A distributed VSG control method for a battery energy storage system with a cascaded H-bridge in a grid-connected mode

With the high penetration of renewable energy, new challenges, such as power fluctuation suppression and inertial support capability, have arisen in the power sector. Battery energy storage systems play an essential role in renewable energy integration. In this paper, a distributed virtual synchronous generator(VSG) control method for a battery energy storage system(BESS) with a cascaded H-bridge converter in a grid-connected mode is proposed. The VSG is developed without communication dependence, and state-of-charge(SOC) balancing control is achieved using the distributed average algorithm. Owing to the low varying speed of SOC, the bandwidth of the distributed communication networks is extremely slow, which decreases the cost. Therefore, the proposed method can simultaneously provide inertial support and accurate SOC balancing. The stability is also proved using root locus analysis. Finally, simulations under different conditions are carried out to verify the effectiveness of the proposed method.