PWM strategy of a novel cascaded multi-level converter for battery management

This paper propose a novel hybrid cascaded multilevel converter which can be used for voltage and state of charge (SOC) balance control of the battery cells. The proposed converter is composed of a group of cascade half-bridges with battery cells and a H-bridge in each phase. The converter can realize the charging and discharging control of each battery cell. A modified carrier-wave-cascaded PWM strategy is proposed for the balance control. To improve the voltage utilization ratio under fault and unbalance state, a dynamic neutral point shift method is studied and applied. The effects have been verified by simulation and experimental results.