RECEARCH OF PHENOMENA APPEARING AT THE SWITCHING OF CAPACITOR BANK IN AZARBAYJAN REGIONAL ELECTEIC CO. NETWORK

At the switching in of capacitor banks the rate of rise & peak value of the inrush current reaches levels at which the switchgear contacts can be highly stressed . This paper shows when due a fualt , circuit breaker at two capacitor banks trip,transient over voltages appear between moving and fixed contacts of circuit breaker. This phenomena isrepresented by using EMTP in computers the curves in computer shows: - If two phases (A,C) opens with delayed time about 0.007 seconds and (B) opensafter 0.09 seconds the amplitud of TRV is about 3.4-4.11 PU and this voltage can damage the circuit breaker poles. - When (A,C) trips restrike appears in arc chamber of (A,C) & (B) trips after 0.09 seconds the amplitude of TRV is about 3.5 3.5 P.U. and this overvoltage destroys the circuit breaker poles.