Control method of cell energy storage system inhibiting renewable energy output power fluctuation

Abstract

The invention provides a control method of a cell energy storage system inhibiting renewable energy output power fluctuation. The control method is characterized in that: based on a low pass filtering principle, through a first order Butterworth filter, a renewable energy output power value is subjected to filtering, a renewable energy output power object value is obtained, by utilizing charge and discharge control of the cell energy storage system, a difference between the renewable energy output power object value and a renewable energy output power measured value is compensated, and a purpose of inhibiting the renewable energy output power fluctuation is achieved. According to the invention, based on a basic filtering principle, by utilizing a good renewable energy output power inhibition effect and adding of an SOC (state of charge) feedback link, over charge and over discharge of a cell are avoided, innovation is carried out, when adding the SOC feedback link, through adjusting a size of a filtering time constant, an output power of the energy storage system is changed indirectly, thus when inhibiting the inhibiting the renewable energy output power fluctuation, the over charge and over discharge of the cell are effectively avoided, stable operation of the cell energy storage system is maintained, and a service life of the cell is prolonged.

Description

technical field [0001] The invention is a control method of a battery energy storage system that suppresses output power fluctuations of renewable energy sources, in particular an energy storage control method based on the state of charge (SOC) and variable filter time constant of the battery energy storage system, belonging to Distributed power generation energy supply technology field. Background technique [0002] Renewable energy generation technologies, such as photovoltaic power generation and wind power generation, have received more and more attention due to their advantages of non-pollution, renewable, and wide distribution. However, renewable energy power generation has the characteristics of large volatility and strong randomness. Therefore, configuring an energy storage system with a certain capacity on site can effectively suppress the fluctuation of the output power of renewable energy generation and improve the ability of the grid to accept renewable energy g...

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Problems solved by technology

[0006] In the first control strategy, the energy storage system can suppress the fluctuation of renewable energy very well, but the time constant of the filter is a single constant value, and it is easy to cause overcharging and over-discharging of the battery energy storage system when the capacity of the energy storage system is constant. , so that the battery is out of operation, resulting in large fluctuations in the output power of renewable energy; in the second control strategy, the SOC feedback link is introduced to effectively avoid overcharging of the battery while suppressing the fluctuation of output power of renewable energy. Over-discharge prolongs the service life of the battery, but the correction amount obtained by the SOC feedback link directly corrects the output power value of the energy storage system, which affects the smoothing effect of the output power of renewable energy

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