A wavelet packet-dual fuzzy control method for hybrid energy storage to suppress wind power fluctuations

In order to smooth the wind power output, a wavelet packet-double fuzzy control for hybrid energy storage is proposed to smooth the wind power fluctuation. Firstly, the wavelet packet decomposition is used to decompose the wind power output to obtain the grid-connected power signal and the power signal allocated to the hybrid energy storage. Then, the double fuzzy control algorithm is used to optimise the hybrid energy storage SOC to maintain it within a reasonable range, and to make a secondary correction to the hybrid energy storage power allocation, taking into account the charge states of lithium batteries and super capacitors. The results of the analysis show that the proposed method can smooth out the wind power fluctuations while keeping the energy storage SOC within a reasonable range.