A Novel Realization of ZVS and Efficiency Optimization for Double-Clamped ZVS Buck-Boost Converter without Current Sampling

An innovative and simple method to enhance soft-switching capability and improve efficiency of the double-clamped zero-voltage-switching (DCZVS) buck-boost converter is presented in this paper. Compared with the conventional method, the proposed method utilizes the parasitic parameters of the converter and two additional passive devices to achieve ZVS and efficient energy transfer. Therefore, the soft-switching can be realized without sensing any current information and the efficiency is further improved due to secondary-resonance and damping resonance without increasing the difficulty of control, which is conducive to the improvement of converter power density. Based on the ZVS and resonance analysis, the preferable parameters are determined. Finally, the proposed method is verified on a 1MHz DCZVS prototype.