A smoothing method for wind power fluctuation using hybrid energy storage

Battery energy storage is used for dispatching the fluctuations of wind power, but it has a slow response and limited life cycle. Therefore, capacitor energy storage is interconnected with battery energy storage to make a hybrid energy storage system for absorbing the high frequency part of the wind power output. The wavelet decomposition method is applied to decompose the wind power into high and low frequency parts. The capacitor absorbs the high frequency part, and two batteries absorb the low frequency part. In the low frequency region, the power allocation is conducted to batteries that have different capacities, but the same lifecycle characteristics. The simulation is examined with MATLAB, and the result shows that the proposed method has good smoothing performance and can prolong the battery life.