Optimal Economic Allocation Strategy for Hybrid Energy Storage System under the Requirement of Wind Power Fluctuation

The addition of hybrid energy storage system (HESS) can effectively suppress the random fluctuation of wind power. However, how to determine the capacity of HESS has always been a hot issue according to different types of energy storage. Firstly, the frequency domain characteristics of wind power are analyzed according to the national standards for wind power volatility. On this basis, the optimal cutoff frequency and operation cycle of the battery are calculated to obtain the minimum absorbed power of the energy storage system. Then, the objective function of average daily minimum cost of HESS is established by considering the impact of energy storage device life on investment cost. Finally, the results of numerical shows that choosing a reasonable battery operation cycle and cutoff frequency can effectively prolong the service life and improve the economy of the HESS.