A novel SVPWM technique for capacitor voltage balancing in modular multilevel converters(MMCs)

Abstract

This paper proposes a novel space vector pulse width modulation (SVPWM) technique to address the capacitor voltage balancing issue in MMCs. The MMC topology consists of cascade connected identical and individual controllable submodules (SMs) to generate higher level output voltages. The characteristic of DC floating capacitor of SM complicates the modulation technique for MMC. This work presents a study of different carrier based modulation techniques for MMC. In this paper, a novel SVPWM technique and analogue sorting algorithm are implemented to control the SM capacitor voltages. The proposed SVPWM technique and existing carrier based modulation techniques for a five level MMC are implemented in MATLAB/Simulink environment. The simulation results of the proposed modulation technique is presented and compared with the existing carrier based modulation techniques.