Novel pulse width modulation control of a multilevel inverter design with reduced number of switches

This study presents an innovative multilevel inverter design that introduces some attractive features, such as a reduced number of elements and a fixed number of switches in the current path. We selected pulse width modulation (PWM) with a level-shifted carrier as the most suitable modulation method to control the modified seven-level reduced-switch multilevel inverter configuration capable of generating seven voltage levels using only eight power switches in the converter. We used a novel method for PWM in the seven-level inverter. The developed inverter system offers numerous advantages compared to a commercially available cascaded H-bridge multilevel inverter and other traditional designs. These advantages include reduced harmonic distortion, the capability to construct an electrical circuit with smaller dimensions, a smaller number of switches and lower switching losses. In addition, the design allows extension to any number of output voltage levels. We introduce an alternative form of level-shifted multicarrier. The comparison demonstrates that the configuration with variable frequency and phase opposition (VF-POD) and the configuration with variable frequency and alternative phase opposition (VF-APOD) yield an optimal design and reduce the harmonic distortion by approximately 10% with the same switching frequency.