Optimization Design of Inverter Bridge Snubber Circuit

One of the key links in power system design of an electric power torpedo is the design of inverter circuit by using power semiconductor devices to form inverter bridge. This device will be subject to sharp variations of current and voltage as well as current and voltage spikes at its ‘turning on’ or ‘turning off’ moment. If these parameters beyond the safe operating area of the device, damage would occur, so it is necessary to design a snubber circuit. This paper analyzes the turning on or turning off process of an insulated gate bipolar transistor(IGBT) , compares different applications of snubber circuits with different structures, and discusses the advantages and disadvantages of the snubber circuits. Comparative analysis and theoretical derivation are performed for different inverter bridge snubber circuits, and simulation is conducted. Simulation result shows that the resistance capacitance diode(RCD)-type snubber circuit has the ability of strong suppression to turning-off surge voltage, and has low switching loss. It is hence suggested that the RCD-type snubber circuit be selected in design of high power high frequency power electronic system.