Comparison of Different Types of Sinusoidal PWM Techniques for Double-Star Chopper Cell with Embedded Energy Sources

Double-star chopper cell topology of modular multilevel converter is attractive for high voltage and high power applications. The converter can be controlled with many techniques such as PDPWM (Phase Disposition Pulse Width Modulation), APODPWM (Alternate Phase Opposition Disposition Pulse Width Modulation) and PSPWM (Phase Shift Pulse Width Modulation). In this converter each submodule consists of an embedded cell. The submodules are connected in series and modulated to produce the desired line voltage. This paper presents a comparison of the converter performance under different sinusoidal PWM techniques for multilevel converters. The parameters considered for the performance comparison are the output line voltage waveform quality, the total harmonic distortion in the line voltage and the circulating current flowing in the arms of the converter.