A high gain soft switched DC-DC converter for renewable applications

This article presents a novel high gain soft-switching DC-DC converter with low component count and low voltage stress across switching devices. The proposed converter employs coupled inductor and voltage multiplier techniques to achieve high gain at low duty and low turn ratios. An active clamp circuit is also used to reduce voltage stress across the switch. As a result, lower voltage rating switches having lower on-state resistance (Rds-on) are used, lowering system cost. It also helps to achieve zero voltage switching (ZVS) turn-on across both MOSFETs, reducing switching losses and improving efficiency. The leakage energy of the coupled inductor is recycled to improve the voltage gain, and the quasi resonance formed by the leakage inductance and switched capacitors helps to achieve zero current switching (ZCS) across diodes. This also helps in controlling the falling rate of output diode current, helping to mitigate the reverse recovery problem. The steady-state analysis has been carried out. A 500W prototype of the proposed converter is built up and tested to validate the working of the converter.