Voltage Stability Studies Of Wind Power Integrated With Power Grid

With the continuous development of the society, the consumption of energy is also growing, the traditional energy is gradually exhausted. New energy takes more and more proportion in the power system. As most mature, the most large-scale development, the most commercial prospects power generation in new energy technologies, wind power is gradually welcomed by all countries in the world. However, due to the intermittency, randomness and uncontrollability of the wind power, the effects of grid power connected wind to the safe and stable operation of power system and the voltage stability is more and more serious. So it’s very necessary to study the impact on the Wind Power Grid.However, due to the complex structure of wind power generation systems and diversity of control method, large-scale wind power grid will affect all aspects of the system, mainly reflects the impact of the system’s dynamic and static impact. This paper mainly does the research on the impact of wind power on the system voltage, and has done the following work on the dynamic characteristic of grid connected wind generators and static voltage stability.First, Double Fed Wind Generator has been selected as the research subject after understanding the development situation of wind turbine. Based on the research of the principle of doubly fed wind power generation system, this paper established the combination model of different wind speed, the model of double fed wind power generation field, the model of double fed wind power generation field connecting Power Grid, and the complete dynamic model of Wind Power Grid.Secondly, based on the simulation results of the doubly fed wind power grid dynamic model, this paper analyzed the power system voltage dynamic response characteristic, with the doubly fed wind power generator working in the normal operation state, the wind speed exceeding the rated state and the line grounding fault state, analyze the influence of the DGIG on power system transient voltages under different circumstances. And validate the LVRT capability of DFIG with crowbar working in the three-phase grounding fault state. Finally, this paper compared the analysis method of static voltage stability the static voltage stability in Power Grid with DFIG. Combined with the conventional power flow calculating methods, power flow calculation method with doubly fed wind power generation system was determined. According to the relationship between wind speed and power in the model of double fed wind power generation field, the power flow of the example with wind power EPRI-36nodes and Voltage Stability ware calculated. The system voltage stability problem was analyzed and researched through the sensitivity and stability margin analysis method.