Dynamic simulation of operating mechanism in low-voltage moulded-case circuit breaker

A novel dynamic model of low-voltage moulded-case circuit breaker operating mechanism is created using the multibody software package ADAMS (automatic dynamic analysis of mechanical system). The model is proved by experiment. To analyse the influence of electrodynamic repulsion forces on the breaking process of the circuit breaker, the real-time repulsion force values are calculated by a binary-cubic interpolation method. The circuit, electromagnetic field and mechanism coupling equations are solved by a self-programming routine of the ADAMS secondary development to simulate the breaking process. All simulation results show that the repulsion forces accelerate the breaking of the circuit breaker. Under the condition of a prospective current of 10 kA the breaking time is shortened by about 1 ms.