Double-layer control method for large-scale energy storage participating in frequency modulation at power distribution network side

Abstract

The invention discloses a double-layer control method for large-scale energy storage participating in frequency modulation at a power distribution network side, and belongs to the technical field of power systems. The method is characterized in that the switching time of two modes of ACE signal distribution and ARR signal distribution when the large-scale BESS participates in frequency modulationis determined; meanwhile, the technical characteristics of different BESSs are comprehensively considered, upper-layer and lower-layer double-layer control is adopted, wherein the upper-layer control(power economic distribution) aims at minimizing the frequency modulation cost of the frequency modulation power supply, and optimal distribution is carried out on the frequency modulation output of the unit and the BESS within the allowable range, and the economic optimal distribution result of the frequency modulation output is taken as the output reference value of each frequency modulation power supply; and the lower-layer control (frequency dynamic control) performs distributed control on the unit and the BESS by utilizing model prediction control according to the frequency deviation of the system and the frequency modulation power supply output reference value provided by the power optimization distribution layer, so that the dynamic optimization control of the frequency modulation power supply is realized, and the frequency deviation of the system is reduced.

Description

technical field [0001] The invention relates to the technical field of electric power systems, in particular to a two-layer control method for large-scale energy storage on the distribution network side to participate in frequency regulation. Background technique [0002] With the large-scale integration of renewable energy such as wind power and photovoltaics, its intermittent and uncertain output characteristics will bring pressure to the frequency regulation of the power grid. As the main force of frequency regulation, traditional thermal power units face problems such as limited frequency regulation capacity, insufficient regulation accuracy, and increased unit wear and tear, threatening the frequency security of the power grid and becoming one of the factors restricting the acceptance of renewable energy by the power grid. In recent years, battery energy storage (Battery Energy Storage System, BESS) has gradually been favored by automatic generation control (AGC) of the...

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Problems solved by technology

[0003] In order to solve the problem of unreasonable signal distribution under the two modes of ARR and ACE in the existing frequency modulation control method, the present invention proposes a two-layer control method in which large-scale energy storage on the distribution network side participates in frequency modulation, and determines the large-scale BESS When participating in frequency modulation, the switching timing of the two modes of ACE signal distribution and ARR signal distribution is fully considered. At the same time, the technical characteristics of different BESSs are fully considered. In the upper layer, based on the power supply cost function, the optimal power distribution under multiple constraints is realized. In the lower layer, based on model predictive control ( Model Predictive Control, MPC) realizes frequency distributed optimal control, making full use of the advantages of the two signal distribution modes

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