A Parallel-Output CLTCL Multi-Resonant Soft-Switching DC-DC Converter

In this paper, a novel CLTCL multi-resonant soft-switching DC-DC converter is proposed. It employs the dual transformers architecture, whose secondary sides are connected in parallel. The resonant tank contains multiple resonant components of capacitors and inductors. Through the appropriate parameter design, the converter can transmit the 1st and the 3rd harmonic active power simultaneously. Consequently, the utilization rate of the resonant current and high efficient conversion are both guaranteed. Widely adjustable DC voltage gain range is also achieved within a narrow frequency range. Besides, all the power switches obtain the turn-on zero-voltage-switching (ZVS), while the diodes attain the turn-on and turn-off zero-current-switching (ZCS) or quasi ZCS (Q-ZCS). To verify the feasibility of the converter, a 500W prototype is built and tested. The proposed converter is able to maintain relatively high efficiency (around 95%) among a wide load range. The highest efficiency reaches 95.4% at 300W.