Design and Application of Electric Life Test System for DC Contactor

In recent years, the new energy industry has ushered in a golden period of rapid development, and DC switches have been widely concerned. In view of the problems such as no zero crossing of DC switch and difficulty in extinguishing DC arc, the research objective of this paper is to build a DC contactor electrical life test system to assist the research and test verification of DC breaking performance of low-voltage appliances, and to cover DC contactors of different models and specifications (250V-1500VDC, 10-600A) in the market. Firstly, the principle of LC discharge is analyzed, and the voltage and current generated by the non-oscillating discharge process is used to provide the breaking conditions for DC contactor. Then, the design of the main circuit, the establishment of the simulation model, the determination of parameters, the test verification and the optimization of the circuit are introduced. The results of numerical simulation and experimental measurement show that the test system can support the electric life prediction of DC switches such as DC contactor and DC circuit breaker, the most difficult to break current and arc test research.