3-D finite element analysis of repulsion forces on contact systems in low voltage circuit breakers

Low voltage circuit breakers which interrupt fault currents rapidly are widely used in power distribution systems. It is necessary, for the optimum design of circuit breakers, to analyze electromagnetic forces on the contact systems equipped with arc rupturing parts. In this paper, the forces generated by currents and flux densities are obtained by using the 3-D finite element method taking into account current constriction and variations in arc diameter. It is shown that the 3-D analysis is capable of evaluating new designs of LV circuit breaker contact systems.