Simulation and Design of Modified SPWM and Single-Phase Five-Level Inverter

Abstract

In this paper, a modified single-phase five-level inverter is proposed. This inverter is designed by connecting an auxiliary switch and one extra switch to the existing conventional single-phase three-level inverter. Using MATLAB/SIMULINK five different types of SPWM techniques (PD, POD, APOD, CO, and MCVF) and a new modified SPWM scheme are implemented on this inverter for resistive& inductive loads. The basic advantage of the modified switching scheme is to improve both the fundamental voltage and Total harmonic Distortion (THD) of the output voltage. The proposed inverter is also implemented on a single-phase induction motor for both capacitor-start and capacitor-start-run type to evaluate its performance for varying modulation index.