Electromagnetic rotating arc characteristics of generator circuit breaker

The generator circuit breaker (GCB) needs to break large short-circuit currents, which can easily lead to breaking failure. In order to improve the breaking capacity of GCB, this paper proposes a control strategy of electromagnetic rotating arc. The arc can exchange energy with the high-speed cold gas flow in the arc chamber during the rotation process, which promotes the dissipation of arc energy. At the same time, it can disperse energy and prevent ablations caused by excessive local temperature. Finally, the breaking capacity of the GCB is improved by arc rotation. To verify the feasibility of this strategy, the current density and magnetic field distribution on the arc rings are obtained by simulation. Additionally, the rotating arc experiments are carried out on the GCB prototype under different short-circuit currents. The process of dynamic rotation of the arc and the variation of zero-zone parameters are obtained. Combined with the zero-zone parameters and Mayr arc model, the evaluation method of post-arc thermal breakdown is verified. The results show that with increase in the short-circuit current, the velocity of arc rotation is accelerated, and the number of rotations around the center rod is also increased. The effectiveness of the post-arc thermal breakdown evaluation method is verified based on experimental results. The results of this study can provide a reference for improving the breaking capacity of GCBs.