Control of a Single Phase Modular Multilevel Converter based on a New Modulation Technique

Abstract

Modular Multilevel Converter (MMC) topologies have a bright future for high-power applications. In order to operate them, the first objective is to control the current at MMC terminals. Therefore, the arm currents must be controlled. The second objective is to control the capacitor voltages. Therefore, the internal circulating current must be controlled too. Additionally, the third objective is to reduce the switching losses. As of late, there has been an extensive effort towards addressing the technical constraints associated with the control and operation of MMC. The control of single phase MMC is however not widely developed. This paper proposes a complete scheme for controlling the MMC load current and capacitor voltages. The proposed control scheme presents a new modulation technique called the Integral Modulation technique. Finally, the effectiveness of the control scheme with its new modulation technique is tested on a single phase MMC using MATLAB/Simulink.