Modeling and simulation of switched capacitor converters for electric vehicle energy storage systems

This paper presents the analysis and novel controller design for a hybrid 4-quadrant (4-Q) switched-capacitor (SC) Luo and a conventional buck-boost bidirectional DC/DC converters, for HEV/PHEV energy storage system applications, based on power of traction motor and battery current gradient. Features of voltage step-down, voltage step-up, and bi-directional power flow are integrated into a single circuit. The novel hybrid controller strategy enables simpler dynamics compared to a standard buck converter, with input filter, good regulation capability, low EMI, lower source current ripple, ease of control, and continuous input current waveform in both modes of operation (buck and boost modes).