Fault Interrupting Tests on a 500-kV SF6Gas Circuit Breaker at the Grand Coulee Consolidated 230-kV Switchyard,

摘要

Fault current-interrupting tests were performed on a 500-kV SF sub 6gas circuit breaker at the Grand Coulee Consolidated 230-kV Switchyard. Tests consisted of both bus and short-line faults with the initial component of transient recovery voltage (TRV) modified to duplicate as nearly as possible Grand Coulee 500-kV Switchyard TRV characteristics for similar faults. Three breaker configurations were tested,each representing a different interrupting capability. The fully modified version successfully cleared the maximum attainable asymmetrical bus fault of 59.6kA rms equivalent. On the short-line faults and on the 50percent asymmetrical bus faults,the breaker interrupting time exceeded the specified two-cycle requirement.