IMPLEMENTATION OF MULTILEVEL INVERTER FOR POWER CONDITIONING

This paper presents a comparative analysis of Total Harmonic Distortion (THD) and output harmonics in cascaded H-bridge multilevel inverters using MATLAB/SIMULINK. Conventional inverters are limited by high harmonic con-tent, which affects power quality. To address this, cascaded H-bridge topologies with different levels—3, 5, 7 and 9 - are studied. These configurations are select-ed due to their ability to reduce THD and enhance output waveform quality. A significant reduction in harmonics is observed as the number of levels increases. Level-shifted Pulse Width Modulation (PWM) strategies are employed for gating the switches. Simulation results validate that higher-level inverters provide near-sinusoidal output with reduced distortion. The performance of single-phase de-signs is also examined in the study. Furthermore, the influence of passive filters on output quality is analyzed. The inverter design is tested under equal and unequal DC voltage inputs. The results highlight the trade-offs between complexity and harmonic suppression. The use of fewer switching devices in optimized de-signs ensures reduced cost and better efficiency. Industrial converters, electric drives, and renewable energy systems are a few examples of applications.