Remote Harmonic Mitigation within Offshore Wind Power Plants by Embedded Active Filters in Grid-Side Converters

This paper proposes a control system of active filter, which is embedded in the grid-side converters (GSCs) of wind turbines (WTs), to mitigate the harmonics on remote busbars within offshore wind power plants (OWPPs). Superior to the existing filters with extra devices, the proposed active filter is embedded in the control system of GSC without additional device. Firstly, the embedded active filter (EAF) detects the harmonics and calculates the compensation current based on instantaneous measurements in the time-domain. In addition, both general compensation module for total harmonic distortion (THD) and specific compensation module for selected-order harmonics are combined in EAF. Furthermore, the proposed EAF improves the power quality for remote Point of Common Couplings (PCCs). Finally, an OWPP connected with island distribution grid and external grid is implemented in DIgSILENT/PowerFactory with field measurements to validate the performance of proposed EAF.