Dual Series-Resonant Active-Clamp Converter

A dual series-resonant active-clamp dc-dc converter is proposed to obtain high efficiency. The proposed converter employs an active-clamp technique, while a series-resonant scheme controls the output voltage with the complementary pulsewidth modulation controller. The active-clamp circuit serves to recycle the energy stored in the leakage inductance or the magnetizing inductance and provides zero-voltage turn-on switching. The voltage stresses of the main switch are clamped. Moreover, the proposed dual series-resonant circuit provides two resonant-current paths formed by the leakage inductance and the output resonant capacitors, and a zero-current turn-off switching of diodes is achieved by its dual resonance. In addition, voltage stresses of the output diodes are clamped to the output voltage. Thus, the proposed active-clamp dc-dc converter using a dual series-resonant circuit is analyzed and optimized for high power efficiency. Experimental results for a 400 W dc-dc converter at a constant switching frequency of 100 kHz are obtained to show the performance of the proposed converter.