Application of Numerical Distance Relay

8/10/2019 Application of Numerical Distance Relay

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APPLICATION OFAPPLICATION OF

NUMERICAL DISTANCENUMERICAL DISTANCERELAYSRELAYS

A PRESENTATION BYA PRESENTATION BY

OS DEPARTMENTOS DEPARTMENT

ERER--II,KOLKATAII,KOLKATA


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FOREWORDFOREWORD Gazette Notification from GOI datedGazette Notification from GOI dated

09.03.2007 regarding Grid09.03.2007 regarding Grid

connectivity standards applicable toconnectivity standards applicable toTransmission lines & substationTransmission lines & substation--

PartPart--III(3) stipulates that:III(3) stipulates that:

Two Main Numerical DistanceTwo Main Numerical Distanceprotection scheme shall be providedprotection scheme shall be provided

on all the Transmission Lines ofon all the Transmission Lines of

220KV & above for all new220KV & above for all newsubstations. For existingsubstations. For existing

substations,this shall besubstations,this shall be

implemented in a reasonable timeimplemented in a reasonable time

frameframe


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POWERGRIDs compliancePOWERGRIDs compliance

Technology made large populationsTechnology made large populationspossible; large populations now makepossible; large populations now maketechnology indispensabletechnology indispensable

POWERGRID is extensively usingPOWERGRID is extensively usingNumerical relays for protection schemes ofNumerical relays for protection schemes ofall new Lines & substations.all new Lines & substations.

All regional OS departments haveAll regional OS departments have

undertaken retrofitting of old relays withundertaken retrofitting of old relays withNew generation Numerical relays.New generation Numerical relays.

POWERGRID,ERPOWERGRID,ER--II has completed 1II has completed 1stst

stage of retrofitting of Numerical distancestage of retrofitting of Numerical distanceprotection. The work for the 2protection. The work for the 2ndnd stage isstage ispresently being executed.presently being executed.

Old static type differential relays for all EHVOld static type differential relays for all EHVTransformers are also being retrofitted withTransformers are also being retrofitted withNew Numerical differential protection.New Numerical differential protection.


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ADVANTAGESADVANTAGES

Improves dependability as well

as security

Has Self checking facility

ers ery ow ur en More flexible because of

programmable capability

Adaptive relaying schemes

Permit Historical data storage


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ADVANTAGESContd.ADVANTAGESContd.

Fiber optical communication with

substation LAN Allow GPS (Geographical

Positioning System) Time stamping

Numerical relays simplify interfacingwith CTs and VTs

Separate connection is not required,

zero sequence voltages and currentscan be derived inside the processor


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ENGINEERS CHOICEENGINEERS CHOICE

Numerical relays represent

best compromise between:

a) Economy and performance

b) epen a y an secur yc) Complexity and simplicity

d) Speed and accuracy

e) Credible and conceivable


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COMPARISON STATEMENTCOMPARISON STATEMENT


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Numerical Distance RelayNumerical Distance Relay

main functionsmain functions

A single Numerical distance relay

has: Distance protection

Power swing Blocking

Phase-fault (highset) overcurrentprotection

Directional earth-fault protection

Sensitive earth-fault protection Overvoltage and undervoltage

protection


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SPECIAL FUNCTIONSSPECIAL FUNCTIONS

Broken conductor detection - To

detect network faults such as opencircuits, where a conductor may be

broken but not in contact with

another conductor or the earth. Circuit breaker failure protection -

Generally set to back-trip upstream

circuit breakers, should the circuitbreaker at the protected terminal fail

to trip.


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Numerical Distance protectionNumerical Distance protection

Other functionsOther functions

ControlControl

Autoreclose Check synchronising

Monitoring

Voltage transformer supervisionSystem data

Sequence of event records

Fault records Disturbance recorder


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Existing Numerical DistanceExisting Numerical Distance

protection in POWERGRIDprotection in POWERGRID--ERER--IIII


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Numerical Differential relayNumerical Differential relay

main functionsmain functionsA single Numerical differential relayhas:

DIFFERENTIAL PROTECTIONDIFFERENTIAL PROTECTION

Matching to the vector groupStabilization under inrush

(eg:based on the presence of second

Stabilization under overfluxingconditions

(eg:based on the ratio of the fifth harmonicthe ratio of the fifth harmonicto the fundamental wave)to the fundamental wave)

RESTRICTED EARTH FAULTPROTECTION

DEFINITE TIME AND INVERSE TIMEOVERCURRENT PROTECTION


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Numerical Differential protectionNumerical Differential protection

main functionsContd.main functionsContd.

THERMAL OVERLOAD PROTECTION

OVER-/UNDERVOLTAGE PROTECTION

OVER-/UNDERFREQUENCY PROTECTION

OVEREXCITATION PROTECTION

impermissible high magnetic flux densitiy in

the iron core of power transformers in case of

increase in voltage and/or decrease in

frequency. Flux density above the rated valuesaturates the iron core & result in power

transformer overheating due to large iron

losses.


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Numerical DifferentialNumerical Differential

protection:Other functionsprotection:Other functions

Monitoring

Voltage transformer

supervision

ys em a a Sequence of event records

Fault records

Disturbance recorder


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Existing Numerical DifferentialExisting Numerical Differential

protection in POWERGRIDprotection in POWERGRID--ERER--IIII

MICOM P-633

-

7UT613


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A TOOL TO SYSTEMA TOOL TO SYSTEM

ENGINEERSENGINEERS

Numerical relays provide comprehensiveNumerical relays provide comprehensivefault reporting data for the analysis offault reporting data for the analysis ofpower system faults and relay operations.power system faults and relay operations.

Valuable information from relaysValuable information from relaysthroughout their grid may be gathered.throughout their grid may be gathered.

After a fault, most precise fault location canAfter a fault, most precise fault location canbe reached to narrow the search forbe reached to narrow the search forpossible damage on the line and to cut thepossible damage on the line and to cut thedown time for restoration.down time for restoration.

Software system for relay fault records canSoftware system for relay fault records canprovide the desired precision to the utilityprovide the desired precision to the utilitypersonnel.personnel.


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FAULT STUDYFAULT STUDY


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Disturbance reportDisturbance report--11

Complete and reliableComplete and reliableinformation about disturbancesinformation about disturbances

in the primary and/or in thein the primary and/or in thesecondary system together withsecondary system together withcontinuous eventcontinuous event--logging islogging is

disturbance report functionality.disturbance report functionality.

The disturbance report, includedThe disturbance report, included

in the IED, acquires sampledin the IED, acquires sampleddata of all selected analoguedata of all selected analogueinput and binary signalsinput and binary signalsconnected to the function blockconnected to the function block


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Disturbance reportDisturbance report--22

Any change in Digital Inputs orAny change in Digital Inputs or

Analog Thresholds functionAnalog Thresholds function

blocks may be set to trigger theblocks may be set to trigger thedisturbance recorderdisturbance recorder..

--

time to the end of posttime to the end of post--faultfaulttime, will be in the recording.time, will be in the recording.

Every disturbance reportEvery disturbance reportrecording is saved in the IED inrecording is saved in the IED in

the standard formats.the standard formats.


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Event recorderEvent recorder

Quick, complete and reliableQuick, complete and reliableinformation about disturbancesinformation about disturbances

in the primary and/or in thein the primary and/or in thesecondary system is vital e.g.secondary system is vital e.g.time tagged events loggedtime tagged events logged

..

This information is used forThis information is used fordifferent purposes in the shortdifferent purposes in the short

term (e.g. corrective actions)term (e.g. corrective actions)and in the long term (e.g.and in the long term (e.g.Functional Analysis).Functional Analysis).


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Time synchronizationTime synchronization

Time synchronization sourceTime synchronization source

selector selects a commonselector selects a common

source of absolute time for thesource of absolute time for theIED.IED.

This makes com arison ofThis makes com arison of

events and disturbance dataevents and disturbance databetween all IEDs possible.between all IEDs possible.

It is done now with the IRIGIt is done now with the IRIG--BB

Protocol available with the GPSProtocol available with the GPS

Clock.Clock.


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STATION COMMUNICATIONSTATION COMMUNICATION

Each IED is provided with a communicationEach IED is provided with a communicationinterface, enabling it to connect to one orinterface, enabling it to connect to one ormany substation level systems or equipment,many substation level systems or equipment,either on the Substation Automation (SA)either on the Substation Automation (SA)bus or Substation Monitoring (SM) bus.bus or Substation Monitoring (SM) bus.

IEC 60870IEC 60870--55--103 communication protocol103 communication protocol

A single glass or plastic port allows designA single glass or plastic port allows designof simple substation automation systemsof simple substation automation systems

..

Disturbance files uploading is provided.Disturbance files uploading is provided. IEC 61850IEC 61850--88--1 communication protocol1 communication protocol

Single or double optical Ethernet ports forSingle or double optical Ethernet ports forthe new substation communication standardthe new substation communication standard

IEC61850IEC61850--88--1 allows intelligent devices1 allows intelligent devices(IEDs) from different vendors to exchange(IEDs) from different vendors to exchangeinformation and simplifies SA engineering.information and simplifies SA engineering.


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Return on InvestmentReturn on Investment

Investing on Numerical relaysInvesting on Numerical relays

has greater return as it was nothas greater return as it was notrequired to invest for discreterequired to invest for discreterelays line OV/UV,LBB,AR,relays line OV/UV,LBB,AR,

FL,DR etc.FL,DR etc. Failure Rate of Numerical relaysFailure Rate of Numerical relays

in POWERGRID has been veryin POWERGRID has been very

small, requiring lesssmall, requiring lessmaintenance cost.maintenance cost.


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Return on InvestmentReturn on Investment

A simple example.A simple example.

As per the New tariff regime, Outage of aAs per the New tariff regime, Outage of a420/220/33 KV 315MVA Autotransformer420/220/33 KV 315MVA Autotransformer

results a monetary loss of Rs. 2.5L perresults a monetary loss of Rs. 2.5L perDay.Day.

Tripping in case of even for extraneousTripping in case of even for extraneousreasons & not on Transformer fault followsreasons & not on Transformer fault follows

Health check test program,requiring a fullHealth check test program,requiring a fullday.day.

DR print, if available may help detect theDR print, if available may help detect theabove & Transformers can be restoredabove & Transformers can be restoredwithin 10within 10--15 Minutes.15 Minutes.

A single event of that order may renderA single event of that order may rendersaving of the amount invested for a newsaving of the amount invested for a newNumerical differential protectionNumerical differential protection


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POWERGRID & NUMERICALPOWERGRID & NUMERICAL

RELAYSRELAYS

Technology does not drive

change -- it enables change All new substations in POWERGRIDAll new substations in POWERGRID

are coming with Substationare coming with Substation

utomat on,w c nev ta y comesutomat on,w c nev ta y comeswith numerical relays with IEC61850with numerical relays with IEC61850Communication protocol.Communication protocol.

Automation alongwith NumericalAutomation alongwith Numerical

relays eventually results in costrelays eventually results in costeffectiveness as well as Better grideffectiveness as well as Better gridsecurity.security.


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TYPICAL ARCHITECTURE

SUBSTATION AUTOMATION SYSTEM INPOWERGRID


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POWERGRID & NUMERICALPOWERGRID & NUMERICAL

RELAYS.. Cond.RELAYS.. Cond.

Once a new technology rolls over you, ifOnce a new technology rolls over you, ifyou're not part of the steamroller, you'reyou're not part of the steamroller, you'repart of the roadpart of the road

For Older stations, POWERGRID isFor Older stations, POWERGRID isreplacing old & obsolete relays withreplacing old & obsolete relays withnumer ca re ays.numer ca re ays.

Competitive bidding for Numerical distanceCompetitive bidding for Numerical distancerelays has resulted an average cost of Rs.relays has resulted an average cost of Rs.1.5L per relay for the retrofitting work.1.5L per relay for the retrofitting work.

In a few cases, repairing of old relays hasIn a few cases, repairing of old relays hasbeen found costlier than retrofitting with abeen found costlier than retrofitting with anew numerical relays.new numerical relays.


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ADAPTATIONADAPTATION

Our very survival depends on our ability toOur very survival depends on our ability tostay awake, to adjust to new ideas, tostay awake, to adjust to new ideas, toremain vigilant and to face the challenge ofremain vigilant and to face the challenge of

changechange Control & relay schemes usually cameControl & relay schemes usually came

from OEMs like ABB,AREVA,from OEMs like ABB,AREVA,, ., .

POWERGRID has achieved expertise inPOWERGRID has achieved expertise inadaptation of Numerical relay of Make sayadaptation of Numerical relay of Make sayX to be installed in the C&R scheme ofX to be installed in the C&R scheme ofMake YMake Y..

However, problem of Lower MakingHowever, problem of Lower Makingcapacity of the Numerical relays incapacity of the Numerical relays incomparison to the old distance relay had tocomparison to the old distance relay had tobe solved by incorporating CMRs ofbe solved by incorporating CMRs ofsuitable capacity.suitable capacity.


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LASTWORDLASTWORD

Science and technologyScience and technologyrevolutionize our lives, butrevolutionize our lives, butmemory, tradition and mythmemory, tradition and myth

frame our response.frame our response. Numerical relays are here as theNumerical relays are here as the

product as on date.product as on date. The advantages are many &The advantages are many &

nobody can deny that thenobody can deny that theNumerical relays came to stayNumerical relays came to stayfor years until a further betterfor years until a further betterproduct replaces them.product replaces them.


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Application of Numerical Distance Relay