A Survey of Harmonic Emissions of a Commercially Operated Wind Farm

In this paper, harmonic voltage and current measurements performed at the point of common coupling (PCC) of a commercially operated wind farm comprising 40 variable-speed wind turbines are analyzed, and their most important characteristics are presented. Important issues under consideration are the characteristics of the measured harmonic spectrum, the effect of the application of the grouping calculation method according to IEC 61000-4-7, the interharmonic problems, and the probability distribution of harmonic magnitude. In addition, an investigation of the separation of wind farm and grid contributions of the harmonic distortion at the PCC is included. Finally, the dependence of harmonic emission on wind farm output power is addressed.