Application Case: Mitigation of HFR in MMC-HVDC System

This chapter demonstrates the mitigation of high-frequency resonance/oscillation (HFR/HFO) events in an actual modular multilevel converter (MMC)-based high-voltage DC (HVDC) system using adaptive notch filters. The EMT software simulations verify that the adaptive notch filter with adaptive online measurement of oscillation frequency can suppress the HFO effectively. The results are verified through EMT software simulations and analytically derived impedance-based analysis.