Studies On Voltage Stability Of Wind Power Intergrated Grid

In recent years, as mining and burning of fossil fuels, the ecological environment has a sharp deterioration and the energy crisis is underline so that humans began to develop and utilize the clean energy such as solar energy, wind energy. Wind power technology is relatively mature and China is rich in wind energy resources, therefore, wind power is the fastest growing mode of new energy power generation. However, the wind farm integrating can change the original power flow of power system. At the same time, the uncertainty of wind turbine output characteristics is much different from conventional generators, that causes the impact of wind power integrated system cannot be ignored.The thesis focuses on the analysis of the wind power integrated system voltage stability problem, through learning the analysis methods of the wind power integrated system static voltage and analyzing wind power system static voltage instability mechanism; bulid wind speed mathematical model; detailed introduce the operation principle of both CSCF wind turbines represented by induction generator and VSCF wind turbines represented by doubly-ded induction generator; set up two types of the wind turbine mathematical model of wind turbine, simulate test and verify in matlab.Combine with the running characteristic of wind turbine and power flow calculation model, with the analyze for characteristics and structure of wind farm grid system convergence flow equation Jacobi matrix,this thesis has obtained the relevant information about the system voltage stability and determined worst bus and system stability region.Simulating and calculating on 30 nodes in IEEE-system,we can get the conclusion as follow:If wind farms is directly incorporated into the system, the system voltage static stability margin and the bus voltage amplitude will increase. At the same time, with the wind power participation increase, the wind power integrated factor of each node is improved and system weak stability region expanded. If wind farm instead of conventional generators oncorporate into system, because of the wind turbines need to absorb reactive power from the grid side, the node voltage is decreased and the weak voltage stability region compared to the conventional system are expanded and the system voltage static stability margin declines, and the load power margin reduces. Thus, it can be seen that parallel operation of wind power will not change the voltage stability of the worst bus in original power system, it just expand the system weak area, and decline system static voltage stability. The simulation analysis shows that it is advanced that using characteristics of the structure analysis method to analysis contain the wind power system static voltage stability, as the result is comfort to expected result.