Figure 1 . Test System
2.1 Type 1 WECS
Type 1 WECS is based on the squirrel cage induction generator (SCIG). In this study, each SCIG is rated at 2.3MW and in order to achieve an approximately 9MW capacity windfarm, 4 WECSs are considered operational. Fig. 2 shows the general schematic of Type 1 WECS. A simple 4 staged resistive starter [20] has been used to limit the inrush currents associated during their synchronization to the system. Parameters of the SCIG are obtained in [21].