Simulation research on the pre-strike characteristics of SF6 circuit breaker

Abstract

The pre-strike duration of SF6 circuit breaker closing is one of the indicators to measure the ablative state of contacts, obtaining the pre-strike characteristics of SF6 circuit breaker closing is very important to evaluate the electrical life state of circuit breakers. In this paper, the simulation model of the electrical and fluid coupling simulation of the 110kv SF6 circuit breaker is established, and the pre-strike characteristics of the closing process are studied. The results show that the maximum point of the synchronous midfield is always on the surface of the static arc contact. The density of SF6 on the arc-extinguishing chamber is almost constant; the pressure output of the pressure chamber has little effect on the pre-strike voltage curve. Under the phase voltage of 110kv voltage, the duration of the circuit breaker pre-strike duration is 0.9054ms, which is close to the measured value. Results can provide the basis for the actual life circuit life evaluation.