Power Distribution and Individual Phase Control of Asymmetrical Three-Phase Cascaded Multilevel Hybrid Energy Storage System in Star Configuration

Considering the coupling among chains and links, a power distribution and individual phase control method is proposed for asymmetrical three-phase cascaded multilevel hybrid energy storage system in star configuration. Based on a three-phase system with battery and capacitor operating as two different sources, an individual phase control method is utilized to distribute active and reactive power in each phase independently. The stable operating range has been derived to avoid over modulation, and common range of asymmetrical links is also obtained to achieve individual phase control. A 5MW/35kV system with proposed control strategy is experimented on RT-LAB platform to validate the feasibility of this method.