Dissolved Gas Analysis & Monitoring-GE

Digital Energy

Dissolved Gas Analysis & Monitoring Mo nitoring

05 June 2013, Argentina

GE Monitoring & Diagnostic Diagnosticss

Technology, Products and applications June 2013 Donal Skelly

Introduction & Monitoring

Two factors are important to t o assess transformers: Dissolved gas This may be indicative that there is an active fault. If concentrations are changing faster than normal aging would result in, a fault may be present. present . If gas concentrations or gas concentration changes indicate that there is a fault a look at the relative concentrations of one gas to an other can be used to diagnose the nature of the fault

Moisture content As a general rule, for every doubling of moisture in oil (and ( and my inference moisture in the paper) the life of the transformer will be halved. Additionally Add itionally increased moisture exposes the transformer to increased risk of short circuit

 Periodic testing If a customer does not have on-line monitoring the only way to verify a transformer is to perform periodic off line DGA and moisture analysis. This involves: • Manually collecting 2 separate oil samples from the transformer and ship to a laboratory. • Wait for analysis (several days normally) • Laboratory GC for analysis of dissolved gas. • Karl Fischer titration for determination of moisture content. content .

You then compared the measured values with the values from previous tests looking for any increase and for the trend of this increase.

Why do on line Monitoring Disadvantages of periodic testing: • Periodic testing is not without cost: it takes time, ties up workers and requires the transformer to be drained of some oil. • Because of the requirement to visit the transformer to collect the sample, tests are generally carried out only every 1 to 2 yrs. • It is performed per formed on a sample that is normally several days removed from the condition when the sample was collected resulting in possible loss of sample integrity. • Significant or even critical transformer faults can develop in a fairly short period time and in between annual offline tests check. Periodic tests will not detect quickly progressing problems. On-line dissolved gas analysis a nalysis systems can now continuously monitor dissolved gas content and relative saturation of moisture, detect developing dev eloping faults at an early stage, enabling to t o schedule an outage for maintenance /replacement and prevent a catastrophic failure fail ure from occurring

Why Dissolved Gas Analysis? Dissolved Gas Analysis (DGA) is the industry defacto standard for transformer main tank and tap changer health assessment. •

Normal paper aging indicated by slow rise in CO2 – Accelerated or abnormal aging indicated by rapid rise in Carbon Monoxide

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Local low temperature hot spot indicated by rise in CH4

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Local High temperature hot spots indicated by rise in C2H4

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Detection of increasing quantities of Acetylene show arching occurring within transformer transformer..

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Rules available to allow for quick and accurate determination of the presence of a fault and the nature and severity of that fault

GE Multigas Products - History o

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Product line developed by a private company named Kelman Kelman looked at all available technology for measurement measurement of gas and for gas extraction from oil. Decision was to employ Infra-red spectroscopy and headspace gas extraction. Many reasons why. All multigas products now based on these two core techniques. Kelman went on to dominate the market for multigas DGA  were acquired by GE in 2007 –

GE product are now market leader in almost every country global and are overall global leaded for online monitoring.

GE Multigas DGA Products

All based on Photoacoustic MULTITRANS* TRANSFIX* Spectroscopy and Headspace gas extraction

TRANSPORT X*

 Portable DGA  7 fault gases + moisture  Simple & reliable

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TAPTRANS*  Full 8 gas on-line DGA for main tank & LTC in one unit •

 Full 8 gas multi tank DGA

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 Full 8 gas + moisture on-line DGA •

MINITRANS*  Cost-Effective on-line DGA  Discrete gas measurement (H2, CO, C2H2 + H2O)

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Photoacoustic Spectroscopy

Photoacoustics - Basics •

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Photo-acoustic affect discovered by A. G. Bell Measures individual gas in a mixture without physical separation.

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Spectral domain identification

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Photo-acoustic Photo-acou stic effect quantification

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No carrier gases - operates in ambient environment.

Photoacoustic Spectroscopy - History  –  –  –

1960s environmental monitoring (CO, NOx, SOx) 1970s Operating theatre (Nitrous Oxide, CO2) 1990s Auto and construction industry (Sox, Nox, CO, CO2, H20, Hydrocarbons)

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2000s Dissolved Gas Analysis - KELMAN (CO, CO2, CH4, C2H2, C2H4, C2H6, H2O)

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200,000 PAS based detectors worldwide for all the above application, and others There are 7000+ GE PAS instruments worldwide

What is IR

Infrared absorption • Almost every compound in the universe will absorb IR energy Every compound in existence has a unique absorption profile  like a finger print. If we target a region of the IR energy spectra that is unique for a compound we can measure its concentration. For DGA application, compounds are all simple gases –

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Photo-Acoustics  Basic Components –

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Radiation Source at approx 900oC. Chopper pulses radiation at 29.5hz Filters optically distinguish one gas in a mixture. Sample sealed in analysis chamber. Microphones measure intensity of pressure pulse.

Evolution of Photoacoustic Signal START: Optical IR Absorption

END: Acoustic detection

Pressure waves

Heating of gas

Thermal expansion of gas

Simple IR Spectrum  CO2 –

Photoacoustic IR Filters GAS IR-light pulses

Sound wave proportional to gas concentration

Photo-acoustic affect discovered by A. G. Bell Measures individual gas in a mixture without physical separation. Spectral domain identification Photo-acoustic effect quantification Employs one detector and no carrier gases Operated in ambient environment.

PAS Layout

DGA Gases Spectra Simple broad absorption peaks –

DGA Gases Spectra

Full Spectrum & Filter positions for DGA #1 CO2 #0 water #5 methane CH 4 #4 ethane C2H6 #6 acetylene C2H2

#2 CO

IR-active vib modes (rough guide)

Full Spectrum & Filter positions for DGA Where are Hydrogen, Nitrogen and Oxygen? #1 CO2

#0 water #5 methane CH 4 #4 ethane C2H6 #6 acetylene C2H2

#2 CO

IR-active vib modes (rough guide)

Benefits of PAS •

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No regular calibration or maintenance required No costly consumables such as calibration or carrier gases Capable of measuring at very low detection levels (e.g. 0.5ppm for acetylene) and very high detection levels (>50,000ppm) Capable of measuring individual gases in a mixture Ability to move from high gas levels to lower gas levels without cross contamination (TRANSPORT X, Tap TRANS Direct measurement of both CO & CO2, vital gases for understanding cellulose condition, giving increased accuracy & repeatability

User Benefits of choosing PAS Minimal maintenance required so not an O&M burden  with no ongoing support costs of either parts or labor Through rugged technology, repeatability is enhanced  this is vital for online monitoring as it is trend changes we are looking for Ability to monitor both multiple compartments (TapTrans) and multiple tanks (MultiTrans) No requirement for carrier or calibrati calibration on gases these can be expensive and difficul difficultt to transport

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Gas Extraction from oil

Gas Extraction Techniques •

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No technique allows for measurement of the gas while it is still a component of the oil. The gas must be removed from the oil or a representative sample sample of it removed prior to analysis. After removal the gas is passed to the detector eg, GC, PAS, solid state sensors etc.

Gas Extraction by online monitoring equipment •

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All online equipment use headspace technique for gas extraction. Coil = Cgas X Partition Coefficient x Volumetric Ratio

A membrane is a type of headspace extraction but there Is no volumetric ratio to consider

GE use headspace as laid out in ASTM 3612 : Standard Test Method for Analysis of Gases Dissolved in Electrical Insulating Oil by Gas Chromatography.

Transfix Plumbing Basic

Transfix Plumbing Visualisation

TRANSPORT X Schematic

Products

Product Summary TRANSFIX What is it? An on-line system that continuously monitors: • The concentration of 9 key gases in the insulating oil of electrical equipment. • The concentration of moisture in insulating oil. • Optionally transformer load and tank temperatures around others

Differentiated Value • •

It will alert personnel of fault conditions at an early stage and provide vital health information on the transformer or tap changer. •

An integrated solution from a sole supplier. When the TRANSFIX is integrated with a BMT 300 bushing monitor monitor unit, GE can offer a unique all-in-one solution that provides a more indepth view of the transformer's health Enabling more condition based maintenance, resulting in reduced maintenance costs.

What does the TRANSFIX measure Using separate separate oil collection and return point point for sampling, TRANSFIX can collect a discreet representative oil sample up to once every hour for analysis •

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DGA: Measurement of 9 key gases o

Hydrogen

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Methane

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Ethane

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Ethylene

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Acetylene

DGA is measured as follows:

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Carbon Dioxide

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Carbon Monoxide

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Oxygen

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Nitrogen

Oil pumped through the TRANSFIX unit, past an oil immersed Oxygen and Moisture sensor and on to fill a sample chamber to a predetermined volume. Gas extracted out of sample in sample chamber and analysis of this gas using a photo-acoustic gas analyzer

Oil moisture analysis o

Moisture (ppm)

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Relative Saturation

Moisture is measured as follows: Oil flows over a capacitance moisture sensor and during sampling and together with oil temperature (if recorded) ppm and RS are determined

TRANSFIX – View of an Installed Unit

TRANSFIX  Complete DGA –

Real-time Online DGA 8 gas + moisture analyser Hourly Measurements* Extensive communication/alarm options No consumables or calibration 6 Analog Inputs, 3 Digital inputs i nputs Full PERCEPTION integration Can be upgraded to include fibre optic temperature sensors

TRANSFIX – Technical Specifications

TRANSFIX – Technical Specifications

TRANSFIX – Technical Specifications

Simplified Overview of TRANSFIX

Host Board: 1. Co Cont ntro rols ls un unit it me meas asur urem emen entt scheduling 2. Stores re records

PGA: 1. Performs me measurement on extracted gas

Oil Manifold: 1. Takes oil sample from Transformer 2. Extracts Gas from oil System Board: 1. Provi vission of of I/ I/O 2. Pr Prov ovis isio ion n for for co comm mmun unic icat atio ions ns modules

MINITRANS is similar - simplified manifold, PGA & system board

TRANSFIX Communications options Standard • Two separate channels for remote communications, communication s, local USB connection and Ethernet connection. Protocols supported • MODBUS®, • MODBUS/TCP, • DNP3.0, • IEC61850®. Modules options available for connection • RS232, RS485, • Ethernet Ethernet,, PSTN modem and GSM or CDMA wireless modems. • 16 channel 4-20mA analogue output (All options are mounted inside TRANSFIX enclosure)

TRANSFIX Communications options Fiber Convertors available •

Ethernet to Fiber, Singlemode

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Ethernet to Fiber, Multimode

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RS232 to Fiber, Singlemode

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RS232 to Fiber, Multimode

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RS485 to Fiber, Singlemode

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RS485 to Fiber, Multimode

(All options are mounted inside TRANSFIX enclosure)

TRANSFIX – View of Installed Units

MINITRANS  Cost Effective DGA –

Real-time Online DGA Measures • • • •

Hydrogen Carbon Monoxide Acetylene Moisture

Hourly Measurements* Extensive communication/alarm options Load Sensor input No consumables or calibration Full PERCEPTION integration

MINITRANS  Cost Effective DGA –

MINITRANS  Cost Effective DGA –

MiniTrans Simplified PGA and simplified construction

PG  A

Measureme nt of: H2 C2H2 H2O CO ΣCnHn

MULTITRANS  Multi tank DGA –

Multi tank Real-time Online Transformer Monitoring Monitors up to 3 separate single phase tanks 8 gas + moisture analyser Hourly Measurements* Extensive communication/alarm options No consumables or calibration 6 Analog Inputs, 3 Digital inputs Full PERCEPTION integration

MULTITRANS  Multi tank DGA –

MULTITRANS  Multi tank DGA –

Simplified Overview of MULTITRANS PGA: 1. Performs me measurement on extracted gas

Host Board: 1. Co Cont ntro rols ls un unit it me meas asur urem emen entt scheduling 2. Stores re records

PGA

Oil Manifold: 1. Takes oil sample from Transformer 2. Extracts Gas from oil

Oil Switching: 1. Selects tank

System Board: 1. Provi vission of of I/ I/O 2. Pr Prov ovis isio ion n for for co comm mmun unic icat atio ions ns modules

TAPTRANS  DGA for LTCs –

Complete Online DGA for Transformer & Load Tap Changer Monitors Main, Selector & Diverter tanks in one unit 8 gas + moisture analyser Hourly Measurements Extensive communication/alarm options No consumables or calibration 6 Analog Inputs, 3 Digital inputs i nputs Full PERCEPTION integration

TAPTRANS  DGA for LTCs –

TAPTRANS  DGA for LTCs –

Simplified Overview of TAPTRANS PGA: 1. Performs me measurement on extracted gas

Host Board: 1. Co Cont ntro rols ls un unit it me meas asur urem emen entt scheduling 2. Stores re records

Oil Manifold 2: Divertor 1. Takes oil sample from Transformer 2. Extracts Gas from oil

Oil Manifold 1: Main & Selector 1. Takes oil sample from Transformer 2. Extracts Gas from oil

Oil Switching: 1. Sele lect ctss Mai ain n or Sele leccto torr ta tan nk

System Board: 1. Provi vission of of I/ I/O 2. Pr Prov ovis isio ion n for for co comm mmun unic icat atio ions ns modules

Failure Modes

 Australia and and New Zealand 457 failures over 10 years 30

%

25 20 15 10 5 0

 g s  o r  i e  e s  n   n   i  d  s  n   n   i  s  e   W  a c c  s  g  n   n  d  i  n   n   i   W

 r  s   l  i n  g  s  e  s   s  e  t   t  r s  r e  g   n  r  g  e  n   n  o   i  a  n  o   h  C   h a  t   h  p  o  s  O  s  C  u  e  C   B  v   i v  p  r  a  d   T  r  o   o  t   M o

ESKOM 1996 to 2006 136 severe and intermediate 35 failures

% 30 25 20 15 10

5 0

 s  g  n   n   i  d  n   n   W  i

 r .  s  s  e   t  e  r e  e   e  g  s   i  g  o  n   n  r   i  a  a  C  s  y   i   h  a n   l   l   i  s   i   h   x  u  o  C  u   B  &  p  A  a   k   T  n  a   a   t  n   i n  a   M

 s  s  r  e  O  t  h

CEA outages between 1997 to 2006 35

% 30 25 20 15 10 5 0

 g s   i n  g s   L  T C  n   n   n   i  O  s  h  n  n d   i  u   B   W

 e  a d s  n  t   t  h e r  n  t  r e  e  e  o  C  O  p m  p m  u  i p   L e  q  u  i p  q    E   E  g   i a  r  y  n   n   i   a   l   l   i  o   x  o  u  C  A

Combining the 3 set of data along transformer elements •

Core and coils (including leads and winding accessory)

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Tap changer (including driving mechanism)

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Bushings

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Cooling system (including main tank)

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Others (including auxiliary components)

Relative importance of each component as a contributing factor 40 35 30

   )    %    ( 25   e   g   a 20    t   n   e   c   r   e 15    P

 Aus  Australia tralia Eskom CEA

10 5 0

Core and coils

Tap Changer 

Bush Bushiings

Coo Cooling System

Other 

TAPTRANS  DGA for LTCs –

Complete Online DGA for Transformer & Load Tap Changer Monitors Main, Selector & Diverter tanks in one unit 8 gas + moisture analyser Hourly Measurements Extensive communication/alarm options No consumables or calibration 6 Analog Inputs, 3 Digital inputs i nputs Full PERCEPTION integration

TRANSFIX - Application Example Reliable uninterrupted power is the lifeblood of many industries, transformers are a critical tool in the production cycle Solutions Monitoring transformer health using TRANSFIX can reduce the requirement for routine transformer maintenance and provide for condition based maintenance and early fault detection.

TRANSFIX Features & Benefits Feature

Benefit

On-line DGA

Advance warning of Transformer needing maintenance/replacement Enables Condition Based Maintenance (CBM) Avoids catastrophic failure and /or transformer loss Avoids need for routine visits to site and manual sampling Early warning of possible arcing in main transformer tank Tracks load current, moisture content and ambient temperature for advanced trending capabilities

Integration with MO150 (TRNSFIX Plus)

Addition of models data for a more complete view of transformer internal faulth activity

Integration with BMT300 Bushing monitor

Provides a complete transformer solution to eff ectively monitor the majority of root causes of transformer failures. Uses same PERCEPTION software to visualize data Less vendors installing equipment in your switchyard Single vendor integrated solution that works/communicates

TRANSFIX Plus Online DGA with Models •

Combines TRANSFIX and MO150 in one enclosure

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Ethernet switch available for combined communications

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Will be integrated into PERCEPTION PER CEPTION at next release release (Feb 2011)

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TRANSFIX with BMT300

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M&D’s Integrated Solution The GE’s Intellix BMT 300 can easily be integrated with a GE’s TRANSFIX DGA analyzer, analyzer, giving the end user a unique all-in-one solution that provides a more comprehensive view of the transformer's overall condition: from bushing diagnostic and PD to complete main tank monitoring. Having an all-in-one GE integrated solution will significantly increase the ability to detect potential transformer problems at an early stage, decreasing the risk of unplanned downtime and improving asset reliability. The integrated solution will provide provide:: o Developing key fault gases H2, CO, C2H2, C2H4, C2H6 as well as O2, CO2, CH4 o Moisture content in oil o Partial discharge activity o Deterioration Deterioratio n of the bushing insulating All this information can be downloaded and visualized on the same PERCEPTION software software as with TRANSFIX, thus increasing familiarity and reducing learning curve. Finally , the solution comes from a single supplier, ensuring reliable communication between Finally, components compone nts and reducing the number of vendors working in i n the customer’s switchyard switchyard..

M&D Integrated Solution – Substation Application

associated with TRANSFIX multigas

standalone Software

Diagnostics

Transformer failure locations & modes Location of Transformer Failure

Main tank LTC Bushing Cooling Cooli ng system system Other 

: Windings failure, Partial Discharge, Excessive Excessive H2O, surface contamination, connection failure, circulating currents, overloading hazard.  contact overheating and coking, desynchronization, desynchronization, excessive number of operations, mechanical damage, neutral switch inactivity  moisture penetration, oil leak, partial discharge  clogged coolers by pollen or dust , fan/pump failure, failure, sludge, oil leak

External, such as lightning, animal interference, operation error,

Key DGA gasses, and what they indicate

H2

Hydrogen

Nearly all fault conditions, low energy PD

CH4

Methane

Oil overheating between 200ºC and 500ºC

C2H6

Ethane

Oil overheating between 300ºC and 500ºC

C2H4

Ethylene

Oil overheating over 500ºC, possible formation of carbon particles

C2H2

 Acetylene

High energy arcing, oil overheating over 800ºC, strong formation of carbon particles, metal melting

CO

Carbon Monoxide

Paper insulation overheating

CO2

Carbon Dioxide

Oil oxidation, paper degradation

O2

Oxygen

Oxidation, leak

TRANSFIX – DGA for Fault detection

Bushing  Power Factor –

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Transfix is equipped with a direct connection, via USB for data download capability

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Remote download available available when utilizing one of the various communication protocols

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TransConnect TransConne ct is used for Transfix settings and the configuration of Alarm limits

Perception is used for data downloading and analysis of DGA results to provide a diagnosis of the fault, if one is detected

What is Perception Advanced Transformer Management Software • Specially designed for the power industry • Provides simplified trending • Provides advanced transformer diagnostics • Intuitive/configurable interface

Utility value

What is Perception

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Shipped with Transfix unit Designed for single user/local database Requires manual result download Recommended for low number of DGA units

Utility value

Enterprise version of Perception. In addition to Express features: • Multiple users • Central database • Scheduler (Console) for automated results download • Email alarm notification

Transformer Services

Transformer Field Services Team of transformer design and test experts available to perform In-depth condition assessments Condition based ranking of fleet Design reviews Training. • • • •

Our methodology uses extensive On-Line testing. test the transformer in its real life state. less reliance on outages and less disruption to the customer. • •