alstom - digital integrated generator protection relay

7/29/2019 Alstom - Digital Integrated Generator Protection Relay

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Type LGPG111Digital Integrated Generator Protection Relay


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Features

An optimum mix of generatorprotection functions

Applicable to a wide range ofgenerators

User configurable scheme logic

An alternative setting group

Wide operative frequency range

Display of measured values

Fault, event and disturbancerecording

Integral testing to aidcommissioning

Remote serial communications

Power-on diagnostics and self-monitoring

Eight optically isolated logicinputs for monitoring externalplant.

Type LGPG111Digital Integrated Generator Protection Relay

Figure 1: Relay Type LGPG111

Introduction

The LGPG111 is a multi-functionrelay which integrates a number ofcommon generator protectionfunctions and associated schemelogic into a single relay case.

Models Available

LGPG111Incorporating 14 separategenerator protection functions

(see Figure 2).

Application

The LGPG111 can be applied to awide range of generators. Each ofits protection functions can beenabled or disabled to suitindividual requirements.This approach avoids the need forapplication-specific relay versions,and simplifies the tasks of relayspecification, evaluation and projectplanning. The integrated schemelogic eliminates much panelengineering work by reducing theneed for auxiliary relays andassociated external wiring.

Contacts from external protection

and plant monitoring equipment canbe connected to any of the eightoptically-isolated inputs. This allowsexternal information to beincorporated into the relays user-configurable scheme logic.The optically-isolated inputs andrelay outputs may be labelled in thesoftware for local or remotemonitoring.These functions can be recorded inthe alarm and event recording

facilities.

The protection functions provided bythe LGPG111 relay are as shown inFigure 2.

Functions

Generator differential (87G)

The generator differential function isfor the protection of phase to phaseor three-phase stator windings faults

which normally involve high faultcurrents, so that fast fault clearanceis required. This function works on aper phase basis and has a dualslope bias characteristic as shown


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in Figure 3: the lower slopeprovides sensitivity for internalfaults, whereas the higher slopeprovides stability under through faultconditions, especially if thegenerator CTs saturate.

Stator earth fault (51N)

The stator earth fault function iscurrent operated and can betypically set to cover up to 95% ofthe stator windings. It is generallyused on resistively earthedgenerators, but can also be used torespond to current in the secondarycircuit of an earthing transformerloaded with a resistor. A time-delayed low set element and aninstantaneous high set element areprovided.

Neutral displacement (59N)

The neutral displacement function isvoltage operated and is used fordetecting stator winding earth faultson generators which are earthed viaa distribution transformer. Two timeroutput elements are provided.

Sensitive directional earthfault (67N)

When two or more generators are

connected in parallel directly to abusbar, the sensitive directionalearth fault function is used todiscriminate between internal andexternal earth faults. A dedicatedsingle-phase CT input is availablefor the operating current, which canaccept the residual current fromthree line CTs or current from adedicated core-balance CT.The polarising signal for thedirectional decision is either the

voltage signal applied to the neutralvoltage VT input or the currentsignal applied to the stator earthfault current input.

The stator earth fault, neutraldisplacement and sensitivedirectional earth fault functions allhave third harmonic rejection builtin by means of a software filter.

Voltage dependent

overcurrent (51V)The voltage dependent overcurrentfunction is used for system backupprotection and can trip thegenerator circuit breaker, if a fault

Figure 2: Protection functions provided by LGPG111

Figure 3: Generator differential bias characteristic

Figure 4: Voltage dependent overcurrent functions

Currentpick-uplevel

Currentpick-uplevel

I>

KI>

Vs Voltage

levelVoltage controlled mode Voltage restrained mode

I>

KI>

Vs2 Vs1 Voltage

level

Trip

Differentialcurrent

No TripIs1

Percentagebias K2

Percentagebias K1

Maximum mean bias currentIs2

has not been cleared by otherprotection after a certain period oftime. The voltage dependentfunction can be either voltagecontrolled or voltage restrained.

When voltage controlled, the timingcharacteristic is changed from aload to a fault characteristic whenthe voltage drops below a set level.

It is mainly used for generatorsconnected directly to the busbar.

When voltage restrained, thecurrent pick-up level is

proportionally lowered as thevoltage falls below a set value,producing a continuous variation oftiming characteristics. This isapplicable to generators connected

87G Generator dif ferent ia l

51N Stator earth fault

59N Neutral displacement

67N Sensitive directional earth fault

51V Voltage dependent overcurrent

32R Reve rse powe r

32L Low forward power

46 Negat ive phase sequence40 F iel d f ailu re

27 Unde rvol tage

59 Over voltage

81U Under frequency

81O Overf requency

60 Voltage balance

67N 51N

59N

51V 32R32L

40 46

2759

81U81O

60

87G


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to the busbar, each via a step-uptransformer.A voltage vector compensationfeature is also available todetermine the HV phase-phasevoltage signals where a Yd1 or aYd11 step-up transformer is used.

The timing characteristic can either

be definite time or IDMT.

The effects of the voltage level onthe current pick-up level for bothfunctions are shown in Figure 4.

Reverse power (32R) and lowforward power (32L)

Reverse power protection is used todetect loss of the prime mover.Low forward power protection canbe applied to steam turbine

generators where sequentialshutdown is preferable, under lessurgent operations, to avoid over-speeding. Both are balancedconditions, therefore a single phasemeasurement is sufficient. For thisfunction, the relay calculates VIcosfor the A-phase.

In order to provide the requiredsensitivity, a special current input isused for both of these functions.A compensation angle setting is alsoavailable to compensate for phaseerror of the generators CT and VTsignals. A delayed drop-off timer isincluded in the timing logic whichacts as an integrating timer. Thisallows the relay to trip within thepre-determined time delay, underpulsating power conditions.

Negative phase sequence (46)

Negative phase sequence function

is for the detection of sustainedunbalanced load conditions.Under such circumstances doublefrequency eddy currents are inducedin the rotor of a generator and cancause rapid overheating.The function has a thermal replicacurve which simulates the effects ofpre-fault heating due to low levels ofstanding negative phase sequencecurrent I2. When the I2 value is wellabove threshold, the thermal replica

approximates to a t = K/I22

characteristic, where K is thegenerators per-unit current thermalcapacity constant in seconds.

Figure 5: Negative phase sequence tripping characteristic

tMAX

t

tmin

I2>> I2

K

Figure 6: Field failure protection characteristic

The tripping characteristic is shownin Figure 5.

When high values of K are selectedand the negative phase sequencecurrents measured are near to thethreshold, the operating time maybe too slow. In this case, amaximum time setting tMAX isavailable to provide a safe trip time.

When I2 is high, the operating timemay become too fast and cause lossof discrimination with other powersystem protection under faultconditions. To reduce this risk, the

inverse characteristic is providedwith an adjustable minimumoperating time setting tMIN.

A separate thermal capacityconstant setting Kreset is alsoprovided for use when the generator

is cooling, due to a reduction in I2.This is to cater for rotor componentswith differing cooling time constants.

An independent alarm element witha definite time output is available forpre-trip warning purposes.

Field failure (40)

Severe loss of excitation caused byfield failure can cause a high valueof reactive current to be drawn from

the power system which canendanger the generator. The fieldfailure protection provided by thisrelay is a single phase impedancemeasuring element with an offset

Xa

Xb

X

R


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mho characteristic, as shown inFigure 6. An integrating timingarrangement, identical to that for thepower functions, is also provided.This allows the relay to trip withinthe pre-determined time delay eventhough the impedance measurementmay temporarily fall outside the mho

characteristic, eg. under pole-slipping conditions.

Undervoltage (27) andovervoltage (59)

An undervoltage element and a2-stage overvoltage element areprovided. They are primarily usedfor backing up the speed controlgovernor and the automatic voltageregulator. When severe overvoltageoccurs, the high set of the

overvoltage element can be set toprovide fast operation.Both elements are three-phasedevices.

Underfrequency (81U) andoverfrequency (81O)

Two underfrequency elements andone overfrequency element areprovided. The underfrequencyelements are used to detectoverloading of the generator caused

by various system disturbances oroperating conditions.The overfrequency element is usedto back-up the speed controlgovernor if overspeeding occurs.

Voltage balance (60)

The voltage balance function isprovided to detect VT fuse failure.It compares the secondary voltagesof two sets of VTs (or from twoseparately fused circuits of a singleVT) and can be used to blockpossible incorrect tripping of thoseprotection functions whoseperformance may be affected by theapparent loss of voltage such aswhen a VT fuse ruptures.

Timer held facility

Both the overcurrent function, thelow set element of the stator earthfault function and the neutraldisplacement function are providedwith a timer held facility.The purpose is to enable fasterclearance of recurrent intermittentfaults, for example, self-sealinginsulation faults. This facility allows

the relay timer to hold its valuewhen the current drops off, providedthat the drop-off period is less thanthe tRESET timer setting.This adjustable reset facility alsoenables closer co-ordination withelectromechanical induction discrelays.

Integrating timer facility

Time integration is required for thepower function to allow forreciprocating load conditions wherethe measuring element may pick upbriefly and periodically. The samefeature is also provided for the fieldfailure function for pole-slippingconditions. Time integration allowsthe function to operate within its pre-determined operating time.

To implement timing integration, anadditional delayed drop-off timer isprovided. Once the protectionmeasurement element has pickedup, the relay will operate after theset time delay, provided that thetime interval when the elementdrops off is within the setting of thedelayed drop-off timer tDO.

Frequency tracking

The relay tracks the power systemfrequency and continuously adjustsits internal sampling clock to exactmultiples of the system frequency.This provides correct measurementsand operation of the protectionfunctions during start-up and run-down of the generator set when thegenerator unit is operated at

abnormal frequency. The operatingfrequency range is from 25Hz to70Hz for the differential functionand from 5Hz to 70Hz for the otherprotection functions.

Configuration

Scheme logicThe protection scheme logic for agenerator set normally involves alarge number of protection functionscombined together to drive a fewcommon trip outputs. Some blockingand interlocking logic may also berequired. In order to accommodatedifferent generator applications, thescheme logic is flexible andreconfigureable.

The LGPG111 scheme logic is in theform of logic arrays with anarchitecture commonly found inprogrammable logic array devices,having an internal AND-ORstructure shown in Figure 7.

The OR functions allow one or moreof the AND function outputs tocontrol each output relay, whilst theAND functions provide blocking orinterlocking for two or more inputs,or just a through connection for one

input. There are 32 inputs to thescheme logic: 19 from theprotection functions, 8 optically-isolated inputs and a selection ofinverted inputs to allow blockinglogic to be created. The schemelogic controls a total of 15 outputrelays and has 32 selectable ANDfunctions.

Figure 7: Block diagram of the scheme logic

From protection elementsand status inputs

Output matrix

Input matrix

AND

AND

AND

OR OR OR

To output relays


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20ms. Thus the duration of a recordvaries with the data type. For rawdata, the duration is 64 electricalcycles, but for magnitude and phasedata, the duration is 7.68s.The latter set-up allows longduration events such as pole-slipping to be captured. In either

case, each data entry is timestamped. This is particularly usefulfor the raw data recording, sincethe sampling interval varies with thepower system frequency, due to thefrequency tracking.

The disturbance recorder can betriggered from selected relay outputsand status inputs. A maximum oftwo records can be stored in volatilememory. A record remains in thebuffer area until it is uploaded to a

PC, after which the buffer isreleased. If the two buffers are full,no further recording can be made.

Time synchronisation

The clock for event record timetagging has a resolution of 1ms.To provide time synchronisation withother equipment in the generatorstation, the clock can besynchronised by external clockpulses (0.5, 1, 5, 10, 15, 30 or 60minute period) from an optically-isolated input.

Print functions

Several print functions are providedto allow the relay to provide hard-copy documentation, via the frontpanel parallel port. This consists ofthe system settings, protectionsettings, scheme logic settings, eventrecords and fault records.

The scheme logic print-out isformatted so that it can becompared directly with the schemelogic diagram.

Test features

A number of features are providedto enable the relay to be thoroughlytested during commissioning, routinemaintenance and fault findingoperations:

The measurement functions allow

the analogue input and itsassociated wiring to be checked.

Display the on/off states of thestatus inputs and relay outputs.

The input and output matrices allowthe desired connections to becreated. Each intersection of thematrix represents a programmableinterconnection. By designing theappropriate interconnections andthen entering the information intothe relay, through the scheme logic

settings, the required tripping logiccan be configured.

The presence of the optically-isolated inputs to the scheme allowsexternal devices such as rotor earthfault relay, temperature sensingdevices and mechanical relays to beconnected to the scheme, so that thetripping facilities, together with thealarm and remote communicationfacilities, can be utilised.

The optically-isolated inputs andrelay outputs used in a scheme maybe allocated to any functionrequired by the application.The relay has a facility to label eachof these by providing an identifier.The identifiers are used during theconfiguration of the scheme logic,by the input and output statusdisplays and by the event, fault anddisturbance recording systems.

Alternative setting groupThe relay provides an alternativesetting group which consists of allthe protection and scheme logicsettings. It can be used during start-up or run-down of generators orduring changes in power systemconfiguration. This setting group canbe selected by either energising theappropriate optically-isolated inputs,or via the relay settings menu.

Ancillary Functions

Measurements

The magnitudes of all 17 analogueinputs to the relay are available fordisplay. Other derived quantities arealso available. This provides suchinformation as the three-phase,

residual and earth currents, thephase to phase voltages, differentialand bias currents, negative phasesequence current, phase A activeand reactive power plus the phaseangle and power system frequency.All measurements can be displayedin either primary or secondaryquantities, selectable by the user.Primary display quantities are basedon the settings for the CT and VTratios used by the relay.

Event and fault records

Up to 100 event records areavailable, all of them stored in non-volatile memory. The latest recordwill automatically overwrite theoldest one. Event records aregenerated whenever there is aprotection function operation,energisation of a status input,operation of an output relay or anyhardware failure.

Fault records are also stored asevents. Out of the 100 eventrecords, up to 50 fault records canbe accommodated. Fault recordsare initiated when user selectedrelay outputs operate. The recordconsists of the date and time of thefault, the state of the optically-isolated inputs, relay outputs andprotection functions, together withthe measurement values during the

fault.

Disturbance records

The internal disturbance recordercan store up to eight analoguechannels, together with all the statusinput and relay output information.The analogue channels are userselectable from the relays 17inputs.

The data in the analogue channels

can be stored as either raw data oras magnitude and phase data.The raw data is sampled at 12samples per electrical cycle,whereas the magnitude and phasedata are calculated once every


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Testing the four indicating LEDs.

Testing the relay outputs and theirassociated circuits by operatingthe relay output contacts.

Display the operation of eachprotection function as apercentage of the time-to-trip.

This allows the pick-up, progressand operation of each protectionfunction to be checked.

Testing the set-up of the schemelogic settings by manuallyentering an input pattern to thescheme, and then examining itslogical output. This test can beperformed at any time withoutinterfering with the relaysoperation.

Power-on diagnostics and selfmonitoring

Power-on diagnostic tests arecarried out by the relay when it isenergised. These tests includechecks on the timer, microprocessor,memory and the analogue inputmodule. Continuous self-monitoring,in the form of watchdog circuitry,memory checks and analogue inputmodule tests, is also performed. Inthe event of a failure, the relay willeither lock-out or attempt a recovery,depending on the type of failuredetected.

Hardware Description

The relay is housed in a 4U(178mm) high case suitable foreither rack or panel mounting.Internally, it consists of a number ofplug-in modules which areindividually tested and calibrated.The modular hardware architectureis shown in Figure 8.

The microcomputer module consistsof a powerful 16-bit microcomputerwhich controls all of the subsidiarymodules through a 64-way ribboncable called the I/O Bus.The processor performs all of themajor software functions such asinput signal processing, protectionalgorithms, scheme logic, relayoutput controls and handling of the

operator interface.The analogue input module consistsof 12 CTs, 5 VTs and 6 optically-isolated inputs. The CTs and VTs areused to isolate and condition theanalogue inputs from the maintransformers connected to thegenerator. Their output signals arethen converted into digital data forfurther processing.

In addition to the 6 optically-isolated

inputs on the analogue module, afurther 8 are provided by the statusinput module, making a total of 14optically-isolated inputs available tothe relay. Six of these have pre-defined functions, such as clocksynchronisation, setting groupselection, etc., which leaves 8 inputsto be fed into the scheme logic.

All of the optically-isolated inputsoperate from an auxiliary supplyVx(2), which is independent of themain auxiliary supply Vx(1).The ratings of Vx(1) and Vx(2) maybe different (see Technical Data).

Two relay output modules areprovided; each module contains 8

miniature relays. All relays are self-reset. However, a software functionis available which allows the user toselect outputs to be latched whenoperated.

The front panel consists of a 2 x 16character alphanumeric liquidcrystal display (LCD) and a 7 push-button keypad. It provides localaccess to all of the relays features.There are also 4 light emitting

diodes for visual indication of therelays status, a non-isolatedIEC 60870 serial port forconnection to a PC, and a parallelport for connection to a printer.

At the rear of the relay, apart fromthe normal dc supply and plantconnections, there is an isolatedIEC 60870 port and a K-Bus portfor permanent connection to aremote PC.

The remote communications moduleis responsible for handling thecommunications protocol and forcontrolling the three communicationports.

Figure 8: Hardware architecture

Relay

outputs

Remote

comms

Status

input

Analogue

inputs

Front

panel

Microcomputer

Powersupply

I/O bus


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User Interface

Front panel user interface

The features of the relay can beaccessed through a user-friendlymenu system. The menu is arrangedso that related items (menu cells) aregrouped into individual sections,

each of which is identified by a title.The user navigates around the menuby using the arrow keys, first toselect a particular section title andthen to select an item within it.The front panel liquid crystal displayis limited to displaying one menucell at a time.

Remote access user interface

The menu can be accessed via theremote communications facility.

This allows all of the menu cells in asection to be displayed on thescreen of a PC. Changes to themenu cell can be made from the PCkeyboard.

Relay interconnection

Three communication ports areavailable: the front panel, non-isolated IEC 60870 port; the rear,isolated IEC 60870 port; and theK-Bus port. The IEC 60870 ports useRS232 signal levels and allow point-to-point connection. It is applicablewhen networking is not required orduring commissioning.

Alternatively, the relays can beconnected via a shielded, twistedpair called K-Bus. Up to 32 relaysmay be connected in parallel to thebus.K-Bus can be connected through aprotocol converter, type KITZ, either

directly or via a modem, to theRS232 port of a PC. K-Bus is RS485based and runs at 64kbits/s.The K-Bus connection is shown inFigure 9.

Software is available with each KITZto provide access to the relays, toread and change settings.Additional software entitledProtection Access Software andToolkit is available to give access tothe event recorder, together withother additional functions.

Each relay is directly addressablevia the bus to allow communicationwith the PC. It should be noted thatprotection tripping and blockingsignals are not routed via the K-Bus.Separate conventional wiring isused for these functions.

Figure 9: K-Bus terminals connection arrangement

SK1


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10

Figure 11: Type LGPG111 scheme logic

Relay14

Relay15

Logic 0Logic 1Logic 2Logic 3

&&&&


&&&&


&&&&


&&&&

Logic 16Logic 17

Logic 18Logic 19

&&

&&


&&&&


&&&&


&&&&

Input13

Input12

Input11

Input10

Input9

Input9

Input8

Input8

Input7

Input7

Input6

Input6

60VBProt(Blocking)

60VBComp

60VBProt

40FieldFailure

67NSensitiveDirEF

59N2NeutralDisp

59N1NeutralDisp

51N>>StatorEF

51N>StatorEF

46>>NPSTrip

46>NPSAlarm

59OverVoltage

27Undervoltage

81U2Underfreq

81U1Underfreq

81OOverfreq

32LLow

ForwardPower

32RReversePower

51VOverCurrent

87GGeneratorDiff

Input Matrix

Output Inhibited

EN

Note: Speed of the relay outputs are:

Relays 1, 2, 8, 9, 10 8ms pick-up, 8 ms drop-off

Relays 3, 11 2ms pick-up, 2ms drop-off

Relays 4, 5, 6, 7,

12, 13, 14, 152ms pick-up, 8ms drop-off


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Technical Data

Ratings

Inputs

AC current In 1A or 5A

AC voltage Vn 100V to 120V

Nominal dc Operative range(V) (V)

Auxiliary voltage Vx(1) 24/27 19.2 32.4(Relay power supply) 30/34 24 40.8

48/54 38.4 64.8110/125 88 150220/250 176 300

Auxiliary voltage Vx(2) 24/27 19.2 32.4(Optically isolated status input supply) 30/34 24 40.8

48/54 38.4 64.8110/125 88 150220/250 176 300

Note: Vx(2) may be different fromVx(1)

Frequency Fn 50/60Hz

Burdens

AC current

Generator differential


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CT requirements


Biased differential Vk 50In (Rct + 2RL + Rr) where maximumsettings at Is1=0.05In, through fault currentk1=0%, Is2=1.2In, = 10 x In andk2=150% maximum X/R = 120

Vk 30In (Rct + 2RL + Rr) where maximum

through fault current= 10 x In andmaximum X/R = 60

Note: Minimum knee point voltage = 34V

Earth fault protection functions

Sensitive directional Vk 6In (Rct + 2RL + Rr) where maximumearth fault, using three X/R = 5 andresidually connected maximum earth faultline CTs current = 1 x In

Sensitive directional Vk 6NI

n(R

ct+ 2R

L+ R

r) where maximum

earth fault, using core X/R = 5 andbalance CT maximum earth fault

current = 2 x In

Stator earth fault Vk 6NIn (Rct + 2RL + Rr)

Ancillary protection functions

Voltage dependent Vk 20In (Rct + 2RL + Rr)overcurrent, field failureand negative phasesequence

where Vk = Minimum current transformer knee-point voltage for stabilityIn = Relay rated current (1A or 5A)

Rct = Resistance of current transformer secondary winding ()

RL = Resistance of a single lead from relay to current transformer ()

Rr = Resistance of any other protection functions sharing the currenttransformer ()

N =Maximum earth fault current

Core balanced CT or earth CT rated primary current

Note: N should not be greater than 2. The core balance CT or earth CT

ratio must be selected accordingly.

Power function

For settings >3% Pn Use correctly loaded class 5P protection CT

For settings 3% Pn Use metering class CT. See table below.


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Metering CT class recommended forpower setting less than 3%Pn

Reverse/low forward Power Setting Metering CT Class(%Pn)

0.20.1

0.4

0.6

0.80.2

1.0

1.2

1.4

1.6

1.8

2.0 0.5

2.2

2.4

2.62.8

1.03.0

Thermal withstand

Continuous withstand CT input 4 x InVT input 400V

Short time withstand CT input 100A for 1s (In = 1A)400A for 1s (In = 5A)

Setting ranges


Basic differential current setting Is1 0.05In to 0.1In in 0.01In steps

Threshold for increase bias Is2 1In to 5In in 0.1In steps

Bias K1 (Ibias < Is2) 0% to 20% in 5% steps

Bias K2 (Ibias > Is2) 10% to 150% in 10% steps

Stator earth fault

Low set element:

Characteristic Standard inverse/Definite time

Current setting Ie> 0.005In to 0.5In in 0.005In steps

Time multiplier setting TMS 0.05 to 1.2 in 0.05 steps

IDMT Operating characteristic t =0.14

(I/Ie>)0.021x TMS

Definite time setting t> 0.1s to 10s in 0.1s steps

Reset timer setting tRESET 0s to 60s in 1s steps

High set element:

Current setting Ie>> 0.005In to 2In in 0.005In steps

Time setting t>> 0s to 5s in 0.1s steps


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Neutral displacement

Voltage setting Ve> 1V to 25V in 1V steps

Timer 1 setting t1 0.5s to 5s in 0.5s steps

Timer 2 setting t2 1s to 10s in 1s steps

Timer 2s reset timer t2RESET 0s to 60s in 1s steps

Sensitive directional earth fault

Operating current Ires> 0.005In to 0.02In in 0.005In steps

Polarising voltage Vp> 1V to 10V in 1V steps

Polarising current Ip> 0.005In to 0.02In in 0.005In steps

Relay characteristic angle RCA 95 to 95 in 1 steps

Voltage dependent overcurrent

Functions Voltage controlled/Voltagerestrained/Simple

Characteristic Standard Inverse/Definite Time

Current setting I> 0.5In to 2.4In in 0.05In steps

Time multiplier TMS 0.05 to 1.2 in 0.05 steps

IDMT Operating characteristic t = 0.14(I/I>)0.021

x TMS

Definite time setting t 0s to 10s in 0.1s steps

Reset timer setting tRESET 0s to 60s in 1s steps

Voltage settings:

Vs (for voltage controlled) 20V to 120V in 1V steps

Vs1 (for voltage restrained) 80V to 120V in 1V stepsVs2 (for voltage restrainted) 20V to 80V in 1V steps

K factor 0.25 to 1.00 in 0.05 steps

Voltage vector rotate None or Yd

Current pick-up level

Voltage Controlled Voltage Restrained

I> for V> Vs I> for V > Vs1

KI> for V Vs KI>I> KI>

VS1 VS2+ (V V

S2)for Vs1 V Vs2

KI> for V < Vs2

Reverse power

Power setting P> 0.2W to 8W in 0.05W steps(for 1A relay)

1W to 40W in 0.25W steps(for 5A relay)

Delayed pick-up timer t 0.5s to 10s in 0.5s steps

Delayed drop-off timer tDO

0s to 5s in 0.1s steps


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Low forward power

Power setting P< 0.2W to 8W in 0.05W steps(for 1A relay)

1W to 40W in 0.25W steps(for 5A relay)

Delayed pick-up timer t 0.5s to 10s in 0.5s steps

Delayed drop-off timer tDO 0s to 5s in 0.1s stepsCompensation angle comp 5 to +5 in 0.1 steps(for both reverse andlow forward power)

Note: The power settings are single phase quantities.

Negative phase sequence trip element

Trip threshold setting I2>> 0.05In to 0.5In in 0.01In steps

Thermal capacity constant (heating) K 2s to 40s in 1s steps

Thermal capacity constant (cooling)

Kreset 2s to 60s in 1s stepsOperating characteristic K

I2>>2t = 1loge

I2>>I2

2

(under no pre-heating condition)

Maximum operating time tmax 500s to 2000s in 10s steps

Minimum operating time tmin 0.25s to 40s in 0.25s steps

Negative phase sequence alarm element

Alarm threshold I2> 0.03In to 0.5In in 0.01In steps

Alarm timer setting t> 2s to 60s in 1s steps

Field failure

Mho offset Xa 2.5 to 25 in 0.5 steps(for 1A relays)0.5 to 5 in 0.1 steps(for 5A relays)

Mho diameter Xb 25 to 250 in 1 steps(for 1A relays)5 to 50 in 0.2 steps(for 5A relays)

Delayed pick-up timer t 0s to 25s in 0.1s steps

Delayed drop-off timer tDO 0s to 5s in 0.1s steps

Undervoltage

Voltage setting V< 30V to 110V in 1V steps

Timer setting t 0.1s to 10s in 0.1s steps

Overvoltage

Voltage settings V> ,V>> 105V to 185V in 1V steps

Timer settings t>, t>> 0s to 10s in 0.1s steps


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Underfrequency

Frequency settings F1< ,F2< 40Hz to 65Hz in 0.05Hz steps

Timer settings t1, t2 0.1s to 25s in 0.1s steps

Overfrequency

Frequency settings F> 40Hz to 65Hz in 0.05Hz steps

Timer settings t 0.1s to 25s in 0.1s steps

Voltage balance

Voltage setting Vs 5V to 20V in 1V steps

Digital inputs

Optically isolated inputs 14 (6 dedicated, 8 available to thescheme logic)

Contacts

Output relays 10 dual make

2 single make3 change-over

Power supply failure alarm 1 single make1 single break

Relay inoperative alarm 1 change-over

Contact rating Make: 30A and carry for 0.2sCarry: 5A continuousBreak: dc 50W resistive

25W inductive(L/R = 0.4s)

ac 1250VA

Subject to maxima of 5A and 300V

Durability

Loaded contact 10,000 operations

Unloaded contact 100,000 operations


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Communications

Language Courier

IEC 60870 port (front/rear)

Transmission mode Asynchronous

Signal levels RS232

Message format IEC 60870 FT1.2

Data rate 600 19200 bits/s

Connection Single-ended

Cable type Screened multi-core

Cable length 15m

Connector 25-way D-type female

Isolation Front (non-isolated)

Rear (1kV rms for 1 minute to case

earth and other circuits)

K-Bus portTransmission mode Synchronous

Signal levels RS485

Message format HDLC

Data rate 64 kbits/s

Connection Multidrop (32 units)

Cable type Screened twisted pair

Cable length 1000m

Connector Screw terminals

Isolation 2kV rms for 1 minute

Voltage withstand

Dielectric withstandIEC 60255-5: 1977 2.0kVrms for 1 minute between all

terminals and case earth

2.0kVrms for 1 minute betweenterminals of independent circuits,including contact circuits

1.0kVrms for 1 minute acrossopen contacts of output relays

1.0kVrms for 1 minute betweenIEC 60870 rear port and earth

High voltage impulseIEC 60255-5: 1977 Three positive and three negative

impulses of 5kV peak, 1.2/50s,0.5J between all terminals of thesame circuit (except outputcontacts), between independentcircuits and between all terminalsconnected together and case earth

Insulation resistanceIEC 60255-5: 1977 >100M


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Electrical environment

DC supply interruptionsIEC 60255-11: 1979 The relay will withstand a 10ms

interrupt in the auxiliary supply,under normal operating conditions,without de-energising

AC ripple on dc supply

IEC 60255-11: 1979 The unit will withstand 12% acripple on the dc supply

High frequency disturbanceIEC 60255-22-1: 1988 Class III 2.5kV peak between

independent circuits and betweenindependent circuits and case earth

1.0kV peak across terminals ofthe same circuit (except metalliccontacts)

Electrostatic dischargeIEC 60255-22-2: 1996 Class 2 4.0kV discharge in air with cover

in place.

4.0kV contact discharge with coverremoved.

Fast transient disturbanceIEC 60255-22-4: 1992 Class III 2.0kV, 5kHz applied directly to

auxiliary supply2.0kV, 5kHz applied directly toall inputs

Class IV 4.0kV, 2.5kHz applied directly toauxiliary supply

4.0kV, 2.5kHz applied directly toall inputs

Radio frequency interference

Radiated immunityIEC 60255-22-3: 1989 Class III field strength 10V/m

Extended frequency range 20MHzto 1000MHz

Conducted immunityIEC 60801-6: 1994 10V rms, 0.15MHz to 80MHz

Radiated emissionsEN55022: 1994 Class A

Conducted emissionsEN55022: 1994 Class A

EMC compliance89/336/EEC Compliance with the EuropeanEN50081-2: 1994 Commission Directive on EMC isEN50082-2: 1995 claimed via the Technical

Construction File route.Generic Standards were used toestablish conformity


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Product safety73/23/EEC Compliance with the European

Commission Low Voltage Directive.

EN 61010-1: 1993/A2: 1995 Compliance is demonstrated byEN 60950: 1992/A11: 1997 reference to generic safety

standards.

Atmospheric environment

TemperatureIEC 60255-6: 1988 Storage and transit

-25C to +70C

Operating25C to +55C

HumidityIEC 60068-2-3: 1969 56 days at 93% relative humidity

at 40C.

Enclosure protectionIEC 60529: 1989 IP50 (dust protected)

Mechanical environment

VibrationIEC 60255-21-1: 1988 Vibration response Class 2

Vibration endurance Class 2

Shock and bumpIEC 60255-21-2: 1988 Shock response Class 2

Shock withstand Class 2

Bump Class 1

SeismicIEC 60255-21-3: 1993 Class 2


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Case

The relay is housed in a multi-module Midos case as shown inFigure 12.

Additional Information

LGPG111 Service Manual R5942

Courier Communications leaflet R4113

Figure 12: Case outlines

432

438

Removablecover

Hinged frontpanel

465483

178 101.6

Front

252

10

Push buttonprojection 10mm max.

10

450 min.

465.1 1.6

7 max.

31.750.4

12.70.4

Tolerance betweenany two holeswithin a distance

of 1mm 0.4

10.67

Fixing hole detail

U ScaleU = 44.45

Allow a minimum of50mm for terminal blockand wiringSide

Rack mounting

Panel mounting

483mm Rack detailsDimensions to IEC 297

432

438

Removablecover

Hinged frontpanel

443

201

Front

252

10

Push buttonprojection

10mm max.

10

440

Allow a minimum of 50mm forterminal block and wiring

Side

Panel cut-out detail

37

178

400

200

191180.5

Fixing holes5.4

All dimensions in mm

Mounting screws are not provided

Terminal screws:M4 x 8 brass Cheese Head withLockwashers are provided

37


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Unit type: L G P G 1 1 1 0 1

Case mounting

Flush panel PRack R

Vx(1) auxiliary voltage

24 27V dc 1

30 34V dc 2

48 54V dc 3

110 125V dc 4

220 250V dc 5

Vx(2) auxiliary voltage

24 27V dc 130 34V dc 2

48 54V dc 3

110 125V dc 4

220 250V dc 5

VT and CT rating

100/120V 1A L

100/120V 5A M

Language

English E

French F

German G

Spanish S

Information Requiredwith Order


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St Leonards Works, Stafford, ST17 4LX England

Tel: 44 (0) 1785 223251 Fax: 44 (0) 1785 212232 Email: [email protected] Internet: www.alstom.com

1999 ALSTOM T&D Protection & Control Ltd

ALSTOM T&D Protec tion & Control Ltd

alstom - digital integrated generator protection relay

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