Studies On Voltage Level Of A Regional Power Grid Containing Wind Power

With the rapid development of wind power technology and the enlargement of the wind farm scale and the capacity of wind turbines, the influence on the voltage level of grid is becoming more and more important. The wind resource in our country is often at the edge of the main power grid, so the distance of transmission is very long. At the same time, the regional loads is relatively scattered and network structure is relatively weak. In addition, wind farm itself with the reactive characteristics, so that the impacts of grid-connected wind farms on voltage level of the regional grid become more significant.Based on the model of wind speed, wind turbine and the general asynchronous wind generators, the voltage level of grid-connected wind farms is calculated and the mechanism of the voltage stability of regional grid access with the wind farm is analyzed in this paper. Based on power system simulation software PSAT, the voltage fluctuation characteristic of regional grid by changing the output power of the wind farm is analyzed. Then the voltage level of all nodes is compared under the condition that the output of wind farm is same. The minimum voltage of each node is obtained with different wind power into grid by power flow analysis and then the minimum value is contrasted. Based on the dynamic simulation results of voltage fluctuation, a static reactive power compensation device of SVC is added into the bus and its influence on the improvement of voltage level is analyzed.An actual regional power grid is used as an example and the impact of wind power integration on regional power grid and the effect of the installation of SVC is analyzed. The simulation results show that, the voltage level is affected when the output power of wind farm is an initial value. At this time the stability of the grid isn’t affected. However, when the output power increases to 1.2 times of initial value, voltage level falls sharply and will be below limit value. The research of this paper will provide theoretical support and application reference to Sihong grid which will be integrated with wind power.