Research On Paralleling Of High-Power IGBT And Designing Snubbers For Pulsed Power Supply

This paper investigates the insulate gate bipolar transistor (IGBT) used as the main switch in pulsed power supply. Firstly, the IGBT' s Characteristics, principle and applications are introduced. Secondly, the methods of paralleling IGBTs are presented to enlarge output power of the power supply. When IGBT paralleled, due to tolerances of semiconductors, gate-drive, and mechanical parameters, the total load current is not shared equally between paralleled IGBT power modules. The methods to achieving balanced current are presented and simulated in this paper. Thirdly, the snubbers are designed to compress the switching voltage transient. When IGBT is abruptly turned off, trapped energy in the circuit stray inductance is dissipated in IGBT, causing a voltage overshoot and damaging IGBT. This paper analyzes the principle of the snubber and discusses the impact of the parameters of the snubber on voltage overshoot. The proper snubber is designed and simulated for practical power supply. Finally, the solutions above-mentioned are used in designing practical power supply. The effectiveness is verified by simulations and experiments.