Direct power control of DFIGs based wind energy generation systems under distorted grid voltage conditions

Harmonic elimination of quasi-sine rotor injected DFIG-based wind power generation systems connected to electric power networks

“…Eq. (18) verifies that the harmonic components of À5x r and þ7x r appear at the frequencies of AE6x r in the ða r b r Þ reference frame. Thus, the control scheme proposed for eliminating the harmonic components of À5x r and þ7x r should be designed and implemented in the ða r b r Þ reference frame.…”

“…A proposed control scheme consisting of a resonant (R) controller was also designed and presented for a DFIG operating under distorted grid voltage conditions in [15]. Some other researches related to the first and second abnormal problems such as the analysis of voltage faults have been reported in [16][17][18][19][20]. The third abnormal problem is nonsinusoidal rotor voltage injection that effectively reduces the performances of a DFIG [3].…”

Sliding mode direct power control of RSC for DFIGs driven by variable speed wind turbines

“…In these strategies, two hysteresis controllers, namely torque and flux controllers are selected to determine the inverter instantaneous switching state [6]. Similar to the DTC, a direct power control (DPC) of DFIG based wind turbine systems has proposed recently [6][7][8][9][10][11][12][13][14][15]. The instantaneous switching state of the rotor side converter is determined based on the stator active and reactive power errors.…”

“…In [9], an active and reactive power proportional-integral controllers and space vector modulation technique (SVM) were combined to replace the conventional hysteresis controllers. For operation under unbalanced and harmonically grid voltage, different DPC algorithms were designed to overcome the bad effects under these conditions and improve the overall performance [10][11][12][13][14][15]. In [10], two resonant controllers were designed to regulate the active and reactive power without sequential decomposition involved.…”

“…In [11], the electromagnetic torque oscillations at double supply frequency under unbalanced stator supply were eliminated. In [15], an improved DPC strategy of a wind turbine driven DFIGs connected to distorted grid voltage conditions was presented.…”