Abstract: Considering the uncertainty of wind power,this paper proposes a new method to estimate the frequency regulation capacity of wind farms based on the probability prediction intervals of wind power and energy storage equipment. Firstly,based on the abandoned data of wind power in the wind farm,the capacity allocation of its energy storage system can be obtained by using particle swarm optimization（PSO）. Then,the Copula quantile regression model is established to get the probability prediction intervals of wind power.Finally,the estimated optimal capacity for frequency regulation is generated by combining the probability prediction curves under different confidence probabilities and the day-ahead limits of wind power. The simulation of the actual data provided by a wind farm proves the effectiveness of this method,which provides a useful exploration for the study of the frequency regulation ability of wind farms.