A single active edge-resonant snubber cell-assisted ZCS half-bridge DC-DC converter with constant frequency asymmetrical PWM scheme

A newly-developed zero current soft-switching (ZCS)-PWM cell-assisted asymmetrical half-bridge (AHB) DC-DC converter topology with a high frequency (HF) link is presented in this paper. The soft-switching half-bridge DC-DC converter consists of a PWM-controlled single-ended half-bridge HF inverter and a center-tapped rectifier linked by a HF transformer. In order to attain the wide range of ZCS commutation in the primary-side HF inverter, the active edge resonant snubber cell composed of a switched capacitor and a lossless inductor is adopted in the half-bridge leg, providing ZCS commutation for a wide range of output power under constant switching frequency. The operation characteristics of the proposed DC-DC converter are described, and its feasibility data is demonstrated and evaluated with simulation and experimental results.