Working Principle And Daily Maintenance Of Sf6 Circuit Breaker Operating Mechanism

Abstract: Since SF6 gas has many excellent electrical insulation and arc extinguishing properties compared with air and transformer oil, the application of SF6 in electrical equipment has been greatly developed in recent years, especially in high-voltage and ultra-high-voltage circuit breakers, as well as fully enclosed combination electrical appliances. This paper summarizes the sf6 circuit breaker operating mechanism and its working principle, combined with the currently used GL314 circuit breaker, mainly from the fault of the secondary control circuit, combined with the circuit breaker anti-trip, gas interlock, non-full-phase operation, opening and closing conditions, and finally introduces the maintenance cycle and specific maintenance items and standards.
Keywords: circuit breaker; SF6 gas; arc extinguishing; anti-trip; opening and closing; maintenance
I.
Circuit breakers can be divided into air circuit breakers, vacuum circuit breakers, oil circuit breakers,
sf6 circuit breaker spring mechanism, etc. according to different arc extinguishing media. Since SF6 gas has many excellent electrical insulation and arc extinguishing properties compared with air and transformer oil, the application of SF6 in electrical equipment has been greatly developed in recent years, especially in high-voltage and ultra-high-voltage circuit breakers, as well as fully enclosed combination electrical appliances.
The 220kV booster station distribution system of our plant uses the GL314 SF6 circuit breaker manufactured by Suzhou Alstom High Voltage Electrical Switch Co., Ltd. The circuit breaker is divided into two types according to the single-phase reclosing requirements: split-phase operation type (GL314) and three-phase mechanical linkage type (GL314F1). The split-phase operation type circuit breaker (GL314) has three operating mechanisms, which can be single-phase operated or three-phase electrically linked according to the operating requirements, and is installed on the external transmission line; the three-phase linkage type (GL314F1) circuit breaker has only one operating mechanism, and the three-phase contacts are mechanically linked, and do not have the function of single-phase operation. It is installed between the high-voltage side of the transformer and the booster station busbar, and cooperates with the isolation knife switch to achieve the disconnection and isolation of the line.