Two-stage Optimal Sizing of Hybrid Energy Storage System for Wind Energy Integration in Microgrid

Abstract

The inherent volatility and intermittency nature of wind power complicates the challenge of wind energy integration, especially in microgrid. For the dual-purpose of wind power fluctuation mitigation and peak shaving, a hybrid energy storage system (HESS) consisting of power-type ESS and energy-type ESS is introduced and a novel two-stage optimal sizing method of HESS for wind power integration in microgrid is proposed. Firstly, based on spectrum analysis, wind power is decomposed into different frequency components to control different ESS. Then, the capacity of power-type ESS is estimated by the statistical characteristics of the decomposed high-frequency component fitted by t-location scale (TLS) distribution. Finally, the capacity of energy-type ESS is optimized to achieve the best system economy. The detailed charging/discharging characteristics of ESS are considered in the optimization model. The impact of the power-type ESS on the lifetime of energy-type ESS is also discussed. The feasibility of the proposed model and the effectiveness of size configuration method are verified by simulation results based on an actual 5min interval wind power data.