Improvement generating powers quality of a doubly-fed induction generator with a second-order LC filter in the rotor circuit

In this paper, a vector control strategy for a doubly-fed induction generator (DFIG) driven by a wind turbine and connected to grid utility is presented. Although the rotor inverter is controlled with an optimized space vector modulation algorithm (SVM), the rotor currents are not perfectly sinusoidal which causes undesirable fluctuations of generating active and reactive stator powers. In order to more improve the rotor current waveform, a second-order output LC filter is inserted between the inverter and the rotor circuit. Simulation studies of the proposed power generation system were carried out. The obtained results show that the control performances of the DFIG are clearly improved with the proposed solution.