In response to the issues of double frequency and even-order harmonics in the inter-phase circulating cur-rents of the modular multilevel converter(MMC),this paper proposes a novel circulating current suppression strategy based on the virtual impedance VPI resonance controller.This strategy effectively suppresses the double frequency and even-order high-frequency harmonics in the circulating currents by combining virtual impedance with the VPI resonance controller.Firstly,a mathematical model of the MMC is established to analyze the internal circulating cur-rents.Subsequently,the double frequency components of the circulating currents are accurately extracted using a notch filter and suppressed using the VPI resonance controller,then a virtual impedance is designed to suppress the high-frequency harmonic components in the circulating currents.A three-phase MMC simulation model is constructed using Matlab/Simulink and validated.
维普
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