Design of an efficient controller for double fed induction generator

Stator windings of double fed induction generators (DFIG) used in wind turbines are directly connected to grid while rotor windings are connected to line through a back-to-back converter. In this study a system with an efficient controller has been designed and implemented for controlling DFIG?s active power in several speed and load condition. In the system, two vector controlled PWM converters have been used between DFIG?s rotor windings and grid. The converter used in rotor side controls the active and reactive power of DFIG after parallel connection conditions are fulfilled. For parallel connection condition, generator?s voltage is adjusted by PI controller, frequency and phase angle is determined by phase locked loop (PLL). Active power of the DFIG has been controlled using PI, fuzzy logic and self tuning fuzzy logic controllers (STFLC) after parallel connection and then performance of the controllers has been compared. The converter used in line side achieves stability of DC link voltage with unity input power factor. It also ensures that current harmonics drawing from line are in the limit specified by the standarts. Furthermore a user interface has been prepared using LabVIEW program for remote monitoring and control of the system. Implemented system has been simulated and validated with experimental results. As a result among the controllers used to control DFIG? active power, STFLC more adapts to variable speed and load conditions and tracks the reference power adequately.