A Current driven Half-Bridge ZCS with asymmterical PWM operation

In this paper, for the high voltage step up application, a current driven half-bridge ZCS (Zero Current Switching) boost converter with the asymmetrical PWM control is presented. ZCS is achieved in main switches and rectifier diodes by an internal resonant circuit operating in asymmetrical PWM. The leakage inductance of the transformer is used as the resonant inductor and the junction capacitance of the rectifier diode can be absorbed into the resonant capacitor. The current stress of the switches is decreased by a clamping diode. The operation principle and simplified voltage conversion ratio of the circuit is presented. The experimental results are verified with a 300W 42V-312V prototype converter.