Influence of Moveable Mass on the Opening Velocity and Buffering Characteristics of Fast Vacuum Circuit Breaker with a Gas Pressure Buffer

The objective of this paper is to determine the influence of moveable mass on the opening velocity and buffering characteristics of fast vacuum circuit breakers (FVCB) with a gas pressure buffer. A multi-physics field simulation model was built, which coupled the flow field, transient electromagnetic field, mechanical motion and external circuit. The average velocity in the first 1/3 stroke (10 mm) was defined as the opening velocity. Simulation results showed that with the increase of moveable mass from 4 to 12 kg, the opening velocity decreased following a negative exponent function from 6.13 to 3.50 m/s; the momentum at the end of 30 mm full stroke increased following a positive exponent function from 12.26 to 21.01 kg.m/s; and the work done by the buffering force decreased following quadratic function from 443.61 to 203.02 J. The relationship between buffering force and the displacement of the moveable part was described as a power function.