Abstract: With the continuous increase of the wind power penetration rate, the power system gradually presents the characteristics of low inertia. The rate of change of frequency（RoCoF） and the maximum frequency deviation in low-inertia systems at faults increase significantly, the effect of traditional frequency control methods is weakened and the frequency safety and stability are facing challenges. In view of the above problems, the fast frequency response（FFR） which is prior to primary frequency regulation has become an important way to solve the frequency stability problems of low-inertia system. Firstly, the frequency response model of the wind-thermal-storage power system is established, and the influence of FFR on the frequency response of low-inertia system is analyzed. Secondly, an optimal dynamic response strategy for supercapacitor participating in wind power frequency regulation is proposed based on fuzzy logic inference to control the energy storage. So it can dynamically respond to the system frequency changes, restrain the frequency drop during the frequency drop period and regulate the energy storage recovery power during the frequency recovery period to maintain the stability of state of charge. Finally, the proposed control strategy is verified by simulation. The simulation results show that, the proposed strategy can use the supercapacitor to dynamically respond to the system frequency changes quickly, so as to provide power support for the low-inertia system and make up for the shortage of wind power frequency regulation. Compared with the traditional virtual inertia control strategies of wind turbines, the effects of reducing the maximum RoCoF and inhibiting the maximum frequency deviation are greatly improved.