Sequential Multiphysics Modeling of Current Commutation Between Contacts in DC Hybrid Relays Considering Electromagnetic Actuation

Hybrid relays can effectively reduce arc erosion on relay contacts, with the key technology lying in the commutation process between electromagnetic relays and power electronic switches. Accurate prediction of the commutation process remains challenging because the interaction between electromagnetic actuation, contact motion and arc behavior is often simplified or neglected. This paper proposes a sequential multiphysics modeling framework for the electromagnetic system drive and arc in a DC hybrid relay, building a multiphysics model of the hybrid relay during the commutation process. An electromagnetic finite element model is established to obtain the armature dynamics under actual driving conditions. The resulting contact displacement and velocity are then introduced as time-varying boundary conditions into a magnetohydrodynamic arc model to simulate the commutation process. The electromagnetic system model enables the calculation of contact arc dynamics under variable-speed conditions, thereby supporting the analysis of hybrid relay performance across different ambient temperatures. Furthermore, a dual-coil electromagnetic model of the relay is developed, and the coil power-up timing is optimized based on energy consumption. Simulation results demonstrate that the model effectively reflects the commutation process of the hybrid relay under electromagnetic drive. Moreover, experimental verification of the key components confirmed the model's accuracy. The work provides a universal theoretical tool for accelerating the design cycle of hybrid relays in the equipment manufacturing industry.