A bidirectional multi-port DC-DC converter integrating voltage equalizer

A novel bidirectional multi-port dc-dc converter integrating voltage equalizer based on switched-capacitor voltage accumulator (SCVA) is proposed. It has two operating modes of charging and discharging for battery modules. All battery modules are connected in series indirectly and can be equalized with a uniform voltage level while eliminating the voltage imbalance. In addition, high step-down and step-up ratios with low component voltage stress can be achieved in the proposed converter. A bidirectional four-port dc-dc converter is presented to do theoretical analysis for the voltage equalization of three battery modules with different voltages. Simulation results has shown the feasibility of the proposed converter.