Since DFIG is the prevailing wind generation type nowadays, variable-speed wind generator is modeled as DFIG in this study. WT3 wind model has been developed in PSS®E to simulate the performance of a DFIG-based wind generator with basic active power control . There are four basic components within DFIG model (usually referred to as WT3 model, whose structure shown in Fig. 8.1), namely:
• WT3G: generator/converter model
• WT3E: electrical control model
• WT3T: mechanical control (wind turbine) model
• WT3P: pitch control model.
Typical parameters of a GE 1.5 MW wind generator from PSS®E are employed in the simulation. And in order to add fast active power control functions to current DFIG model in PSS®E, a user-defined electrical control model is developed by the author (control structure shown by Fig. 8.2). Note that since pitch control and reactive power control are not considered in this study, WT3P part is ignored and constant reactive power control mode is selected in all the simulations.