| The traditional fossil energy exhausting and the deterioration of the environment, the rapid rise of the new energy revolution, plays an important role in the transformation of energy production and operation mode. In the case of large scale wind power integration, the randomness of wind farm power brings adverse effects to the frequency control of the power grid, and the application of power storage technology is an effective way to solve the above problems. Therefore, this thesis is aimed at the large-scale wind power grid connected conditions, for the wind power, thermal power and energy storage of the regional power grid, the secondary frequency control algorithm.In this paper, based on the basic principle of the one or secondary frequency control of the power system, the equivalent regional power network model is established by simplifying the participation frequency control of the thermal power unit. On the basis of this model, a frequency regulation model is obtained. At the same time, an in-depth analysis of the characteristics of the primary frequency regulation in the traditional regional power grid is carried out. At the same time, analysis of interconnected grid secondary frequency regulation control mode and equivalent mathematical model, a clear, secondary frequency control process with response on the order of difference and frequency regulation capacity difference, pointed out the defects existing in the two region model, and the improved model of secondary frequency decoupling control, and in the secondary frequency control link considered the influence of power constraint (GRC), communication delay and frequency bias coefficient is simulated and analyzed, the reasonable regional power grid frequency regulation model is constructed.For large scale wind power generator of wind turbine power frequency control mode, the control unit set a reserve capacity of frequency regulation of the rotor speed, making wind turbines can participate in the primary frequency regulation, and the method is verified by the simulation. Based on the analysis of four components of wind speed, the characteristics of wind power with random fluctuation are analyzed. In the frequency domain of actual wind farm power data analysis, combining the transfer function model of the two area interconnected system, the fluctuation of wind power influence on grid frequency adjustment, clear the fluctuations of wind power to traditional grid a, secondary frequency regulation effect of different, for the next step develop secondary frequency control strategy to provide a theoretical basis for analysis.According to the power frequency characteristics of the energy storage, a mathematical model of the two primary frequency regulation of the power storage auxiliary power system is proposed. And compared with the thermal power unit to study the frequency of the frequency regulation performance, fully utilize the advantages of these two frequency regulation power supply, based on low pass filtering algorithm to participate in power grid frequency regulation. The energy storage power output of the SOC range is adjusted by considering the SOC constraints of energy storage. The filtering algorithm is simulated and verified by the proportion of the energy storage in the system, which can provide reference for the study of the application of power grid frequency control strategy for large scale storage.Finally, according to the adverse effects of wind power on the frequency regulation, the AGC controller of fuzzy PI is proposed to improve the traditional PI controller. The superiority of the control method is verified by the simulation of interconnected two regional power grid with wind power disturbance. The algorithm is compared with the two CPS standard. |
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