Probabilistic Approach for Power Capacity Specification of Wind Energy Storage Systems

To accommodate the wind power fluctuations, a hybrid energy storage system (HESS) consisting of a battery energy storage system (BESS) and a supercapacitor is evaluated in this paper. A probabilistic approach for economically determining the power capacity specification for the HESS is proposed. This method would allow the capacities of the BESS and the supercapacitor to be properly designed to optimize the characteristics of high energy density of the BESS and high power density of the supercapacitor. Results show that the supercapacitor within the HESS helps to process the high frequency fluctuations, which contributes to the extension of the BESS lifetime. In addition, the supercapacitor helps to address the peaks in wind power fluctuations without the severe penalty of round-trip losses associated with a BESS. The proposed approach has been simulated using real wind data from an existing wind power plant in Iowa.