Research on Dielectric Recovery Process of Circuit Breaker under Multiple Lightning Impulse

In view of the frequent occurrence, destructive and multiplicity of lightning accidents in transmission lines, the arc characteristics of circuit breakers under multiple lightning conditions are studied. The model of dielectric recovery process of circuit breaker under multiple lightning impulse is established by using the multi physical field simulation software. The transient process of arc development under multiple lightning impulse and the distribution characteristics of temperature field, air flow field and electric field in arc extinguishing chamber are obtained. The results show that the process of arc temperature is consistent with the development of multiple lightning impulse current, and the maximum temperature increases with the increase of lightning current amplitude; The distribution and time-varying characteristics of electric field in arc extinguishing chamber are analyzed under different time nodes. The maximum value of electric field is mainly concentrated in the dynamic and static contact; With the increase of lightning current, the air velocity increases rapidly. The arc shape is gradually developed from the original column to the arc with bending shape along the direction of the increase of the gas flow velocity. The research provides the basis for the high voltage insulation coordination and the optimal design of the circuit breaker.