PV power smoothing in regional grid based on self-adaption wavelet packet decomposition

Distributed PV and their impact on regional grid have become an important research field over the last decade years. Aiming at this problem, a new smoothing method based on self-adaptive wavelet packet decomposition in hybrid energy storage system is proposed. It can adjust the wavelet decomposition level according to the change range of PV output power, so that the low frequency component of PV power can be extract accurately. The mechanism of voltage fluctuation caused by PV power changes is analyzed, and the wavelet packet decomposition level is determined by the voltage fluctuation degree, which eliminates the delay effect of real time wavelet packet decomposition. The simulation results show that the effect of using the self-adaptive wavelet packet decomposition is better than the traditional wavelet packet decomposition.