High Gain Non-isolated ZCS Current-fed Full-Bridge Partial Series Resonance Based Voltage Quadrupler for Fuel Cell Vehicles

A transformer-less high-gain current-fed dc/dc converter topology is proposed, analyzed, and designed. Current-fed converter is boost derived topology and so offer natural voltage gain along with additional 4x gain owing to voltage quadrupler at the output. Natural commutation of the semiconductor devices is obtained by achieving their zero-current-switching (ZCS) turn-off through a resonance pulse developed by a series LC tank. It also supports the smooth voltage clamping of the semiconductor devices getting-rid-of the traditional snubber requirement to absorb the turn-off voltage spike across them. Variable frequency modulation with fixed duty cycle is adopted to obtain wide operating range ZCS operation of the devices. Simulation results at 500W are demonstrated to validate the converter operation while reporting an efficiency of 97.6% at full-load that is improved by 3.3% compared to the hard-switching converter.