Abstract:

The operating mechanism is the power output source of the vacuum circuit breaker,which provides the necessary energy of short-circuit breaking and closing.The counterforce characteristic matching curve of the operating mechanism determines whether the circuit breaker can close smoothly and the mechanical characteristic parameters can meet the design requirements during the closing process.From the perspective of statics mechanics,one calculation method that solves the relationship between the dynamic torque and resistance torque of the main shaft during closing process at any time is introduced,and the influence of the energy storage spring final force on the counterforce characteristic matching curve is studied,which has a great engineering significance for the optimal design of parameter variables such as energy storage spring,break-brake spring and contact spring in the operating mechanism of circuit breaker.

Key words: medium voltage vacuum circuit breaker, operating mechanism, counterforce characteristic matching, calculation analysis