The need for the reduction of emissions especially from electricity generating facilities has led to an increased interest in electricity generation from renewable sources. Wind generation seems to be a favourable renewable generation considering, the growth rate of wind generation. But increase in wind generation is influencing the overall power system operation and planning in terms of voltage control, stability issues, system security and power quality. Also the local power flow pattern and the system's dynamic characteristics change with a large percentage of wind generation connected to the grid.