Topology Review of Grid-Connected Multilevel Inverters Supplied by Photovoltaic Panels using Switched-Capacitor Based Circuits

Abstract

The appealing features of multilevel inverters (MLIs) have made them suitable for many applications like in photovoltaic (PV) systems. Traditional MLIs suffer some issues like complicated control scheme and incapability in utilizing the full capacity of the input source. In order to overcome these points, switched capacitor (SC) based MLIs have been introduced. In these structures, the applied capacitors are charged and discharged when connecting in series or parallel with the input supply, contributing in multiple output stages. In this paper, some of the latest grid-connected SC MLIs supplied by PV modules are introduced. Each structure is discussed in terms of advantages and disadvantages. Moreover, two main problems of these topologies including inrush currents and leakage currents are investigated in details