A comparison between real-time harmonic elimination procedures for single phase CHB 5-level inverter

In this paper, single phase cascaded H-bridge (CHB) 5-level inverters are considered and a pulse amplitude modulation (PAM) procedure operating at fundamental frequency, ables to remove the third and fifth harmonics and their respective multiple, is proposed. Each H-bridge is fed by equal voltage sources linearly dependent on modulation index. This procedure is compared with another PAM procedure that uses disequal dc voltage sources and with the classical selective harmonic elimination (SHE) technique working at fundamental frequency. The presented procedure eliminates more harmonics, therefore it returns lower Total Harmonic Distortion (THD) in comparison to the other considered strategies. Experimental results are shown, confirming the validity of the proposed procedure.