A novel fault-tolerant control for battery-energy-storage system based on cascaded multilevel converter with battery/BMS failure

摘要

This paper proposes a novel fault-tolerant method for battery energy storage system (BESS) based on cascaded multilevel converter. During the occurrence of batteries or battery management system (BMS) fault, an asymmetrical cascaded multilevel BESS is formed which includes several batteries and several capacitors. Traditionally, it is challenging to achieve the active power distribution between different cascaded H-bridges with different DC sources. With the proposed fault-tolerant control method, it can distribute active power between batteries and capacitors as well as enables continuous operation in four quadrants. This enhances both system reliability and availability. Meanwhile, the stable operation region has been derived by vector analysis. Simulation results demonstrate the validity and effectiveness of the proposed fault-tolerant control.