Research on the Contact Bounce During the Closing Process of a Repulsion Mechanism Applied in a Superconductivity Direct-Current Vacuum Circuit Breaker

This paper studies the contact bounce during the closing process of a repulsion mechanism applied in a superconductivity direct-current vacuum circuit breaker. A multi-physics field coupling simulation model is established to describe the whole closing process for the repulsion mechanism. The relationship between the V
₁
and D
_max
is obtained for the repulsion mechanism, where the V
₁
is an instantaneous closing velocity for the movable contact just mating with the stationary contact at the first time, and the D
_max
is the maximum contact bounce distance. According to this relationship, the critical instantaneous closing velocity V
_cri
for the case of no contact bounce is determined. According to V
_cri
, a novel oil buffer is designed to adjust the closing displacement of the repulsion mechanism to realize a nonclosing bounce. A prototype repulsion mechanism with an oil damper is developed. Its closing characteristics are tested and compared with the simulation results to verify the absence of a contact bounce.