Quasi-Resonant Boost-Half-Bridge Converter With Reduced Turn-Off Switching Losses for 16 V Fuel Cell Application

An active-clamped current-fed converter can achieve not only lossless clamping but also zero-voltage switching. In particular, a boost-half-bridge (BHB) converter is one of the most suitable candidates for high-current, high-step-up applications owing to its low transformer turn ratio, reduced voltage rating of diodes, zero magnetizing dc offset, and symmetrical structure for all components. In this letter a quasi-resonant switching technique for a BHB converter with active clamping is proposed to significantly reduce turn-off switching losses. Experimental results for a 16 V, 1.2 kW prototype validate the effectiveness of the proposed concept.