Study On Voltage Problems Of Power System Integrated With Large Scale Wind Farms

The area of Dabancheng has abundant wind energy in XinJiang province. It had constructed three large-scale wind farms at present. The thesis bring forward a assume about building a new wind farm (call as Dabancheng new wind farm) for further development of the wind power in Dabanchegn district. Owing to the capacity of the existing three wind farms are large comparatively, besides the output of wind farms has the characteristic of intermittence and fluctuation, the integration of the Dabancheng new wind power will undoubted reduce the system's voltage stability consequently. Therefore, the research on the interplay between the Dabancheng new wind farm and the power network becomes a important issue which need to be solved urgently so as to farther developing the Dabancheng wind power. In this thesis, according to the practical condition of Dabancheng power network, the operation character of Dabancheng power network when new wind farm on-line is analyzed, mainly including the the following contents:(1)The present status and existent problem of Dabancheng wind farm are analyzed. The mathematical model of power system including wind farms is established, which mainly includes the mathematical model of wind speed, the model of the blade and electrical machine. Besides, it briefly depicts diversified functions of the power system simulation software PSS/E.(2)Taking common asynchronous generator as a studied object, analyze some interior parameter of wind generator that impact on voltage stability. The simulation result indicates that augmenting rotor resistance and enhancing wheel inertia both can stabilize generator's voltage.(3)The thesis takes the Dabancheng new wind farm as a object of research. The experiment analyzed amply about wind generator capacity,type and the length of the electricity transmission line from the view of keeping the stability of the regional voltage. The research reveal that generator capacity,generator type,gust intensity,load fluctuation and transmit electricity line length, etc are the important factors about impacting on wind farm voltage stability. The author brings forward three kind of reactive compensation scheme which aims at the Dabancheng new wind farm voltage fluctuation in the sixth chapter. The experiment shows that STATCOM has best compensation effect.(4)In the last chapter, put forward"super-high voltage power network +intelligence power network"thought to solving the obstacle of wind farm on grid in Xinjiang. Finally, the future research task about wind power integrating on the power network is proposed.This thesis is supported by Xinjiang education administration patronage(XJEDU2007I05).