Calculation Method of DC Contactor Temperature Field and Arc Heating in Life Test

When the DC contactor operates, arc with high instantaneous power will be generated, which will increase the temperature of the arc extinguishing chamber. When the operating frequency of the contactor is low, the effect of the arc on the overall temperature rise of the contactor is not obvious and is often ignored. However, under the working conditions of frequent actions such as life experiments, the arc will cause the contactor to heat up significantly, which will affect the key parameters of predicting life and working reliability. Aiming at the calculation problem of temperature rise caused by arc in the contactor life test, this paper combines the arc simulation model based on magnetohydrodynamics (MHD) and the dynamic characteristic model of the contactor, and proposes a method including electromagnetism-thermal-motion-fluid Multiphysics coupled arc heating and contactor temperature rise calculation method. In the model, the arcing when the contactor is opened and the bouncing arcing when it is closed are considered, and the influence of temperature on the permanent magnetic field and thus on the arcing time and arcing energy is considered. Through the comparison of simulation and experimental data, the feasibility of the method proposed in this paper is proved, which can provide a reference for the thermal design, life and reliability prediction of contactor products.