Research On Electromagnetic Design And Control Of High Power DC Permanent Magnet Contactor

As an important automatic control component,the high power direct current(DC)contactor can be used to switch on/off the main circuit with low current.It is widely used in aerospace,weapon and electric vehicle fields.In recent years,the voltage and current of DC contactor have been further improved,which puts forward higher requirements for the performance of the contactor's operating mechanism.Based on the comprehensive analysis of domestic and overseas DC contactors,the paper investigated the electromagnetic design,modeling and parameters optimization of 250A/450 V high power DC contactors.The paper proposed a permanent magnet contactor based on the analysis of the characteristics of the existing high-power DC contactor,and the topology structure and working principle of the contactor are described.The parameters of dynamic and static iron core,permanent magnet,coil of the contactor are designed.The static and dynamic characteristics of the contactor are simulated and analyzed by Ansoft Maxwell software.The control circuit of the permanent magnet contactor is designed,including hardware and software,so as to realize the switching on/off of the contactor.The hardware includes STM32-based CPU processors,power supply circuits,sampling circuits,driving circuits,and protection circuits.The software includes data acquisition program,data processing program,protection program,and driving program.An experimental platform for permanent magnet DC contactor was built.The parameters such as making time,coil current,capacitance voltage were measured,and compared with the simulated results.The effectiveness and correctness of the electromagnetic design and the control circuit were verified by the experimental results.