Sliding mode control for direct power regulation of doubly fed induction generator

This paper presents direct control of active and reactive powers of grid connected doubly fed induction generator (DFIG) driven by wind turbine. Stator winding of DFIG is directly connected to grid whereas rotor winding is connected to inverter. Sliding mode control (SMC) strategy is used to control the instantaneous active and reactive powers of DFIG. For this, the frequency of ac current fed into the rotor winding of the DFIG is continually adjusted to counteract any variations of active and/or reactive power references. Space vector modulation technique (SVM) is used to achieve the constant switching frequency. As a result, transient performance is enhanced when it is compared with vector control (VC) method.