Multi-switch driving circuit with LLC resonant circuit for high pulsed-voltage generator

This paper proposes a multi-switch driving circuit with LLC resonant circuit for high pulsed-voltage generator. The proposed circuit structure adopts full-bridge inverter associated with LLC resonant circuit and pulse transformers to generator ac pulse voltage at high frequency. The ac pulse voltage is rectified through a rectifier circuit to form a low frequency pulse voltage which drives a series multi-switch module. In the proposed circuit structure, full-bridge inverter with LLC resonant circuit is operated in second area, where switches and output rectified diodes of inverter can separately be operated with zero-voltage switching at turn on and with zero-current switching at turn off, for reducing switching losses and increasing conversion efficiency, and reduce rising and falling times in switch to increase operational reliability. As compared with conventional full-bridge inverter with hard-switching circuit, the proposed inverter can reduce voltage and current stresses of switches and increase conversion efficiency with soft-switching features. Finally, a prototype for driving thirteen IGBTs connected with series has implemented to verify the feasibility of the proposed multi-switch driving circuit.