The Dynamic Performance Of The Small Circuit Breaker Breaking Research

Miniature circuit breaker (MCB) is used widely in household and similar place, and it plays a key role for safety of electrical equipment and people. Breaking short-circuit current is the most important function of MCB, and the breaking process is very complicated process, involving electrics, magnetic, mechanics, thermal, and other fields, so how to analysis and research breaking of MCB is an important topic. This paper focused on dynamic performance of mechanism in MCB and integrated calculation of magnetic force in breaking to research the effect of several factors, the detailed research carried out as below:1. Introduced the history, domestic and international research overview and development trends of MCB, and analyze its structure and functions. Aiming at the breaking function, performed a detailed analysis of the breaking process and current-limiting principle.2. On this basis, established the 3D virtual model of MCB, and adopting FLUX, which is a finite element analysis software for electromagnetic, to calculate the electric magnetic force of magnetic release device and electric repulsion force of contact system under different current and locations. Then, input the results of FLUX to the multi-body dynamic simulation software ADAMS, set up a link between electromagnetic force and current, movement of mechanism, realized the joint simulation of FLUX and ADAMS, accomplished the dynamic simulation of MCB's breaking process, and studied quantitatively several effect factors impacting dynamic performance of mechanism, such as magnet mobile core, spring stiffness, moving contact, electric repulsion force, closing angle, etc.3. Finally performed a short-circuit breaking experiment to verify the simulation method. By comparing the oscillogram of short-circuit test and simulation results, found that the movement of mechanism by simulation can match the arc voltage waveform of short-circuit tests, it prove that the simulation method is correct and feasible, it's important to improve the breaking capacity of MCB.