Experimental investigation on impact phenomena in a permanent magnetic actuator of a 126kV vacuum circuit breaker

The objective of this paper is to experimentally investigate the impacting phenomenon in a permanent magnetic actuator of a 126kV vacuum circuit breaker. The dynamic impact forces between an armature and a static core have a significant influence on a deformation of the operating mechanism that will affect the reliability of the operating mechanism. PVDF (Polyvinyldene Fluoride) piezoelectric sensors were used to measure impact force of 126kV vacuum circuit breaker. And a displacement sensor was used to record a displacement characteristic of the movable contact. The stroke of the permanent magnetic actutor is 84mm. Three different closing velocities were tested which were 2.0 m/s, 2.1 m/s and 2.2 m/s respectively during closing operations. Moreover, three different opening velocities were tested which were 2.3 m/s, 2.4 m/s and 3.0 m/s respectively during opening operation. The experimental results showed that the maximum impact force in the permanent magnetic actuator of a 126kV vacuum circuit breaker is almost 10⁶N during an opening operation without any damping. The maximum impact force is about 10⁵N during a closing operation.