10 kV High Voltage Generator with LLC Resonant Circuit for Sterilizing Microbe Applications

Abstract

This paper proposes a high step-up voltage ratio of full-bridge converter associated with LLC resonant circuit for sterilizing microbe applications. The proposed circuit structure adopts full-bridge converter to generate a high DC voltage, while the LLC resonant circuit is used to recover the energy trapped in leakage inductance of transformer and to reach zero-voltage switching feature increasing conversion efficiency. Moreover, the LLC one can also avoid generating a large resonant current which occurs in between the large leakage inductance and the large equivalent capacitor of primary winding in transformer due to transformer with a high turns ratio. As compared with a conventional full-bridge converter with hard-switching circuit or phase-shift control method, the proposed converter can reduce voltage and current stresses of switches and increase conversion efficiency with soft-switching features. Finally, a prototype of high voltage generator under output voltage of 10 kV and maximum output power of 1 kW has been implemented to prove the feasibility of the proposed high voltage generator.