Numerical Simulation of Residual Plasma Evolution in DC Vacuum Circuit Breakers Based on Artificial Current Zero

The plasma generated by a vacuum arc remains in the contact gap at current zero. This residual plasma at current zero is important to the later dielectric recovery process. Therefore, the evolution of plasma in the arcing phase is of great significance to obtain the characteristics of the residual plasma. During the arcing phase, the calculation of plasma is based on the rate equation and the Clausius-Clapeyron equation. Different kinds of particles, the fast ions, the fast atoms, the slow ions, and the slow atoms, are taken into consideration. Besides, the charge exchange and particle diffusion are involved. Then the calculation results of residual plasma are compared with the experimental results of DC current interruption. Finally, the effects of different factors on the simulation results of residual plasma are also studied.