by twowinding type 7UT512 plus high-impedance-type restricted ground-fault relay 7VH80. However, class X c.t. cores would additionally be necessary in this case. (See small transformer protection) 2) 51G may additionally be provided, in particular for the protection of the neutral resistance, if provided. 3) Relays 7UT512/513 provide numerical ratio and vector group adaption. Matching transformers as used with traditional relays are therefore no more applicable.

7SJ60 Load bus, e.g. 13.8 kV

52

52

Load

Load

Fig. 57

Siemens Power Engineering Guide · Transmission & Distribution

6/31

Power System Protection

9. Dual-infeed with single transformer Notes: 1) Line c.t.s are to be connected to separate stabilizing inputs of the differential relay 87T in order to guarantee stability in case of line through-fault currents. 2) Relay 7UT513 provides numerical ratio and vector group adaption. Matching transformers, as used with traditional relays, are therefore no longer applicable.

Protection line 2 21/21N or 87L + 51 + optionally 67/67N 52

Protection line 1 same as line 2 52

7SJ60 I>>

I>, t

IE>, t

50

51

51N

46

49

I2>

ϑ>

63

87N

7SJ60

87T

7UT513

51G

I>>

IE>

51

51N

7SJ60

52 52

52

Load bus

52

Load Fig. 58

10. Parallel incoming transformer feeders

7SJ60

HV infeed 1

Note:

52

1) The directional functions 67 and 67N do not apply for cases where the transformers are equipped with transformer differential relays 87T.

I>>

I>, t

50

51

HV infeed 2

IE>, t ϑ> 51N

52

I2>, t

49

46 Protection

63 51G

IE>, t

I>, t IE>, t 51

7SJ60

same as infeed 1

7SJ512 I> 67

51N

IE> 67N

1) 52

52 Load bus 52

52 Load

52 Load

Load

Fig. 59

6/32

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

11. Parallel incoming transformer feeders with bus tie

7SJ60

Infeed 1 I>>

I>, t

50

51

Infeed 2

IE>, t ϑ> 51N

I2>, t

49

46 Protection same as infeed 1

51G

7SJ60

7SJ60

I>, t IE>, t

IE>, t I>, t

51

51N

51N

Note: 1) Overcurrent relays 51, 51N each connected as a partial differential scheme. This provides a simple and fast busbar protection and saves one time-grading step.

51

7SJ60

52

52 52

52

52 Load

Load

Fig. 60

12. Small- and medium-sized motors < about 1 MW 52

I>>

IE>

ϑ>

50

51N

49

Locked rotor 49 CR

a) With effective or low-resistance grounded infeed (IE ≥ I N Motor)

I2> 46

7SJ60

General hint: – Applicable to low-voltage motors and high-voltage motors with low-resistance grounded infeed (IE ≥ IN Motor).

M Fig. 61a

b) With high-resistance grounded infeed (IE ≤ IN Motor) 52

7XR96 1) 60/1A

I>>

ϑ>

50

49

IE> 51G

Locked rotor 49 CR

I2>

I<

46

37

2)

Notes:

7SJ531 or 7SJ551

1) Window-type zero sequence c.t. 2) Sensitive directional ground-fault protection 67N only applicable with infeed from isolated or Peterson-coil grounded network.

67G

M Fig. 61b

Siemens Power Engineering Guide · Transmission & Distribution

6/33

Power System Protection

13. Large HV motors > about 1 MW Notes:

7SJ531 or 7SJ551

1) Window-type zero sequence c.t. 2) Sensitive directional ground-fault protection 67N only applicable with infeed from isolated or Peterson-coil grounded network. 3) This function is only needed for motors where the run-up time is longer than the safe stall time t E. According to IEC 79-7, the tE -time is the time needed to heat up a.c. windings, when carrying the starting current I A, from the temperature reached in rated service and at maximum ambient temperature to the limiting temperature. A separate speed switch is used to supervise actual starting of the motor. The motor breaker is tripped if the motor does not reach speed in the preset time. The speed switch is part of the motor delivery itself. 4) Pt100, Ni100, Ni120 5) 49T only available with relay type 75J551

52

I>>

ϑ>

50

49

IE> 7XR96 1) 60/1A

51G

Locked rotor 49 CR

M

46

27

37

67G

Start-up 49T supervisior 3) 3) Speed switch

U<

Optional

I<

2)

I2>

7UT512

87M

RTD's 4) optional

Fig. 62

14. Smallest generators < 500 kW LV

G

I>, IE>, t

I2>

ϑ>

51 51N

46

49

I>, IE>, t

I2>

ϑ>

51 51N

46

49

7SJ60

Fig. 63a: With solidly grounded neutral

MV

G1

Generator 2

RN =

7SJ60

VN √3 • (0.5 to 1) • Irated

Fig. 63b: With resistance grounded neutral

6/34

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

15. Small generator, typically 1 MW Note: 1) Two c.t.s in V-connection also sufficient.

52

1)

Field

G

64R

P

I>, t

32

51

L.O.F

I2>

7UM511

40

46

IE>, t 51G

Fig. 64

16. Large generator > 1 MW MV

Notes:

52 3) 51

2) 87

O/C v.c.

7SJ60

I IG 87G

27

U<

81

f>

59

U>

1)

G

64R Field

1)

RE Field<

I>, t

P

I2>

L.O.F.

51

32

46

40

IE>, t

ϑ> 49

1) Functions 81 und 59 only required where prime mover can assume excess speed and voltage regulator may permit rise of output voltage above upper limit. 2) Differential relaying options: – 7UT512: Low-impedance differential protection 87 – 7UT513: Low-impedance differential 87 with integral restricted groundfault protection 87G – 7VH83: High-impedance differential protection 87 (requires class X c.t.s) 3) 7SJ60 used as voltage-controlled o/c protection. Function 27 of 7UM511 is used to switch over to a second, more sensitive setting group.

7UM511

51G

Fig. 65

Siemens Power Engineering Guide · Transmission & Distribution

6/35

Power System Protection

17. Generator-transformer unit Notes:

52

Transf. fault press

63

Unit trans.

71

87 TU

Oil low

51 TN 87U

1) 100% stator ground-fault protection based on 20 Hz voltage injection 2) Sensitive field ground-fault protection based on 1 Hz voltage injection 3) Only used functions shown, further integrated functions available in each relay type (see ”Relay Selection Guide“, Fig. 27).

Transf. neut. OC

Unit aux. back-up

Unit diff. 51 Oil low Transf. fault press

71 63

Over volt

Unit aux.

59 81N 78

Loss of sync.

Volt/Hz

Trans. diff. 32

E 87G

Reverse power

Relay type

Gen. diff.

2) 64 R2

64R

Field grd.

Field grd.

87T

A

Loss of field

49S

G

Trans. neut. OC

24 40

Stator O.L.

51 TN

Over freq.

46 Neg. seq.

51 1) GN

Functions 3)

Number of relays required

7UM511

40

46

59

81N

7UM516

59 GN

32

21

78

7UM515

24

51 GN

7UT512

87G

87T

7UT513

87U

7SJ60

51N

49

64R

1

21 Sys. back-up

59 GN Gen. neut. OV

1)

64 R2

1

2)

and optionally

1 87 TU

2 optionally 3 1

51

3

Fig. 66

6/36

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

18. Busbar protection by O/C relays with reverse interlocking General hint: Infeed

Applicable to distribution busbars without substantial (< 0.25 x IN) backfeed from the outgoing feeders

reverse interlocking I>, t0 50 50N

I>, t 51 51N

7SJ60

52 t0 = 50 ms

52 I>

I>, t

50 50N

51 51N

52 I>

I>, t

50 50N

51 51N

7SJ60

7SJ60

52 I>

I>, t

50 50N

51 51N

7SJ60

Fig. 67

Siemens Power Engineering Guide · Transmission & Distribution

6/37

Power System Protection

19. High impedance busbar protection General hints:

Transformer protection

– Normally used with single busbar and 1 1/2 breaker schemes – Requires separate class X current transformer cores. All c.t.s must have the same transformation ratio

51 51N

7VH83 87 BB

86 52

52

52

Feeder protection

G

Feeder protection

87 S.V.

Alarm

Feeder protection

G

Load

Fig. 68

20. Low-impedance busbar protection Infeed

General hints: – Preferably used for multiple busbar schemes where an isolator replica is necessary – The numerical busbar protection 7SS5 provides additional breaker failure protection – C.t. transformation ratios can be different, e.g. 600/1 A in the feeders and 2000/1 at the bus tie – The protection system and the isolator replica is continuously self-monitored by the 7SS5 – Feeder protection can be connected to the same c.t. core.

Transformer protecton 50 50N 52

52

Isolator replica

Bus tie protection

87 BB

52

52 Feeder protection Load

7SS5

86 Feeder protection

BF

Back-feed

Fig. 69

6/38

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

Protection coordination

Peak value of inrush current

Relay operating characteristics and their setting must be carefully coordinated in order to achieve selectivity. The aim is basically to switch-off only the faulted component and to leave the rest of the power system in service in order to minimize supply interruptions and to guarantee stability.

^ IRush ^ IN

12.0 11.0 10.0 9.0

Sensivity

8.0

Protection should be as sensitive as possible to detect faults at the lowest possible current level. At the same time, however, it should remain stable under all permissible load, overload and through-fault conditions.

7.0 6.0 5.0 4.0 3.0

Phase-fault relays The pick-up values of phase o/c relays are normally set 30% above the maximum load current, provided that sufficient shortcircuit current is available. This practice is recommmended in particular for mechanical relays with reset ratios of 0.8 to 0.85. Numerical relays have high reset ratios near 0.95 and allow therefore about 10% lower setting. Feeders with high transformer and/or motor load require special consideration.

2.0 1.0 2

Ground-fault relays Residual-current relays enable a much more sensitive setting, as load currents do not have to be considered (except 4-wire circuits with single-phase load). In solidly and low-resistance grounded systems a setting of 10 to 20% rated load current is generally applied.

100 400 Rated transformer power [MVA]

Time constant of inrush current

Transformer feeders The energizing of transformers causes inrush currents that may last for seconds, depending on their size (Fig. 70). Selection of the pick-up current and assigned time delay have to be coordinated so that the rush current decreases below the relay o/c reset value before the set operating time has elapsed. The rush current typically contains only about 50% fundamental frequency component. Numerical relays that filter out harmonics and the DC component of the rush current can therefore be set more sensitive. The inrush-current peak values of Fig. 70 will be nearly reduced to one half in this case.

10

Nominal power [MVA]

0.5 . . . 1.0

1.0 . . . 10

>10

Time constant [s]

0.16 . . . 0.2

0.2 . . . 1.2

1.2 . . . 720

Fig. 70: Transformer inrush currents, typical data

High-resistance grounding requires much more sensitive setting in the order of some amperes primary. The ground-fault current of motors and generators, for example, should be limited to values below 10 A in order to avoid iron burning. Residual-current relays in the star point connection of c.t.s can in this case not be used, in particular with rated c.t. primary currents higher than 200 A. The pick-up value of the zero-sequence relay would in this case be in the order of the error currents of the c.t.s. A special zero-sequence c.t. is therefore used in this case as earth current sensor. The window type current transformer 7XR96 is designed for a ratio of 60/1 A. The detection of 6 A primary would then require a relay pick-up setting of 0.1 A secondary.

Siemens Power Engineering Guide · Transmission & Distribution

An even more sensitive setting is applied in isolated or Peterson-coil grounded networks where very low earth currents occur with single-phase-to-ground faults. Settings of 20 mA and less may then be required depending on the minimum ground-fault current. Sensitive directional ground-fault relays (integrated in the relays 7SJ512, 7SJ55 and 7SA511) allow settings as low a 5 mA.

6/39

Power System Protection

Differential relays (87) Transformer differential relays are normally set to pick-up values between 20 and 30% rated current. The higher value has to be chosen when the transformer is fitted with a tap changer. Restricted ground-fault relays and high-resistance motor/generator differential relays are, as a rule, set to about 10% rated current.

Time in seconds 10000 1000 100 10 1

Instantaneous o/c protection (50) This is typically applied on the final supply load or on any protective device with sufficient circuit impedance between itself and the next downstream protective device. The setting at transformers, for example, must be chosen about 20 to 30% higher than the maximum through-fault current. Motor feeders The energizing of motors causes a starting current of initially 5 to 6 times rated current (locked rotor current). A typical time-current curve for an induction motor is shown in Fig. 71. In the first 100 ms, a fast decaying assymetrical inrush current appears additionally. With conventional relays it was current practice to set the instantaneous o/c step for short circuit protection 20 to 30% above the locked-rotor current with a short time delay of 50 to 100 ms to override the asymetrical inrush periode. Numerical relays are able to filter out the asymmetrical current component very fast so that the setting of an additional time delay is no longer applicable. The overload protection characteristic should follow the thermal motor characteristic as closely as possible. The adaption is to be made by setting of the pick-up value and the thermal time constant, using the data supplied by the motor manufacturer. Further, the locked-rotor protection timer has to be set according to the characteristic motor value. Time grading of o/c relays (51) The selectivity of overcurrent protection is based on time grading of the relay operating characteristics. The relay closer to the infeed (upstream relay) is time-delayed against the relay further away from the infeed (downstream relay). This is shown in Fig. 73 by the example of definite time o/c relays. The overshoot times takes into account the fact that the measuring relay continues to operate due to its inertia, even when the fault current is interrupted. This may

6/40

.1 .01 .001 0

1

2

3

4

5

6

7

8

9

10

Current in multplies of full-load amps Motor starting current

High set instantaneous o/c step

Locked rotor current

Motor thermal limit curve

Overload protection characteristic

Permissible locked rotor time

Fig. 71: Typical motor current-time characteristics

Time 51

51

51

Main 0.2–0.4 seconds Feeder

Maximum feeder fault level

Current

Fig. 72: Coordination of inverse-time relays

be is high for mechanical relays (about 0.1 s) and neglectable for numerical relays (20 ms). Inverse time relays (51) For the time grading of inverse-time relays, the same rules apply in principle as for the definite time relays. The time grading is first calculated for the maximum fault level and then checked for lower current levels (Fig. 72).

If the same characteristic is used for all relays, or when the upstream relay has a steeper characteristic (e.g. very over normal inverse), then selectivity is automatically fulfilled at lower currents.

Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

Operating time 52 M 51 M

52 F

52 F 51 F

51 F

0.2–0.4 Time grading

Fault Fault inception detection t51F

I>

Set time delay

Interruption of fault current t52F Circuit-breaker Interruption time Overshoot* tOS Margin tM

I> t51M

* also called overtravel or coasting time

t51M– t51F = t52F + tOS + tM Time grading tTG

Example 1 Mechanical relays: tOS = 0.15 s Oil circuit breaker t52F = 0.10 s Safety margin for measuring errors, etc.: tM = 0.15

tTG = 0.10 + 0.15 + 0.15 = 0.40 s

Example 2 Numerical relays: tOS = 0.02 s Vacuum breaker: Safety margin:

t52F = 0.08 s tM = 0.10 s

tTG = 0.08 + 0.02 + 0.10 = 0.20 s

Fig. 73: Time grading of overcurrent-time relays

Siemens Power Engineering Guide · Transmission & Distribution

6/41

Power System Protection

Calculation example The feeder configuration of Fig. 74 and the assigned load and short-circuit currents are given. Numerical o/c relays 7SJ60 with normal inverse-time characteristic are applied. The relay operating times dependent on current can be taken from the diagram or derived from the formula given in Fig. 75. The IP /IN settings shown in Fig. 74 have been chosen to get pick-up values safely above maximum load current. This current setting shall be lowest for the relay farthest downstream. The relays further upstream shall each have equal or higher current setting. The time multiplier settings can now be calculated as follows:

Example: Time grading of inverse-time relays for a radial feeder Load F4

A

F3

B

F2

C

51 7SJ60

Station

Max. Load [A]

51 7SJ60

51 7SJ60

Iscc. max.* [A]

CT ratio

Ip/IN **

Load

Iprim*** [A]

I /Ip =

300

4500

400/5

1.0

400

11.25

170

2690

200/5

1.1

220

12.23

50

1395

100/5

0.7

70

19.93

–

–

–

–

–

523

■ For coordination with the fuses, we

*) Iscc.max. = Maximum short-circuit current ** Ip/IN = Relay current multiplier setting *** Iprim = Primary setting current corresponding to Ip/IN

The relay in B has a back-up function for the relay in C. The maximum through-fault current of 1.395 A becomes effective for a fault in location F2. For the relay in C, we obtain an operating time of 0.11 s (I/I P = 19.9). We assume that no special requirements for short operating times exist and can therefore choose an average time grading interval of 0.3 s. The operating time of the relay in B can then be calculated: ■ t B = 0.11 + 0.3 = 0.41 s ■ Value of IP /I N = 1395 A = 6.34 (see Fig. 74). 220 A ■ With the operating time 0.41 s and I P /IN = 6.34, we can now derive TP = 0.11 from Fig. 75.

1.0 MVA 5.0%

B C

F1

L.V.

A

D

Station B:

Fuse: D 160 A

Load

13.8 kV

Station C: consider the fault in location F1. The short-circuit current related to 13.8 kV is 523 A. This results in 7.47 for I /I P at the o/c relay in location C. ■ With this value and TP = 0.05 we derive from Fig. 75 an operating time of tA = 0.17 s This setting was selected for the o/c relay to get a safe grading time over the fuse on the transformer low-voltage side. The setting values for the relay at station C are therefore: ■ Current tap: IP /I N = 0.7 ■ Time multipler: TP = 0.05

13.8 kV/ 0.4 kV

Iscc. max. Iprim

Fig. 74

The setting values for the relay at station B are herewith ■ Current tap: IP /I N = 1.1 ■ Time multiplier TP = 0.11 Given these settings, we can also check the operating time of the relay in B for a close-in fault in F3: The short-circuit current increases in this case to 2690 A (see Fig. 74). The corresponding I/IP value is 12.23. ■ With this value and the set value of TP = 0.11 we obtain again derive from Fig. 75 an operating time of 0.3 s. Station A:

t [s] 100 50 40 30 Tp [s]

20 10

3.2 5 4 3

1.6

2

0.8

1

0.4

0.50 0.4 0.3

0.2

0.2

0.1

■ We add the time grading interval of

0.3 s and find the desired operating time tA = 0.3 + 0.3 = 0.6 s. Following the same procedure as for the relay in station B we obtain the following values for the relay in station A: ■ Current tap: IP /I N = 1.0 ■ Time multiplier: T P = 0.17 ■ For the close-in fault at location F4 we obtain an operating time of 0.48 s.

0.05

0.1 0.05 2

4

6 8 10

Normal inverse 0.14 . Tp [s] t= (I/Ip)0.02 – 1

20 I/Ip [A]

Fig. 75: Normal inverse time characteristic of relay 7SJ60

6/42

Siemens Power Engineering Guide · Transmission & Distribution

Imax = 4500 A

Iscc = 2690 A

I – 0.4 kVmax = 16.000 kA Iscc = 1395 A

t [s]

t [min]

Power System Protection

Setting range

IN A

Ip = 0.10 – 4.00 xIn I>> I>, t 7SJ600 Tp = 0.05 – 3.2 s I>>= 0.1 – 25. xIn

400/5 A

100 1

Setting

5

Ip = 1.0 xIn Tp = 0.17 s I>>= ∞

52 2 Bus-B

10 5

200/5 A

2 1

52

5

IA>,t

2

IB>,t

.1

IC>,t

Ip = 0.10 – 4.00 xIn I>> I>, t 7SJ600 Tp = 0.05 – 3.2 s I>>= 0.1 – 25. xIn

Ip = 1.1 xIn Tp = 0.11 s I>>= ∞

Bus-C Ip = 0.10 – 4.00 xIn I>> I>, t 7SJ600 Tp = 0.05 – 3.2 s I>>= 0.1 – 25. xIn

100/5 A

5 2

Ip = 0.7 xIn Tp = 0.05 s I>>= ∞

52

.01 5

TR

13.8/0.4 KV 1.0 MVA 5.0%

fuse

VDE 160

fuse

2 .001 10 I [A]

2

5

1000 2

100 2

5 1000 2

5 10 4 2

5 10 4 13.80 kV 0.40 kV 5 10 5 2

HRC fuse 160 A

Fig. 76: O/c time grading diagram

The normal way

Note:

To prove the selectivity over the whole range of possible short-circuit currents, it is normal practice to draw the set operating curves in a common diagram with double log scales. These diagrams can be manually calculated and drawn point by point or constructed by using templates. Today computer programs are also available for this purpose. Fig. 76 shows the relay coordination diagram for the example selected, as calculated by the Siemens program CUSS (computer-aided protective grading).

To simplify calculations, only inverse-time characteristics have been used for this example. About 0.1 s shorter operating times could have been reached for high-current faults by additionally applying the instantaneous zones I>> of the 7SJ60 relays.

Siemens Power Engineering Guide · Transmission & Distribution

6/43

Power System Protection

Coordination of o/c relays with fuses and low-voltage trip devices The procedure is similar to the above described grading of o/c relays. Usually a time interval between 0.1 and 0.2 seconds is sufficient for a safe time coordination. Very and extremely inverse characteristics are often more suitable than normal inverse curves in this case. Fig. 77 shows typical examples. Simple consumer-utility interrupts use a power fuse on the primary side of the supply transformers (Fig. 77a). In this case, the operating characteristic of the o/c relay at the infeed has to be coordinated with the fuse curve. Very inverse characteristics may be used with expulsion-type fuses (fuse cutouts) while extremly inverse versions adapt better to current limiting fuses. In any case, the final decision should be made by plotting the curves in the log-log coordination diagram. Electronic trip devices of LV breakers have long-delay, short-delay and instantaneous zones. Numerical o/c relays with one inverse time and two definite-time zones can be closely adapted (Fig. 77b).

Time

MV Inverse relay

51

other consumers

Fuse

n a

LV bus

0.2 seconds

Fuse a)

Maximum fault available at HV bus

Current

Time

MV bus 50 51

o/c relay I1>, t1

Secondary breaker

I2>, t2

n a 0.2 seconds

LV bus

I>> b) Maximum fault level at MV bus

Current

Fig. 77: Coordination of an o/c relay with an MV fuse and a low-voltage breaker trip device

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Siemens Power Engineering Guide · Transmission & Distribution

Power System Protection

Grading of zone times Operating time Z3A

t3 Z2A

t2 Z1A

t1

~

Z1B ZLA-B

A

Z2B Z1C ZLB-C

B Load

Z1A = 0.85 • ZLA-B

ZLC-D

C

D

Load

Load

The first zone normally operates undelayed. For the grading of the time intervals of the second and third zones, the same rules as for o/c relays apply (see Fig. 73). For the quadrilateral characteristics (relays 7SA511 and 7SA513) only the reactance values ( X values) have to be considered for the reach setting. The setting of the R values should cover the line resistance and possible arc or fault resistances. The arc resistance can be roughly estimated as follows:

Z2A = 0.85 • (ZLA-B+Z1B) Z3A = 0.85 • (ZLA-B+Z2B)

RArc

Fig. 78: Grading of distance zones

=

IArc = Iscc Min =

X

IArc x 2kV/m Iscc

Min

arc length in m minimum short-circuit current

Fig. 80

D

■ Typical settings of the ratio R/X are:

X3A

– Short lines and cables (≤ 10 km): R/X = 2 to 10 – Medium line lengths < 25 km: R/X = 2 – Longer lines 25 to 50 km: R/X = 1

C

X2A

B X1A

Shortest feeder protectable by distance relays The shortest feeder that can be protected by underreach distance zones without the need for signaling links depends on the shortest settable relay reactance. R1A

A

R2A

R3A

R

XPrimary Minimum = = XRelay Min x

Fig. 79: Operating characteristic of Siemens distance relays 7SA511 and 7SA513

Coordination of distance relays The reach setting of distance times must take into account the limited relay accuracy including transient overreach (5% according to IEC 255-6), the c.t. error (1% for class 5P and 3% for class 10P) and a security margin of about 5%. Further, the line parameters are normally only calculated, not measured. This is a further source of errors. A setting of 80–85% is therefore common practice: being 80% used for mechanical relays while 85% can be used for the more accurate numerical relays.

Where measured line or cable impedances are available, the reach setting may also be extended to 90%. The second and third zones have to keep a safety margin of about 15 to 20% to the corresponding zones of the following lines. The shortest following line has always to be considered (Fig. 78). As a general rule, the second zone should at least reach 20% over the next station to ensure back-up for busbar faults, and the third zone should cover the largest following line as back-up for the line protection.

Siemens Power Engineering Guide · Transmission & Distribution

Imin =

VTratio

[Ohm]

CTratio

XPrim.Min [Ohm] X’Line [Ohm/km]

[km]

Fig. 81

The shortest setting of the numerical Siemens relays is 0.05 ohms for 1 A relays, corresponding to 0.01 ohms for 5 A relays. This allows distance protection of distribution cables down to the range of some 500 meters.

6/45

Local and Remote Control

Introduction State-of-the-art Modern protection and substation control uses microprocessor technology and serial communication to upgrade substation operation, to enhance reliability and to reduce overall life cycle cost. The traditional conglomeration of often totally different devices such as relays, meters, switchboards and RTUs are replaced by a few multifunctional, intelligent devices of uniform design. And, instead of extensive parallel wiring, only a few serial links are used (Fig. 82 and 83). Control of the substation takes place with menu-guided procedures at a central VDU work place.

Traditional protection and substation control

To network control center

Alarm annunciation and local control

Remote terminal unit

Marshalling rack Approx. 20 to 40 cores per bay

F

F

Control

Monitoring

Protection

Mimic display Pushbuttons Position indicators Interposing relays Local/remote switch

Indication lamps Measuring instruments Transducers Terminal blocks Miniature circuit breakers

e.g. Overcurrent relays Ground-fault relays Reclosing relays Auxiliary relays

Fig. 82

6/46

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Coordinated protection and substation control system LSA 678

System control center

VDU Compact central control unit including RTU functions

*

Keyboard

Printer (option)

2 fiber-optic cores per feeder

**

Control I/O unit

Protection relay

shown with open door

Protection Control relay I/O unit

Low-voltage compartment of the medium-voltage switchgear

* The compact central control unit can be located in a separate cubicle or directly in the low-voltage compartment of the switchgear ** Protection relays are serially connected to the control I/O units Fig. 83

Siemens Power Engineering Guide · Transmission & Distribution

6/47

Local and Remote Control

Technical proceedings The first coordinated protection and substation control system LSA 678 was commissioned in 1986 and continuously further developed in the following years. It now features the following main characteristics: ■ Coordinated system structure ■ Optical communication network (star configuration) ■ High processing power (32-bit MP technology) ■ Standardized serial interfaces and communication protocols ■ Uniform design of all components ■ Complete range of protection and control functions ■ Comprehensive user-software support packages. Currently (1996) over 400 systems are in successful operation at all voltage levels up to 400 kV. System structure and scope of functions The LSA system performs supervisory local control, switchgear interlocking, bay and station protection, synchronizing, transformer tap-changer control, switching sequence programs, event and fault recording, telecontrol, etc. It consists of the independent subsystems (Fig. 84): ■ Supervisory control 6MB51/52 ■ Protection 7S**5 Normally, switchgear interlocking is integrated as software program in the supervisory control system. Local bay control is implemented in the bay-dedicated I/O control units. For complex substations with multiple busbars, however, these functions are often provided as an independent back-up system: ■ Interlocking and local control 8TK

Communication and data exchange between components is performed via serial data links. Optical-fiber connections are preferred to ensure EMI compatibility. The cummunication structure of the control system is designed as a hierarchical star configuration. It operates in the polling procedure with a fixed assignment of the master function to the central unit. The data transmission mode is asynchronous, half-duplex, protected with a hamming distance d = 4, and complies with the IEC Standard 870-5. Each subsystem can operate fully in standalone mode even in the event of loss of communication.

6/48

System control center LSA

Operator’s desk

VDU

Supervisory control system 6 MB

Station level

”Master unit“ …n

1…

Bay level

Time signal

PROCESS

Interlocking system 8TK

Supervisory control system 6 MB

Protection 7S

”Bay unit“

”I/O unit“

”Bay protection“

8TK master unit Switchyard Serial

Parallel

Fig. 84: Distributed structure of coordinated protection and control LSA

Data sharing between protection and control via the so-called informative interface according to IEC 870-5-103 is restricted to noncritical measuring or event recording functions. The protection units, for example, deliver RMS values of currents, voltages, power, instantaneous values for oscillographic fault recording and time-tagged operating events for fault reporting. Besides the high data transmission security, the system also provides self-monitoring of individual components. The distributed structure also makes the LSA system attractive for refurbishment programs or extensions, where conventional secondary equipment has to be integrated. It is general practice to provide protection of HV and EHV substations as separate, self-contained relays that can communicate with the control system, but function otherwise completely independently. At lower voltage levels, however, higher integrated solutions are accepted for cost reasons. For distribution-type substations combined protection and control feeder units (e.g. 7SJ531) are available which integrate all necessary functions of one feeder, including: local feeder control, overcurrent and overload protection, breaker-failure protection and metering.

Supervisory control The substation is monitored and controlled from the operator‘s desk (Fig. 84). The VDU shows overview diagrams and complete details of the switchgear on a color display. Current/actual measurands can be called up on request. All event and alarm annunciations are selectable in form of lists. The control procedure is menu-guided and uses either a mouse, or an easy to handle keyboard with a minimum number of function and cursor keys. The operation is therefore extremely user-friendly and does not require special training of the operating staff. Automatic functions Apart from the provided switchgear interlocking, a series of automatic functions ensure an effective and secure system operation. Automatic switching sequences, such as changing of busbars, can be user-programmed and started locally or remotely. Furthermore, two important automation functions have been integrated into the system software and are available as options: synchronizing and transformer tap-changer control.

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Both functions run on the relevant bay level units, controlled by the central master unit. The performance of these functions corresponds to modern digital stand-alone units. The advantages of the integrated solution, however, are: ■ External auxiliary relay circuits for the selection of measurands are no longer applicable. ■ Adaptive parameter setting becomes possible from local or remote control levels. High processing power The processing power of the central control unit has been enormously increased by the introduction of the 32-bit MP technology. This permits, on the one hand, a more compact design and provides, on the other hand, sufficient processing reserve for the future introduction of additional functions.

Fig. 85: Digital substation control, operator desk. Control of a 400 kV substation (double control unit)

Static memories A decisive step in direction of user friendliness has been made with the implementation of large nonvolatile Flash EPROM memories. The system parameters can be loaded via a serial port at the front panel of the central unit. Bay level parameters are automatically downloaded. A change of EPROM hardware is no longer necessary when parameters have to be changed or added for the implementation of new functions or the extension of substations. Analog value processing The further processing of raw measured data, such as the calculation of maximum, minimum or effective values, with assigned real time is contained as standard function. A Flash EPROM mass storage can optionally be provided to record measured values, fault events or fault oscillograms. The stored information can be read out locally or remotely by a telephone modem connection. Further data evaluation (harmonic analysis, etc.) is then possible by means of a special PC program (LSA PROCESS). Compact design A real reduction in space and cost has been achieved by the creation of compact I/O and central units. The processing hardware is enclosed in metallic cases with EMI-proof terminals and optical serial interfaces. All units are type tested according to the latest IEC standards. In this way, the complete control and protection equipment can be directly integrated into the MV or HV switchgear (Fig. 86, 87).

Fig. 86: Switchgear-integrated control and protection

Fig. 87: View of a low-voltage compartment

Switchgear interlocking and local control In simple distribution stations, the interlocking can be part of the control software. For larger stations with a multiple busbar layout, in particular on the EVH level, an independent, digital interlocking system (8TK) with integrated local control elements is applied in many cases. It ensures fail-safe switching and personnel safety down to the lowest control level, i.e. directly at the switch panel, even when supervisory control is not available. The interlocking system consists of distributed, feeder-dedicated MP units and one central unit which is normally assigned to the bus-coupler bay. The information exchange is performed via serial links in the switchyard. The front panel of each unit contains control elements with switch position indicators for local (site) control. This system has also been frequently applied as a standalone function in substations up to 800 kV.

Siemens Power Engineering Guide · Transmission & Distribution

6/49

Local and Remote Control

Management terminal

System control center

Modem VF Remote control

Telephone network

Modem

VF

Substation level ERTU Fig. 88: Numerical protection, standard design

A complete range of fully digital (numerical) relays is available (see chapter Power System Protection 6/8 and following pages). They all have a uniform design compatible with the control units (Fig. 88). This applies to the hardware as well as to the software structure and the operating procedures. Metallic standard cases, IEC 255-tested, with EMI-secure terminals, ensure an uncomplicated application comparable to mechanical relays. The LCD display and setting keypad are integrated. Additionally a RS232 port is provided on the front panel for the connection of a PC as an MMI. The rear terminal block contains an opticalfiber interface for the data communication with the LSA control system. The relays are normally linked directly to the relevant I/O control unit at the bay level. Connection to the central control system unit is, however, also possible. The numerical relays are multifunctional and contain, for example, all the necessary protection functions for a line feeder or transformer. At higher voltage levels, additional, main or back-up relays are applied. The new relay generation has extended memory capacity for fault recording (5 seconds, 1 ms resolution) and nonvolatile memory for important fault informations. The serial link between protection and control uses standard protocols in accordance with IEC 870-5-103. In this way, supplier compatibility and interchangeability of protection devices is achieved.

6/50

Printer

Marshalling rack

Numerical protection

Bay level

Operator terminal

Interposing relays, transducers

Existing switchgear

Extended switchgear

Fig. 89: Enhanced remote terminal unit 6MB55, application options

Enhanced remote terminal units

Communication with control centres

For substations with existing remote terminal units, an enhancement towards the LSA performance level is feasible. The telecontrol system 6MB55, based upon LSA components, replaces outdated remote terminal units (Fig. 89). Conventional RTUs are connected to the switchgear via interposing relays and measuring transducers with a marshalling rack as a common interface. The centralized version of the LSA control system (SINAUT-LSA) can be directly connected to this interface. The total parallel wiring can be left in its original state. In this manner, it is possible to enhance the RTU function and to include substation monitoring and control with the same performance level as the decentralized LSA system. Upgrading of existing substations can thus be achieved with a minimum of cost and effort.

The LSA system uses protocols that comply with IEC Standard 870-5. In many cases an adaption to existing proprietary protocols is necessary, when the system control center has been supplied by another manufacturer. For this purpose, a larger number of protocol converters have been developed and an extensive protocol library now exists. Further protocol converters can be provided on demand. By adding software that runs on the communication processor of the ERTU, the different protocol converters can be implemented.

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Engineering system LSATOOLS

PC input

Parameterizing

Documentation Engineering system

Single-line diagram

Circuit diagram

Device configuration

Parameters

Function, processing diagram

Fig. 90: Engineering system LSATOOLS

LSATOOLS parameterization station

In parallel with the upgrading of the central unit hardware, a novel parameterizing and documentation system LSATOOLS has been developed. It uses modern graphical presentation management methods, including pull-down menus and multiwindowing. LSATOOLS enables the complete configuration, parameterization and documentation of the system to be carried out on AT-compatible PC workstations. It ensures that a consistent database for the project is maintained from design to commissioning (Fig. 90). The system parameters, generated by LSATOOLS, can be serially loaded into the Flash EPROM memory of the central control unit and will then be automatically downloaded to the bay level devices (Fig. 91). Care has been taken to ensure that changes and expansions are possible without requiring a complete retest of the system. Supplier independent system modifications and extensions are therefore possible.

Network control center

Documentation CAD system SIGRAPH-ET Master unit

Loading of parameters

Downloading of parameters during startup PC inputs

Input/output units

Fig. 91: PC-aided parameterization of LSA 678 with LSATOOLS and downloading of parameters

Siemens Power Engineering Guide · Transmission & Distribution

6/51

Local and Remote Control

Substation control system 6MB51/52 In the 6MB51/52 substation control system the functions are distributed between station and bay control levels. The input/output devices have the following tasks on the bay control level: ■ Signal acquisition ■ Acquisition of measured and count values ■ Monitoring the execution of master control unit commands, e.g. for – Control of switchgear – Transformer step changing – Setting of Peterson coils Data processing, such as – Limit monitoring of measured values, including initiation of responses to limit violations – Calculation of derived operational measured values (e.g. P, Q, cos ϕ ) and/or operational parameters (for example r.m.s. values, slave pointer) from the logged instantaneous values for current and voltage – Deciding how much information to transmit to the control master unit in each polling cycle – Generation of group signals and deriving of signals internally, e.g. from self-monitoring ■ Switchgear-related automation tasks – Switching sequences in response to switching commands or to process events – Transformer control – Synchronization ■ Transmission of data from numerical protection relays to the control master unit ■ Local display of status and measured values. Bay control units A complete range of devices is available to meet the particular demands concerning process signal/capacity and functionality (see Fig. 98). All units are built-up in modern 7XP20 housings and can be directly installed in the low-voltage compartments of the switchgear or in separate cubicles. The smallest device 6MB525 is designed as a low-cost version and contains only control functions. It is provided with an RS485-wired serial interface and is normally used for simple distribution-type substations together with overcurrent/overload relays 7SJ60 and digital measuring transducers 7KG60. (see application example, Fig. 118).

6/52

Higher-level control system

Station control center

Central evaluation station (PC)

Telecontrol channel

Telephone channel

Normal time

Master control unit 6MB51 Station level 1

n

Switchgear interlock master unit 8TK2 1

Station protection 7SS5 n

Bay level Switchgear interlock bay unit 8TK1

Bay control unit 6MB52

Protection relays 7S/7U

Substation Serial interface

Parallel interface

Fig. 92: LSA 678 protection and substation control system with the 6MB substation control system

All further bay control devices contain an optic serial interface for connection to the central control unit, and an RS232 serial interface on the front side for connection of an operating PC. Further, integral displays for measuring values and LEDs for status indication are provided.

Compact devices 6MB522/523

Minicompact device 6MB525 It contains signal inputs and command outputs for substation control. Analog measuring inputs, where needed, have to be provided by additional measuring transducers, type 7KG60. Alternatively, the measuring functions of the numerical protection relays can be used. These can also provide local indication of measuring values. The local bay control is intended to be performed by the existing, switchgear integrated mechanical control.

They provide a higher number of signal inputs and outputs, and contain additional measuring functions. One measuring value or other preprocessed information can be displayed on the 2-row, 16-character alphanumeric display. For local bay control an additional small mimic board with control elements (device 6MB531) can be added, or, where applicable, the integrated bay control panel of the 8TK interlocking system can be used.

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Compact devices with bay control 6MB524 This bay control device can be delivered in four versions dependent on the peripheral requirements. It provides all control and measuring functions needed for switchgear bays up to the EHV level. Switching status, measuring values and alarms are indicated on a large alphanumeric display. Measuring instruments can therefore be widely dispensed with. Bay control is, in this case, performed by the additionally integrated keypad.

Fig. 93: Minicompact I/O device 6MB525

Fig. 94: Compact I/O device 6MB523

Fig. 95: Compact I/O device 6MB522

This fully integrated device provides all protection, control and measuring functions for simple line/cable, motor or transformer feeders. Protection is limited to overcurrent, autoreclosure, overload, ground-fault and breaker-failure protection. Only one unit is needed per feeder. Space, assembly and wiring costs can therefore be considerably reduced. Measured value display and local bay control is performed in the same way as with the bay control unit 6MB524 with a large display and a keypad.

Fig. 97: Combined protection and control device 7SJ531

Fig. 96: Compact I/O unit with local (bay) control 6MB5240-0

Type

Design

Combined protection and control device 7SJ531

Commands Double Single

Signal inputs Double Single

Components

Analog inputs Direct connection to transformer

Connection to measure transducer

–

–

Double commands and alarms also as ”single“ configurable

1xI

–

for simple switchgear cubicles with one switching device

Minicompact*

6MB525

2

–

6

Compact*

6MB523

1

–

3

5

6MB522-0 6MB522-1 6MB522-2

3 6 6

1 2 2

3 6 6

5 10 10

2 x U, 1 x I 3 x U, 3 x I 4 x U, 2 x I

2 – 2

4 6 8 20

1 1 2 5

8 12 16 40

– – – –

2 x U, 1 x I 3 x U, 3 x I 3 x U, 3 x I 9 x U, 6 x I

1 2 2 5

1

–

–

–

3 x U, 3 x I

* * * Compact with local (bay) control and large display

6MB5240-0 -1 -2 -3

Combined control and protection device with local (bay) control

7SJ531

–

with P, Q calculation Double commands and alarms also usable as ”single“

Double commands and alarms also usable as ”single“

* Local (bay) control has to be provided separately (device 6MB531). In distributiontype substations, mechanical local control of the switchchgear is normally sufficient. Fig. 98: Standardized input/output devices with serial interfaces

Siemens Power Engineering Guide · Transmission & Distribution

6/53

Local and Remote Control

The 6MB51 control master unit This unit lies at the heart of the 6MB substation control system and, with its 32-bit 80486 processor, satisfies the most demanding requirements. It is a compact unit inside the standard housing used in Siemens substation secondary equipment. The 6MB51 control master unit manages the input/output devices, controls the interaction between the control centers in the substation and the higher control levels, processes information for the entire station and archives data in accordance with the parameterized requirements of the user. Specifically, the control master unit coordinates communication ■ to the higher network control levels ■ to the substation control center ■ to an analysis center located either in the station or connected remotely via a telephone line using a modem ■ to the input/output devices and/or the numerical protection units (bay control units) ■ to lower-level stations. This is for the purpose of controlling and monitoring activities at the substation and network control levels as well as providing data for use by engineers. Other tasks of the control master unit are ■ Event logging with a time resolution of 1 or 10 ms ■ Archiving of events, variations in measured values and fault records on mass storage units ■ Time synchronization using radio clock (GPS, DCF77 or Rugby) or using a signal from a higher-level control station ■ Automation tasks affecting more than one bay: – Parallel control of transformers – Synchronizing (measured value selection) – Switching sequences – Busbar voltage simulation – Switchgear interlocking ■ Parameter management to meet the relevant requirements specification ■ Self-monitoring and system monitoring.

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Fig. 99: Compact control master unit 6MB513 for a maximum of 32 serial interfaces to bay control units. Extended version 6MB514 for 64 serial interfaces to bay control units (double width) additionally available

Fig. 100: SINAUT LSA PC station control center with function keyboard

System monitoring primarily involves evaluating the self-monitoring results of the devices and serial interfaces which are coordinated by the control master unit. In particular, important EHV substations, some users require redundancy of the control master unit. In these cases, two control master units are connected to each other via a serial interface. System monitoring then consists of mutual error recognition and, if necessary, automatic transfer of control of the process to the redundant control master unit.

The operator can access the required information or initiate the desired operation quickly and safely with just a few key strokes. The station control center can take the form of ■ A standard PC with selectable monitor size ■ An industry-standard PC (e.g. built into a switchgear cubicle top unit) or as ■ A laptop (also portable). It can be operated at a distance from the station. Two station control centers can be installed if required by the user.

The SINAUT LSA station control center The standard equipment of the station control centre includes ■ The function keyboard with eight function keys and four cursor control keys or (alternatively) a full PC keyboard optionally with a mouse ■ The PC with color monitor and LSACONTROL software package for displaying – A station overview – Detailed plant displays – Event and alarm lists – Alarm information ■ A printer for the output of reports. Various operating options are clearly displayed in the eight menu fields on the color monitor. These correspond to the eight function keys.

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Local control functions Tasks of local control The Siemens 6MB station control system performs at first all tasks for conventional local control: ■ Local control of and checkback indications from the switching devices ■ Acquisition, display and registration of analog values ■ Acquisition, display and registration of alarms and fault indications in real time ■ Metered-value acquisition and processing ■ Fault recording ■ Transformer open-loop and closed-loop control ■ Synchronizing/paralleling Unlike the previous conventional technology with completely centralized processing of these tasks and complicated parallel wiring and marshalling of process data, the new microprocessor-controlled technology benefits from the distribution of tasks to the central control master unit and the distributed input/output units and of the serial data exchange in telegrams between these units. Tasks of the input/output unit The input/output unit performs the following bay-related tasks: ■ Fast distributed acquisition of process data such as indications, analog values and switching device positions and their preprocessing and buffering ■ Command output and monitoring ■ Assignment of the time for each event (time tag) ■ Isolation from the switchyard via heavyduty relay contacts ■ Run-time monitoring ■ Limit value supervision ■ Paralleling. Analog values can be input to the bay control unit both via analog value transducers and by direct connection to c.t.s and v.t.s. The required r.m.s. values for current and voltage are digitized and calculated as well as active and reactive power. The advantage is that separate measuring cores and analog value transducers for operational measurement are eliminated.

Control master unit The process data acquired in the input/output unit are scanned cyclically by the control master unit. The control master unit performs further information processing of all data called from the feeders for station tasks ”local control and telecontrol“ with the associated event logging and fault recording and therefore replaces the complicated conventional marshalling distributor racks. Marshalling is implemented under microprocessor control in the control master unit. Serial protection interface All protection indications and fault recording data acquired for fault analysis in protection relays are called by the control master unit via the serial interface. These include instantaneous values for fault current and voltage of all phases and earth, sampled with a resolution of 1 ms, as well as distance-to-fault location. Serial data exchange The serial data exchange between the bay components and the control master unit has important economic advantages. This is especially true when one considers the preparation and forwarding of the information via serial data link to the control center communication module which is a component of the control master unit. This module is a single, system-compatible microprocessor module on which both the telecontrol tasks and telegram adaptation to telegram structures of existing remote transmission systems are implemented. This makes the station control independent of the telecontrol technology and the associated telegram structure used in the network control center at a higher level of the hierarchy.

Siemens Power Engineering Guide · Transmission & Distribution

Fig. 101: Fiber-optic connections on the control master unit

Station control center The peripheral devices for operating and visualization (station control center) are also connected to the control master unit. The following devices are part of the station control center: ■ A color VDU with a function keyboard

or mouse for display, control, event and alarm indication, ■ A printer for on-line logging (event list), ■ A mass storage. VDU with function keyboard The display is output via the VDU. To simplify operation, a function keyboard is normally used instead of an alphanumeric keyboard with only eight function keys and five keys for cursor positioning. Alternatively, operation with the mouse can be supplied. Handling is simplified as ”user guidance“ is used. Note fields in the lower portion of the screen are assigned to eight function keys. These contain a text indicating what is executed or selected with the key. In this way, various detailed diagrams and lists can be selected. The contents of the diagrams and lists can be parameterized, i.e. they can be altered subsequently.

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Local and Remote Control

Switchyard overview diagram A switchyard single-line diagram can be configured to show an overview of the substation. This diagram is used to give the operator a quick overview of the entire switchyard status and shows, for example, which feeders are connected or disconnected. Current and other analog values can also be displayed. Information about raised or cleared operational and alarm indications are also displayed along the top edge of the screen. It is not possible to perform control actions from the switchyard overview. If the operator wants to switch a device, he has to select a detailed diagram, say ”110 kV detailed diagram“. If the appropriate function key is pressed, the 110 kV detailed diagram (Fig. 103) appears. This display shows the switching state of all switching devices of the feeders. Function field control In the menu of the function fields, it is possible, for example, to select between control switching devices and tap changing. By pressing key “Control“, the yellow signal of the cursor control jumps to the first switching device in the top left-hand corner of the screen. At the same time, new functions are assigned to the fields along the bottom edge of the screen, e.g. ON or OFF. The cursor is now positioned on the switching device to be switched. When the function key for the required position of a switchig device is pressed, e.g. OFF, the switching device blinks in the switch position to which it is to move (control acknowledgement switch principle). At this point it is still possible to check whether the selected switching command is really to be executed. The actual command is output using another key, the ”command output“ key. If the command is found to be safe after a check has been made for violations of interlock conditions, the switching device in question is operated. In the case where a mouse is available, the appropriate device is selected by the usual mouse operation. Once the switching command has been executed and a checkback signal has been received, the blinking symbol changes to the new actual state on the VDU. In this way, switching operations can be performed very simply and absolutely without error. If commands violate the interlock conditions or if the switch position is not adopted by a switching device, for example, because of a drive fault, the relevant fault indications or notes are displayed on the screen.

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Fig. 102: Compact I/O unit with local (bay) control, extended version 6MB5240-3

Event list

Example alarm list (Fig. 105)

All events are logged in chronological order. The event list can be displayed on the VDU whenever called or printed out on a printer or stored on a mass-storage medium. Fig. 104 shows a section of this event list as it appears on the VDU.

When the alarm list is selected, it is displayed on the VDU. In this danger alarm concept a distinction is made between cleared and raised and between acknowledged and unacknowledged indications. Raised indications are shown in red, cleared indications are green (similar to the fast/slow blinking lamp principle). The letter Q is placed in front of an indication that has not yet been acknowledged. Indications that are raised and cleared and acknowledged are displayed in white in the list. This system with representation in the alarm list therefore supersedes danger alarm equipment with two-frequency blinking lamps traditionally used with conventional equipment. As stated above, all events can also be continuously logged in chronological order on the associated printer, too. The appearance of this event list is identical to that on the VDU.

Example event list (Fig. 104) The date can be seen in the left-hand area and the events are shown in order of priority. Switching commands and fault indications are displayed with a precision of up to 1 ms and events with high priority and protection indications after a fault-detection are shown with millisecond resolution. A command that is accepted by the control system is also displayed. This can be seen by the index ”+“ of the command (OP), otherwise ”OP–“ would appear. If the switchgear device itself does not execute the command, ”FB–“ (checkback negative) indicates this. ”FB+“ results after successful command execution. The texts chosen are suggestions and can be parameterized differently. The event list shows that a protection fault-detection (general start GS) has occurred with all the associated details. The real time is shown in the left-hand column and the relative time with millisecond precision in the right-hand column, permitting clear and fast fault analysis. The fault location, 17 km in this case, is also displayed. The lower section of the event list shows examples of raised (RAI) and cleared (CLE) alarm indications, such as ”voltage transformer miniature-circuit-breaker tripped“. This fault has been remedied as can be seen from the corresponding cleared indication. The letter S in the top line, called the indication bar, indicates that a fault indication has been received that is stored in a separate ”warning list“.

Mass storage It is also possible to store historic fault data, i.e. fault recording data and events on mass-storage medium. It can accept data from the control master units and stores it on Flash EPROMs. This static memory is completely maintenancefree when compared to floppy or hard disc systems. 8Mbyte of recorded data can be stored. The locally or remotely readable memory permits evaluation of the data using a PC. This personal computer can be set up separately from the control equipment, e.g. in an office. Communication then takes place via a telephone-modem connection. In addition to fault recording data, operational data, such as load-monitoring values (current, voltage, power, etc.) and events can be stored.

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Fig. 103: 6MB substation control, example: detailed diagram of a 110 kV switchgear on the VDU

Fig. 104: 6MB substation control, example: event list on the VDU

Fig. 105: 6MB substation control, example: alarm list on the VDU

Fig. 106: 6MB substation control system, example: fault recording

Example fault recording (Fig. 106) After a fault, the millisecond-precision values for the phase currents and voltages and the ground current and ground voltage are buffered in the feeder protection. These values are called from the numerical feeder protection by the control master unit and can be output as curves with the program OSCGRA (Fig. 106). The time marking 0 indicates the time of fault detection, i.e. the relay general start (GS). Approx. 5 ms before the general start, a three-phase fault to ground occurred, which can be seen by the rise in phase currents and the ground current. 12 ms after the general start, the circuit breaker was tripped (OFF) and after further 80 ms, the fault was cleared.

After approx. 120 ms the protection reset. Voltage recovery after disconnection was recorded up to 600 ms after the general start. This format permits quick and clear analysis of a fault. The correct operation of the protection and the circuit breaker can be seen in the fault recording (Fig. 106). The high-voltage feeder protection presently includes a time range of at least 5 seconds for the fault recording. The important point is that this fault recording is possible in all feeders that are equipped with the microprocessor-controlled protection having a serial interface according to IEC 870-5-103.

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Local and Remote Control

Switchgear interlocking system Switchgear Switchgear interlocking bay unit The Siemens 8TK switchgear interlocking is used in multiple busbar switchyards with power-operated switching devices. For each switching bay, the switchgear interlocking bay unit performs a combination of local control and bay-internal interlocking. Fig. 108 shows the bay control unit with integrated local control mimic pad and control keys. Interlocking bay unit

Switchgear interlocking central unit A switchgear interlocking central unit is available for cross-bay switchyard interlocking. It is usually assigned to the bus tie of the multiple busbar system. The switchgear interlocking central unit communicates with the feeder units via separate shielded four-wire serial data lines separate from other control components.

Further bay units

Shielded cables

SCC bay unit

Interlocking bay unit Further bay units

Shielded cables

SCC bay unit

SCC bay unit

OF

Serial connection of the switchgear interlocking units The switchgear interlocking feeder units are connected to the switchgear interlocking central unit in a star configuration via the serial connections. The advantages of this star configuration are: ■ Considerably reduced wiring for switchyard interlocking ■ Higher availability ■ Monitoring of the serial data exchange ■ Simple expansion ■ Self-monitoring of the switchgear interlocking units, the switchyard connection and the interlock conditions. Fig. 109 shows the equipment of a switchyard with a switchgear interlocking central unit and the associated switchgear interlocking bay units.

Interlocking master unit

OF

Substation control (SSC) Parallel wiring

OF Serial connection Optical fibers

Fig. 107: Function overview of the 8TK switchgear interlocking system

Fig. 108: Switchgear interlocking bay unit with local (bay) control and indication

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Local and Remote Control

Use and application The switchgear interlocking system can be used both as an autonomous system and as a component of the overall coordinated protection and substation control system. It can therefore replace the traditional hardwired switchgear interlocking devices used so far with decisive added advantages. In both applications, the switchgear interlocking system is always the back-up control system in the lowest control level, i.e. in the immediate vicinity of the switchyard. This means that safe operation of the switchyard is ensured in the event of failure of a higher-level control system taking both the bay-internal interlocking and the overall switchgear interlocking into account. Moreover, even in the event of faults in one bay, the rest of the switchyard can also be operated subject to the switchyard interlocking conditions and the last switching device positions of the defective bay. This ensures that the device where the fault was detected does not perform malfunctions or maloperations. The defective bay can in an emergency still be operated authorized personnel using a keyswitch. This is even possible if the power supply module has failed in a bay. In accordance with DIN VDE 101, Section 4.4 (safe local operation) and DIN 31 005 (”The interlock acts by blocking or releasing in the event of element initiation on condition that it is only possible to change between blocking and releasing if all other elements are in their defined initial positions.“), the switchgear interlocking has been consistently matched to the requirements of the switchgear. The interlocks do not have a gap anywhere and deserve the designation ”switchgear interlocking“. The switchgear interlocking was the first supplied subsystem of coordinated substation control and protection. Extensive tests have been run with the switchgear interlocking equipment both in the laboratory and in high-voltage and extra-high-voltage switchyards including the NEMP* test. These tests for dielectric strength and especially for electromagnetic compatibility (EMC) have shown that the new microprocessor-controlled technology can even be used in the immediate vicinity of extrahigh-voltage switchgears.

* Nuclear

Electrical Magnetic Pulse

Q 15, 25, 35

Q 10, 20, 30

Q 1, 2, 3

Q 11, 21, 31

Q 1, 2, 3

Q 1, 2, 3

Q51 Q0

Q52

Q7

Q75

Q0

Q0 Q6

Q9 Q7

Central unit for a maximum of 14 switching devices for a bus tie/bus coupler

Large bay unit for a maximum of 14 switching devices

Station

Small bay unit for a maximum of 6 switching devices

Power supply

Small bay unit for a maximum of 6 switching devices

Serial datatransmission line

Fig. 109: 8TK switchgear interlocking system in a high-voltage switchyard with triple busbar system

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Local and Remote Control

Application examples The flexible use of the components of the Coordinated Protection and Substation Control System LSA 678 is demonstrated in the following for some typical application examples.

Bay

1

2

n

Bus coupler

Application in high-voltage substations with relay kiosks Fig. 110 shows the arrangement of the local components. Each two bays (line or transformer) are assigned to one kiosk. Each bay has at least one input/output unit for control (bay control unit) and one protection unit. In extra-high-voltage, the protection is normally doubled (main- and back-up protection). For important substations an independent switchgear interlocking system is additionally recommended. It also provides integrated local (bay) control functions with control switches and a small mimic pad that displays isolator and circuit breaker positions. In this way, safe interlocked switching is even possible when the main control system has failed. The protection relays are serially connected to the bay control unit by optical-fiber links.

SIL(B) FPR IOU

Control building

SIL(B) FPR IOU

Relay kiosks

SIL(B) FPR IOU

SIL(M) FPR IOU

To the network control center

CSM with CCC and MS

Modem To the operations and maintenance office

Parallel Serial

VDU

Key: CSM CCC MS VDU

Control system master unit Control center coupling Mass storage Visual display unit

FPR SIL(B) SIL(M) IOU

Feeder protection relays Switchgear interlocking bay unit Switchgear interlocking master unit Control input/output unit

Fig. 110: Application example of outdoor HV or EHV substations with relay kiosks

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Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

In extremely important substations, mainly extra-high-voltage, there exists a doubling philosophy. In these substations, the feeder protection, the DC supply, the operating coils and the telecontrol interface are doubled. In such cases, the station control system with its serial connections, and the master unit with the control center coupling can also be doubled. Both master units are brought up-to-date in signal direction. The operation management can be switched over between the two master units (Fig. 111).

Network control center Printer

Printer Control/ annunciation

Control center coupling

Control system master unit 1 with mass storage 1 Local control level

Control/ annunciation

Switchover and monitoring*

••••••••••••

Control center coupling

Control system master unit 2 with mass storage 2

••••••••••••

Bay control level ••••••••••

ProtecControl tion relay input/ output unit

Feeder 1

Switchgear interlocking

••••••••••••

Switchgear interlocking

Control input/ output unit

Switchgear

*only principle shown

Protection relay

Feeder n

Parallel

Serial

Fig. 111: System concept with double central control

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Local and Remote Control

Application in indoor high-voltage substations The following example (Fig. 112) shows an indoor high-voltage switchgear. All decentralized control system components, such as input/output unit, feeder protection and switchgear interlocking system are also grouped per bay and installed close to the switchgear. They are connected to the control system master unit in the same way as described in the outdoor version via fiber-optic cables.

Control room

VDU To the office

Switchgear room Switchgear bay 1 bay 2 …

Modem

SIL(B) SIL(B) Control

Application in medium voltage substations The same basic arrangement is also applicable to medium-voltage (distribution-type) substations (Fig. 113 and 114). The feeder protection and the compact input/output units are, however, preferably installed in the low-voltage compartment of the feeders (Fig. 113) to save costs. There is now a trend to apply combined control and protection units. The relay 7SJ531, for example, provides protection, metering (current display) and has an integrated bay control with mimic and LCD pad. Thus, only one device is needed per cable, motor or O.H. line feeder.

Bus coupler

FPR

FPR

IOU

IOU

and protection cubicles

SIL(M) FPR IOU CSM

To the network control center Parallel

Serial

Key: CSM Control system master with control SIL(B) Switchgear interlocking bay unit center coupling and mass storage SIL(M) Switchgear interlocking master unit VDU Monitor IOU Control input/output unit FPR Feeder protection relays Fig. 112: Application example of indoor substations with switchgear interlocking system

Protection and substation control LSA 678 with input/output units and numerical protection installed in low-voltage compartments of the switchgear VDU with keyboard

1

Printer

Network control center

2

3

Operation place

4

5

Control system master unit with optical-fiber link

1

Feeder protection unit (e.g. 7UT51 transformer protection)

2

Feeder I/O contol unit (e.g. 6MB524)

3

Combined control and protection feeder unit 7SJ531

4 5

Miniature I/O unit 6MB525 Feeder protection (e.g. 7SD5 line differential protection)

Fig. 113: Protection and substation control system LSA 678 for a distribution-type substation

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Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Control room

VDU To the office

Fig. 115 shows an example for the most simple wiring of the feeder units. The voltages between the input/output unit and the protection can be paralleled at the input/output unit because the plug-in modules have a double connection facility. The current is connected in series between the devices. The current input at the input/output unit is dimensioned for 100xIN, 1 s (protection dimensioning). The plug-in modules have a short-circuiting facility to avoid opening of c.t. circuits. The accuracy of the operational measurements depends on the protection characteristics. Normally, it is approx. 2% of IN. If more exact values are required, a separate measuring core must be provided. The serial interface of the protection is connected to the input/output unit. The protection data is transferred to the control master unit via the connection between the input/output unit and the master unit. Thus, only one serial connection to the master unit is required per feeder.

Switchgear room Bus coupler

Switchgear

Modem

IOU FPR IOU FPR

Parallel

CSM

IOU FPR

To the network control center

Serial

Key: CSM Control system master

FPR Feeder protection

with mass storage and control center coupling VDU Monitor

relay IOU Input/output unit

For o/c feeder or motor protection also as one combined unit (7SJ531) available

Fig. 114: Application example of medium-voltage switchgear

Plug-in module

Control I/0 unit 1) 6MB52

Numerical 1) Protection

Switching status

c.b. ON/OFF 2)

Protection core

I

close or 2) open

close or 2) trip

Short-circuiting facility

U

1) For o/c feeder protection or motor protection also as combined control and protection unit 7SJ531 available 2) Only one circuit shown

Serial data connection

Fig. 115: Principle wiring diagram of the medium-voltage feeder components

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Local and Remote Control

System configuration The system arrangement depends on the type of substation, the number of feeders and the required control and protection functions. The basic equipment can be chosen according to the following criteria: Central control master unit has to be chosen according to the number of bay control units to be serially connected: ■ 6MB513 for a maximum of 32 serial interfaces ■ 6MB514 for a maximum of 64 serial interfaces At the most 9 more serial interfaces are available for connection of data channels to load despach centers, local substation control PCs, printers, etc. Substation control center It normally consists of a PC with a special control keyboard or normal keyboard with a mouse, color monitor, LSA CONTROL software and a printer for the output of reports. For exact time synchronization of 1 millisecond accuracy, a GPS or DCF77 receiver with antenna may be used. Bay control units Normally, a separate bay control unit is assigned to every substation bay. The type has to be selected according to the following requirements: ■ Number of command outputs

that means the sum of circuit breakers, isolators and other equipment to be centrally or remotely controlled. The stated double commands are normally provided for double-pole (”+“ and ”–“) control of trip or closing coils. Each double-pole command can be separated into two single-pole commands where stated (Fig. 98, page 6/53). ■ Number of digital signal inputs as the sum of alarms, breaker and isolator positions, tap changer positions, binary coded meter values, etc, to be acquired, processed or monitored. Position monitoring requires double signal inputs while single inputs are sufficient for normal alarms. ■ Number of analog inputs depends on the number of voltages, currents and other analog values (e.g. temperatures) to be monitored. Currents (rated 1 A or 5 A ) or voltages (normally rated 100 to 110 V) can be directly connected to the bay control units. No transducers are required. Numerical protection relays also acquire and process currents and voltages.

6/64

They can also be used for load monitoring and indication (accuracy about 2% of rated value). In this way, the number of analog inputs of the bay control units can be reduced. This is often practised in distribution-type substations. The device selection is discussed at the following example.

Incoming transformer bays To the central control unit

OF OF OF

Example: Substation control configuration Fig. 116 shows the arrangement of a typical distribution-type substation with two incoming transformers, 10 outgoing feeders and a bus tie. The required inputs and outputs at bay level are listed in Fig. 117 for the incoming transformer feeders and in Fig. 118 for the outgoing line feeders, the bus tie and the v.t. bay. Each bay control unit is connected to the central control unit via fiber-optic cables (graded index fibers). The o/c relays 7SJ60, the mini-compact I/O units 6MB5250 and the measuring transducers 7KG60 each have RS 485 communication interfaces and are connected to a bus of a twisted pair of wires. A converter RS485 to fiber-optic is therefore additionally provided to adapt the serial wire link to the fiber-optic inputs of the central unit. Recommendations for the selection of the protection relays are given in the section System Protection (6/8 and following pages). The selection of the combined control/protection units 7SJ531 is recommended when local control at bay level is to be provided by the bay control unit. The low-cost solution 7SJ60 + 6MB5250 should be selected where switchgear integrated mechanical local control is acceptable.

Typical distribution-type substation

6MB5240-2

7SJ511

7UT512

HV

M M

I

50/ 51

V

87T RTD's

63

M M

MV

Data acqusition 1 x DSI 1 x DSI 1 x DSI 1 x DSI 8 x DSI

Isolator HV side Circuit breaker HV side Isolator MV side Circuit breaker MV side Transformer tap-changer positions Alarm Buchholz 1 1 x SSI Alarm Buchholz 2 1 x SSI 3 x V, 3 x J, 8 xϑ Measuring values

Control

115 kV

115 kV

13.8 kV

13.8 kV

5 feeders

5 feeders

Fig. 116: Typical distribution-type substation

2 x DCO 2 x DCO 2 x DCO 2 x DCO 2 x SCO 1 x SCO SSI DSI DCO SCO

Isolator HV side Circuit breaker HV side Isolator MV side Circuit breaker MV side Tap changer, higher, lower

Single signal input Double signal input Double command Single command

Fig. 117: Typical I/O signal requirements for a transformer bay

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

To load dispatch center Central control unit To transformer feeders

6MB513

GPS

OF OF

VDU

Printer (option)

Mass storage

OF

RS485/O F

RS485

7KG60

6MB 7SJ60 5250

6MB 7SJ60 5250

6MB 7SJ60 5250

7SJ531

7SJ531

51

M

M 51

Voltage tronsformer-bay

Per feeder

M

51

51

Bus tie

Isolator

1 x DSI

Isolator

1 x DSI

Grounding switch

1 x DSI

Grounding switch

1 x DSI

Circuit breaker

Circuit breaker

1 x DSI

Circuit breaker

9 alarms

5 x SSI

5 alarms

5 alarms

1 x DSI 9 x SSI

51

Per feeder

1 x DSI

5 x SSI 1 x 7KG60

M

Load currents are taken from the protection relays

Measuring values (3 x V, 3 x I) from protection

2 x DCO Circuit breaker

2 x DCO Circuit breaker

Control

2 x DCO

Circuit breaker

Fig. 118: Typical I/O signal requirements for feeders of a distribution-type substation

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Local and Remote Control

Enhanced remote terminal units 6MB551 The 6MB55 telecontrol system is based on the same hardware and software modules as the 6MB51/52 substation control system. The functions of the inupt/output devices have been taken away from the bays and relocated to the central unit at station control level. The result is the 6MB551 enhanced remote terminal unit (ERTU). Special plug-in modules for control and acquisition of process signals are used instead of the bay dedicated input/output devices: ■ Digital input (32 DI) ■ Analog input (32 AI grouped, 16 AI isolated) ■ Command output (32 CO) and ■ Command enabling These modules communicate with the central 6MB modules in the same frame via the internal standard LSA bus. The bus can be extended to further frames by parallel interfaces. The 6MB551 station control unit therefore has the basic structure of a remote terminal unit but offers all the functions of the 6MB51/52 substation control system such as: ■ Operating and monitoring from station control level ■ Serial connection of numerical protection equipment ■ Archiving of process results and events ■ Implementation of automation tasks. The following options are possible: ■ Radio clock ■ Serial interfaces to system control

centers (up to 3) with separate communication protocols each, as applicable ■ Up to 64 serial fiber-optic interfaces to distributed bay control units ■ Expanded measured-value processing ■ Logic and automatic programs ■ Mass storage ■ Up to 5 expansion frames Configuration including signal I/O modules can be parameterized as desired. Up to 121 signal I/O modules can be used (21 per frame minus one in the baseframe for each expansion frame, i.e. totally 6 x 21 – 5 = 121). The 6MB551 station control unit can therefore be expanded from having simple telecontrol data processing functions to assuming the complex functionality of a substation control system.

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System control center

Station control center (option)

Central evaluation station (PC)

Remote control channel

Telephone channel

Radio time (option) Enhanced terminal unit 6MB551 1 … … n Switchgear interlock master unit 8TK2

Marshalling rack Transducers and relays interposing

Station protection 7SS5

Station control level Bay control level

(option)

Switchgear interlock bay unit 8TK1

(option)

Protection relay 7S/7U

Substation

Input/output device 6MB52*

Extension to substation Serial interface

Parallel interface

Fig. 119: Protection and substation control with the enhanced terminal unit 6MB551

The same applies to the process signal capacity. In one unit, more than 4 000 data points can be addressed and, by means of serial interfacing of subsystems, this figure can be increased even further. The 6MB551 station control unit simplifies the incorporation of extensions to the substation by using the decentralized 6MB52* input/output devices for the additional substation bays. These distributed input/output devices can then be connected via serial interface to the telecontrol equipment. Additional parameterization takes care of their actual integration in the operational hierarchy. The 6MB551 RTU system is also available as standard cubicle version SINAUT LSA COMPACT 6MB5540. The modules and the bus system have been kept, the rack design and the connection technology, however, have been cost-optimized (fixed rack only and plug connectors). This version is limited to a baseframe plus one extension frame with altogether 33 I/O modules.

Fig. 120: 6MB551 enhanced remote terminal unit, installed in an 8MC standard cubicle with baseframe and expansion frame

Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Remote terminal units (RTUs) The following range of intelligent RTUs are designed for high-performance data acquisition, data processing and remote control of substations. The compact versions 6MB552/553 of SINAUT LSA are intended to be used in smaller substations, while the version 6MD2010 of SINAUT RTU has the full functionality for control of large substations with up to 2000 data points.

Fig. 121: 6MB552 compact RTU for medium process signal capacity

Fig. 122: 6MB5530-0 minicompact RTU for small process signal capacity

Fig. 124: 6MD2010 telecontrol system for large process signal capacity

Fig. 123: 6MB5530-1 remote terminal unit (RTC) with cable-shield communication

Analog Serial ports inputs to control centres

Serial ports to bay units

Design

Type

Minicompact RTU*

6MB5530-0A 6MB5530-0B 6MB5530-0C

8 8 8

8 24 32

– 8 –

1

–

Remote terminal unit with cable shield communication (RTC)

6MB5531-0A 6MB5531-0C

8 8

8 32

– –

1 additional gateway

–

Compact RTU

6MB552-0A 6MB552-0B 6MB552-0C 6MB552-0D

331)/8 331)/8 331)/8 8

1

7

Telecontrol system SINAUT RTU

6MD2010

up to 2000 data points,

2

–

Single Alarm commands inputs

– 72 40 104 136

32 162) – –

configurable * Further 3 minicompact RTUs can be serially connected in cascade for extension (maximum distance 100 m) With switching-current check 2) Potential free 1)

Fig. 125: Remote terminal units, process signal volumes

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Local and Remote Control

RTU-interfaces The descripted RTUs are connected to the switchgear via interposing relays and measuring transducers (± 2.5 to ± 20 mA DC) (Fig. 126). Serial connection of numerical protection relays and control I/O units is possible with the compact RTU type 6MB552. The communication protocols for the serial connection to system control centers can be IEC standard 870-5-101 or the Siemens proprietary protocols 8FW. For the communication with protection relays, the IEC standard 870-5-103 is implemented. Automation Functions The SINAUT RTU telecontrol system is based on SIMATIC S7-400, which provides numerous communication options and a universal automation system. For the user, it opens up the possibility to introduce project-specific functions for local automation tasks. They can be configured with minimum engineering effort, combined with the features offered by the user-programmable SIMATIC S7-400 automation system. A typical task is the central monitoring or control and automation of geographically widespread processes, such as networks for electricity, gas, water, sewage, district heating, oil, pollution control, traffic and industry.

System control center

Modem

Telecontrol channel

Substation level

Modem

Optical fiber

RTU

*

Marshalling rack

Bay level Interposing relays, transducers Existing switchgear

*

* Protection relays and I/O units

Extended switchgear * Only for compact RTU 6MB552

Fig. 126: RTU interfaces

Cable-shield communication The minicompact RTU can be delivered in a special version for communication via cable shield (Type 6MB5530-1). It does not need a separate signaling link. The coded voice frequency (9.4 and 9.9 kHz) is coupled to the cable shield with a special ferrite core (35 mm window diameter) as shown in Fig. 127. The special modem for cable-shield communication is integrated in the RTU. Fig. 128 shows as an example the structure of a remote control network for monitoring and control of a local supply network.

Fig. 127: VF coupler with ferrite core 35 mm

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Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

Higher telecontrol level Power cable (typically 5 km) … VF couplers

Modem (optional)

VF couplers Signal loop

VF couplers Modem Channel 1 Channel 2

Mini RTU 6MB5530-1 (RTC)

Mini RTU 6MB5530-1 (RTC)

Distribution station

Distribution station

Branch 1

1 2 3 4 5 6 7

VF couplers

Modem Channel 1 Channel 2

8

Multiplexer (optional) Modem Channel 1 Channel 2

… Branch 2 …

1st station of branch 1

16th station of branch 1

Power cable (typically 5 km)

Communication control unit 6MB5530-1 (CCU)

… VF couplers Signal loop

VF couplers

VF couplers

VF couplers

Modem Channel 1 Channel 2

Modem Channel 1 Channel 2

Mini RTU 6MB5530-1 (RTC)

Mini RTU 6MB5530-1 (RTC)

Substation 1st station of branch 8

Substation 16th station of branch 8

Fig. 128: Remote control network based on remote terminal units with cable-shield communication

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Local and Remote Control

Panel cutout and drilling dimensions

6MB5130

29.5

Panel cutout

Rear view

Side view 172

37 39

7.3 13.2

225 220

7.3 13.2

206.5 180

5.4

ø 5 or M4 266

245

244

255.8

ø6

277.5

221

All dimensions in mm. Fig. 129: Compact central control unit 6MB513

6MB5140

29.5

Panel cutout

Rear view

Side view

172

37 39

7.3 13.2

450 445

7.3 13.2

431.5 405

5.4

ø5 266

255.8

245

ø6

277.5

446

All dimensions in mm. Fig. 130: Compact central control unit 6MB514

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Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

6MBB522

Side view 29.5

30

FSMAoptical-fiber connector

Panel cutout

Rear view 7.3

220

206.5 180

5.4

4

ø 5 or M4 266

244

245

255.8

ø6 231.5 277

All dimensions in mm.

221

225

Fig. 131: Compact input/output device 6MB522

6MB523

Panel cutout

Side view

Front view 145

30

7.3

29.5

131.5 105

ø6 ø5 244

160

All dimensions in mm.

245

231.5

255.8

5.4

146

Fig. 132: Compact input/output device 6MB523

6MB524-0, 1, 2

Rear view

Side view 29.5

172

30

225 220

9

7.3 13.2 8 7 6 5

266

FE D C

244

All dimensions in mm.

Terminal blocks

Terminal blocks

Panel cutout

4 3 2 1

206.5±0.3 180±0.5

5.4

ø 5 or M4 BA

Optical-fiber sockets

255.8±0.3

245+1

ø6 221+2

Fig.133: Compact I/O unit with local (bay) control 6MB524-0, 1, 2

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Local and Remote Control

6MB5240-3

Rear view

Side view 172

29.5

30

Panel cutout

445

266

8 7 6 5

244

ML K J H G F E

Terminal block

431±0.3 405±0.5

7.3 13.2

450

9

4 3 2 1

D C BA

255.8±0.3

245+1

ø5 ø6

Optical-fiber sockets

Terminal block

5.4

446+2

All dimensions in mm. Fig. 134: Compact I/O unit with local (bay) control, extended version 6MB5240-3

6MB525

Side view 29.5

172

Rear view 37

75 70

Panel cutout 7.3

71+2

56.5±0.3

ø5 or M4 266

255.8±0.3

245+1

244

Terminal block

ø6

All dimensions in mm. Fig. 135: Minicompact I/O device 6MB525

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Siemens Power Engineering Guide · Transmission & Distribution

Local and Remote Control

6MB552

172

29.5

Panel cutout

Rear view

Side view 39

220

206.5 ±0.3 180 ±0.5

7.3

8

13.2 Bus cover

266

ø 5 or M4 1)

BNC socket for antenna

244

5.4

2)

255.8 ±0.3

245+1

ø6

Optical-fiber socket FSMA for connection of bay units

221+2

225

All dimensions in mm. Fig. 136: Compact RTU 6MB552 in 7XP20 housing

6MB5530-0 and -1

300

Rear view

Side view

Front view 1.5

200

20

Wall mount 18

A

20 35

20

8

20

8.2

10

400

25

Section A-A

45 15

225

A

Cable bushing

All dimensions in mm. Fig. 137: Minicompact RTU 6MB5530

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Measurement and Recording

Introduction Measurement and recording technology for electrical networks: a field with a long tradition at Siemens. More than 3,500 Siemens systems, installed in 65 countries around the world, record, meter, condition and transmit electrical signals – tasks they perform with a proficiency that’s particularly effective when faults occur. Measurement and recording equipment for power systems: a field where our innovation potential and know-how define the range of products available on the market – from analog transducers (AFM) systems to intelligent recording systems such as the OSCILLOSTORE® P351, products equipped with analytical software based on expert systems. OSCILLOSTORE P: Systematic troubleshooting The ability to minimize plant faults and downtime while optimizing machine and resource utilization: that’s the secret of success of the OSCILLOSTORE P531. In production, faults which would normally lead to process errors and stoppages are detected while still in their early stages. The P531 keeps self-extinguishing, transient, semitransient and permanent faults under tight control in all major power supply operations. The OSCILLOSTORE systems are also widely used in computer centers to monitor the quality of the power supply and record the history of faults. Clear fault detection, precise documentation, reliable evaluation – all the hallmarks of the OSCILLOSTORE P system. Also active in monitoring and analyzing the quality of the mains supply An optimum solution for every task: this is the founding principle on which the OSCILLOSTORE P product range was based. Another member of the family is the QUALIMETRE® /OSCILLOSTORE P512, developed in cooperation with the EDF (Electricité de France), for recording the quality of mains supplies. And the OSCILLOSTORE P513, a portable unit with integrated analytical software, completes the lineup.

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The real-time specialists: OSCILLOSTORE E sequence-of-events recorders OSCILLOSTORE E systems are ideal for a wide range of tasks in the real-time acquisition of digital signals. Siemens provides both stand-alone equipment and intelligent integrated solutions for the SIMATIC range of programmable controllers. Customized applications in power plants, switchgear and industrial production processes are just some of the strengths of OSCILLOSTORE E systems. And, with the trend towards increased levels of automation, real-time acquisition with a resolution of 1 ms is a capability that makes these systems highly popular. OSCOP: The trendsetter in application software One thing is clear: the better the software, the more the user benefits. And this is where OSCOP stands out from the field. The OSCOP software is based on the MS Windows user interface, a fact that already speaks for itself. Remote calibration, data transmission and PC-based evaluation have long been standard concepts in power utility recording technology. The OSCOP system software forms the actual core of the recording data networks and combines automatic operation with the high functionality required by field specialists. SIMEAS T The modular transducer system: An ideal state-of-the-art solution Digitization does not herald the demise of analog transducing. Quite the opposite, in fact: power generation and distribution continues to rely on the ideally refined modular solution of the 7KG61 series. That shouldn’t come as a surprise considering the wide range of user-friendly analog measurement transducers available today. An increasingly significant role is, however, being played by the programmable numerical transducers 7KG60. They allow measurement of all measurands with just one instrument. The advantages for users are clear: enhanced cost efficiency of stocks, simplified menu-guided PC operation and a reduction in the number of different product types. The serial interface further allows the integration of 7KG60 transducers directly into microprocessor-based control and automation systems.

Siemens Power Engineering Guide · Transmission & Distribution

Measurement and Recording

Fault recording OSCILLOSTORE P531 and OSCOP P – The digital fault recorder with diagnosis and evaluation software OSCILLOSTORE systems like the P531 have been standing watch in renowned utility companies for years, looking out for self-rectifying, transient, semitransient, and permanent faults. In computer centers and in industrial plants, they monitor the quality of the power supply and document the fault history. What is well recorded can be better evaluated – one of the more pleasing aspects of accurately recording electrical signals. Thanks to this source of information, one can now optimize operating resources – and simultaneously minimize down-time and avoid defects of equipment. The fault diagnosis in electrical power supply is efficiently automated, thus facilitating the expert’s work. Fault recorders must be capable of processing a wide variety of signals. The OSCILLOSTORE P531 has the right solution for this: ■ Up to 31 data acquisition units (Fig. 141) can be connected to the central unit – even when they are remotely installed at distances up to two kilometers from the process ■ The modules are ideally equipped for signal matching and digital preprocessing – even if the application requires a 1 MWord of storage capacity Still more important is that: The OSCILLOSTORE P531 only records what you really need! Whoever needs to evaluate data, needs data reduction (which the system memory also employs to reduce its load). The OSCILLOSTORE P531 embodies this principle: It records only the anomalies, thanks to the built-in start selectors! This includes the fault history (the troublefree period preceding the fault), the fault itself, and the fault’s sequel (the period after the fault occurred). High-functionality start selectors are available for each channel, and are software-controlled. The system recognizes the fault characteristics itself, which means that the recording time is automatically adapted to each recording.

Fig. 138: OSCILLOSTORE systems are used in power plants …

Fig. 140: Fault record

Fig. 139: … and to monitor transmission lines.

And what’s more: even prolonged disturbances don‘t cause any problems. The recording time is always adjusted to the signal characteristics. Automatically, of course. Channel-related inhibit functions effectively prevent memory overflow, e.g. in case of intermittent faults on one (or more) phase(s). Before the recorded data is stored in the acquisition module, the FDAU and PDAU modules calculate any necessary quantities – for example, active power, reactive power, and power factor. Because measurand transducers are an integral part of the modules, external transdurcers are not required. User-programmable gradient criteria allow to select the optimum moment for recording – which again is a contribution to data reduction.

Siemens Power Engineering Guide · Transmission & Distribution

Five data acquisition units capture and process all kind of measuring signals: ■ ADAU (Analog Data Acquisition Unit) – replaces the traditional fault recorder with 4 channels for the real-time recording of currents and voltages, scanning rate 1 to 5 kHz adjustable per channel; storage capacity 50 to 250 sec. ■ BDAU (Binary Data Acquistion Unit) – replaces the sequence-of-events recorder with 32 channels for recording digital status changes; scanning rate 1 kHz; storage capacity 900 status changes ■ DDAU (DC Data Acquisition Unit) – replaces the process recorder with 4 channels for recording process variables (e.g. 0 to 20 mA or 0 to 10 Volt); scanning rate 0.2 Hz to 5 kHz adjustable; storage capacity 50 sec to 14 days. ■ FDAU (Frequency Data Acquisition Unit) – replaces the frequency recorder with 4 channels for recording the power supply frequency; resolution 1 mHz; storage capacity 50 sec to 14 days. ■ PDAU (Power Data Acquisition Module) – replaces the power and frequency recorder with one channel for recording the active power, reactive power, power factor, and optionally, the power supply frequency or rms voltage; storage capacity 50 sec to 14 days.

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Measurement and Recording

The DAU (Data Acquisition Units) allows decentralized as well as centralized intelligent data acquisition and processing. The recorders can be linked to a central unit and can communicate with PC/AT compatible evaluation systems via modem – or via a ”dedicated line“ if no modem is available. Depending on the application, frontend data concentrators with mass memory (DAKONs) can also be integrated using standard software. And the same standard software allows a data network of fault recorder systems to be set up. High-quality acquisition deserves highquality evaluation. And that’s what one gets with the OSCOP P system program. This system is designed for all kinds of performance demands – thus tailored to fit with any user requirements. It is available in all major languages. And, of course, it is supported by an around-the-clock hotline service and our software maintenance service. In addition, the Siemens experts offer their competence for the analysis of the data recorded and provide assistance in finding the optimum solution based on the network topology.

Distributed fault recording system Evaluation station with system software OSCOP P

Remote Transmission Telephone network, X.25, ISDN; LAN; WAN ”Local Printer“ Data concentrator DAKON with software for automatic data collection, archiving and diagnosis Further OSCILLOSTORE units

Central unit OSCILLOSTORE P531

Further OSCILLOSTORE units

Control + communication unit

RS485-Bus

1

2

3

Analog or binary data acquisition modules

30

31

Fig. 141: Distributed fault recording system

Fig. 142: OSCILLOSTORE P531, rear view

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Fig. 143: OSCILLOSTORE P531, front view

Siemens Power Engineering Guide · Transmission & Distribution

Measurement and Recording

OSCOP P The user software with automatic diagnosis There are no communication problems between OSCOP P and the OSCILLOSTORE P531 central units. Up to 100 of them (each with up to 31 acquisition modules) can communicate with the software via the public telephone network. All parameters can be set up remotely. OSCOP P has a built-in database which receives the measured values and their related parameters. It can be used as a central archive. The filter functions allow easy retrieval of the archived data even after years. The MS Windows operating system is particularly suited because of its ease-of-use and the efficient time-sharing characteristics (that means, the recorded data can be evaluated in foreground, while the data is being transferred and an automatic diagnosis performed in the background). We make the plant management’s life easier with time-controlled automatic operation and automatic screen display. This includes the option of a fault printout with analysis so that one can store and analyze results without pressing a button. And the diagnostic system provides for perfect automatic analysis. If the OSCILLOSTORE P531 is used to monitor high-voltage supplies and cables. The diagnostic system is a powerful ”fault locator“. No longer will line and cable faults go undiscovered, they are pinpointed with a high degree of accuracy. DAKON with OSCOP P for decentralized automatic diagnosis All these automatic functions (diagnosis, r.m.s. values, fault locator ...) can also be performed on the local DAKON, e.g. in the switchyard. This solution allows you to still reduce data for the remote transfer so that only the relevant information and, if required, the “r.m.s. values window“ are transferred. Data archiving in the DAKON database can efficiently relieve the central evaluation station.

Fig. 144: OSCOP P operating surface

OSCOP P is also open for other systems In particular when monitoring the operating resources, it is important that the information stored in these resources is also available. Via an additional function of OSCOP P or directly on the DAKON, it is thus possible to read the records and operating messages of numerical protective relays. For data in the IEEE (Comtrade) standard format, import and export functions are provided. This functionality allows to compare the ”subjective“ data of the operating resource with the ”objective“ data of the OSCILLOSTORE P531.

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Measurement and Recording

Power quality assessment QUALIMETRE*/ OSCILLOSTORE P512 All functions of a complete equipment family in one unit Previously a multitude of instruments was required for recording variables – now QUALIMETRE does it all alone. It replaces voltmeters and ammeters, active- and reactive-power recorders, harmonics analyzers, RMS value recorders and much more. Of particular advantage for the user is the parallel recording of all significant network data. QUALIMETRE monitors all the electrical characteristics of a network. This is a real benefit, because faults of a widely differing nature may occur: ■ Voltage variations – Changes in amplitude (difference between maximum and minimum voltage) – Surge voltage (sudden amplitude change) – Voltage fluctuation (number of changes in amplitude within a specific time) ■ Long-time interruptions (such as complete power failure for more than 1 min) ■ Short-time interruptions (such as complete power failure between 10 ms and 1 s or 1 s and 1 min) ■ Voltage drop (changes in amplitude over a long period) ■ Asymmetry (differing voltage amplitudes and/or phase angles) ■ Harmonic components of the fundamental wave QUALIMETRE can be used both for examining and monitoring supply networks. Immune to transient overvoltages QUALIMETRE can be easily installed near switchgear and industrial supply circuits. To cope with this environment, measuring instruments must have special properties in oder to operate reliably despite transient overvoltages. QUALIMETRE has therefore been designed in accordance with IEC 255 protection standards with interference immunity in mind. Spurious peaks of 2.5 kV, 1 MHz do not impair the measurement result – an insulation voltage of 2 kV is included, naturally.

Fig. 145: QUALIMETRE*/OSCILLOSTORE P512

Designed for installation QUALIMETRE includes the necessary signal conditioner for current and voltage and is therefore particularly suitable for permanent installation. For stationary operation a 19" rack-mounted model of compact design is offered. QUALIMETRE saves paper It is fairly obvious that large amounts of data come up in continuous network recording. In conventional instruments this quickly leads to a flood of paper. Not so with QUALIMETRE: The data measured is stored electronically. Remote parameter input, data transmission and evaluation are thus also possible – the proven OSCOP evaluation programs take care of this. Transmission of data via the public telephone network is also optimized thanks to an integrated modem. The modern design concept permits easy expansion with portable data carriers and transient detection and flicker meter functions. All in all, there are many advantages with QUALIMETRE, making it the ideal solution for monitoring and analysis in electrical supply networks.

* QUALIMETRE is a joint development of Siemens and EDF (Electricité de France). EDF, a world leader in quality assurance of supply networks, was responsible for the functionality of QUALIMETRE, and Siemens provided the know-how for OSCILLOSTORE, the proven fault monitor.

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Siemens Power Engineering Guide · Transmission & Distribution

Measurement and Recording

OSCILLOSTORE P513 For measurement, recording, and evaluation: OSCILLOSTORE P513 is a new portable instrument for continuous analysis and documentation of the quality of power systems at any location. Ideal for power company customer service technicians The generation and distribution of electrical power in the desired quality and quantity are taken for granted today. Nevertheless, customers sometimes report that their supply is not as it should be, and disturbances fed back into the system can lead to a loss of quality in the utility’s product-electrical energy. In such cases, the customer service technician is called upon to measure and analyze the quality of the electrical power delivered to the customer – whether the problem appears at a privat residence, a small business, a medium-sized operation, or a large corporation. The OSCILLOSTORE P513 is just the instrument you need to obtain fast, accurate, reliable and meaningful information on the spot. That means one can analyze and record measurement data in the field applying consistent evaluation criteria to data obtained simultaneously, without having to connect several different instruments. Additionally, results can be read out on the spot, making it even easier to get system problems under control. It is further possible to check the performance of uninterruptable power supplies, and also to record the signal shape at converters and inverters. The OSCILLOSTORE P513 determines all relevant system parameters: voltage, current, frequency, and harmonic contents, as well as active and reactive power. Even on the low voltage level, the OSCILLOSTORE P513 ensures high-precision measurements, so that it can even be used at the ”wall socket“ level. Of course, all of the P513’s functions, including the 12 measurement functions, are housed in a single unit, which even includes a built-in floppy drive and printer and, as a special feature, an integrated evaluation program.

FIg. 146: OSCILLOSTORE P5 13

The P513 is an intelligent, portable measuring instrument that monitors all of the characteristic electrical parameters on a power system: ■ 8 measurement channels for continuous

recording of: – Voltage – Current (both with r.m.s. value calculation over one period) – Transient voltages with 2.6 kV peaks at a 2 MHz sampling rate ■ Continuous calculation of: – Frequency – Phase angle in tan phi/cos phi – 1- to 3-phase active and reactive power (all connection types possible) – Harmonics up to the 50th order. Averaging times and recording times in the range from one period to 9999 hours can be selected for all measurement types See what’s going on right now – without losing the big picture All measurement results can be displayed directly on the built-in screen, either numerically or graphically as an XT diagram or a bar graph. Vertical and horizontal zoom functions are provided so that one can examine relevant signal patterns in detail using the cursor. When one selects the histogram display, one can see at a glance the complete record of voltage and current levels and their statistical distribution during the monitoring period.

Siemens Power Engineering Guide · Transmission & Distribution

A backlit LCD display is also provided to make it easy to read all the information on the screen clearly – without depending on the local lighting conditions. The information can be printed out on any screen as a hard copy at any time. Transient voltage measurement section One of the many features of the OSCILLOSTORE P513 is the separate measurement section with integrated transient voltage recording unit. It is isolated from the rest of the electronics using fiber optics. Thus, a complete electrical isolation is obtained. It means that one can measure more confidently than ever before, without worrying about feedback. Complementing this design is the P513’s ability to record transient peaks up to 2.6 kV at a scanning rate of 2 MHz. Memory for more than half a million readings The built-in memory of 1.4 Mbyte makes it possible to store up to 500,000 readings. And the OSCILLOSTORE P513 is just as impressive when it comes to convenience: ■ Because of the P513’s large memory

capacity, it is ideally suited to long-term monitoring. Depending on the parameter settings used, up to over 1 year of data can be recorded!

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Measurement and Recording

SIMEAS T – Universal transducers for electrical quantities in power systems

Block diagram

Serial interface

Areas of application With the SIMEAS T universal transducer (Order designation 7KG60) all measurands in any desired power grid can be measured with just one instrument. The instrument is equipped with 3 electrically isolated analog outputs, a digital output, and a serial interface. Each analog output can be assigned an individual measurand (current, voltage, active power, reactive power, etc.) and any desired measurement range. The measurement is a real/r.m.s. measurement, which can also measure distored waveforms and waveforms with a large harmonic content. The output signals (e.g. 0 to 10 mA, 4 to 20 mA, 0 to 10 V, etc.) can also be userprogrammed for each output. The digital output can be used as a trigger output for recording the results, or as a limit signal. Any desired input current or input voltage up to maximum of 10 A or 600 V, can be connected at frequencies between 45 and 65 Hz (16 2/3 Hz). Depending on the measurement task, the unused input terminals remain free. The transducer can be ordered either preconfigured in accordance with plaintext specifications, or programmable with the capability for a custom setup. Setup data and a specific connection diagram are delivered with factory set instruments. Programmable instruments can print out this data as required. A PC connecting cable and a disk containing Windows software, with which one can easily set up the transducer oneself, can be ordered optionally. During operation you can reprogram the transducer, or display the measured values on-line on a graphics instrument (contained in the software), either on a PC or on-site using a laptop. The instrument requires an auxiliary power supply. Variants are supplied for the AC/DC ranges from 24 to 60 V, and from 100 to 230 V. Inputs, outputs, and the auxiliary power supply are electrically isolated from one another.

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UH

RS 232 RS 485

Digital output

IL1 Analog output 1 IL2 IL3 Analog output 2 UL1 UL2 UL3 N

Analog output 3

AC

Fig. 147: Measuring transducer 7KG60, block diagram

Front view

75

90 Fig. 148: Measuring transducer 7KG60

Side view Connection terminals

Serial interfaces The RS232/RS405 interface of the 7KG60 can be used to communicate with a PC for setting and readout of data or to integrate the transducers as measuring-data acquisition units into substation control systems. In the latter case, an IEC 870-5-103-compatible protocol is used. Design The housed version of the transducer is a hardwired, certified functional unit. It has snaptype catches for attachment to 35 mm top hat rails (DIN EN 50022). Terminal screws allow inputs and outputs to be securely connected. The measurands and ranges of measurement can be configured as desired.

90 105 All dimensions in mm Fig. 149: Measuring transducer 7KG60, dimensions

Siemens Power Engineering Guide · Transmission & Distribution

Measurement and Recording

SIMEAS PAR The software SIMEAS PAR consists of the three following subprograms: ■ 1. Configuration ■ 2. Calibration ■ 3. Data Export SIMEAS PAR was designed for the MS DOS platform of common PCs or laptops. The program is operated via the graphical user interface MS WINDOWS V3.1 by mouse and keyboard. Communication with the transducer occurs via the standard serial interface of a PC or laptop and an optional connection cable. Description 1. Configuration (Fig. 150) The “Configuration“ function allows setting of the variables, measuring ranges, output signals, etc. for the transducer. It provides the user with straightforward setting of the parameters in just a few steps.

Entering the data in the respective windows is simple and clear. This procedure is supported by additional dialog guidance. If required, the following data can be printed on the local PC printer: ■ Parameters entered ■ The connection diagram of the specific measuring task ■ A self-adhesive configuration label with the settings of the transducer 2. Calibration (Fig. 151) Since the transducer does not include any potentiometers or other hardware setting facilities. Balancing the transducer is made via the software with the ”Calibration“ function. Generally, the transducers are delivered with factory-made calibration and setting. Recalibration is necessary only after repair work or for rebalancing. The screens and graphical characteristic curves of the ”Calibration“ subprogram are also easy to operate.

Fig. 150: Window for configuration of the output values

A description of the test configuration and instructions on the program operation are provided by the help system. 3. Data Export (Fig. 152) With graphics instruments, up to 9 measuring signals can be displayed on-line on a PC or laptop screen in analog and digital form. For better resolution, the user can select the number of measuring instruments on the screen and assign measuring signals and ranges to the displays. The assignment does not depend on the analog outputs of the device. If required, the measuring data can be stored or read to the local PC printer.

Fig. 151: Calibration

Fig. 152: Display of 3 selected measurement values and measuring ranges

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Measurement and Recording

Hints for application Fault recording The OSCILLOSTORE P531 is used in all kinds of power systems to record fault histories for fast and precise fault analysis. It also supplements the fault recording of numerical relays with the following extended recording capabilities: ■ Independent recording of events with high sampling rate (up to 5 kHz) and long recording times (up to 14 days). ■ Integrated start selectors for recording of frequency excursions and power swings. The recording channels are normally chosen as follows:

The transducer outputs can either be analog, for example, 4 to 20 mA (7KG61 analog series) or serial at a RS485 port (7KG60 digital series). The transducers are in general used with devices that cannot be directly connected to the LV network or c.t.s and v.t.s. This range of devices include meters, indicators, recorders and remote terminal units.The digital SIMEAS transducers (7KG60) series are intelligent electronic devices (IEDs) that can be used for data acquisition and preprocessing of data. They can be directly connected to control and automation systems through their RS485 interface. Standard protocol IEC 870-5-103 is used for communication. For further information please contact: Fax: ++ 49-9 11-4 33- 85 89

■ Per busbar section:

4 analog values (4 x V) ■ Per EHV bay:

8 analog values (4 x V, 4 x I) and 16 binary signals ■ Per HV bay: 4 analog values (4 x I) and 16 binary signals The following derivated values are additionally calculated and recorded: ■ Frequency at busbar sections ■ Optionally active, reactive power and frequency at infeeds. Power system quality The QUALIMETRE/OSCILLOSTORE P512 is normally installed at infeeds. It is general practice to record 8 channels: 4 x V, 4 x I. Measuring transducers SIMEAS transducers are normally installed at busbars for voltage and frequency measurement, or at infeeds and feeders, where required, for the measurement of active/reactive power and cos phi. They can be connected to the low-voltage network directly or to the secondary winding of v.t.s and c.t.s. Standard rated input values are for example 110/ 3 V and 1 or 5 A.

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Siemens Power Engineering Guide · Transmission & Distribution

Power Systems Control

Contents SCADA, EMS, DMS Control Room Technology Power Network Telecommunication

Page 7/2–7/5 7/6–7/10 7/11–7/24

SCADA/EMS/DMS

Introduction The requirements on network control systems are growing as secure and economic energy management is becoming ever more important. Planning and implementation of SCADA systems (Supervisory Control and Data Acquisition), Energy Management Systems (EMS) as well as Distribution Management Systems (DMS) involve coordinating a wide range of engineering tasks. Siemens is in a position to deliver optimum, state-of-the-art solutions in close cooperation with the customers. SINAUT (Siemens Network Automation) is Siemens’ modern product family for Power Systems Control. It reflects the experience of more than 540 electricity grid control systems installed worldwide since the early sixties. As technological pacemaker Siemens invests considerable funds annually in the further development of the SINAUT product family. Planned for the long term, this user-oriented product line has release compatibility to guarantee that the benefits of tomorrow’s R&D investments can still be adopted by systems delivered today.

Siemens furthers this strategy by participating in a variety of IEEE, IEC, EPRI, CIGRE and CIRED committees and by enlisting support from active user groups. The quality management certified by DQS according ISO 9001 ensures quality products and a smooth and reliable project implementation within contractual schedule and budget. Siemens Power Systems Control has a large support staff of dedicated experts with power industry experience. With its broad range of products Siemens is able to supply the control systems, all necessary components (communication equipment, control room equipment, uninterruptible power systems, etc.) from one supplier on a turnkey basis.

SINAUT Spectrum General SINAUT Spectrum is the open, modular and distributed control system for electrical networks as well as for gas, water and remote heating networks. Its extensive and modular functionality provides scalable solutions tailored to the needs and budgets of:

■ ■ ■ ■

Municipal utilities and Large industries with own networks Regional distribution utilities National and regional generation and transmission utilities

Modular and distributed architecture Each SINAUT Spectrum system consists of individual functional subsystems which are distributed among an optimum number of workstations and servers. Shortest reaction times are achieved by assigning timecritical applications and applications requiring a lot of computation power to dedicated servers (Fig. 1). The database is distributed among the workstations and servers for fast and independent data access with low LAN-loading. The modules of the network control system SINAUT Spectrum are shown in Fig. 3 on page 7/4 and 7/5. Due to its modular and distributed system architecture SINAUT Spectrum offers unlimited horizontal and vertical growth opportunities, e.g. from a small entry-level SCADA system up to a large EMS or combined SCADA/EMS/DMS.

Communication with other control centers, e.g. ICCP or ELCOM-90

Mimic diagram

Mimic diagram interface

Administrator, archives, schedules

Operator console

Operator console

Spare

Expert system

Gateway

LAN

Data acqusition

to/from RTUs

SCADA

Network analysis

Basic components Hot standby

Power and scheduling applications

Training simulator

Distribution management functions

Bridge

Office LAN

GIS

PC Database

Fig. 1: SINAUT Spectrum – system architecture of a large SCADA/EMS/DMS

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Siemens Power Engineering Guide · Transmission & Distribution

SCADA/EMS/DMS

SINAUT Data Gateway SINAUT Data Gateway exactly meets the requirements of an integration tool needed for data maintenance. With SINAUT Data Gateway control center data can be maintained with one database instead of maintaining modeling information in several different formats for each application. For the update of an existing control center system, the necessary data can simply be exported in a format recognized by the new control center system.

Available services

Fig. 2: Control room of Northern States Power Company, Minneapolis, MN

Open architecture SINAUT Spectrum is solidly based on industry standards. Therefore the system can be upgraded to take advantage of the rapidly moving technology in the workstation and server market, without losing any of the software investment built up over the years. SINAUT Spectrum runs under a UNIX operating system, strictly adhering to the IEEE POSIX standards, thus providing hardware platform independence. SINAUT Spectrum may be delivered either on SUN or on IBM workstations. The user interface employs a graphical environment that the operator can tailor to his specific tasks and preferences. Based on the X-Window System and OSF/Motif, this user interface provides multiple-window displays, full pan and zoom capabilities and excellent display call-up times. Other standards used in SINAUT Spectrum: ■ Structured Query Language (SQL) for relational database access ■ TCP/IP for LAN/WAN communication ■ IEC 870-5 as well as many other protocols for RTU communication ■ IEC 870-6 TASE 2 (ICCP), WSCC and ELCOM 90 for communication with other control centers.

Siemens offers services for all important areas: ■ Studies, planning, engineering ■ Project implementation ■ Installation, supervision of installation ■ Commissioning ■ Training ■ Hardware/software maintenance ■ System upgrading ■ System migration

Further SINAUT products SINAUT ACES Accounting, Contracts and Energy Scheduling The volume of wholesale transactions will increase dramatically due to regulatory and economic pressures. SINAUT ACES provides sophisticated software that can manage commodity trading, accounting, billing, monitoring, and contract compliance. SINAUT ACES allows to take full advantage of the growing complexity of contract provisions. SINAUT ACES operates within an open-systems environment that can be fully integrated with SCADA/ EMS/DMS and corporate information systems. SINAUT ICCPNET, SINAUT ICCPNT Communications Products Siemens offers a full range of communication products which support ICCP. The field-proven SINAUT ICCPNET which executes under UNIX, offers a commercial relational database manager to handle configuration and object-set definition with an OSF/Motif operator interface. SINAUT ICCPNT executes on a PC platform and combines a low-cost solution and UCA (Utility Communications Architecture) open-systems technology in order to interconnect utilities.

Siemens Power Engineering Guide · Transmission & Distribution

Siemens Power Systems Control – a key to success Network Control Centers have to operate economically and efficiently over long periods. Therefore Siemens is committed to: ■ Designing systems that can incorporate new standards and technologies over time to keep the system current ■ Avoiding dependence on proprietary tools and methods ■ Using accepted and de facto standards ■ Meeting the growing need for information management throughout a public utility company The long-term commitments also include: ■ ■ ■ ■ ■

A full product spectrum Complete turnkey projects Complete spectrum of services An active user group Strong R&D

For further information please contact: Fax: ++49-9 11-4 33 - 8122

7/3

SCADA/EMS/DMS

Network Control System

Hardware

Basic system

SCADA functions

Distribution management functions

UNIX server

Database

Data acquisition and processing

Data import from a GIS

Spatial control and queries

UNIX workstation

Information management system

Supervisory control, control jobs, manual update

Tracing

Jumpers, cuts, grounds

Data acquisition subsystem

User interface

Report generation system

Switching procedure management

Fault location and isolation; service restoration

Gateway

Computer network management

Dynamic network colouring

Outage management system

Feeder estimation

Ethernet-LAN

Tools for test and diagnostics

Energy demand control

Load modeling

Online load flow calculation

Communication system

Softbus

Load management

Online short-circuit calculation

Transformer load management

RTU

UNIX operating system

Energy accounting

V/Var control

Cold load pickup

High-level language compiler

Operation optimization for gas and water networks

Archives and schedules

Fig. 3: Modules of the network control system SINAUT Spectrum

7/4

Siemens Power Engineering Guide · Transmission & Distribution

SCADA/EMS/DMS

SINAUT Spectrum

Network analysis

Power and scheduling applications

Training simulator

Expert system

Communication

Model update

Network reduction

Automatic generation control

Interchange scheduling

Instructor functions

Intelligent alarm processing

To other control centers (ICCP)

State estimator

Network parameter adaption

Economic dispatch

Reserve monitoring

Complete functionality of the control system

Disturbance analysis

Geographical information system (GIS)

Dispatcher power flow

Fault calculations

Interchange transaction evaluation (A+B)

Load forecast

User interface of the control system

Network restoration/ load transfer

Multisite control center operation

Security analysis

Network sensitivity

Unit commitment

Hydro scheduling

Process simulation

Optimal power flow

Security checked switching

Hydrothermal coordination

Production costing

Network model

Planning

Voltage scheduler

Study case management

Water worth value calculation

Wheeling loss calculation

Generation model

Maintenance

Protection model

Billing

Security dispatch

Other utility IT systems

Outage scheduler

Siemens Power Engineering Guide · Transmission & Distribution

7/5

Control Room Technology

SINAUT Visualization Introduction With its SINAUT Visualization large-screen rear projection system, the Siemens AG offers the solution for the large-screen display of text or graphics. Thanks to the modular design of SINAUT Visualization with projection modules which can stacked horizontally and vertically without paths, screens of practically any size can be built. The SINAUT Visualization large-screen rear projection system can be used whereever a large-area presentation of computer data is required. For example, in power distribution. SINAUT Visualization can be used in an energy management system as a substitute for or adddition to conventional mosaic panels. All dynamic data, from an overview of topological information about the area supplied to detailed information and special messages for the operators in case of fault, can be visualized so that all operators can read it (Fig. 4).

Fig. 4: Control room of Victorian Power Exchange, Australia

VGA, Video, X.11 controller

Description Design of SINAUT Visualization-mX The LCD projection technology used in SINAUT Visualization-mX is based on the TFT LCD (thin-film transistor liquid crystal display) light-valve technology. This socalled active matrix LCD has a better contrast and display switching rate than the lower-cost passive LCDs. Each individual red, green and blue color pixel of the LCD is controlled by a transistor that is, in turn, directly linked to the computer electronics of the integrated mX-Terminal*. This eliminates color shift and drift effects because no analog technology is used (Fig. 5).

LCD light valve Mirror, lamp

Projection lens

Screen

Observer

Fig. 5: Principle of rear projection using an LCD

Modularity SINAUT Visualization-mX is a modular system in order to cover different requirements for projection area, resolution and size. Each projection module is an individual rear projection system with a 50"-inch screen and a resolution of 640 x 480 or 1024 x 768 pixels. It has no seam and the edges of the module correspond with the picture borders (Fig. 6).

340 1213

Illumination unit Darkbox

Screen

750

1000

Screen module * mX-Terminal designates the multiscreen-cable x-Terminal from Siemens AG

7/6

Fig. 6: Projection module with dimensions in mm

Siemens Power Engineering Guide · Transmission & Distribution

Control Room Technology

Therefore seamless pictures of any size can be built by horizontal and vertical stacking of several modules. Fig. 7 shows an example of a 3 x 2 configuration of modules, offering a resolution of either 1920 x 960 or 3072 x 1536 pixels. The more modules are configured horizontally or vertically, the higher is the resulting resolution. The projection modules can be set up in horizontal direction linear as well as polygonal with an angle of 8 degrees to each other in order to obtain a slightly curved display wall. Other angles are possible on request (Fig. 8).

1213

Screen 0

Screen 2 1500

Screen 3

Screen 4

Screen 5

Illumination unit

Connectivity as mX-Terminal The mX-Terminal integrated in OVERVIEWmX and the X-server installed on it conform 100% to the internationally standardized protocol definition X window system (X-Windows, X.11.). Up to 4 projection modules can be connected to one mX-Terminal. If they are arranged in a 2 x 2 designs, they provide a resolution of 1280 x 960 or 2048 x 1536 pixels. The system operates like an X-Terminal with all X.11 tool kits such as OSF/Motif and the X-applications based on them. All X-clients can make unrestricted use of the entire projection area of 2 m x 1.5 m (Fig. 9).

Screen 1

Darkbox

3000

Screen module Fig. 7: 3 x 2 horizontal and vertical stacking of projection modules

Operator

Operator

Fig. 8: Linear or polygonal setup of several SINAUT Visualization-mX projection modules (top view)

SINAUT Visualization-mX projection modules

mX-Terminal

Ethernet, TCP/IP X-Windows

Fig. 9: Integration of SINAUT Visualization-mX into a computer network based on Ethernet, TCP/IP and X-Windows

Siemens Power Engineering Guide · Transmission & Distribution

7/7

Control Room Technology

Mosaic-tile systems 24 modules with 3480 x 1920 pixels

Distributed X-Server

Introduction

6 mX-Terminals as rendering machines

mX-Terminal as central device

Workstations/ Windows NT-PCs

Ethernet TCP/IP, X-Windows

Visualization of the electric systems to be controlled and optimization of the working environment are of utmost importance for the control room operators’ ability to concentrate. By combining the latest ergonomic findings with an appropriate design Siemens provides an environment that allows the operators to work well, even in critical situations. Control boards and mimic displays of mosaic tile design must have a straightforward layout. They must also be costeffective and capable of being shaped to suit customer requirements. It must be possible to modify or extend them quickly, simply and at minimum cost. The ergonomics and design of Siemens control rooms exceed the scope of all DIN and international standards. A broad selection of standard modules and components form the basis of our control rooms. They range from mosaic tile systems and control desks to large-screen rear projection systems, and from optimized mapboards to ergonomically perfect operator workstations. Siemens manufacture of control room technology is certified to ISO 9001. Controlling of the mimic board Control room technology by Siemens has been developed generally over the last few years. Controlling of the mimic board is no longer done by a costly 1:1 wiring system but via an Ethernet bus (SINEC H1) to the PLC (Programmable Logic Controller) system and an internal mimic board bus (SINEC L2). This new idea – Mimic Board Controlling (MBA-L2) – has been successfully realized in several projects (Fig. 12). LAN-controlled mimic board

Fig. 10: SINAUT Visualization-mX as 6 x 4 setup

If more than 4 projection modules are required, there is the possibility to have nearly any number of modules as one large display. With the distributed X-Server (1 central device mX-Terminal with keyboard and mouse and several rendering machines) it is possible to control nearly any number of modules as one single display.

7/8

This means that both the user and the application software “see” one single display. Installation, operation and service do not differ from that of a standard X-Terminal (Fig. 10).

The mimic board consists of the following elements: ■ PLC ■ Power supply including fuses ■ Bus terminal ■ Main module for the control of 32 twincolored LEDs ■ Extension module for the control of 32 twincolored LEDs ■ Low consumption diodes ■ Protocol as per DIN 19245

Siemens Power Engineering Guide · Transmission & Distribution

Control Room Technology

Description The PLC from the S5 automation system consists of: ■ Power supply module ■ Central processing unit (CPU) ■ Communication processor module

to a host processor

The use and the selection of the different types of S5 PLCs depend on the requirements of the controlled LEDs and on the parameters which are to be transmitted from the host processor to the PLC. The communication processor to a host processor is determined by the structure of the protocol and the physical interface (e.g. SINEC H1, L1, L2 and so on).

■ Communication processor module

(CP 5430) to internal LAN connection of the mimic board ■ Eventual memory extensions in case of bigger systems

The bus terminal The bus terminal is designed to connect to the internal LAN one main module and 16 extension modules. In addition to the LAN connections, the following are connected to the bus terminal: power supply, shielding for the cables between bus terminals and modules, and digital input for synchronization of blinking. The bus system, protocol structure The LAN controlling the main module is an RS 485 interface. The protocol is according to DIN 19245 (profibus). This LAN is supplied by a communication processor CP 5430 which supports the protocol DIN 19245 by hardware implementation.

SINEC H1/Ethernet

1 2 3 4

PLC

1 2 3 4

Power supply module CPU module CP to SINEC H1 CP to mimic board Ian SINEC L2

Fig. 11: Control room of Schluchseewerke AG, Germany

1

Mimic board

SINEC L2

32

1 LED 32 Main module

LED 32 Main module

SINEC L2

32 1

PLC

16

RS 485 Online test Parametrizing Commissioning

SINEC 1/ Ethernet

SINAUT spectrum Fig. 12: Mimic board wiring with MBA-L2

Siemens Power Engineering Guide · Transmission & Distribution

Analog output submodule

1

8

Display submodule

1234 MW

Fig. 13: Hardware structure of MBA-L2

7/9

Control Room Technology

Main module The main module is connected by a 16-pole cable including power supply, LAN connection and synchronizing input. Each main module is a slave partner on the SINEC L2 LAN and is able to control up to 32 twincolored LEDs. The intensity of the LEDs can be controlled via messages from the PLC. Thus the brightness of the indicator lights can be adapted to the light conditions in the control room. The LEDs can be operated in steady-state mode (on/off) or in flashing mode with a frequency of 0.5 to 8 Hz in 5 steps. A red LED on the module’s rear side indicates following errors:

8RS

User software

8RU

8RT

SINEC H1-Bus

CPU Process and distribution of LED data

Standard interface

■ LED failure ■ Number and color (monocolored,

twincolored) of LEDs to be used do not match with the number of plug-in LEDs ■ Failure or error of RAM, EPROM, E2PROM A green LED indicates healthy operation. Errors can be read out and failures can be exactly located. LED failures can be located as well. Thus detection and replacement of defective LEDs are not timeconsuming. A defective LED can also be found by a ”lamp test“ message (operation of all LEDs). Each main module can be used to control up to 16 extension modules. Each extension module will be addressed directly over Profibus by a subaddress. Extension module The extension module can control up to 32 twincolored LEDs. As described above, the extension module is addressed by a main module. Each extension module is cyclicly updated by the main module. This message can be interrupted by messages of higher priority. These are: ■ Synchronous blinking ■ Lamp test

All further functions of the extension module are the same as described above for the main module.

7/10

Data areas for LED information Data preparation

SINEC L2-Bus

Fig. 14: Software structure of Mimic Board Controlling (MBA-L2)

Fig. 15: 8RU-8RS-8RT mosaic tile systems

Parameteriziation software

Mechanical Design

The menu-driven software allows designing of main and extension modules locally at the module or on line during operation.

The 8RU-8RS-8RT mosaic tile systems are of self-supporting and self-locking design. The tiles are in fact designed to support one another and thus give the finished control board or mimic display a strong structure. No metal supporting grid or any other extra parts are needed for mounting the individual tiles. All the systems can be modified or extended quite simply. Once the board has been erected, mosaic tiles can simply be exchanged or added. The 8RU-8RS-8RT mosaic tile systems have been tested to DIN 40046 seismic requirements and are thus fully able to withstand heavy mechanical loads.

Features of MBA-L2 ■ Automatic background LED test,

faulty LED can be detected at any time ■ All errors can be located and transmitted

to host computer system ■ Steady-state mode, on/off ■ Flushing mode, 0.5 up to 8 1/s in

5 steps ■ Smooth brightness control ■ No need for marshalling racks or distri-

bution units ■ Reduced number

of cable connections to and inside the mimic board ■ Simple erection on site, no wiring ■ Easy extension and modification because of using plug-in technology

For further information please contact: Fax: ++49 - 9 11-4 33 -81 83

Siemens Power Engineering Guide · Transmission & Distribution

Power Network Telecommunication

Introduction Safe, reliable and economical energy supply is also a matter of fast, efficient and reliable transmission of information and data. International operation, automation and computer-controlled optimization of network operations, as well as changing communications requirements and the rapid change in technology have considerably increased the demands placed on systems and components of communications networks. The same careful planning and organizing of communications networks are as necessary in the power industry as for the generation and distribution of energy itself. Siemens offers a wide range of systems and network elements specifically designed to solve communications problems in this area. All systems and network elements are adapted to one another in such a way that the power industry’s future communications requirements can be satisfied optimally both technically and economically. Siemens is offering advice, planning, production, delivery, installation, operation and training – one source for the customer. Providing expertise and commitment as the complexity of the problem requires. Put your trust in the extensive know-how of our specialists and in the solidity of the internationally proven Siemens communications systems.

As shown in the block diagram below, we are offering systems and network elements for analog transmission as well as systems for digital transmission. The systems and network elements shown in this survey of products have been specially developed for power industry applications and therefore fulfill the requirements with regard to quality and workmanship as well as reliability and security.

All systems and network elements described meet the relevant international recommendations and are designed, developed and manufactured in accordance with the requirenments of the quality systems of DIN EN ISO 9001.

up to 500 km Line trap PLC CC or CVT AKE

Distance protection

SWT F6

50 ... 2400 Bd

FWT

64 kbit/s ESB

Hicom O.F. Dig. current comparison and distance protection

Flexible network configuration with communications systems and network elements

SWT D

Data 50 Bd ... n x 64 kbit/s

The gradual transition from analog to digital information networks in the power industry and other privately operated networks requires a great variety of systems and network elements for widely differing uses. Prior to a decision as to which system could be used for the best technical and economical solution, it is first necessary to clarify such requirements as quantity of speech, data and teleprotection channels to be transmitted, length of transmission link, existing transmission media, infrastructure, reliability, etc. Depending on those clarifications the most cost-efficient and best technical solution can be chosen.

MUX Speech LFH AKE PLC CC CVT SWT F6 FWT ESB Hicom SWT 2 D MUX LFH O.F.

Coupling unit Power line carrier communication Coupling capacitor Capacitive voltage transformer Teleprotection signaling system for analog transmission links Telecontrol – and data transmission system Power line carrier system ISDN telephone system Teleprotection signaling system for digital transmission links Multiplex system Fiber optic transmission system Optical fiber cable

Fig. 16: General overview

Siemens Power Engineering Guide · Transmission & Distribution

7/11

Power Network Telecommunication

Power Line Carrier (PLC) Communication

1 Conduit with weather-resistant

13

PLC cable screw connection

12

2 Terminal for coupling capacitor 3 Grounding switch with

11 AKE 100 coupling unit For carrier frequency communication via power lines or via communication circuits subject to interference from power lines, the high-frequency currents from and to the PLC terminals must be fed into or tapped from the lines at chosen points without the operating personnel or PLC terminals being exposed to a high-voltage hazard. The PLC terminals are connected to the power line via coupling capacitors or via capacitive voltage transformers and the coupling unit. In order to prevent the PLC currents from flowing to the power switchgear or in other undesired directions (e. g. spur lines), traps (coils) are used, which are rated for the operating and short-circuit currents of the power installation and which involve no significant loss for the power distribution system. The AKE 100 coupling unit described here, together with a high-voltage coupling capacitor, forms a high-pass filter for the required carrier frequencies, whose lower cut-off frequency is determined by the rating of coupling capacitor and the chosen matching ratio. The AKE 100 coupling unit is supplied in four versions and is used for: ■ Phase-to-ground

coupling to overhead power lines ■ Phase-to-phase coupling to overhead power lines ■ Phase-to-ground coupling to power cables ■ Phase-to-phase coupling to power cables ■ Intersystem coupling with two phase-to-ground coupling units The coupling units for phase-to-phase coupling are adaptable for use as phaseto-ground coupling units. The versions for phase-to-ground coupling can be retrofitted for phase-to-phase coupling or can be used for intersystem coupling.

9

switch-rod eye Main ground connection External shock hazard protection 1- or 2-pole coarse voltage arrester Drain and tuning coil Isolating capacitor Isolating transformer Resistor for phase-to-phase coupling (balancing resistor) 11 Gas-type surge arrester (optional extra) 12 PLC cable terminals 13 HF hybrid transformer

10

4 5 6 7 8 9 10

1 8 7 6 2

5

4 3

Fig.17: AKE 100 coupling unit with built-in HF hybrid transformer

A: Phase-to-ground coupling Line trap CC or CVT AKE 100

PLC System

B: Phase-to-phase coupling Line trap CC or CVT AKE 100

PLC System

C: Intersystem coupling Line trap

Line trap CC or CVT

AKE 100

HF hybrid

CC or CVT

AKE 100

PLC System Fig. 18: Coupling modes

Coupling mode

Costs

Attenuation

Reliability

A: Phase-to-ground coupling

Minimum

Greater than B&C

Minimum

B: Phase-to-phase coupling

Twice than A

Minimum

Greater than A

C: Intersystem coupling

Twice than A

Greater than B

Maximum

Fig. 19: Comparison of the coupling modes

7/12

Siemens Power Engineering Guide · Transmission & Distribution

Power Network Telecommunication

ESB 2000i power line carrier system

PAX/ PABX

64 kbit/s MUX

SDH PDH

DEE Communication system e. g. Hicom

So

LAN PAX/ PABX

Coupling capacitor

BMX

Coupling unit

V.24/V.28

Remote Service subscriber telephone

64 kbit/s

2/4-wire E&M

Protection relay

Line trap

64 kbit/s

Distance protection

SWT 2000 F6

Data Data V.28 up to 2400 Bd or via MODEM

Modem, ≤ 19,2 kbits/s

Power system control

ESB 2000i

Data V.28 up to 2400 Bd

FWT 2000i

Service PC

Fig. 20: ESB 2000i power line carrier system

Siemens Power Engineering Guide · Transmission & Distribution

7/13

Power Network Telecommunication

ESB 2000i power line carrier system Modern PLC systems must not only take into account the specific characteristics of the high-voltage line but must guarantee first and foremost that they will be economically and technically usable in future digital networks. The ESB 2000i digital PLC system meets these requirements through ■ Use of state-of-the-art digital signal pro-

cessor technology (DSP) ■ User-oriented service features, e. g.

– automatic line equalization – automatic frequency control (AFC) – remote supervision/maintenance – programming of parameters by PC ■ Integration of data transmission systems (channel circuits KS 2000 and KS 2000i) ■ Digital interfaces for transmission up to 64 kbit/s Use of the ESB 2000i PLC system also enables the full advantages of digital transmission to be exploited when employing the high-voltage line as a transmission medium. The ESB 2000i PLC system also satisfies economic requirements such as low investment costs, reduction of expenditure for maintenance and service and technical requirements with respect to security, availability and reliability.

Modulation

Power amplifier

-Interfacemodules

Digital signal processing

Central control

-Demodulation

Receive selection

Fig. 21: ESB 2000i functional units

Application The ESB 2000i PLC system permits carrier transmission of speech, fax, data, telecontrol and teleprotection signals in the frequency range from 24 kHz to 500 kHz via: ■ Overhead power lines and ■ Cables in high- and medium-voltage systems. The information is transmitted using the single-sideband (SSB) method with suppressed carrier. This method permits: ■ Large ranges due to maximum utilization of the transmitter energy for signal transmission ■ The smallest possible bandwidth and therefore optimum utilization of the spectrum space of the frequency range permitted for the transmission ■ Improved privacy due to carrier suppression

7/14

Fig. 22: ESB 2000i PLC System with 40 W amplifier

Siemens Power Engineering Guide · Transmission & Distribution

Power Network Telecommunication

Digital interface of the ESB 2000i PLC System The ESB 2000i PLC system with ITU-T standardized digital interface for transmission rates up to 64 kbit/s significantly increases the possible applications. By using external multiplex systems providing ITU-T standardized interfaces X.21/V.11 or G 703.1, it is possible to adapt the ESB 2000i PLC system more flexibly to the number of transmission channels and the various interfaces for the digital transmission of speech and data.

ESB 2000i

Digital transmission from 1.2 to 64 kbit/s

Digital interface X.21/V.11 or G 703.1 or V.28

SSBmodulator/ demodulator

PLC-lineunit

HFbandwidth 2.5 to 8 kHz

Service channel

Central processor

Service telephone

Service PC network management

Fig. 23: Basic diagram of the ESB 2000i PLC System for digital transmission

19.2 kbit/s

32 kbit/s

40 kbit/s

64 kbit/s

Bandwidth 2.5 kHz

Bandwidth 4 (3.75) kHz

Note: A service channel for remote maintenance and for service telephone is provided in addition to the above nominal bit rates.

Bandwidth 5 kHz

Bandwidth 8 (7.5) kHz

Fig. 24: Transmission rates of the digital interface of the PLC system according to the available bandwidth

Siemens Power Engineering Guide · Transmission & Distribution

7/15

Power Network Telecommunication

SWT 2000 F6 protection signaling system for analog transmission links The task of power system protection equipment in the event of faults in highvoltage installations is to selectively disconnect the defective part of the system within the shortest possible time. In view of constantly increasing power plant capacities and the ever closer meshing of highvoltage networks, superlative demands are placed on power network protection systems in terms of reliability and availability. Network protection systems featuring absolute selectivity therefore need secure and high-speed transmission systems for the exchange of information between the individual substations. The SWT 2000 system for transmission of protection commands provides optimum security and reliability while simultaneously offering the highest possible transmission time.

Fig. 25: SWT 2000 F6 teleprotection signal transmission system (stand-alone version)

Application The SWT 2000 F6 system is for fast and reliable transmission of one or more protection commands and / or special switching functions in power networks. ■ Protection – Protection commands can be transmitted for the protection of two three-phase systems or one threephase system with individual-phase protection – High-voltage circuit-breakers can be actuated either in conjunction with selective protection relays or directly ■ Special switching functions – When the system is used for special switching functions, it is possible to transmit four signals. Each signal is assigned a priority.

Distance protection

IF 4 CLE

PU

Annunciations

OMA

Electrical line connection

Optical line connection

IF 4M PS

Transmission paths Depending on the type of supply network, the following transmission paths can be utilized: ■ High- and medium-voltage overhead lines ■ High- and medium-voltage cables ■ Aerial and buried cables ■ Radio relay links

7/16

Service PC

Alarms

24 ... 60 V dc 110/220 V dc/ac

Fig. 26: Block diagram of the SWT 2000 F6

Siemens Power Engineering Guide · Transmission & Distribution

Power Network Telecommunication

FWT 2000i telecontrol and data transmission system for analog/digital transmission links In all areas related to the telemonitoring of systems, automation technology and the control of decentralized equipment, it must be possible to transmit signals and measured values economically and reliably. The new FWT 2000i System for telecontrol and data transmission can be flexibly used to perform the various transmission tasks involved in system management not only in public utility companies, railway companies and refineries, but also in the areas of environmental protection and civil defense, as well as in hydrographic and meteorological services. The following characteristics of the FWT 2000i system make it suitable for meeting users’ special requirements: ■ Safe operating method around

high-voltage systems High degree of reliability and safety Short process cycle times Easy handling Economical use The FWT 2000i system offers a variety of modules for the widest possible range of transmission tasks. Thanks to the unlimited equipping options of the frame, virtually all system variants necessary for operation can be implemented on a customer-specific basis.

■ ■ ■ ■

Universal for all frequencies and transmission rates up to 2400 Bd The KS 2000i channel unit accommodates a transmitter and receiver assembly. All transmission rates from 50 to 2400 Bd can be set in all frequencies within the 30-Hz raster, including in the frequency raster to ITU-T. Transmission in the superimposed frequency band The FWT 2000i System permits transmission in the frequency range from 300 to 7200 Hz. Modularity The modularity of the KS 2000i channel unit is typified by its integration in various other systems, i.e. its use is not limited to the FWT 2000i system. For instance, the channel unit can be integrated in: ■ The ESB 2000i PLC system ■ The SWT 2000 F6 protection signaling system ■ Telecontrol systems.

Fig. 27: FWT 2000i telecontrol and data transmission system

Transmitter and receiver as separate modules Separate modules that function only as a receiver or only as a transmitter are available for this operating method. Flexibility By using additional modules the system can be extended for alternative path switching or transmission of the control frequencies of a multistation control system. Fast and easy fault localization A variety of supervisory facilities and automatic fault signaling systems ensure optimum operation and fault-free transmission of data.

Additional benefits In addition to the system features, the FWT 2000i system provides all users with the cost-effective and technical benefits expected and required when this system is used. ■ Economical stocking of spare parts

is possible since, from now on, only one module is needed for all rates and frequencies. ■ The system can be placed in service quickly and easily thanks to automatic level adjustment and automatic compensation of distortion. ■ The use of the state-of-the-art digital processors and components ensures that the system will have a long service life and a high rate of availability.

Transmission media Suitable transmission media are underground cables, grounding conductor aerial cables, aerial cables on crossarms of power line towers, PLC/carrier frequency channels via power lines, carrier links, PCM links and Telecom-owned current paths. The overall concept of the FWT 2000i system meets the stringent demands placed on power supply and distribution networks. The FWT 2000i meets the special requirements with regard to reliable operation and electromagnetic compatibility.

Siemens Power Engineering Guide · Transmission & Distribution

7/17

Power Network Telecommunication

KS 2000i channel unit The new KS 2000i channel unit is suitable for transmission of asynchronous data on analog media and such forms a complete and versatile VFT modem. Both transmitter and receiver are accomodated on only one plug-in card either to be used as stand-alone unit (seperate frame) or to be integrated in ESB 2000i PLC terminal or in remote terminal unit (RTU). Frequency shift as well as transmission speed are independently adjustable. With a maximum transmission speed of up to 2400 Bd the VFT channel approaches applications traditionally realized with highspeed modems only. Beside others the KS 2000i channel unit provides the following features: ■ High reliability ■ High flexibility ■ Easy detection of faults ■ Excellent transmission characteristics

Fig. 28: KS 2000i channel unit

7/18

Siemens Power Engineering Guide · Transmission & Distribution

Power Network Telecommunication

Fiber optic communication

The LFH 2000 system Telecommunication requirements in power utilities Electrical link (CU) Fiber-optic link

OLE 2 SWT MUX

O D F

MDF

LWL

34 Mbit/s

Protection

34 Mbit/s

LSA

PABX

Energy management system

Communications network management center

4 x 2 Mbit/s

34 Mbit/s

2 Mbit/s

4 x 2 Mbit/s Office

LAN

Communications room

2 Mbit/s

OLE 34 OLE 34

2 Mbit/s

OLE 8

MUX/CC MUX/CC DSMX

MDF PABX

SWT O O D D F F

PABX

34 Mbit/s 4 x 2 Mbit/s

4 x 2 Mbit/s

4 x 2 Mbit/s

Fig. 29: The LFH 2000 fiber optic transmission system – Telecommunication requirements in power utilities

Siemens Power Engineering Guide · Transmission & Distribution

7/19

Power Network Telecommunication

LFH 2000 fiber optic transmission system Flexible network configuration and future communications requirements of private network users, such as power companies, call for universal network elements for transmission in digital communications networks. LFH 2000 has been designed and developed on the basis of extensive experience gained with fiber optic transmission systems in public networks and transmission elements specially developed for such systems. It was tailored to the needs of power companies and other private network users. In its basic version LFH 2000 consists of a 19-inch subrack equipped with an optical line terminating unit TRCV2 and a service channel module. Even in its simplest configuration, LFH 2000 offers various types of interfaces for the transmission of speech and data channels such as:

The incorporation of the SWT 2000 D digital protection data system provides additional functions required for most applications in power companies. The basic version can be optionally equipped with service telephone units, optical line terminating units with higher transmission speeds or with other service channel modules so that the system can be conveniently adapted to the individual transmission requirements. Further network elements may be connected to LFH 2000 via internationally standardized interfaces if the number of required channels and the types of interfaces, i.e. the capacity of the system, have to be extended. Depending on the number and type of the transmission interfaces required, LFH 2000 can be expanded by connecting flexible multiplex systems.

■ Line interfaces up to 34 Mbit/s ■ So-interface for networking digital

telephone systems (e.g. Hicom)

LFH 2000 is provided with internationally standardized interfaces so that transmission systems of other manufacturers which are also equipped with internationally standardized interfaces can communicate with LFH 2000. This also makes it possible to combine LFH 2000 with digital transmission system of other manufacturers. The incorporation of LFH 2000 with the expansion element e.g. flexible multiplex system into a network hierarchy with differing transmission rates as currently planned and implemented by private network operates can be easily achieved using the compatible network elements available today. The call for a user-friendly network management can be fulfilled by adding the required hardware and software. LFH 2000 meets the requirements of the power companies and private network operators due to its flexibility, availability of internationally standardized interfaces and compatibility with regard to its incorporation into existing private networks.

■ QD 2-interface for network manage-

ment

DPU

Digital processor unit

IF4

Interface module for distance protection relays

OM

Optomodule for connection of digital current comparison protection system

PS

Power supply

ST-A

Module for service telephone with DTMF signaling

ST-B

Module for nondialing service telephone

AUX

Service channel unit

AUX 1+1 Service channel unit with protection switching

AUXBUS Bus channel unit TRCV

Optical transceiver

LWL

Optical fiber

DPU

IF 4 or OM

IF 4 or OM

PS

TRCV 2 or TRCV 8 or TRCV 34

Service telephone ST-A or ST-B

LWL Alarm and event recorder

Distance protection or digital current comparison

OFC (Fiberoptic cables)

TRCV 2 or TRCV 8 or TRCV 34

LWL

AUX or AUX 1+1 or AUX BUS

Telecontrol system PABX

Fig. 30: LFH 2000 fiber optic transmission system

7/20

Siemens Power Engineering Guide · Transmission & Distribution

Power Network Telecommunication

SWT 2000 D protection signaling system for digital communication links In comparison with analog protection signaling the use of digital transmission links provide noise-free communication. Switching operations, atmospheric conditions and other sources of interference on power lines do not impair secure and reliable transmission of protection signals. The SWT 2000 D system for the transmission of protection signals on digital transmission links, mainly fiber optics, provides optimum security and reliability while simultaneously offering the quickest possible transmission speed. Uses SWT 2000 D system is used for fast and secure transmission of one or several independent binary signals for protection and special switching functions in power networks and/or the transmission of serial protection data. The system is avaliable in versions for the transmission of protection data on separate fibers and on 64 kbit/s PCM channels. As an optimized solution between these two possibilities, the system offers transmission of the protection data in the service channel of an optical line termination system (e. g. OLTS, OLTE 8) which ensures maximum independence of the protection data from voice and data transmission despite the common use of fibers in fiber optic cables.

Fig. 31: SWT 2000 D for flush panel mounting with integrated TRCV2 optical line equipment

PCM

2 Mbit/s

40/60 V dc

Applications ■ All types of distance protection

TRCV

(permissive tripping, blocking, etc.) ■ Direct transfer tripping ■ Special switching functions ■ Digital current comparison protection (differential protection) with optical serial interface ≤ 19.2 kBd (e. g. with 7SD511).

Digital longitudinal differential protection (7SD51)

1300 nm 1500 nm

O.F. 820 nm n x 64 kbit/s

Features

■ ■

■ ■ ■ ■

Distance protection

bi-directional Up to 2 serial protection data, bi-directional Simultaneous transmission of serial protection data and up to 4 binary protection commands High-performance microcontroller Permanent self-supervision Automatic loop testing Event recorder with real-time clock (readable via hand-held terminal or PC).

OM

O.F.

X.21/ V.11 G.703

DPU

■ Up to 8 parallel (binary) commands,

O.F.

IF 4 Alternative route IF 4 PS

Service PC

24 ... 60 V dc Alarms 110/220 V dc/ac

Fig. 32: Block diagramm SWT 2000 D

Siemens Power Engineering Guide · Transmission & Distribution

7/21

Power Network Telecommunication

Flexible Multiplexer (FMX) Depending on the number and type of the transmission interfaces required, the LFH 2000 optical fiber transmission system can be extended by connecting the flexible multiplex system (FMX). The FMX multiplexer is based on a flexible design which is considerably different from normal PCM systems. For terminal operation, it contains a central unit CU, CUAD or CUDI unit and, for branch operation, a CUDI central unit as well as the withdrawable channels. Thanks to the software-controlled configuration and parametrization of the multiplexers they can be integrated quickly and easily into the network. The 19'' inset has sockets for two central units (CU, CUAD, CUDI), twelve channel units, a supervision unit and two power supply units.

User Interfaces (see Fig. 33) The LFH 2000 System – overview (see Fig. 34 on page 7/23)

ISDN Basic access unit I4SO

4x

S0 interface

I4UK4 NTP I4UK4 LTP

4x

UK0 interface, 2B1Q or 4B3T, NT-mode or LT-mode

DSC6-nx64G

6x

n x 64 kbit /s G.703 codirectional or n x 64 kbit /s G.703 contradirectional or centralized clock

DSC2-nx64

2x

X.21or V.24/V.28 bis (switchable)

DSC8x21

8x

X.21/ V.11 ≤ 64 kbit/s

DSC4V35 or DSC4V36

4x

V.35 ≤ 64 kbit/s or V.36 ≤ 64 kbit/s Central unit, standard, or central unit for add/drop operation or central unit for ADPCM

CU or CUDI or CUAD

DSC8V24

8x

V.24/ V.28 < 64 kbit/s

DSC104CO

10 x

64 kbit /s G.703 co-directional

SLB62

6x

2-wire LB subscriber

SLX62

6x

Exchange, 2-wire

SUB62

6x

Subscriber, 2-wire

SEM106 or SEM108

10 x

2-wire NF and 2 E&M or 4-wire NF and 2 E&M

CU or CUDI or CUAD

Central unit, standard, or central unit for add/drop operation or central unit for ADPCM

Fig. 33: FMX interfaces

7/22

Siemens Power Engineering Guide · Transmission & Distribution

Power Network Telecommunication

SDH 155 Mbit/s 2,5 Gbit/s

The LFH 2000 System – Overview

EMOS QD2 Network management system EMS Energy management system

2 Mbit/s

34 Mbit/s

34 Mbit/s

SDH 155/622 Mbit/s

34 Mbit/s

34 Mbit/s

2 Mbit/s

Remote subscriber External and/or internal exchange PABX Substation control and protection system

4x2 Mbit/s

4x2 Mbit/s

RTU

Data interfaces e.g. X.21, V.24, LAN

Data

V.11

Protection

V.11

Data and voice of PLC links Distance protection or digital current comparison protection

Protection

4 x 2 Mbit/s

34 Mbit/s

Speech four-wire + E&M Speech four-wire + E&M V.28 V.28

PABX

Data RTU

Service telephone Speech, two-wire

2 Mbit/s

2 Mbit/s

4 x 2 Mbit/s 4 x 2 Mbit/s

TRCV

SMUQ

PLC n x 64 kbit/s

Service channel

MUX

Cross connect

Fig. 34: The LFH 2000 System – Overview

Siemens Power Engineering Guide · Transmission & Distribution

7/23

Power Network Telecommunication

Conclusion The described digital and analog network elements are, of course, only a small selection from the multitude of network elements which Siemens has on hand for the implementation of transmission networks. We have focused on those products which have been specifically developed for the transmission of information in power utilities and which are indispensable for the operation of such companies. It has also been our intention to show the uses for our products and how they can be integrated in transmission networks with varying network elements and network configurations. The great variety of products in the field of digital transmission systems and the different requirements of our customers with regard to the implementation of digital transmission networks make customerspecific planning, advice and selection of network elements an absolute necessity. Detailed descriptions of all products can be sent to you upon request. For further information please contact: Fax: ++49 - 89-7 22-2 44 53 or ++49 - 89-7 22-4 19 82

7/24

Siemens Power Engineering Guide · Transmission & Distribution

Energy Metering

Contents General Areas of application

Page 8/2 8/2–8/4

Energy Metering

General Energy meters are used for measuring the consumption of electricity, gas, heat and water for purposes of billing. In this regard, modern energy meters should be able to handle differing regional tariff structures as well as complex tariffs in industrial applications. The meters must also comply to the general regulations for measuring instruments laid down in OIML D11. Specifications The following international specifications lay down the requirements for the different meters in terms of measuring accuracy, robustness, electromagnetic tolerance, burden, etc: ■ IEC 1036: Electronic current meters with measuring accuracy in class 1 and 2 ■ IEC 687: Electronic precision meters, class 0.5 s and 0.2 s ■ IEC 521: Ferraris meters with measuring accuracy in class 1 and 2 ■ OIML R6: Static gas meters ■ IEC 1107: Specification of optical interfaces ■ EN 50081 and EN 50082: Specification of interference robustness and interference radiation

Areas of application: Domestic

■ Single-phase

measurement of current consumption in low-voltage networks with high and low tariffs ■ High measuring accuracy and stability in extended use (class 2)

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 1: Adaptive meter (1-phase) Fig. 2: Ferraris single-phase meter

Siemens energy meters comply with all these requirements. Stringent quality control ensures functionality in all our products. ■ 3-phase measure-

Certifications High product and service quality is ensured by the implementation of internationally accepted procedures. An independant institute has confirmed this by issuing the ISO 9001 certificate.

ment of active and reactive energy consumption in 3- and 4-wire systems ■ High measuring accuracy and stability in extented use (class 2) ■ 1 and 2 tariff applications ■ Direct connection or connection via current transformer

Fig. 3: Static 3-phase meter 7EC49 Fig. 4: Ferraris 3-phase meter 7CA54

8/2

Siemens Power Engineering Guide · Transmission & Distribution

Energy Metering

Areas of application: Domestic

Commerce and industry

■ Wear-free flow

measurement through the use of ultrasonic technology by the static heat meter ■ Energy measurement in optimal range (class C)

Fig. 5: Sonic heat meter 2WR4

■ Measurement of ■ Prepayment

■

■ ■ ■ ■

■

electricity metering in class 2 Single-phase, 2-phase and 3-phase meters Keypad-based credit transfer Programmable power limiting Intelligent overload protection Fully integrated, flexible credit vending systems Current capability up to 80 A

■

■ ■

■

■

■ ■

Fig. 6: Cashpower 2000. The keypad prepayment electricity metering system that uses no cards, tokens or coins

Siemens Power Engineering Guide · Transmission & Distribution

active energy in two directions with accuracy class 1 and 2 4 tariffs each for demand and energy consumption One tariffless, sumtotal energy register Integrated realtime clock for tariff switching Integrated ripple control receiver (RCR) Storage of up to 15 previous energy/ demand values Maximum demand in all tariff periods Storage of detailed load profile

Fig. 7: 7E.6 – One meter for all special tariffs

8/3

Energy Metering

Areas of application: Large-scale industry

Bulk-energy transfer stations

■ Measurement of active and reactive

■ All of the above

■ ■ ■ ■ ■

consumption in both directions Individual metering of all 4 quadrants 4 different tariffs for each measurement parameter Direct connection or connection via current transformers Reduced wiring requirements Apparent power calculation

Fig. 8: The 7E.6 is able to replace a complete set of meters – at lower connection and operational costs

functions of the 7E.6 in the accuracy class 0.5 s and 0.2 s ■ As build-in and plugin meter

Fig. 9: High-precision energy meter

Siemens Energy Meter Management System SEMMS for power supply and distribution companies and for industry

M

SEMMS

MeterSet Utility

Industry Industrystandard function meter

MeterSet: The software for: ■ configuration ■ clarification ■ interrogation

MeterSet ist object-oriented. This means that it can be connected not only to Siemens meters, but to all foreign manufacturers´ meters well. SEMMS + MeterSet allows consistent management of meter information. All meter information is transferred directly from MeterSet into SEMMS, eliminating transfer errors and increasing operational security.

Utility billing meter

Interchange point Load management Special tariff-rate customer

Check meter Energy cost allocation

Siemens metering technology also contains a wide range of instruments for communication, registration and remote interrogation (such as Ripple Control Receiver)

Tariff-rate customer

Fig. 10: Siemens Energy Meter Management: With SEMMS you can handle the future

Fig. 11

■ SEMMS interrogates all models of

For further information please contact:

meters installed by power supply and distribution companies, eliminating manual meter reading, allowing faster billing and supporting simplified meter maintenance

8/4

■ SEMMS interrogates all kinds of meters

in industrial applications automatically, helping to assign and optimize costs

Fax: ++49 - 9 11- 4 33 -80 37

Siemens Power Engineering Guide · Transmission & Distribution

System Planning

Contents Overall Solutions for Electrical Power Supply

Page 10/2–10/6

System Planning

Overall Solutions for Electrical Power Supply Integral power system solutions are far more than just a combination of switchgear, transformers, lines or cables, together with equipment for protection, supervision, control, communication and some others more. Of crucial importance for the quality of power transmission and distribution is the integration of different components in an optimized overall solution in terms of:

Tasks System design Load development Cable restructuring Upgrading installations Selecting voltage levels System takeover Defining new transfomer substations System interconnection Connecting power stations

Component layout Generator Transformer Circuit breaker Overhead line Cable Compensation equipment Equipment for neutral grounding Protection equipment HVDC FACTS Control equipment Grounding

■ System design, creative system layout,

based on the load center requirements and the geographical situation ■ Component layout, according to technical and economical assumptions and standards ■ Operation performance, analyzing and simulation of system behavior under normal and fault conditions Siemens System Planning Whether a new system has to be planned or an existing system extended or updated, whether normal or abnormal system behavior has to be analyzed or a postfault

Solutions System analysis, system documentation

clarification done, the Planning Division, certified to DIN ISO 9001, is competent and has the know-how needed to find the right answer. The investigations cover all voltage levels, from high voltage to low voltage, and comprise system studies for long-distance transmission systems and urban power networks, as well as for particular distribution systems in industrial plants and large-scale installation for building centers in close cooperation with their customers and other Siemens Groups (Fig. 1).

Results Economical solution of distribution and transmission systems

System calculations, load-flow and short-circuit Planning and calculating AC and DC transmission

Simple and reliable operation

Determining economic alternatives Specifying the configuration of the system Design of electrical installations

Minimization of losses

Design of protection system, selecting equipment, selectivity and excitation tests Testing and customer acceptance inspection of protection equipment Simulation of complete system and secondary equipment

Reduction of the effects, extent and duration of faults

Switching operations, layout of overvoltage protection system, insulation coordination

Priorities in system extension Replacement of old installations, reconstruction, extension or new constructions

Analysis of harmonics, layout of filter circuits, closed-loop and open-loop control circuits for power converters

Extensively standardized system components

Operation performance

Simulation of system dynamics

Voltage quality System perturbations Neutral grounding Fault clearing Overload Overvoltage Asymmetry Transient phenomena Reactive power balance Power-station reserve

Layout of power electronic equipment (FACTS) Method of neutral grounding

Compliance with specified performance values

Reliability analysis Earthing arrangement and measurement

Safety for persons

Investigation of interference Propagation of ripple-control signals

Economical altenatives

Fig. 1: Tasks, Solutions and Results

10/2

Siemens Power Engineering Guide · Transmission & Distribution

System Planning

The Power Supply System The power supply system is like a pyramid based on the requirements of consumers and the applications and topped by the power generation (Fig. 2). The power system is basically tailored to the needs of consumers. Main characteristics are the wide range of power requirements for the individual consumers from a few kW to several MW, the high number of similar network elements, and the widespread supply areas. These characteristics are the reason for the comparatively high specific costs of the distribution system. Thus, standardization of equipment, use of maintenancefree components, and utmost simplification of system configuration have to be considered for an economical system layout. The load situation at the LV level determines the most suitable location of public MV/LV substations and consumer connection stations and, to a high degree, the electrical and geographical configuration of the superposed medium-voltage distribution network as well. HV/MV main substations feeding the medium-voltage distribution system should be located as close as possible to the load centers of the medium-voltage distribution areas. The subtransmission system feeding the main substations is configured according on their location and the location of the bulk power substations of the transmission system. The largely interconnected transmission system, e.g. up to 550 kV, balances the daily and seasonal differences between load requirements and different available generation sources.

Power generation

Transmission system up to 550 kV with HV/HV bulk substations

Transmission function

Subtransmission system up to 145 kV with HV/MV main substations Distribution function

Medium-voltage distribution system up to 36 kV MV/LV transformer public substations and consumer connection substations Low-voltage distribution system up to 1 kV. Public supply system or internal installation system

Consumer power application industry, commerce, trade, public services, private sector

Fig. 2: The Pyramid of Power Supply

Load development System analysis

Network representation

System architecture

Energy Supply ”reliable and economical“

Network calculation

Basic conditions for system design Industry, trade and commerce as well as public services (transportation and communication systems), but not forgetting the private sector (households), depend highly upon a reliable and adequate energy supply of high quality at utmost economical conditions. In order to achieve these aims, several aspects must be considered (Fig. 3). International and national standards are the basic fundamentals for system design. The choice of system voltage levels and steps is of decisive importance for the economical design and operation. Reliability requires adequate dimensioning of components with regard to currentcarrying capacity, short-circuit stress and other relevant parameters. Although interruptions in supply due to environmental

Investment planning

Protection analysis Protection coordination

Fig. 3: Aspects of system planning

influence or faults of components can never be avoided completely, it has to be assured that the time of interruption is minimized. This is a question of reserve in the system. Different degrees of reserve can be provided depending on the requirements.

Siemens Power Engineering Guide · Transmission & Distribution

10/3

System Planning

System Planning, a complex activity System planning and configuration is comparable with architectural work, finding the best technical and economical solution. System planning has therefore to start with a thorough task definition and system analysis of the present status, based on the given quality requirements. Alternative system concepts (system architecture) in several expansion stages ensure the dynamic development of the system, adapted to structure and load requirements of the subposed voltage level. Component design and the infeed from the superposed voltage level has to be considered as well. Technical calculations and economic investigations complete the planning work and are essential for the choice of the final solution (Fig. 4). Load Development The load analysis and estimation in the distribution system are always a matter of distributed loads in an certain area. In urban and rural areas, natural borders – such as rivers, railway lines or major roads and parks or woodlands allows the whole supply district to be subdivided into a number of subareas. In large commercial complexes, such as airports or university and hospital centers as well as in industrial areas, the load estimation is based on the individual buildings and workshops. Different methods are used for load estimation, such as annual growth rates for existing public areas, load density for new developing settlements, installed capacity and simultaneity factor for commercial and industrial supply. Distribution Network configuration for power distribution is a matter of visualization and will not be executed successfully without the geographical information of load and source location for public supply and industrial or large building supply as well. Thus, each distribution system must be planned individually. But, for the basic design, some standard configuration has proved optimal in terms of ■ Simple configuration ■ Easy operation and ■ Economical installation

10/4

Low-voltage systems are usually operated as open radial networks. Industrial systems in particular contain facilities for transfer to standby. Meshed operation is usually only intended for special load situations, such as single loads with great fluctuations or welding systems. Medium-voltage systems are primarily governed in their configuration by the locations of the system and consumer stations to be supplied. The most suitable arrangements for public supplies are open-ring systems or line systems to a remote substation. For industrial and building power supply systems, the higher load densities result in shorter distances between substations. This leads for reasons of economy to the spot system with radial-operated transformers. Industrial power supply differ from public networks inasmuch as they have a high proportion of motor loads and often inplant generation. Depending on the capacity, units will be connected to normal lowvoltage level, intermediate low-voltage level or medium-voltage. The technically and economically optimal configuration of distribution systems calls for wide-ranging practical experience from a large number of different projects and must determine switchgear configuration as well. Transmission The design of transmission systems is to a great extent individually tailored to the location of generating plants and bulk substations feeding the subtransmission system. Planning of high-voltage interconnected networks and transmission networks is a complex matter since they are operating over several different voltage levels and mostly meshed systems are used. This and the regional and seasonal difference of generation input and consumer demand as well as the many different size of lines, cables and transformers, make load-flow distribution complicated and require detailed calculations of system behavior and the operating conditions of power generation during planning work. As well as the actual planning, it includes numerous investigations, for instance, to determine the switchgear configuration and various equipment. This also entails detailed studies of the reactive power, voltage stability, insulation coordination, and testing of the dynamic and transient behavior in the network resulting from faults. Connection of neighboring transmis-

sion systems via AC/DC coupling, the implementation of HVDC transmission or superposing a new voltage level needs comprehensive planning and investigation work (Fig. 5). Tools Beside the great experience and knowhow Siemens Power System Planning applies powerful tools to assist the engineers and their highly responsible work. SINCAL (Siemens Networ Calculation) for analysis and planning purposes. Any size of systems with line and cable routing are simulated, displayed and evaluated with the SINCAL program system. With the help of an integrated database and easy-to-use graphics system, schematic and topological equivalent systems can be digitized or converted to other systems. NETOMAC (Network Torsion Machine Control) is a program for simulation and optimization of electrical systems which consist of network, machines and closed-loop and openloop control equipment. Two modes of time simulation, instantaneous value mode and stability mode can be used separately or in combination. The program serves for ■ Simulation of electromechanical and magnetic phenomena ■ Special load-flow calculations ■ Frequency-range analysis ■ Analysis of eigenvalues ■ Simulation of torsional systems ■ Parameter identification ■ Reduction of passive systems ■ Optimization DISTAL (Distance Protection Grading) calculates the setting values of the impedance for the three steps and for the overreach zones (automatic reclosing and signal comparison) of distance protection equipment in any kind of meshed network. CUSS (Computer-aided Protective Grading) indicates grading paths and grading diagrams, checks the interaction of the current-time characteristics with regard to selectivity and generates setting tables for the protection equipment.

Siemens Power Engineering Guide · Transmission & Distribution

System Planning

DISCHU simulation and testing of numerical protection relays. Technical standards, Reliability requirements

Superposed voltage level Infeed

Task definitions, System analysis of present status

Expansion project Load development

System architecture Alternative system concepts for stages Component design Technical/economical calculations and evaluations

Weak point determination Immediate action

PRIMUS works out the most suitable voltage for a DC transmission project together with the most important electrical data and the costs. SECOND

Subposed voltage level Load structure

is used to calculate the electrical characteristics and costs of a given AC transmission project. FELD

Protective coordination Method of neutral grounding

permits calculation of electrical and magnetic fields which occur during operation and fault conditions in the environment of one-, two- and three-phase systems (e.g. overhead lines and railway lines) in a twodimensional way. LEIKA permits calculation of the electrical characteristics of overhead lines and cables.

Proposal for system layout

TERRA is for calculating the potential fields of grounding installations. KABEIN

Fig. 4: Steps for network planning

Tasks Load development and power plant schedules Voltage steps and transformer substation sizes Installation type and configuration Voltage-control and reactive-power compensation Load-flow control and stability criteria Dynamic and transient behavior System management (normal and faulted)

is used for calculating the inductive interference to which telecommunication lines and pipelines are subjected by the operating currents or fault currents of high-voltage overhead lines or cables at any levels of exposure. SUNICO calculates how to make optimum use of power stations. It indicates the best choice from among the available power units and the best way of dividing up the system load among the individual units used. HADICA is used for calculating harmonic voltages and currents in electrical systems. ACFilt (Filter-circuit design) is for dealing efficiently with harmonic compensation.

Existing system Planned

Fig. 5: Planning tasks for interconnected transmission system

Siemens Power Engineering Guide · Transmission & Distribution

10/5

System Planning

Power Generation

G

∆u, ∆f, ∆φ

…

Positive and Zero Sequence Components

AC/DC Systems …

6 Test Stations

1…4

Digital Sequence Conrollers

5

6

Protection

Custom Power

Measuring, Protection and Control

… HVDC and FACTS

Signal Generation and Recording

Simulator Interfaces =1

Real-Time Computer Simulation

=1

RTDS

Signal Acquisition System

NETOMAC, EMTDC, EMTP

Playback Computer Simulation

Fig. 6: Advanced AC/DC Real-Time Simulator facilities

Advanced AC/DC real-time simulation The development and testing of measuring, protection and control equipment of large power supply installations need to take place under real system conditions. Siemens System Planning utilize a realtime simulator based on a modular principle so that different layouts and structures of the projects can be dealt with flexibly. In the simulator, there are 6 test stations which enable parallel work to be carried out. Four of them are specially designed for testing large power converters such as HVDC and FACTS units. Station 5 has special interfaces for testing system protection schemes. Custom power station 6 is used for Advanced Power Electronic Applications such as SIPCON (Siemens Power Conditioner). In addition to the classic type

10/6

of simulator with physical elements, realtime injection of transient signals from digital simulations is also possible, e.g. with NETOMAC or RTDS, so that computer and analog simulation complement each other. Measurements, Instruction and Training Sometimes only field measurements can provide an accurate picture of the actual situation and will be conducted for acquisition of data, clarification of disturbances and verification of functions. Also, instruction and training matched to the particular needs of the customers, acquainting them with installations or also procedures for use of software and methods of planning are important aspects, provided by Siemens System Planning.

For further information please contact: Fax: ++ 49 - 91 31-73 44 45

Siemens Power Engineering Guide · Transmission & Distribution

High-Voltage Power Transmission Systems

Contents High-voltage Power Transmission Systems

Page 11/2–11/4

High-Voltage Power Transmission Systems

Introduction The supply of power means more than just the combination of individual components. Particularly in countries where demand for power is growing at an above-average rate, there are large-scale projects under way, e.g. transmission systems or industrial complexes (Fig. 1). Setting up such large-scale projects calls for an expert partner, capable of diligently analysing demand and of planning the project integrally, taking all marginal conditions into account. This means a competent partner who produces top-quality components both for power transmission and for system management tasks. Such a partner must also ensure that the systems will be properly installed. Experienced project management – the way to the successful project With all key technologies in house, Siemens can provide turnkey solutions for the individual demands in the field of power transmission and distribution. The scope of supply includes all components from the generator terminals, via AC or DC transmission and the high-voltage grid to the HV, MV and LV distribution system going down to the individual customers. The benefit of the turnkey projects are:

Fig. 1

■ All project coordination is in one hand

and ■ The interfaces between customer and

supplier are minimized ■ The turnkey responsibility of Siemens reduces the project risk for the customer. In close cooperation with the customer, the task definition for the scheduled project is drawn up, and all marginal conditions clarified (Fig. 2).

General contractor

Supply, manufacture

Planning and design of turnkey Power Transmission Systems (PTS)

PTS and components Development and production of key components

Services, e.g.

Consortium member Consortium leadership Consortium member in the construction of PTS

Power Transmission Systems

BOO/BOT projects Project development Feasibility studies Financial engineering Partner & shareholder

Planning, consultancy Planning, project engineering Consultancy Coordination Studies, analyses

Quality assurance Personnel training Maintenance

Site management, installation & commissioning Overall project management On-site implementation On-site supervision

Fig. 2: Scope of supply and services

11/2

Siemens Power Engineering Guide · Transmission & Distribution

High-Voltage Power Transmission Systems

Cost comparison between 3-phase HV AC transmission and HV DC transmission

Costs

Depending on boundary conditions

Distance

Breake-even-point

HVAC HVDC

Fig. 3: AC or DC transmission costs over distance

System optimization and engineering

Training

One major task for the system engineering experts is the comparison and the assessment of various concepts. The basic parameters are transmission capacity and voltage, along with the transmission distance. Having the turnkey responsibility, Siemens can optimize the transmission system technically and economically in order to find the transmission system which is tailored to our customer‘s demands.

Customer training is a very important task in project management and our service department specializes in customer training. In the sessions and courses Siemens distinguishes between operation and maintenance staff training. The station operators are mainly trained in handling of the control and protection systems and their functions, whereas the maintenance teams are specially introduced to the main components. The training activities comprise classroom sessions, giving the theoretical background, as well as practical instruction on site in order to familiarize the customers with the individual items of equipment. Tailored financial solutions As a globally structured company, Siemens is prepared to participate in the financing of a power transmission project. Depending on the requirements, there are different possibilities covering supplier’s credit as well as complete project financing like Build Operate and Transfer (BOT) or numerous alternative models.

Siemens Power Engineering Guide · Transmission & Distribution

11/3

High-Voltage Power Transmission Systems

Service Our service activities cover all necessary checks, inspection and other maintenance activities. With the use of special diagnostic systems, also remote controlled, the causes for outages or malfunctions of individual equipment can be found easily.

For further information please contact: Fax: ++ 49 - 9131- 73 46 72

Fig. 4

11/4

Siemens Power Engineering Guide · Transmission & Distribution

Conversion Factors and Tables

Cross-sectional conductor areas to Metric and US Standards

Temperature

Metric crosssectional areas acc. to IEC

American wire gauge

Crosssectional conductor area

Equivalent Metric CSA

[mm2]

[mm2]

°F

Length °C Non-metric system

AWG or MCM

320° 305°

SI system

1 mil

0.0254 mm

1 in

2.54 cm = 25.4 mm

1 ft

30.48 cm = 0.305 m

1 yd

0.914 m

140°

1 mile

1.609 km = 1609 m

130°

SI system 1 mm

39.37 mil

1 cm

0.394 in

160° 150°

290° 275°

0.75

260°

17 16

245°

120°

230°

110°

1m

3.281 ft = 39.370 in = 1.094 yd

2.080

15 14

212°

100°

1 km

0.621 mile = 1.094 yd

2.620

13

200°

3.310

12

4.170 5.260

11 10

6.630 8.370

9 8

155°

70°

Non-metric system

10.550

7

140°

60°

1 in2

1.310 1.50

2.50 4.00 6.00

10.00 16.00 25.00 35.00 50.00 70.00 95.00 120.00 150.00 185.00 240.00 300.00 400.00 500.00 625.00

Non-metric system

19 AWG 18

0.653 0.832 1.040 1.650

90° 185° 80° 170°

13.300 16.770

6

21.150

4

110°

26.670 33.630

3 2

95°

42.410

1 1/0

53.480 67.430 85.030 107.200 126.640 152.000 202.710 253.350 304.000 354.710 405.350 506.710

125°

5

50° 40°

65°

0.093 m2 = 929 cm2

1

yd2

0.836 m2

1 acre

4046.9 m2

1 mile2

2.59 km2

1 mm2

0.00155 in2

1cm2

0.155 in2

3/0 4/0 250 MCM 300

32°

0°

Siemens Power Engineering Guide · Transmission & Distribution

1

20° 10°

20° –10° 5° –10°

6.452 cm2 = 654.16 mm2

SI system

50°

–20°

–25°

–30°

–40°

–40°

SI system

ft2

30° 80°

2/0

400 500 600 700 800 1000

Area

1

m2

1 km2

Non-metric system

10.76 ft2 = 1550 in2 = 1.196 yd2 0.366 mile2

Conversion Factors and Tables

Volume

Volume rate of flow

Non-metric system

SI system

Pressure

Non-metric system

1 in3

16.387 cm3

1 gallon/s

1 ft3

28.317 dm3 = 0.028 m3

1 gallon/min 0.227 m3/h = 227 l/h

1

yd3

0.765

m3 cm3

1 fl. oz.

29.574

1 quart

0.946 dm3 = 0.946 l 0.473

dm3

1 gallon

3.785

dm3

1 barrel

158,987 dm3 = 1.589 m3 = 159 l

1 pint

SI system

= 0.473 l = 3.785 l

1

ft3/s

1

ft3/min

SI system

3.785 l/s 101.941 1.699

m3/h

0.264 gallon/s

1 l/h

0.0044 gallon/min

1 m3/h

4.405 gallon/min = 0.589 ft3/min = 0.0098 ft3/s

Force

1 dm3 =1l

61.024 in3 = 0.035 ft3 = 1.057 quart = 2.114 pint = 0.264 gallon

Non-metric system 1 lbf

4.448 N

1 m3

0.629 barrel

1 kgf

9.807 N

1 tonf

9.964 kN

1 ft/s

0.305 m/s = 1.097 km/h

1 mile/h

0.447 m/s = 1.609 km/h

SI system

Non-metric system

1N

0.225 lbf = 0.102 kgf

1 kN

0.100 tonf

SI system

1 m/s

3.281 ft/s = 2.237 mile/h

1 lbf in

0.113 Nm = 0.012 kgf m

1 km/h

0.911 ft/s = 0.621 mile/h

1 lbf ft

1.356 Nm = 0.138 kgf m

SI system

Mass, weight

1 Nm

Non-metric system 28.35 g

1 lb

0.454 kg = 453.6 g

SI system

8.851 lbf in = 0.738 lbf ft (= 0.102 kgf m)

1

154.443 bar = 157.488 kgf/cm2

2

Numerical value equation: J = GD = Wr 2

4

Non-metric system

Non-metric system 1 lbf

0.035 oz

1 kg

2.205 lb = 35.27 oz 1.102 sh ton = 2205 lb

ft2

SI system 1 kg

m2

0.04214 kg

Non-metric system

SI system

29.53 in Hg = 14.504 psi = 2088.54 lbf/ft2 = 14.504 lbf/in2 = 0.932 tonf/ft2 = 6.457 x 10-3 tonf/in2 (= 1.02 kgf/cm2)

Energy, work, heat Non-metric system

SI system

1 hp h

0.746 kWh = 2.684 x 106 J = 2.737 x 105 kgf m

1 ft lbf

0.138 kgf m

1 Btu

1.055 kJ = 1055.06 J (= 0.252 kcal)

SI system

Non-metric system

1 kWh

1.341 hp h = 2.655 kgf m = 3.6 x 105 J

1J

3.725 x 10-7 hp h = 0.738 ft lbf = 9.478 x 10-4 Btu (= 2.388 x 10-4 kcal)

1 kgf m

3.653 x 10-6 hp h = 7.233 ft lbf

Moment of inertia J.

0.907 t = 907.2 kg

1g 1t

1.072 bar = 1.093 kgf/cm2

SI system

1 oz 1 sh ton

Non-metric system

0.069 bar = 0.070 kgf/cm2

tonf/in2

Torque, moment of force Non-metric system

4.788 x 10-4 bar = 4.882 x 10-4 kgf/cm2

1

SI system

Non-metric system

SI system

tonf/ft2

1 bar = 105 pa = 102 kpa

0.061 in3 = 0.034 fl. oz.

SI system

0.069 bar

lbf/ft2

1 lbf/in2

Non-metric system

1 cm3

Non-metric system

0.034 bar

1 psi 1

1 l/s

SI system

1 in HG

m3/h

Non-metric system

Velocity

Non-metric system

SI system

SI system m2

Non-metric system 23.73 lb ft2

Siemens Power Engineering Guide · Transmission & Distribution

Conversion Factors and Tables

Power

Examples for decimal multiples and submultiples of metric units

Non-metric system 1 hp

SI system

0.746 kW = 745.70 W = 76.040 kgf m/s (= 1.014 PS)

1 ft lbf/s

1.356 W (= 0.138 kgf in/s)

1 kcal/h

1.163 W

1 Btu/h

0.293 W

1 km2 = 1000 000 m2; 1 m2 = 10 000 cm2; 1 cm2 = 100 mm2 1 m3 = 1000 000 cm3; 1 cm3 = 1000 mm3

Non-metric system

SI system

1 km = 1000 m; 1 m = 100 cm = 1000 mm

1 t = 1000 kg; 1 kg = 1000 g 1 kW = 1000 W

1 kW

1.341 hp = 101.972 kgf m/s (= 1.36 PS)

1W

0.738 ft lbf/s = 0.86 kcal/h = 3.412 Btu (= 0.102 kgf m/s)

Specific steam consumption Non-metric system 1 lb/hp h

0.608 kg/kWh Non-metric system

SI system 1 kg/kWh

SI system

1.644 lb/hp h

Temperature Non-metric system °F

°C

°F

K

5 6 5 9

°F

K

°F

(ϑF – 32) = ϑC ϑF + 255.37 = T Non-metric system

SI system °C

SI system

9 5 9 5

ϑC + 32 = ϑF ϑ T – 459.67 = ϑF

Note: Quantity

Symbol Unit

Fahrenheit temperature

ϑF*

°F

Celsius (Centigrade) temperature

ϑC*

°C

Thermodynamic temperature

T

K (Kelvin)

* The letter t may be used instead of ϑ

Siemens Power Engineering Guide · Transmission & Distribution

Conditions of Sale and Delivery Subject to the “General Conditions of Supply and Delivery for Products and Services of the Electrical and Electronics Industry”. The technical data, dimensions and weights are subject to change unless otherwise stated on the individual pages of this catalog. The illustrations are for reference only.