Multicarrier PWM Control In Modular Multilevel Converter

This paper presents the design and simulation of a single-phase Modular Multilevel Converter (MMC) using MATLAB/Simulink to generate 3-level, 5-level, and 7-level voltages. MATLAB/Simulink was chosen for its capability to accurately simulate complex power electronic systems, providing detailed insights into switching behaviours, harmonic analysis, and power quality metrics like Total Harmonic Distortion (THD). The MMC was simulated at different voltage levels to evaluate the proposed voltage balancing and Multicarrier PWM modulation technique, as increasing voltage levels reduce harmonics and improve power quality. The study focused on Medium Voltage Direct Current (MVDC) and Low Voltage Direct Current (LVDC) applications, despite MMCs typically being used in High Voltage Direct Current (HVDC) systems. The results show a significant reduction in THD as voltage levels increase, with a 2.46% THD for the 3-level converter, 1.19% for the 5-level, and 0.93% for the 7-level converter. Additionally, the dynamic load simulation with a 3-phase induction motor demonstrated superior motor speed and torque performance when compared to a traditional Voltage Source Converter (VSC). These results confirm the efficacy of the proposed approach in enhancing power quality and system stability, with further research recommended to explore optimization of control strategies.