Reduction in Total Harmonic Distortion of Cascaded H-Bridge Multilevel Inverter with Using Phase Method

Multi-level inverter have gained the popularity over traditional inverters due to low total harmonic distortion. Multilevel inverter is used for high power as well as low power applications. This paper analyzes the total Harmonic distortion of 3, 5, 7 and 9 levels by using Equal phase method. Cascaded H-Bridge configuration is used for analysis. The total harmonic distortion analysis of three, five, seven and nine level are studied and then compared their outputs through fast Fourier transform. Cascaded H-Bridge Multi-level inverter is simulated by using MATLAB/Simulink and results are obtained. Simulation results indicates that total Harmonics Distortion reduces with increase of voltage levels. Total harmonic distortion for 3 level is 41.42%, for 5 level is 39.46%, for 7 level is 26.78% and for 9 level is 22.56%.