ZCS Switched-Capacitor Bi-directional Quasi-Resonant Converters

This paper presents the new topologies of zero-current switching switched-capacitor (ZCS SC) quasi-resonant converters with bidirectional power flow control conversion schemes. It possesses the features of quasi resonant switched-capacitor converters: low weight, small volume, high efficiency, low EMI emission and low current stress. A family of zero-current switching switched-capacitor bidirectional converters is proposed to improve the current stress problem during the bidirectional power flow control processing. They are able to provide the voltage conversion ratios from double-mode/half-mode to n-mode/1/n mode by using four power MOSFET main switches and a set of switched-capacitors with a small series connected resonant inductor for non-inverting or inverting modes. The operation principle of converter operation of the proposed bi-directional power conversion scheme is described in detail with circuit model analysis for non-inverting mode. Simulation and experimental results are carried out to verify the concept and the performance of the proposed double-mode/half-mode ZCS SC bi-directional quasi-resonant converters.