Soft switching non-isolated current-fed inverter for PV/Fuel-cell applications

A non-isolated current-fed inverter for fuel-cell/PV applications is proposed. An impulse commutated current-fed half-bridge converter is selected as the front-end dc/dc converter that provides high voltage gain required for such applications. Impulse commutation enables zero current switching (ZCS) of the semiconductor devices. The devices´ voltage gets naturally clamped owing to impulse commutation eliminating the turn-off spike. Voltage doubler has been employed to reduce the device voltage ratings and enhance the voltage gain. Variable frequency modulation ensures output voltage regulation with input and load voltage variations. A 500 W prototype was developed in the laboratory to demonstrate the inverter performance and verify the proposed operation and claims.