A study case on harmonic distortion created by wind turbines

The grid-side converters of variable speed wind turbines inject harmonic currents in the network, which may potentially create voltage distortion problems. In this paper, a case study is presented for a wind farm, intended to be connected to a network with extended HV subsea cable lines. First, the system modelling approach is presented and the harmonic load flow calculation is outlined. Then, the harmonic impedance of the system is calculated for a variety of configurations and operating conditions, and its main characteristics are discussed. Harmonic load flow results are then provided, to indicate potential voltage distortion problems.