The analysis of steady‐state operation characteristic and resonance phenomenon considering all the harmonic components of modular multilevel converter for HVDC

Abstract

Abstract Analysing the steady‐state operation characteristic of the modular multilevel converter (MMC) in time domain poses challenges due to the presence of harmonic components in the arm current and capacitor voltage. While ignoring the influence of the harmonic currents and harmonic voltages would reduce the accuracy of the analysis results for MMC. This paper investigates the circular interaction among the electrical quantities and different order harmonic components in MMC. A new steady‐state model is developed and the general matrix equation is established to accurately describe the explicit analytical expressions for electrical variables in MMC without specific assumptions. Based on the steady‐state operation characteristic analysis, the resonance phenomenon and characteristic are identified for MMC. Finally, the feasibility and accuracy of the proposed method are verified by comparing its analytical results with simulation and experimental results.