New zero-current-transition PWM DC/DC converters without current stress

This paper presents novel zero-current-transition (ZCT) PWM dc/dc converters without additional current stress and conduction loss on the main switch during the resonance period of the auxiliary cell: The auxiliary cell consists of a resonant inductor, a resonant capacitor, an auxiliary switch and an auxiliary diode in parallel with the main switch and the zero-cur-rent-switching (ZCS) range's-of the main. and the auxiliary switch of the proposed converters are entirely achieved by operating the auxiliary cell. In. addition, the resonant inductor of the proposed ZCT cell helps-soft turn-on of the main switch. The theoretical analysis and the operation principle of the new ZCT technique are described in detail using a boost converter as an example: To verify the validity of the proposed ZCT technique, the simulation and the experiment were performed on the nonisolated and the isolated converter; respectively. Here, the nonisolated converter is a boost converter having 100 kHz switching frequency, 1 kW rating power, and the isolated converter is a full-bridge (FB) converter having 50 kHz switching frequency,I kW rating power.