Analysis and Design of Current-Fed Three-Phase-Isolated LCC-T Resonant Converter for Low-Voltage High-Current Applications

A three-phase-isolated current-fed dc-dc converter with LCC-T resonant tank to achieve an efficient and compact design is proposed. Traditional dc-dc converters require an external parallel inductor to increase the transformer magnetizing current to realize soft switching under light-load conditions. The proposed LCC-T configuration eliminates this requirement and realizes light-load soft switching with reduced circulating current. In addition, the proposed topology maintains zero-voltage switching (ZVS) turn-ON of primary switches, ZVS turn-ON and zero-voltage-zero-current switching turn-OFF of secondary diodes for all load conditions. Steady-state operation, analysis, and design of the proposed converter are reported. Experimental results of 1-kW hardware prototype to verify the claims of the proposed analysis and design are presented.