Simulation of an improved operating method for vacuum circuit breakers with permanent magnetic actuators.

One disadvantage of traditional permanent magnetic actuators (PMA) in vacuum circuit breakers (VCB) is that it is difficult to improve the velocity characteristics so that the interruption capacity of VCBs will be constrained. The objective of this paper is to propose a method for controlling PMAs to enhance the velocity characteristics. In contrast to the traditional control method that adopts only one coil in an opening or closing operation, the new method adopts both coils in the PMA simultaneously and controls the direction of the current in coils. Then a simulation model that involves coupled physical fields is constructed according to the new method. Moreover, the simulation results indicate that the initial velocity can be increased in the opening operation and the velocity characteristics in the closing operation can be optimized. In addition, the operating current can be reduced so that it is easy to control. Finally, experimental results validate the simulation results. [ABSTRACT FROM AUTHOR]