180 / 2024-04-15 17:35:29

Study on the influencing factors of asymmetric short-circuit current opening characteristics of high-voltage SF6 circuit breakers

asymmetric short-circuit current; opening performance; physical arc model; high voltage circuit breaker

With the increasing capacity of the power grid and the increase of the time constant of the DC component of the short-circuit current of the power system, the hidden danger of insufficient breaking capacity of the circuit breaker is becoming more and more prominent, so it is crucial to study the factors affecting the breaking performance of the circuit breaker. The research objective of this paper is to obtain the changing law of the factors affecting the breaking performance of circuit breakers, establish the arc physical simulation model based on the internal structure of high-voltage SF₆ circuit breakers, and study the effects of short-circuit current DC component, arc ignition time, contact opening distance, initial pressure of compression chamber and tripping time, etc. on the breaking performance of circuit breakers. The results show that the increase of arc ignition time, contact opening distance and initial pressure of compressed air chamber is beneficial to circuit breaker breaking, the increase of DC component makes circuit breaker breaking tend to fail, and the effect of tripping time on circuit breaker breaking is relatively small, which provides a theoretical basis for improving the asymmetric short-circuit current breaking capability of high-voltage circuit breakers.