Contacts impact phenomena in a 126 kV vacuum circuit breaker

The contacts closing impact phenomenon of vacuum interrupter is a basic event in a vacuum circuit breaker, which reveals lots of information including impact force, bouncing duration, stress distribution and so on. The objective of this paper is to investigate the contacts impact phenomenon in a 126 kV vacuum circuit breakers. PVDF (polyvinyldene fluoride) piezoelectric sensors were used to measure impact force of a 126 kV vacuum circuit breaker at a closing velocity of 1.5 m/s. In addition, a finite element analysis simulation model of contacts impact in a 126 kV vacuum interrupters was set up by using ANSYS / LS-DYNA software. The experimental results showed that the maximum contacts impact force of a 126 kV vacuum circuit breaker was about 10⁵ N at 1.5 m/s closing velocity, which is are in good agreement with the simulation results. And the simulation results also showed that the maximum impact force, durations of contact bounce and the maximum stresses of contact were related with some parameters of vacuum interrupter, such as contact shape, elastic modulus of contact material, impact velocity and contact spring force.