Aircraft lithium battery energy balancing method based on compound balancing topology

The inconsistency within the onboard 28 V series battery pack can decrease its energy utilization and lifespan, potentially leading to flight accidents. This paper introduces a novel energy balancing method for onboard lithium battery packs based on a hybrid balancing topology to address this issue. This balancing topology utilizes simple isolated DC-DC converters and power resistors to implement "peak shaving" or "valley filling" for any individual battery cell, reducing the number of balancing components and system volume. Using state of charge (SOC) as the balancing variable enables rapid energy transfer between individual cells in the onboard 28 V battery pack. Simulation and experimental results demonstrate that the proposed novel balancing method significantly improves balancing efficiency, achieving a maximum reduction of 136 s per 1 % SOC compared to centralized DC-DC topology-based balancing methods.