Abstract: This paper designs a double-layer energy management system（EMS）of FESS,which is applied to improve grid power quality,upper level-decision management of EMS uses the fuzzy algorithm to solve the charging and discharging reference power of the FESS through considering the state of FESS and the demand of stabilizing wind power fluctuations,and lower level-dispatching control layers realize the energy conversion between FESS and grid through back-to-back double PWM converters based on dual-loop control.This paper analyzes the operating state of FESS and compares the voltage fluctuations at the PCC before and after the wind farm uses FESS to regulate the active power in the MATLAB/Simulink simulation environment. The simulation results verify the validity of the model. The model can improve the utilization efficiency of FESS and improve the power quality.