Research On Technology Problems Of Large Grid-Connected Wind Farm

Large wind farms have been fully developed since 1980', because of their scaled benefits except for the particular advantages in energy saving and environment protection. However, wind power is restricted by the nature resource of wind, and the CVCF wind turbine set with induction generator is widely used, so the stability and supply quality of the system will be reduced. And with the enlargement of the wind farm scale, the negative effects of wind power become more and more serious, and turn to be great obstacle of the further utilization of the wind resource. Therefore research on characteristics of grid-connected wind farm becomes an important issue to the design and operation of the power system.With an eye to the interactions of wind power and the grid, especially to the stability and supply quality of the power system, this paper do some basic research work on the technical problems of grid-connected wind farms.In the first part of the paper, the mathematics models of wind turbine generator set and the wind speed are set up, and then the simulation program is developed using MATLAB language and its simulation tool. The developed program can simulate the responds of the wind farm under disturbs of wind speed, grid faults and load changes. Secondly the indices that weight the scale of wind farms are expatiated, which are limit of wind power penetration and short circuit ratio of wind farm. The main factors and the analysis methods about the maximum power injection of wind farm are also discussed. And then in a real power system, the maximum power injection of the wind farm is studied. In the meanwhile, a simple method to solve the problem is put up with.Finally the measures that can improve the operation performance of wind power system are studied, which include the Static Var Compensation device (SVC) and Superconducting Magnetic Energy Storage unit (SMES). And then the use of HVDC Light in the wind farm is also discussed.