An efficient method for improving switching reliability of permanent magnetic vacuum circuit breaker

Based on the analysis of the drive circuit for both mono-stable and bi-stable vacuum circuit breaker (VCB), a controller can control both of them was designed in this paper. A new method was introduced to determine the actual state of the VCB that had just executed the switching command. The method divided the curve of the drive current into three periods, and analyzed the state of the moving contact. An algorithm was implemented, which was used to detect the similarity between the idea drive current and the actual one acquired by the controller, to determine the state of contacts in VCB. Experiments were made on VCB, and it was found out that the reliability of closing the VCB could be improved with the method.