Modulation Optimization Effect on Total Harmonic Distortion of Single Phase H-Bridge Inverter Based Selective Harmonics Elimination Technique

Abstract

Specific odd harmonics can be mitigated by operating the simeconductor switches in H-bridge inverters at optimized switching angles of the PWM signals. These switching angles can be achieved by calculating a set of nonlinear equations using Selective Harmonic Elimination Pulse Width Modulation (SHE PWM) technique. Modulation index (m) is a significant parameter used to control the amplitude of the fundamental output voltage of DC-AC inverter. By changing the value of modulation index the Total Harmonics Distortion (THD) also will change. In this paper, the influence of varying modulation index on the THD, and the performance of H-bridge inverter using SHE PWM scheme is evaluated. To investigate the effect different conditions of modulation index and different number of nonlinear equations to calculate the switching angles to achieve a minimum THD, single phase H-bridge inverter is simulated in Matlab-Simulink.