Quasi-resonant boost-half-bridge converter with reduced turn-off switching losses for 16V fuel cell application

The active-clamped current-fed converter is able to achieve not only lossless clamping but ZVS operation of switches. Among them, a boost-half-bridge(BHB) converter [7] is one of the most suitable candidate for high current high step up applications due to the advantages of low transformer turn ratio, reduced voltage rating of diodes, zero magnetizing dc offset and symmetrical structure of all components. In this paper a quasi-resonant(QR) switching technique for the BHB converter with active clamping is proposed to reduce turn off switching losses. Experimental results on a 16 V 1.2 kW prototype are provided to validate the effectiveness of the proposed concept.