RESEARCH AND DESIGN OF PERMANENT MAGNETIC ACTUATOR FOR 72.5?kV HV VACUUM CIRCUIT BREAKER

High voltage vacuum interrupter (HVVI) has longer separation and needs faster opening closing speed. Because air gap's magnetic resistance is proportional to air gap's length, it is very difficult for the actuator to acquire enough drive force under longer separation. As a result, HVVI has been hardly equipped by permanent magnetic actuator. According to the asymmetry of the reacting force from vacuum interrupter and its mechanical transmission system, this paper presents a method setting magnetism divider around the operating air gap of the opening coil. By which, the magnetic flux through the surface of pole is divided into the central flux and the border flux so as to improve the electromagnetic attraction characteristics and meet the on off need of 72.5?kV high voltage vacuum circuit breaker even under longer separation. The static magnetic field and the dynamic characteristics of permanent magnetic actuator are analyzed, and the calculation results simulation results are presented.