A Fully Coupled Framework of Predicting the Dynamic Characteristics of Permanent Magnet Contactor

A fully coupled simulation framework is developed to predict the dynamic characteristics of the permanent magnet (PM) contactors. Dynamic inductance, magnetic field distribution, and mechanical motion are solved by coupling the electric, magnetic, and mechanical governing equations. The equations are developed in the weak forms and the Weak Form Partial Differential Equation module of Comsol Multiphysics is employed to solve the equations. Influence of PM is taken into account by considering the remanent flux as a static potential. The electromagnetic variables and mechanical variables can be solved in the same discrete time period, which gives much higher calculation efficiency than the existing method. The simulation results show that the framework can predict the changing of the inductance, closing displacement, and excitation current in the time domain. Comparative experiments have been conducted to verify the simulations. Physical measurements show that the dynamic closing process of the contactor can be captured by the model with good precisions.