Analysis of Capacitor Voltage Balancing Method of Modular Multilevel Converter (MMC) for the Application of SPWM, NLC & SHE-PWM Modulation Techniques

Abstract

This paper presents the analysis of the capacitor voltage balancing of Modular multilevel converter (MMC) for the application of various modulation techniques. The modulation schemes namely SPWM, SHEPWM and the NLC technique are used here for generation of pulses for the MMC switches. The generalized capacitor balancing method based on sorting of submodule (SM) capacitor voltages is employed for balancing of SM capacitor voltages. The simulation was performed in the MATLAB/Simulink. The three-phase seven-level MMC converter is simulated to investigate its performance as well as to analyze the capacitor balancing approach. The analysis and performance of MMC for specific load, and for the mentioned modulation techniques is presented as well as validated using the simulated results.