Wavelet Packet-fuzzy Control of Hybrid Energy Storage Systems for PV Power Smoothing

摘要

In this paper, a hybrid energy storage system consisting of energy-type storage system and power-type storage system is used to smooth the PV power generation fluctuations. With a comprehensive analysis of the amplitude-frequency characteristics of PV power signal and the performances characteristics of different energy storage systems, the PV power signal is decomposed and the smoothing objective power and the charging and discharging power of energy storage systems are obtained by wavelet packet decomposition which can get more signals’ detail information. Full consideration is given to the real-time control requirements for computing speed in practical application, and the filter delay effect is compensated through threshold judgment. SOC adaptive control of power-type storage system using fuzzy control method is applied to achieve optimal allocation and improve smoothing result. Numerical results show that the proposed control strategy can smooth the PV power generation fluctuations effectively by taking full advantages of the performance benefits of different types of energy storage systems.

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