A novel control system for harmonic compensation by using Wind Energy Conversion based on DFIG technology

This paper describes a novel control method for a WECS (Wind Energy Conversion System) meant to partially operate as an AF (Active Filter). The control is defined in an equivalent reference frame obtained by applying the Park Transformation to the three-phase quantities. The zero-sequence component is includd in the control system; this feature enables the compensation of zero-sequence harmonics. The effectiveness of the proposed methodology is quantified in terms of current spectra and reduction of the voltage and current THD at the Point of Common Coupling (PCC). The proposed application results in higher power loss in the power converters that connects the generator rotor to the PCC with respect to sinusoidal operation. Nevertheless, it is proved that the WECS derating enables the reduction of the power converters´ power loss. Voltage distortion at the windings terminals and power converters´ terminals is a second consequence of the proposed application, and the peak stator and rotor voltage is an important design parameter in the choice of the solid state devices.