Optimised Control Strategy for Wind Power-Flywheel Energy Storage Systems Based on Multi-Objective Fractional-Order PID and Sliding Mode Control

To improve the frequency stability of the grid after wind power integration and reduce the frequency regulation cost of wind storage systems, a multi-objective optimization based fractional order PID(FOPID) and sliding mode control (SMC) frequency division collaborative optimization control strategy is proposed. Firstly, in response to the different response characteristics of wind power and flywheel, a FOPID-SMC frequency division control strategy is proposed. By decomposing the frequency deviation into high-frequency and low-frequency components suitable for wind power and flywheel energy storage respectively, the frequency modulation goal is achieved by combining rapid adjustment of high-frequency fluctuations with smooth adjustment of low-frequency deviations; Furthermore, combined with a multi-objective optimization framework, a FOPID-SMC control parameter collaborative optimization method considering frequency stability performance and economy is designed to form a “layered control global optimization” control architecture. The simulation results show that the proposed scheme significantly reduces frequency deviation, improves frequency response speed and stability, and balances economy under continuous load fluctuations and disturbances in new energy grid connection scenarios. The frequency performance index J1 has been optimized by 26.8%, and the economy index J2 has been optimized by 30.8%, verifying its robustness and engineering application potential under complex disturbances.