Optimizing Control for System-Wide State-of-Charge Balancing in Cascaded H-Bridge Battery Energy Storage Systems

In battery energy storage systems based on cascaded H-bridge multilevel converter, maintaining a balanced state of charge (SOC) among batteries in different modules is both advantageous and essential. However, traditional methods face challenges in control parameter design, resulting in potential issues such as insufficient balancing effects or over-modulation. To overcome these challenges, this paper proposes a method for designing adjustment coefficients in the system-wide battery balance control strategy. The proposed method enhances the SOC balance effect across the entire system while ensuring stable operation. A simulation model was established in PLECS to verify the effectiveness of the proposed control strategy.