A Brief Review of the Conventional and Multilevel Inverters Topologies

The utilization of renewable energy resources using PV, wind turbines, and fuel cells, has grown significantly over the last decades in the power grids. This makes power electronic inverters an indispensable part of renewable energy systems as a necessary interface between these resources and the power grids. However, conventional two-level inverters (TLIs) cannot satisfy applications in high voltage ranges. Therefore, multilevel inverters (MLIs) are used for this purpose. MLIs have many advantages over conventional TLIs, particularly lower total harmonics distortion, lower electromagnetic interference, suitability for medium voltage-high power applications, minimizing dv/dt across switches, higher efficiency, and larger DC link voltages. To align with high power demands, MLIs can create the desired number of levels. Recent MLIs topologies are produced with increased levels using fewer components resulting in cost minimization and increasing system reliability. Also, modulation techniques play a substantial role in improving the behavior of MLIs. This paper briefly reviews the different topologies of conventional TLIs and MLIs. A comparison between conventional TLI and MLIs is introduced. The basic concepts of the different topologies are discussed in detail. The merits, demerits, and applications of each topology are presented. The recent topologies of MLI are also highlighted. Control and modulation techniques are introduced.