A novel soft-switched trans-inverse ultra-high-gain DC/DC converter with low switch voltage stress

This paper proposes a novel single-switch, soft-switched, ultra-high-gain DC-DC converter featuring a trans-inverse structure and low input current ripple for renewable energy source applications. This circuit employs a three-winding coupled inductor (TWCI) and a voltage multiplier circuit to achieve a high voltage conversion ratio without requiring a large duty cycle. Unlike typical coupled-inductor-based converters, the proposed topology leverages a trans-inverse configuration, allowing higher voltage gains to be achieved by reducing the secondary turns ratio of the TWCI. Moreover, the turns ratios of the TWCI improve the design freedom to increase the voltage gain, which indicates more circuit flexibility of the proposed circuit. Besides, the maximum voltage stress across the single power switch is effectively limited by a regenerative clamp capacitor. The leakage inductances of the TWCI help provide the soft-switching performance for the power switch and low reverse-recovery issues for all diodes of the circuit, leading to an efficiency improvement. Additionally, to further minimize power losses, the leakage inductance of the TWCI is utilized to form a resonant tank. The operation principle, steady-state analysis, and comparison study are discussed thoroughly. Finally, a 250 W, 25-400 V prototype is developed to validate the theoretical analysis.