Three-Level Optimal Scheduling and Power Allocation Strategy for Power System Containing Wind-Storage Combined Unit

To mitigate the impact of wind power volatility on power system scheduling, this paper adopts the wind-storage combined unit to improve the dispatchability of wind energy. And a three-level optimal scheduling and power allocation strategy is proposed for the system containing the wind-storage combined unit. The strategy takes smoothing power output as the main objectives. The first level is the wind-storage joint scheduling, and the second and third levels carry out the unit combination optimization of thermal power and the power allocation of wind power cluster (WPC), respectively, according to the scheduling power of WPC and ESS obtained from the first level. This can ensure the stability, economy and environmental friendliness of the whole power system. Based on the roles of peak shaving-valley filling and fluctuation smoothing of the energy storage system (ESS), this paper decides the charging and discharging intervals of ESS, so that the energy storage and wind power output can be further coordinated. Considering the prediction error and the output uncertainty of wind power, the planned scheduling output of wind farms (WFs) is first optimized on a long timescale, and then the rolling correction optimization of the scheduling output of WFs is carried out on a short timescale. Finally, the effectiveness of the proposed optimal scheduling and power allocation strategy is verified through case analysis. © 2024 The Authors.