Research on the Influence of Contact Geometry on Arc Dynamics in HVDC Relays

Surface erosion of contacts in high-voltage DC relays is a major cause of relay failure, with the generation and motion of electric arcs between contacts during breaking operations being the direct cause of such erosion. To investigate the motion characteristics of arcs under different contact surface geometries, a magnetohydrodynamic (MHD) model was designed for a specific high-voltage DC relay. Utilizing the COMSOL Multiphysics simulation software for multi-physics coupling analysis and physical experiments, multiple configurations of movable and stationary contacts were modeled. The simulations accounted for the influence of varying operating conditions on arc motion, revealing the specific effects of contact surface parameters on arc dynamics and contact surface temperature. This research provides critical insights for optimizing arc-extinguishing designs in high-voltage DC relays.