Simulation and Analysis of an Improved Quality Multilevel Inverter for Linear Types of Load

Abstract

In recent years, there is a tremendous research going on the quality of output of an inverter. As various sources provide the electric supply in dc form, like Solar PV, Fuel cell etc., there is a requirement of improved power quality inverter to convert this dc power into ac one, which can be fed to various ac loads or even, can be fed to the utility grid. Multilevel Inverter has gained much more popularity in recent years, as these provide the output waveform closer to the sinusoidal one. In this paper, a Multilevel Inverter (MLI) scheme has been presented for analysis. The analysis of MLI has been carried out in Matlab/Simulink software for linear RL load at different power factor, keeping the load impedance as same. It is found that the total harmonics distortion (THD) in output waveform reduces with the variation of load power factor. These harmonic contents are further reduced to a desired value (Within IEEE standard range) by inserting a passive LC filter across the linear load. It is observed that after inserting a LC filter, the output voltage and current waveform approach towards nearly sinusoidal waveform. Moreover, the active and reactive power variation with load power factor variation has also been discussed. The various results have been presented in tabular form and also discussed graphically.