Optimal Scheduling Scheme and Battery configuration for Microgrids with Dual Battery Energy Storage Systems

A dual battery energy storage system (BESS) is proposed since the traditional single BESS has difficulty in adapting to multi-task scenarios. The dual BESS consists of two parts, namely the high-power BESS and the high-energy BESS. First, a real-time scheduling scheme for PV microgrids with dual BESSes is formulated as an optimization model, and its optimization objective is to maximize the profit of the microgrid at each sampling time. The power once assigned to the single BESS is now allocated to the high-power BESS and the high-energy BESS according to their task, which is stabilizing the output power of photovoltaic (PV) system and peak-load shifting, respectively. Then, a capacity optimization method for the dual BESS is contrived. The required capacity of the high power BESS is determined by the historical PV power fluctuation, while the capacity of high-energy BESS is optimized with a performance evaluation model of the microgrid. Finally, performance of eight dual BESSes and four single BESSes composed of different kinds of batteries are compared. The results show that the dual BESS has a better performance only when it combines high-power batteries and high-energy batteries, and the optimal battery type for the dual BESS depends on the specific parameters of the microgrid.