A control strategy for hybrid energy storage based on double-layer fuzzy controller integrated with second-ahead control thought

Abstract

With the continuous increase in the penetration of renewable energy resources, such as wind power, into power grids, fluctuations in power output introduce significant challenges to the power grid's safe and reliable operation. The hybridization of energy storage technologies effectively stabilizes fluctuations from wind power. This paper proposes a hybrid energy storage control strategy based on an adaptive wavelet decomposition and fuzzy control theory. Firstly, to meet the fluctuation requirements for the power output from wind farms, a wavelet packet decomposition approach is used to determine the grid-connected wind power and power allocation for different energy storage techniques by considering the power output characteristics and lifecycles. Secondly, the use of prediction results from the energy storage power output combined with a two-layer fuzzy controller enables advanced control of the energy storage system and optimal operation of the power output for different types of energy storage systems. The results show that the proposed strategy can effectively be applied to suppress the second-level wind power fluctuations and allocate the output of the hybrid energy storage system. Furthermore, this approach eliminates possible limit violation phenomena while operating the energy storage device to achieve optimal coordination for different energy storage systems considering the lifecycles of the energy storage device.