Relays of Modern Power Plant

7/31/2019 Relays of Modern Power Plant

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By,Rakesh DasB.P.E-4 th yr.Roll No.-00081150100519 th August 2011


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2. Back-up relayingequipment

It works only when the

primary relaying equipmentfails which means back-uprelaying is inherently slow inaction.

The second job of the back-uprelays is to act as primary protection in case the primary protection equipment is takenout for repair andmaintenance.

1. Primary relayingequipment

It is the first line of defence for

protecting the equipments .

Primary relaying may fail because of failure of Protective

relay, Circuit breaker , D.C.tripping voltage supply,Current or voltage supply tothe relay.


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Transformers are a critical and expensivecomponent of the power system. Due to the longlead time for repair of and replacement of transformers, a major goal of transformer protectionis limiting the damage to a faulted transformer.

Transformer Failures :

Failures in transformers can be classified into winding failures due to short circuits (turn -turn faults, phase-phase faults,phase-ground, open winding) core faults (core insulation failure, shorted laminations) terminal failures (open leads, loose connections, short circuits) on -load tap changer failures (mechanical, electrical, short circuit, overheating) abnormal operating conditions (overfluxing, overloading, overvoltage) external faults etc.


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The DTP-B is a digital relay that provideshigh-speed differential and backup instantaneousdifferential three phase protection functions forpower transformers. Different models of the DTP areavailable for protecting and monitoring transformers with two, three or four windings.

Protection & Control:

Current differential protection2, 3 or 4 windingsDual-slope percentage restraint2nd & 5th harmonic cross-restrainedInternal phase shift compensation7 configurable digital inputs4 trip contacts

20 key keypad Alphanumeric 2-lineLCD16 LED indicators

RS232, plastic or glassfiber optic

User Interface:

DTP-B


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Relays are an important integral part of any power system. As

generating stations are the first element in the power system chain, therequirement of protection starts right from the generator. Generator is one of the costliest equipment in the power house. Its damage causes innumerablefinancial loss as well as deficit of power in the system. Hence, from the very beginning of the history of power generation, relays have been developed for

protection of generator.

Generator Failure

Stator Faults(phase to phase faults , phase to ground faults , interturn fault.

Rotor Faults(Shorts between the turns of the field winding)

Abnormal running condition(unbalance loading , over loading ,over speed, failure of prime mover, Loss of excitation)


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Built on the industry-leading UR platform, the G60offers superior protection for medium and large generators,

including large steam and combustion turbines, combinedcycle generators and multi-circuit hydro units. The G60 may also be used on pumped storage generators without the needof switching the CT secondary circuitry. The G60 providesadvanced communication with a integrated, fully managedEthernet switch reducing network installation costs while

supporting industry standard communication protocols. Application:

Medium to large generators typically driven by steam, gas or hydraulicturbines Pumped Storage generatorsused as pumping motors for reservoirstorage

Stand-alone protection or component inautomated substation control systemStandard protection product offering onnew General Electric generatorinstallations.

Key Features:

Metering - current, voltage, power, energy, frequency Oscillography analog and digitalparameters at 64 samples/cycle Event Recorder - 1024 time tagged events with 0.5ms scanof digital inputs Data Logger - 16 channels with sampling rate up to 1 sample / cycle Advanced relay health diagnostics Synchronised measurement of voltage & current andsequence component phasors - 1 to 60 phasors/sec


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BUSBAR FAULTS:The majority of bus faults involve one phase and earth , but faults

arise from many causes and a significant number are interphase clear of

earth. In fact, a large proportion of bus-bar faults result from human error

rather than the failure of switchgear components. With fully phase-segregated metalclad gear, only earth faults are

possible, and a protection scheme need have earth fault sensitivity only. In

other cases, an ability to respond to phase faults clear of earth is an

advantage, although the phase fault sensitivity need not be very high.

The protection scheme for a power system should cover the wholesystem against all probable types of fault. Unrestricted forms of lineprotection, such as overcurrent and distance systems, meet thisrequirement, although faults in the busbar zone are cleared only aftersome time delay.


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The BUS 1000/2000 is a solid state, high speed

protection system for the detection of phase-to-phaseand phase-to-ground faults on bus bar installations. Itcan be used to protect high voltage bus bar installationsof any voltage.BUS 2000 models add to the functionality of the BUS1000 through the metering, monitoring, eventrecording, waveform capture, and IRIG-B timesynchronization capabilities of theDMS metering and monitoring module.

Application:

Protection of HV bus bar installationsSingle or multiple bus bar ProtectionDifferential overcurrent with percentagerestraintStabilizing resistors Very sensitive differential overcurrent functionOptional breaker failure functionOptional overcurrent supervision

User Interface :

Test points for ease of installationOptional test systemTwo RS232 communicationports

BUS 1000/2000


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In the modern power plant such as device are used which are most costly, that can be damage any time. So without out protection we cant run those equipment.That protective device is called the Relay.

Here I want to discuss about the relays of modern powerplant & the types of relay use in the modern power plant with suitable picture.


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TEXT BOOK OF ELECTRICAL POWER SYSTEM ( C.L.

WADHWA) WIKIPEDIA.COM ASK.COM SCHNEIDER ELECTRIC INDUSTRIS

Prof. GARGI KONAR

Relays of Modern Power Plant

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