Comparison of different third harmonic injected PWM strategies for 5-level diode clamped inverter

In this paper, three modulation strategies based on a multicarrier level shifted PWM and third harmonic injected reference have been implemented; the aim of this paper is to compare these three strategies to know their effect on the output voltage quality of the inverter. The three modulation strategies are: Third Harmonic Injected reference In Phase Disposition (THI-IPD), Third Harmonic Injected reference Alternative Phase Opposition Disposition (THI-APOD) and Third Harmonic Injected reference Phase Opposition Disposition (THI-POD). These three strategies are applied to the single phase 2-legs 5-levels diode clamped inverter under different operation conditions. The study has been implemented via simulation using MATLAB/Simulink and setup experiments in the lab and the comparison between the simulation and experimental results are provided.