RELAY PROTECTION CONTROL METHOD FOR SERIAL CONNECTED REACTOR USED BY 35 KV TRANSFORMER AT 500 KV SUBSTATION

摘要

A relay protection control method for a serial connection between a reactor and a 35 kV transformer at a 500kV substation, comprising the following control steps: step 1, adding a 35 kV impedance protective device to a backup protective device at the 35 kV side of the 500 kV transformer, the impedance protective device comprising direction/deviation phase-to-phase distance protection and direction/deviation grounding distance protection; step 2, the direction/deviation phase-to-phase distance protection and the direction/deviation grounding distance protection point to the impedance of the 35kV bus, and are adjusted according to the sensitivity required by various types of inter-phase short circuits after the 35 kV transformer is connected to a reactor in series; step 3, when inter-phase short circuit occurs after the 35 kV transformer is connected to a reactor in series, a breaker at the 35 kV side or other sides of the 500 kV transformer trips for a preset time delay to remove the fault. The method can provide relay protection against various types of inter-phase short circuits after the 35 kV transformer is connected to a reactor in series at a 500 kV substation.