Simulation Analysis of Arc Motion of High Voltage DC Relay under Non-uniform Magnetic Field

to high voltage and current levels of high voltage DC (HVDC) relays and the absence of natural zero crossings in DC system, the arc generated during the breaking process of the relay has high energy and is difficult to extinguish, which affects the relay’s breaking reliability and electrical life. In order to accelerate arc extinguishing, the permanent magnets are usually placed in the arc extinguishing chamber of the HVDC relay. The existing simulation analysis is mostly based on the uniform distribution of the magnetic field, while the distribution of the magnetic field generated by the permanent magnets is non-uniform. Therefore, based on the theory of magnetohydrodynamics (MHD), this paper establishes the numerical model of arc plasma and permanent magnets of HVDC relay by means of COMSOL Multiphysics software, analyzes the arc motion characteristics under the action of non-uniform magnetic field generated by permanent magnet. The results of the simulation analysis will provide a basis for the application of permanent magnets in HVDC relays.