Harmonic Filtering in DFIG-based Offshore Wind Farm through Resonance Damping

Stimulation of resonance in large-scale DFIG-based Offshore Wind Farm (OWF) may induce large harmonic distortions. To identify and damp resonance effectively, Resonance Mode Analysis (RMA) is conducted to a DFIG-based OWF. Participation Factors (PF) are used to identify the most contributing system buses to certain resonances. On this basis, a Medium Voltage (MV) LC-filtered active damper is proposed and applied on buses with the largest PFs. Active dampers are controlled to adaptively damp resonances at up to several kHz through emulating virtual resistances at detected resonance frequencies. Numerical simulations in MATLAB/Simulink demonstrate the RMA results and effectiveness of the proposed damping strategy.