Analytical investigation of the effect of wind farm equipped with SCIG on voltage stability

In this paper, the effect of wind farm equipped with SCIG on the static voltage stability of the power system is investigated analytically. To achieve this objective, the active and reactive output power of wind farm has been obtained at wind speed and generator terminal voltage. By using an appropriate model for SCIG and by linking the wind farm to a simple two-bus power system, the bus load voltage has been calculated. By calculating deflection point at different wind speeds, the maximum loading curve of the system at wind speed is obtained. This curve shows the stable and unstable regions of the system at different wind speeds. In order to obtain an appropriate criterion for the effect of wind farm on the static voltage stability, a new index has been introduced and by using it the effect of wind farm on static voltage stability is investigated.