Multilevel selective harmonic elimination PWM technique in the nine level voltage inverter

This paper proposes to compare the selective harmonic elimination pulse width modulation strategy (SHEPWM), with the sine-triangular PWM to eight unipolar carriers. The two developed algorithms are applied to the nine level inverter with Neutral Point Clamped (NPC) structure. The objective is to eliminate the 5^th, 7^th and 11^th harmonics. This inverter is associated to an induction machine (IM). The algorithm performances are analyzed on the basis of (Total Harmonic Distortion THD, amplitude of the not eliminated harmonics, current wave form... etc) obtained by the two PWM techniques.