The Control Stratedy Study Of Variable-speed Constant-frequency Wind Turbines Participation In Primary Frequency Regulation

Wind power, as a kind of green energy, is increasingly being attached importance to by the countries of all over the world. In terms of wind power generation, the variable-speed constant-frequency(VSCF) wind power generation technology can improve the energy acquisition and conversion efficiency, and is very suitable for wind turbine generators operating mode, which is the main direction of wind power generation technology in the international world. The conventional variable speed wind generation control system makes the mechanical power and electromagnetic power decoupled, which leads to the wind turbine rotor can not make rapid response automatically with the power system frequency changes, so the conventional variable speed wind turbines have almost no supporting role on power system frequency control. With the rate of the variable speed wind turbines connected to the grid increasing, it will bring adverse influence on frequency control of the power system. Therefore, it is necessary to study the frequency control strategy of the variable speed wind turbines, use variable speed wind turbines to improve the frequency control ability of the power system.This paper introduces the basic theory of primary frequency regulation firstly, analyzes the relative factors to the influence of the primary frequency regulation, and then studies and analyzes the theory and the model of variable speed wind turbines participation in primary frequency regulation in the power system, sums up and analyzes the proposed method inertia control and the proportional control in present study, which variable speed wind turbines participation in frequency control in the power system, and adopting VSCF doubly fed induction generator wind turbines, the paper establishes a test power system model to make the simulation by Matlab/Simulink, analyzes and compares the advantages and the disadvantages of the two control methods, and studies the condition of the variable speed wind turbines suddenly withdrew from participation in primary frequency regulation of the power system, which is not studied in the existing control methods, aim at variable speed wind turbines suddenly withdrew from participation in the frequency control of the power system will have an adverse impact, and considering how to make full use of variable speed wind turbines frequency control capacity synchronously, the paper proposes a fuzzy control method to comprehensive utilization the advantages of the first two control methods as has been noted, and then make an adjustment of the output active power of the fuzzy control loop, to make the influence ignored when the variable speed wind turbines suddenly withdraw from participation in power system frequency control. Finally, the simulation results demonstrate the feasibility and effectiveness of the proposed control method.