Line Frequency Sine Modulation - A Novel Modulation Scheme for Multilevel Inverters and Its Application Towards Enhanced Illumination of Incandescent Bulb

Abstract

Several modulation schemes are proposed and implemented in multilevel inverters (MLIs) to reduce the total harmonic distortion (THD) content at its output. This paper proposes a new approach towards employing an fundamental switching frequency (FSF) modulation scheme to reduce the THD at the output of an MLI. It involves designing two matrices coined as inverter switching characteristics (ISC) matrix and inverter operating modes (IOM) matrix. The switching frequency depends on the line frequency of the MLI output. The presented modulation scheme is implemented in an asymmetrical topology MLI. An experimental setup is also carried for a maximum power rating of 200W. The experimental results show the proposed modulation scheme has improved the parameters of the inverters in terms of the output voltage, output current, THD content of voltage and current waveforms, output power and power factor. Thus the presented modulation control scheme has improved the performance of the inverter.