A Novel QR ZCS Switched-Capacitor Bidirectional Converter

The proposed quasi-resonant (QR) zero current switching (ZCS) switched-capacitor (SC) converter is a new type of bi-directional power flow control conversion scheme. They are able to provide the voltage conversion ratios from 2 versus 1/2 (double-mode/half-mode) to n versus 1/n (n-mode/1/n-mode) by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The low current stress and balance resonance current are the advantage of the proposed quasi resonant switched-capacitor converter. The principle of operation, theoretical analysis of the proposed bi-directional power conversion scheme is described in detail with circuit model analysis. Simulation and experimental results are carried out to verify the performance of the new type ZCS SC bi-directional QR converters.