Performance evaluation of carrier-based modulation strategies for modular cascaded H-bridge multilevel converters

This paper investigated different carrier based modulation schemes for the proper modulation of 3-phase 9-level cascaded H-bridge modular multilevel converter (MMC). In this article, modulations are performed in terms of modulating or reference signals and carrier signals (triangular or sinusoidal). Performance evaluation is done on the basis of percentage of total harmonic distortion (THD) of the converter output voltages, as well as suppression of lower order harmonics and efficient utilization of dc voltages. Modulation signals generation and application are shown with the harmonic profiles of respective modulated output voltages. All the simulation works are carried out in commercially available software environment MATLAB/Simulink.