QUADRAMHOStatic Distance Protection Relay

TGEe ALSTHOM

T&D

QUADRAMHOStatic DistanceProtection Relay

FoaIu....

• Full scheme 3-zone distance relaywith 18 measuring elements.

• Characteristic shopes to suitallline lengths and fault levels,

• Fast operating limes over a verywide range of fault conditions.

• Digital synchronous polarising forclose-upthree phase faults.

• Microprocessor scheme logic: withwide range of built-in schemesselected by option switches.

• Ample input/outputfacilities - 5optically coupled inpub, 2.4outputcontacts, 10 light emitting dio~.

• Full range of lest features forcommissioning and routinetesting.Interfacing enables automatic fieldlest equipment 10 beused ifrequired.

• Continuous self monitoring, on­demand and periodic self-lesting.

• Built-in vollcge transformersupervision.

• Built-in power swing blockingfeature.

2

Figure I: QUADRAMHO relay.

Models available

Two models are availablewith thefollowing characteristics:

• Zone 1 and 2

Shaped partially cross-polarisedmho with partially cron-polariseddirectional line.

Zone 3

Offset lens, (adjustable to offsetcircular mho).

• Zone 1 ond 2 ground foulb:

Quadrilateral with partially cross­polarised directional line.

Zone 1 and 2 phase foults:Shaped partially cross-polarisedmho with partially cron-polariseddirectional line.

Zone 3 ground faults:Offset quodriloteral.

Zone 3 phase foulb:Offset circulor mho.

AppIicalian

The QUADRAMHO distance relay hasbeen designed and developed forhigh speed protection of medium andhigh voltage transmission, sub­transmission and distribution lines.Thefull scheme design offersmanyadvantages over switched relaystraditionallyused in thisapplication.

The full scheme arrangement uses 18comparators eliminating the need forstarting relays and switchingcircuits,thus providing a high degree ofreliability and foster operating times.

The relay is suitable for both threepole ond singl&<lnd-three-poletripping of the circuit breaker.

Either busbar or linevoltagetransformers may be used and theseam be either capacitor VT's orelectro-magnetic VT's.CT requirements are moderote as therelay is highlytoleront of saturatedcurrent transformers.