Control Strategy of Flywheel Energy Storage Machine-Side Converter Based on Fuzzy Reasoning and Sliding Mode Control

Abstract

Installing a certain capacity of flywheel energy storage system (FESS) at the grid connection of wind farms can effectively smooth the grid-connected power and improve the grid friendliness of wind farms. With the traditional control method, the FESS power response speed is slow and the flywheel speed is easy to exceed the limit. Considering these issues, this paper proposes a control strategy for the FESS machine-side converter based on fuzzy reasoning and sliding mode control (SMC). Based on the actual output power of wind farms, the expected grid-connected power and flywheel speed, the correction coefficient is obtained by fuzzy reasoning to correct the reference value of flywheel power in real time. The corrected power reference value is used as the input of the designed SMC to realize the power control of FESS. The simulation results show that the control strategy proposed in this paper can achieve the purpose of smoothing the grid-connected power of wind farms with good dynamic response characteristics, and the flywheel speed does not cross the limit during the smoothing process.