Capacity Configuration and Control Strategy of Hybrid Energy Storage to Smooth Wind Power Fluctuations

Abstract

In order to smooth the output power of wind farms and reduce the influence of wind power fluctuations on power grid, a hybrid energy storage system consisting of energy-based energy storage element electrolyzer and power-based energy storage element supercapacitor is adopted to smooth wind power fluctuations. Firstly, the energy storage output in a large number of time slots is analyzed by probability statistics, and the smoothing effect of wind power fluctuation is evaluated by the probability change of the grid-connected power fluctuation within the limit of wind power fluctuation, and the power at a given confidence level is taken as the rated power of the hybrid energy storage. On this basis, the hybrid energy storage power is decomposed by the adaptive sliding window algorithm considering the economy, and the rated capacity of the supercapacitor and the rated power of the electrolyzer are determined, so as to realize the capacity allocation which takes into account the economy and fluctuation stability effect. Secondly, based on the charging state of the supercapacitor, the rated power of the electrolytic cell and the overall power command of the energy storage system, the operation control strategy of the hybrid energy storage system is formulated. Finally, the simulations results show that this method can effectively reduce the fluctuation of wind power while realizing the power distribution and ensuring the normal operation of each energy storage module.