The voltage impact of wind farms on weak grids is studied using a generic test system. The size of the wind farm is taken as 20% of the grid short circuit MVA to characterize weak grids. The voltage at the point of interconnection (POI) of the wind farm to the grid is analyzed for different values of grid X/R ratios. It is shown that reduction of real power injection at POI brings the voltage at POI within permissible values for the entire range of X/R ratios. A pumped storage unit or a variable frequency transformer as an asynchronous inter connector is suggested to realize this. Complete modeling and simulation of the proposed network topologies are given. The results are discussed with reference to the Indian power system.
IndexTerms-pump storage, variable frequency transformers, wind energy.