Circuit Analysis of Multilevel Converter for High-Power Applications

Abstract

This paper analyses a multilevel inverter configuration which provides single-phase seven-level output. This topology partially adopts the packed u-cell structure and uses series connected DC sources to generate the required number of output voltage levels. The DC-link capacitors are not required in this topology. The operating modes and modulation scheme of this multilevel inverter are explained in detail. For applications requiring high voltage and high power, multilayer inverters (MLI) are one of the most popular choices. Higher voltage levels can be generated with MLI, despite the fact that lower rating components are used. MLI provides greater voltage level, which minimizes total harmonic distortion (THD), and MLI operates at a lower switching frequency than a standard DC-AC inverter, resulting in lower overall power consumption. There are several alternative modulation approaches for MLI that are dependent on either the fundamental switching frequency or the high switching frequency of the device.