ABSTRACT

Phase Shifted Pulse Width Modulation (PS-PWM) is a well-known switching technique for Quasi Z Source (qZS) based Cascaded Multilevel Inverters (qZS-CMI). PS-PWM ensures equal power distribution (among operating modules) and equal switching’s in all the semiconductors of the every given module, however this technique suffers from higher number of switching’s. On the other hand, Level Shifted Pulse Width Modulation (LSPWM) ensures optimal switching but suffers from uneven distribution of power among the all the operating modules and also the all the semiconductors of the same module, of qZSI. This project proposes a novel switching technique which combines the advantages of both PS-PWM and LS-PWM such as equal power distribution (among operating modules) and optimal switching sequence along with equal switch utilization. The proposed method is Phase Opposed Disposed, Phase Shifted Pulse Width Modulation (PODPS-PWM). The Project details the switching technique, along with switching loss analysis and compares it with the PS-PWM technique to show its superiority. Simulation results are carried out to study the CMLI performance.