Research on the application of storage battery to restrain the photovoltaic power fluctuation

The negative influence on grid caused by the characteristic of solar energy can be abated by the use of energy storage. Firstly, FFT algorithm is used to analyze the spectrum of photovoltaic power, through which the low frequency characteristic of PV wave and the feasibility of storage battery is verified. Then an effective way of the use of energy storage battery to stabilize the PV power short-term fluctuation is proposed. By the control of energy storage and output, the uncertainty of photovoltaic power is reduced. On he base of this method, the algorithm for computing the total use of time of battery in the life cycle is carried out. Finally, based on the longest using time of the battery for unit cost, the mathematical model is established for the optimal capacity of energy storage battery. Verified by examples, the key factors of the optimal capacity are summarized, such as prices and cycle life of battery, PV prediction accuracy and so on. Then, maximum efficiency in the use of energy storage battery can be got to ensure the regulation of PV output.