Thirty Seven Level Inverter with Low THD and Less Number Of Power Switches

Abstract: In this paper, simulation of single-phase 5-level, 17-level, 37-level and three-phase37-level asymmetric inverters with reduced number of power switches and total harmonic distortion is carried out. The topology of single phase 17-level and single phase 37-level inverters are obtained by cascading connection of basic unit of single phase 5- level inverter topology twice and thrice respectively. Using single phase 37-level asymmetric inverters, threephase 37- level inverter is developed. This is achieved by connecting three single-phase inverter bridges with 120° phase difference between each inverter bridges in cascade. This phase difference is achieved by generating pulses with a delay of 120° with respect to each bridge. Pulse generation technique used is based on, comparison between amplitude of sine wave and range of numbers. Simulation of single-phase 5-level, 17-level, 37-level, and three-phase 37-level inverters is carried out using the above mentioned pulse generation technique. The simulation is carried out by using MATLAB\Simulink R2015a software. Results include output voltage, and current waveforms and THD for single phase 37-level inverter. Also shown phase voltage, line voltage, phase and line current waveforms and THD for three- phase 37-level inverter.

Keywords: Asymmetric, Multilevel Inverter (MLI), Total Harmonic Distortion(THD), Pulse Generation Technique.