Design and test of vacuum circuit breaker with hybrid fast operating mechanism

To satisfy the requirement of controlling and protection of modern power grid, it is necessary to develop the fast switchgear switching quickly as the executive device. The advances of repulsion and permanent magnetic mechanism are combined fully, the hybrid fast operating mechanism constructed with electromagnetic repulsion and permanent magnetic mechanism was designed in the paper. The switching characteristics of fast mechanism were simulated. The mechanical structures of coil skeleton, shell and T-shaped armature were optimized for the mechanism, and the design to avoid closing bounce was conducted. Based on these, the fast mechanism was developed and the strength of vacuum interrupter was promoted. The prototypes of 12/40.5kV fast vacuum circuit breaker were assembled and the factory performance debugging was carried out. The technical specifications of manufacture were formulated according the current standard of circuit breaker. The technical parameters of devices were provided. Two prototypes have passed the performance verification tests which including insulation, machinery, temperature rise, short-time current endurance, breaking and making ability. All results have shown that the performance parameters of two prototypes both meet the requirements of the technical specifications.