108 / 2024-04-12 16:56:33

Failure Analysis of High-voltage Circuit Breakers Servicing in 500 kV HVDC Converter Stations

AC filter banks,SF6 circuit breaker,HVDC,converter station,failures

The circuit breaker for AC filters (ACF) is the key power equipment that is used to control and protect the energization and de-energization of ACF. The objective of this paper is to survey the classic failures of SF₆ circuit breakers used for ACF in operation and analyze for reasons behind them. All of the failures presented in this paper are analyzed through methods like waveform monitoring, simulation, and ingredient testing after disassembling. The 297 failures mentioned in this paper can be classified into three main types—failures triggered by restriking, flashover of insulating components, and mechanical collapse, which account for 45%, 24%, and 31%, respectively. Among them, restriking usually happens due to the breakdown of the key components like nozzle, contacts, or the particles floating in the tank, while flashover is usually derived from the flawed design of the components or the particles cluttering on the surface of the insulating components.