Research on Overvoltage Suppression of the Battery Discharging in Electromagnetic Launch

This paper introduces a discharging circuit of batteries in hybrid energy storage system for electromagnetic launch. The main switch, integrated gate bipolar thyristor(IGBT), has a high overvoltage at turn-off time in the discharging process. This paper analyzes the causes of the overvoltage based on the circuit structure and the timing discharging method. A stray parameter identification method based on search matching is proposed for the characteristics of the circuit. The overvoltage is effectively suppressed by optimizing the layout to reduce the stray inductance. It does not change the discharging method, nor does it increase the weight of the system. The suppression of IGBT overvoltage ensures the safety of continuous electromagnetic launch. The overvoltage before and after optimization are compared with simulation. The experiments under a variety of working conditions are carried out on the platform of the hybrid energy storage system for the electromagnetic launch. The validity and practicability of the overvoltage suppression method and the stray parameter identification method are verified.