Probability-based method for power capacity specification of wind energy storage systems

To accommodate the wind power fluctuation, a hybrid energy storage system (HESS) consisting of battery energy system (BESS) and super-capacitor is adopted in this paper. A probability-based power capacity specification approach is proposed in this paper. Through this method the capacities of BESS and super-capacitor are properly designed to bridge the characteristics of high energy density of BESS and the characteristics of high power density of super-capacitor. Comparing to BESS for accommodating wind power fluctuations, HESS is more cost-effective due to the extension of BESS lifetime. The super-capacitor can handle the peaks in wind power fluctuations without the severe penalty of round trip losses associated with a BESS. The proposed approach has been verified based on the real wind data from an existing wind power plant.