In the modular multilevel converter (MMC) based high voltage direct current (HVDC) practical projects, the existing voltage feedforward control (VFC) method presents challenges in addressing the frequency shift of high-frequency resonance (HFR) caused by the changes in the interconnected AC system's operating conditions. In this paper, the mathematical characterization function of the impedance real part is used to reveal the mechanism why the existing VFC cannot simultaneously reshape the multiple HFR risk regions into the positive damping characteristics. Therefore, a frequency divided volta...
