High-Frequency Resonance Suppression Based on Active and Passive Joint Damping for MMC-HVDC

High-frequency resonance (HFR) incidents have occurred in several Modular Multilevel Converter-based high voltage direct current (MMC-HVDC) projects recently. The interaction between the impedance characteristic of MMC and the grid is assumed as the main factor of HFR, caused by a large time delay. Complex operating conditions arouse the issue of resonance frequency shifts, making the conventional suppression method ineffective. Thus, an active and passive joint damping suppression method is proposed based on the cross-coupled filter (CCF) and improved C-type filter damper. This method can remove the risk of HFR and provide a sufficient phase margin, enhancing the stability and robustness of the MMC-HVDC system. The effectiveness of the proposed method is verified through simulations.