Control Strategy Of Wind Farm For Power System Auxiliary Frequency Regulation

With the extensive use of traditional energy sources, it has brought serious environmental problems. The development of new energy sources and environmental protection is an urgent need in the world. As the most mature technology of today, the development and utilization of the largest new energy utilization, wind power has gradually become an important power supply mode for each main wind power country. The scale of wind power is incorporated into the power grid, which will replace the conventional power generation units in the power system, which will result in the weakening of the power system frequency control. Based on the analysis of the effects of wind farm integration on power system frequency, it has important theoretical significance and practical value to study the effect of wind farm integration on power system frequency.Firstly, this dissertation analyzed and studied the principle of operation of the wind farm common Wind Turbine classification and variable speed constant frequency wind turbine, on this basis for doubly fed variable speed constant frequency wind turbine for mathematical modeling. Wind speed model, wind turbine model, shaft model, generator model and so on, which are established by the double fed wind power generation system. Analysis of the principle of the active power of DFIG control based on stator flux oriented vector control method, a vector control model of active power generator. This dissertation introduces the basic idea of the double fed wind turbine participating in the system frequency modulation.Secondly, the frequency of power grid and the reason of frequency fluctuation are introduced, and the effect of large scale wind power integration on the system frequency stability is analyzed. Through the simulation analysis, the influence of wind field on the frequency stability of the system is increasing with the increasing of the permeability. In order to improve the frequency stability of large scale wind power integration in of wind turbines in the main method of frequency modulation system based on, combined with the advantages and disadvantages of various methods, proposes to use the load reduction reserve and virtual inertia combined with composite frequency modulation method and in system simulation verification its effectiveness.Finally, based on the wind turbine system frequency regulation research, research on the distribution of active power of wind farm, wind farm is proposed considering the load shedding frequency regulation unit classification method need. On the basis of the priority method determine the active power allocation scheme, increase the frequency controller in wind farm, is incorporated into the power grid wind farm to provide ability to participate in the system frequency adjustment, alleviate the conventional generator frequency to adjust the pressure in a certain extent, accelerate the recovery of frequency speed and time. The effectiveness of the proposed control strategy is verified by the simulation system.