Jihohi na Ikkumomin Kalmomin Kirkiro ko Kalmomin Ingancin Kirkiro
Makaranta mai suna wani Protection Relay
Wani relay shine karamin kwallon kasa da ya shafi abin da ba daidai da karamin kasa ko tsohon fadin kasa da ya shafi abin da ba daidai da fadin kasa, kuma ya fi karamin kasa ta fito. Waɗannan karamin kasa suka fi fito da kula da circuit breaker trip coil circuit kuma ya yi trip circuit breaker don ya gaba ƙarin da ke da duka cikin fadin kasa da ke daidai.
Yanzu ina nemi waɗanda suke so kuɗi game da protection relay.
Pickup Level of Actuating Signal:
Gadi na actuating quantity (voltage ko current) wadanda ana iya kara hanyar ita don relay ya faru zuwa yankin da ake yi aiki.
Idan an saka gadi na actuating quantity, ya ɗauki electromagnetic effect ta relay coil, kuma daga baya kan gadi na actuating quantity, mekanismen da ya zama ya faru zuwa yankin da ake yi aiki.
Reset Level:
Gadi na current ko voltage wadanda an iya kara hanyar ita don relay ya bude karamin kasa ta daidai.
Operating Time of Relay:
Bayan gadi na actuating quantity ta shafi pickup level, mekanismen da ya zama (misali rotating disc) ya faru zuwa yankin da ake yi aiki, kuma ya kala fito karamin kasa ta relay. Waktu na daɗi bayan gadi na actuating quantity ta shafi pickup value zuwa lokacin da karamin kasa ta relay ta fito.
Reset Time of Relay:
Waktu na daɗi bayan gadi na actuating quantity ta shafi reset value zuwa lokacin da karamin kasa ta relay ta bude daidai.
Reach of Relay:
Wani distance relay ya yi aiki idan distance da relay ta shafi ta daidai da impedance. Actuating impedance a cikin relay shine funksiya game da distance a cikin distance protection relay. Wani impedance ko corresponding distance shine reach of relay.
Power system protection relays zai iya faɗinsa a matsayin yanayi na relay.
Matsayin na Relays
Matsayin na protection relays suna da ma'ana da sabon logic, actuating parameter, da kuma mekanismen da ake yi aiki.
Daga baya kan mekanismen da ake yi aiki, protection relay zai iya faɗinsa a matsayin electromagnetic relay, static relay, da mechanical relay. Amsa, wani relay ba ce mutum karamin kasa ko daidai. Dukawa ko wasu karamin kasa ta relay suna ɗauki karfin da suke da su a cikin relay. Yana nufin cewa karamin kasa ta daidai suka fito da karamin kasa ta daidai suka bude. A cikin electromagnetic relay, fitowa da budowa karamin kasa ta relay suna yi haka ne don electromagnetic action ta solenoid.
A cikin mechanical relay, fitowa da budowa karamin kasa ta relay suna yi haka ne don mechanical displacement ta gear level system.
A cikin static relay, wannan ya yi haka ne don semiconductor switches kamar thyristor. A digital relay, on da off state zai iya canza 1 da 0 state.
Daga baya kan Characteristic, protection relay zai iya faɗinsa a matsayin:
Definite time relays
Inverse time relays with definite minimum time(IDMT)
Instantaneous relays.
IDMT with inst.
Stepped characteristic.
Programmed switches.
Voltage restraint over current relay.
Daga baya kan logic, protection relay zai iya faɗinsa a matsayin-
Differential.
Unbalance.
Neutral displacement.
Directional.
Restricted earth fault.
Over fluxing.
Distance schemes.
Bus bar protection.
Reverse power relays.
Loss of excitation.
Negative phase sequence relays etc.
Daga baya kan actuating parameter, protection relay zai iya faɗinsa a matsayin-
Current relays.
Voltage relays.
Frequency relays.
Power relays etc.
Daga baya kan application, protection relay zai iya faɗinsa a matsayin-
Primary relay.
Backup relay.
Primary relay ko primary protection relay shine mafi girman power system protection, amma backup relay ya yi aiki idan primary relay ya juye a yi aiki a lokacin fault. Saboda haka, backup relay ya shiga da aiki daidai da primary relay. Wani relay zai iya juye a yi aiki saboda wasu dalilai,
Relay ta protection ta badde.
DC Trip voltage supply to the relay is unavailable.
Trip lead from relay panel to the circuit breaker is disconnected.
The trip coil in the circuit breaker is disconnected or defective.
Current or voltage signals from Current Transformers (CTs) or Potential Transformers (PTs) respectively is unavailable.
Saboda backup relay ya yi aiki idan primary relay ya juye, backup protection relay ba zai iya da wani abu da primary protection relay.
Wasu misalai na Mechanical Relay shine:
Thermal
OT trip (Oil Temperature Trip)
WT trip (Winding Temperature Trip)
Bearing temp trip etc.
Float type
Buchholz
OSR
PRV
Water level Controls etc.
Pressure switches.
Mechanical interlocks.
Pole discrepancy relay.
List Different Protective Relays are used for Different Power System Equipment Protection
Yanzu ina nemi wasu protective relays wadanda ake amfani da su a different power system equipment protection schemes.
Relays for Transmission & Distribution Lines Protection
| SL | Lines to be protected | Relays to be used |
| 1 | 400 KV Transmission Line |
Main-I: Non switched or Numerical Distance Scheme Main-II: Non switched or Numerical Distance Scheme |
| 2 | 220 KV Transmission Line |
Main-I : Non switched distance scheme (Fed from Bus PTs) Main-II: Switched distance scheme (Fed from line CVTs) With a changeover facility from bus PT to line CVT and vice-versa. |
| 3 | 132 KV Transmission Line |
Main Protection : Switched distance scheme (fed from bus PT). Backup Protection: 3 Nos. directional IDMT O/L Relays and 1 No. Directional IDMT E/L relay. |
| 4 | 33 KV lines | Non-directional IDMT 3 O/L and 1 E/L relays. |
| 5 | 11 KV lines | Non-directional IDMT 2 O/L and 1 E/L relays. |
