Performance analysis of modular multilevel converter based on modified flying-capacitor multicell converter using SPWM

Modular multilevel converters are used to fulfill the medium/high voltage high power demand. This paper investigates the performance of a modular multilevel converter having modified flying capacitor multicell converter as sub-module. The performance of the MMC has been evaluated on the basis of spectral quality of the output a.c. voltage and the utilization of the input d.c. voltage. The utilization of the input d.c. voltage is judged by the fundamental value of output a.c. voltage. The comprehensive simulations of 7-level, 9-level and 13-level MMC with phase-shifted and level-shifted sinusoidal pulse width modulation (SPWM) has been carried out in MATLAB/Simulink software. The various methods of level shifted SPWM such as in-phase disposition (IPD), phase opposition disposition (POD) and alternative phase opposition disposition (APOD) has been applied.