Keywords: battery storage, ultra-capacitors, control strategies, electric vehicles, EVs, power electronics, Luo converter, variable load, energy storage, hybrid controller design, DC-DC converters, voltage step-down, voltage step-up, bi-directional power flow
Design and control of a Luo converter for variably loaded hybrid electric vehicle energy storage system
This paper presents the analysis and novel hybrid controller design for a 4-quadrant (4-Q) switched-capacitor (SC) Luo bidirectional DC/DC converter, applicable for hybrid electric and plug-in hybrid electric vehicle energy storage system (ESS) 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 control 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).