Evaluation of modulation techniques for 5-level inverter based on multicarrier level shift PWM

Abstract

Multilevel inverter has become attractive in the power industries and it can be applied in many applications especially in renewable energy systems and improvement of the power quality. On the other hand, the technique used to generate the required switching pulses plays an important role to improve the inverter characteristics. The paper presents an assessment of three different types of control techniques based on multicarrier level shifted PWM (S-IPD, S-POD and S-APOD) applied to a single phase full bridge five level diode clamped inverter. The main parameters considered are the Total Harmonic Distortion (THD) and harmonic spectrum. The reported results are based on the experimental and simulation realization. In addition, the simulation and experimental output voltages and currents waveforms of all mentioned techniques are presented.