An Analysis on Failure of Circuit Breaker's Closing Resistors in Guiyang 500kV Substation

摘要

3-phase closing resistors on 2 500kV circuit breakers in Guiyang substation failed during a short time out of phase operation and caused a big accident. This paper describes the system situation, breaker conditions, field records of the failure and EMTP reproducing results. It is shown from the analysis, besides the grading capacitors' failure, the aging dielectric between resistor contacts that makes its withstand level decreased might be an essential factor which caused the accident. Some comments on the use of closing resistors are concluded.