An Efficient Diode Clamped Multilevel Inverter for Reducing THD with Selective Harmonic Elimination Pulse Width Modulation (SHEPWM)

Selective harmonic elimination pulse width modulation (SHEPWM) technique is applied to diode clamped multi-level inverter (DCMLI) to reduce total harmonic distortion (THD) and improve the quality of output power. The modulation technique is implemented centered on dog leg optimization method to find the optimized values for switching angles (θ) of switches (IGBTs) employed. Twelve level diode clamped inverter is implemented in Matlab and the results are compared with non-optimized switching angles also 5-level DCMLI using SHEPWM is compared with other modulation techniques.