Optimal control strategy of dual-active-bridge converter for battery energy storage system

As a core link of battery energy storage system (BESS) for grid-connection, the dual-active-bridge (DAB) converter has significant effects on the performance of the whole system. In order to address the mismatch voltage issue of DAB in BESS, an optimal control strategy is proposed. The paper discusses the operation principle of the circulating power, and analyzes the voltage, transmission power and current stress models. On this basis, the switching model of current stress is established, and the optimal modulation algorithm is proposed. At last, the prototype of the system is built to verify the theoretical analysis. Experimental results show that the optimal control strategy can reduce the current stress of the converter effectively.