Analysis of PWM techniques on multilevel cascaded H-Bridge three phase inverter

Abstract

In this paper, investigation of different pulse width modulation (PWM) techniques is presented by multilevel cascaded H-Bridge (CHB) three phase inverter. The role of multilevel inverters (MLIs) has become predominant in low-medium to high voltage applications due to inherent attractive features towards power quality improvement. To control MLIs different modulation control schemes are available. The nature of the modulation technique in carrier based PWM depends on the common mode signal adding to the modulating signal. The effect of continuous and discontinuous PWM schemes on different parameters like DC bus utilization, inverter switching losses, inverter conduction losses and harmonic distortion of inverter output are presented in this paper and investigated. Simulation analyses have been carried out on five-level CHB three phase inverter under a symmetric mode of operation in the MATLAB/SIMULINK tool. For validation, hardware results are presented by using microcontroller on five-level CHB inverter.