A Review on Recent Multilevel Inverter Topologies with Reduced Count of Components

Multilevel inverters (MLIs) are the power electronic devices used to convert DC voltage to AC voltage, with the help of discrete voltage steps. Recently, MLIs have gained a lot of popularity in commercial, transportation, residential and utility applications, due to lower total harmonic distortion (THD), high quality pseudo-sinusoidal voltage step waveform. Furthermore, the improvements in the power quality of MLIs have helped to increase the penetration of renewable energy sources. A lot of research is going on in MLIs due to their several advantages over traditional two-level inverters in terms of lower total harmonic distortion (THD), lower total standing voltage (TSV), lower electromagnetic interference (EMI), increased efficiency, reduced filter size, lower switching losses, better fault tolerance, and improved reliability. This paper provides a review of a few recently proposed multilevel inverter (MLI) topologies and gathers their salient features. Researchers are now focused on reducing component count in MLI topologies to achieve a higher output voltage level, lower voltage stress, and higher efficiency. This paper briefly discusses performance parameters such as total standing voltage (TSV), total harmonic distortion (THD), and cost factor (CF). In addition, a general comparison of these topologies based on the numbers of levels, count of switches, count of diodes, count of the dc voltage source, count of capacitors, count of the driver circuits is provided in tabular and graphical form.