DYNAMIC SIMULATION AND OPTIMUM DESIGN OF LOW-VOLTAGE CIRICUIT BREAKER

A novel dynamic model of low-voltage molded case circuit breaker operating mechanisms was built based on multi-body dynamics adopting virtual prototyping technology. An experiment was done to verify the model. The results showed that the simulation is in good agreement with the test results of the real circuit breaker. It is significant that the model can be used to study the interrupting characteristics of low- voltage circuit breaker and to provide a good basis for circuit breaker optimum design. Considering the electro-dynamic repulsion force effect, the time of the interrupting process was shortened about 2ms. It is indicated that the centroid y coordinates and mass of upper linkage have most influence in angular velocity of moving contact and the centroid position and mass of trip are next to them. After optimization design, the average angular velocity of moving contact is raised 13.3%.