Zero-voltage and zero-current-switching half bridge DC/DC converter

This paper introduces an improved zero-voltage and zero-current-switching half bridge (ZV-ZCS HB) DC/DC converter for medium and high-power applications. The soft switching is obtained by adding only small capacitors. The operation principle and design procedure are presented together with an analysis of the total losses in the switch. By using the proposed operation principle and design procedure zero-voltage-zero-current switching and high efficiency operation for full load range are provided. The operation and design considerations are illustrated and verified on a 6 kW prototype, which has been simulated (PSPICE) and successfully tested at 20 kHz operating frequency. The obtained efficiency is above 97% for full load. Increasing the operating frequency above 50 kHz is possible, which contributes to a decrease of the losses in the transformer and to a reduction the size and weight. The simple topology, high efficiency and low cost make the proposed converter attractive for medium and high power applications.