Digital Substation Alstom

SCADA & Digital Substation Elizabeth Johnson & Ritesh Bharat

GRID

Introduction to Digital Substations

INTRODUCTION The demand of electrical energy − led the Utilities to develop High and Ultra High Voltage networks − using AC and DC technology (1100 – 1200 kVAC ; 800 – 1100 kVDC) Control, Protection, Metering and all other IEDs − are using digital electronics − and should be able to communicate with IEC 61850 Standard Instrument Transformers are the link between the UHV line and the Protections and all secondary equipment ; They have to be designed for − higher insulation levels, − higher short circuit current capability, − higher bandwidth − extended dynamic range and high accuracy (primary current : 1A to 50 kA) New technologies are developed to meet new demanding requirements: − DIT (Digital Instrument Transformers; CT and VT), or “NCIT” − Digital Communications between « Process » apparatus and Bay/Station level − Control and Monitoring of active mechanisms (CB and DSC)

What is « Digital Substation » ? A global association of IEDs in the substation, including: Smart « intelligent » DCS (Digital Control System)

 Smart Grid

New technologies of Instrument Transformers (NCITs) Merging--units for Sampled Values (CTs, VTs, NCITs) Merging Digital Controllers for CircuitCircuit-Breakers and Disconnectors On--line conditioning Monitoring (CB, DSC, GIS, TRANSFO) On

All these IEDs communicating together with digital standardized protocols defined in IEC 61850

Digital Instrument Transformers – How do they work?

Michael Faraday (1791－1867)

Optical CT Principle – Faraday Effect

Optical transparent medium Light polarization vector

I

Light propagation axis

H Current busbar

 Rotation of the polarization plane of an optical wave, traveling in a magneto-optic material, under the influence of a magnetic field parallel to the direction of propagation of the optical wave

PRINCIPLE OF OPERATION

A light source sends light through a waveguide to a linear polarizer, then to a polarization splitter (creating two linearly polarized light waves), and finally to an optical phase modulator. This light is then sent from the control room to the sensor head by an optical fiber. The light passes through a quarter wave plate creating right and left hand circularly polarized light from the two linearly polarized light waves. The two light waves traverse the fiber sensing loop around the conductor, reflect off a mirror at the end of the fiber loop, and return along the same path. While encircling the conductor, the magnetic field induced by the current flowing in the conductor creates a differential optical phase shift between the two light waves due to the Faraday effect. The two optical waves travel back through the optical circuit and are finally routed to the optical detector where the electronics de-modulate the light waves to determine the phase shift. The phase shift between the two light waves is proportional to current and an analog or digital signal representing the current is provided by the electronics to the end user.

Why Optical CTs? Safety Intelligence and flexibility Availability Wire => Electric Power Optical Fiber => Information

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Safety

 The optical CT does not “touch” the electrical power on the line.  High voltage and ground are well separated with all dielectric insulation.  The insulation contains no fuel.

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Intelligence and Flexibility

 The optical sensor is fully self-diagnostic.  Extremely high fidelity current measurements allow for improved system diagnostics  Software configurability

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Availability  Improved system availability is a consequence of safety and intelligence  Unmatched reliability of outdoor equipment  Electronics interchangeability + redundancy means no down time.

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NCIT Benefits DIGITAL − Intelligence for SMART GRIDs, smart redundancy, Ethernet connectivity (IEC 61850), self diagnostic,.. SAFETY − No HV coupling, no measurement service loss in event of a failure ENVIRONMENTAL − No oil, no SF6, no copper, zero footprint (for CTs), less mass ACCURACY − Wide dynamic range (extended range) frequency response DC to 10 kHz (includes the 100th harmonic) ADAPTABILITY − Easy installation and cabling, easy on-site testing, universal design software configurable, flexible form factor AVAILABILITY − Zero outdoor maintenance, electronics inter-changeability, HV passivity, short lead time, redundancy

Hardware modification in Analogue Modules” No need of Analogue CT & VT inputs

Digital CT & VT input board with IEC 61850-9-2

Analogue inputs are replaced by Ethernet connection 13

IEC 61850 Process Bus Digitalization and Transmission of CT and VT measurements multicast “Digital Standardized Interface” are a challenge But, It gives major benefits − − − − − −

cabling simplifications costs reductions introduction of NCIT measurement systems permanent self-monitoring safety etc.…

And Digital Control of Circuit-Breakers and Disconnectors

on

Types of Merging Units

 AMU : Analog Merging Unit  Interface with conventional instrument transformers

 DMU : Digital Merging Unit  Interface with CB / isolators / earth switches

 IMU : Integrated Merging Unit  Combination of AMU and DMU

 NMU : Numerical Merging Unit  Interface with digital instrument transformers

Typical Merging Unit

CT / VT Signals in the Protection

Comtrade file NCIT measurement In the protection

Comtrade file CIT measurement In the protection

Distance Protection P444 - results

With digital 9-2LE interface

Conventional analogue interface

Intelligent Primary Equipments

GIS Local Cubicle (LCC) CEVT-P/M CEVT-P/M

Analogue connections Synchro – 1pps

CEVT-P/M

PCtri-U

FO - Ethernet 100BaseFx

PCtri-I

N M U

IEC 61850-8-1

IEC 61850-9-2LE Or other protocol

MICOM P594

X

X

RECT-P/M IEC 61850-9-2LE

RECT-P/M RECT-P/M

Analogue

Or other protocol

connections

Digital/Analog Converter METER

PCtri-I : 3-phased current Primary Converter with Ethernet ports PCtri-U : 3-phased voltage Primary Converter with Ethernet ports

X

GRIDBOX – Controller and Monitoring for Circuit Breaker GRIDBOX can control and monitor standard alarms on breaker, transformer, disconnectors etc….

GRIDBOX – Controller and Monitoring for Circuit Breaker Main Features • Replace copper by optic fibber • Circuit breaker “full monitoring” • Trip Coil Supervision • Electrical/mechanical wear • Open/close travelling signature • Local static command of coils • Network synchronized time stamps of events • (GPS or IEEE1588) • IEC61850 communication Advantage • Decrease substation reconstruction cost • Increase communication reliability between the field equipment and control building • Benefit from accurate planning of maintenance/refurbishment/replacement • Obtain real time detection of equipment availability • Reduce command response time

DMC (Digital Motorized Control) for Disconnectors

The DMC device is installed inside motor operating mechanism applied to disconnect switches. The DMC device is designed to totally control the movement of the disconnect switch during opening and closing operations with an integrated electronic module The DMC allows the control mechanism (mechanical parts can be monitored both locally and remotely)

Features New operating mechanism equipped with DMC device features:

•Stainless steel box •Irreversible gearbox •Robust design to cope with adverse environmental conditions •Can be adjusted for any motor supply voltage •Less cabling and wiring •Reduced maintenance cost by preventive maintenance •Variable speed during the operations GRID •Modularity on the configuration to suit any type of installation

DMC Installation

DMC device is installed inside ALSTOM motor operating mechanism CMM series.

GRID

Monitoring Benefit DMC device permit to the user to:

• • • • • • • •

Archive curve which facilitates ageing and maintenance studies Evaluate the state of kinematic chain and live part position during the operation Continuously monitor the control circuit Control the real end open-close position of disconnector Obtain a precise indication of the operation times Record load curves in real time for a general evaluation before and after the maintenance and repairing Controls torque to operate the disconnector

GRID

Offer a flexible configuration based on the different disconnector type

Monitoring Specification DMC device monitors/controls following parameters as a function of position and time:

• • • • • • • •

Voltage Current Operating time Disconnector in motion/not in motion N° of operation cycle Max current reached Minimum voltage reached GRID Data are recorded in non-volatile memory and transferred via telecommunications serial RS 232.

Summary • • • • • • • • • • •

Motor power supply voltage : from 90Vdc – 250Vdc / 110-400 Vac 50/60Hz Remote control command power supply voltage: from 90Vdc-250Vdc / 90Vac-220Vac Variable speed configurable Mode of operation : Remote-Local-Manual Electrical connection on terminal board and connectors Electrical interlocking motor/manual operation Real time monitoring of the disconnector’s state Data recording for diagnostic Cams switch positioning system Serial output comunication RS 232 with local PC

GRID

Programmable positioning signal management with dedicated free contacts on terminal board

DMC Architecture with a “concentrator D-DSC”

3 x DMC A

B

3 x DMC C

A

B

C

D-DSC

I²CBus

Prot1

IEC 61850-8-1

Prot2

BCU

Met A

B

C

A

3 x DMC

B

Optical Fibers

C

3 x DMC

Prot A Met

DMC / IEC 61850-8-1

B 3 x DMC

C

System Architecture in Digital Substations

COSI

Digital Substation

SYSTEM ARCHITECTURE IEC 61850-8.1 & 9.2

GPS LOAD CENTERS IRIG-B

OPERATOR WORKSTATION

IEC 60870-5-101 Protections

IEC 60870-5-104

ENGINEERING WORKSTATION

REMOTE ACCESS

Ethernet

SNTP MODEM

RS232

MODEM

GATEWAY

Switch

Switch

ETHERNET OPTICAL LAN IEC61850-8.1 100MBps

IRIG-B

SNTP

Bay Computer

SNTP

Bay Computer

Bay Computer

Bay Computer

SNTP

Protections xn

IRIG-B

Protections xn

IEC 61850-8.1

Protections xn

MODBUS

IEC 60870-5-103

IEC 60870-5-103

IEC 60870-5-103

IEC 61850-8.1

CT/VT

IRIG-B

Protections xn

AVR

IRIG-B SNTP

AVR

TC TS TM 4-20mA

IEC 61850-9.2

GPS

IRIG-B

Switch 1PPS

1PPS

Switch

Merging Units

1PPS

IEC 61850-8.1

CIT = Conventional Instrument Transformers

NCIT = Non Conventional Instrument Transformers

System Architecture

XMU SELECTOR BB

DMC

DMC

DMC

DMC

DDSC

DDSC

DCCB

DCCB

PROT XMU DMC

DMC

BCU

PROT XMU DMC

DMC

BCU

Process Bus SV Process Bus GOOSE Station Bus

DCS PACIS – ETHERNET OPTICAL LAN – 100 Mbps – IEC 61850-8-1

COSI-NXCT Mounted on Live Tank CBs

National Grid, UK NXCT on a Siemens 420 kV live tank circuit breaker

Alstom GL317 with NCIT Enel Terna, Italy Candia S/S, 420 kV COSI-NXCT on VATECH live tank circuit breaker

COSI NXCT on CB Example of 400 kV OHL feeder 400kV OHL feeder bay

400kV OHL feeder bay with NXCT on LTCB

OHL feeder Comparison : footprint saving 15%

Conclusions NCITs & Process Bus offer huge potential advantages Cost and Space savings Interoperability : Digital Standard IEC 61850 Safety Reliability Availability Measurement Improvements

Thank You

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