46 / 2021-05-25 23:26:02

MHD SIMULATION STUDY OF DC MULTI-CONTACT CIRCUIT BREAKER FOR EQUALIZING BREAKING ARC

This paper is based on a DC natural current commutation topology, which uses the current-loading branch contacts carrying rated current and multiple sets of series arcing branch contacts in parallel to achieve circuit breaking. Satisfying aviation, aerospace and new demand for DC switching in the energy and other fields towards higher voltage levels. An magnetohydrodynamic (MHD) arc model was built using COMSOL Multiphysics, and the different arc breaking characteristics of the arcing branch contacts were simulated. Then, two adjustment methods, structural adjustment and magnetic field adjustment, are proposed to study the effect of equalizing breaking of arcing contacts under different adjustment methods. It defines a method to measure the voltage uniformity coefficient of arcs in series with multiple breaks during dynamic breaking process, and obtains a structure control method that optimizes the action characteristics of the arcing contact. Aiming at the dispersion of the arcing contact action, the magnetic field control method is further adopted to improve the voltage uniformity coefficient. The uniform voltage distribution can improve the breaking capacity and electrical life of the series connection structure.