GSC control strategy for harmonic voltage elimination of grid-connected DFIG wind turbine

This article describes a new control strategy to compensate the most significant voltage harmonics generated by nonlinear loads in the point of common coupling (PCC) using a grid-connected Double-Feed Induction generator (DFIG). The voltage distortion affects the performance of others loads connected to the PCC and generates power oscillations in the DFIG. The proposed control strategy uses the grid side converter (GSC) to compensate these voltage distortions, improving the voltage quality at the PCC and reducing the power and torque oscillations in the DFIG. The voltage references are extracted using the Fast Fourier Transform (FFT). This algorithm reduces the number of filters required in the compensation control and bring the possilibity to filter selectively the most significant voltage harmonics. The GSC current-loop uses two Integral Proportional Resonant Controllers (PIR), part is tuned at 6ω_e and the other at 12ω_e to regulate the 5^th, 7^th, 11^th, and 13^th voltage harmonic components respectively in the fundamental reference frame. Resonant controllers are also included to calculate the compensation currents required to regulate the voltage harmonics at the PCC.