Optimal Planning of Battery Energy Storage in the Wind-Thermal-Hydro Power System

In view of the high proportion of wind power integration that has brought challenges to the operation of traditional thermal-hydro power system, this paper establishes an optimal planning model of battery energy storage (BES) based on robust optimization framework for wind-thermal-hydro power system. Considering that the planning problem of BES is coupled with its operation problem, this paper takes into account the uncertainty and accommodation capacity of wind power in the operation stage, so as to ensure the effectiveness of the optimal solution in the feasible intervals. At the same time, based on the number of equivalent full cycles of BES in the process of discharging, this paper considers the constraints of BES’s investment capacity to ensure the economy of the decision-making. The proposed planning model of BES in the wind-thermal-hydro power system is finally transformed into a bi-level mixed integer linear programming model, which can be solved by efficient commercial solvers. Furthermore, the effectiveness and feasibility of the proposed method are analyzed and verified on the modified IEEE 30-bus system. The comparative analyses show that the proposed method can balance the actual life of BES and the economy of its operation. Moreover, the flexible adjustment capabilities of hydropower units can help reduce the planned capacity and the number of locations for BES. Also, the planned water flow and the BES’s investment capacity are mutually constrained.