Harmonic Suppression Strategy Based on High-voltage Active Resonance Suppressor for Offshore Wind Farms using AC Transmission Scheme

Aiming at the serious problem of background harmonic amplification in Offshore Wind Farm with Long-distance AC Submarine Cable (OWF-LACSC) integrated system, impedance model of a domestic OWFs-LACSC system is established firstly. In consideration of the positive and negative sequence properties of sub-background harmonics in the power grid, a single channel is designed to mitigate two odd background harmonics with opposing positive and negative sequence characteristics by leveraging the fundamental frequency shift feature of Parker transform. Combining with resistive active power filter technology, a high-voltage active resonance suppressor and its control strategy are proposed, and the parameter feasible domain of the channel under different frequency harmonic suppression targets is established to carry out parameter optimization design. Finally, the electromagnetic transient model of an OWFs-LACSC system is built in PSCAD to verify the feasibility and robustness of the proposed device and control strategy.