Abstract: Through the analysis of the operational characteristics of the wind power system and the flywheel energy storage system,a sensorless control strategy based on adaptive nonsingular fast terminal sliding mode observer is proposed to address the specific problem of difficult installation of position sensors for the flywheel rotor. This strategy improves the accuracy of rotor position estimation.Furthermore,to tackle the issue of lagging reference power commands in the flywheel energy storage system,an adaptive filtering algorithm is introduced as the power reference for the flywheel energy control system,building upon the sensorless control approach,in order to reduce the lagging phenomenon of power commands. Experimental verification is conducted using the Typhoon HIL 602 +simulation platform,and the results demonstrate that the flywheel energy storage system exhibits good operational performance,the observer possesses superior estimation capability,and it can meet the control requirements of rapid charge and discharge of the flywheel while effectively smoothing wind power fluctuations,thereby enhancing energy storage utilization.