New ZVS-PWM converters with zero-current-switched auxiliary switch for low power applications

A new family of ZVS-PWM converters, which contain auxiliary resonant circuit, is proposed and designed for low power applications in this paper. The auxiliary circuit consists of a resonant inductor, a resonant capacitor, auxiliary diodes, and an auxiliary switch. The auxiliary circuit is only activated during the main switch turn-on. Also, the added auxiliary circuit of the converter provides soft switching of all switches, which main switch and main diode operate under satisfying ZVS, and auxiliary switch operates under satisfying ZCS. A boost typed converter is selected to describe the operation of the family of ZVS-PWM converter. The converter is analyzed for steady state and graphical state plane. The operation characteristics and performances of the converter have been verified by 100 kHz, 90 W breadboarded boost typed converter.