Switched-Capacitor-Based Multilevel Inverter for Grid-Connected Photovoltaic Application

Abstract

In order to approach a voltage of high magnitude in photovoltaic (PV) application, several PV modules are connected in series to form a PV string, then the voltage of PV string is converted to an ac voltage through an H-bridge inverter. This system causes harmful harmonics, brings about leakage current, and increases the voltage stress of the components. To tackle the issue, this article proposes a new switched-capacitor-based multilevel inverter topology that uses series-connected dc sources as the input dc source and generates a staircase ac voltage of high quality and mitigates the leakage current. The proposed topology can be constructed as a three-phase inverter as well, in the three-phase configuration all the phases are connected to only one series-connected PV module or dc sources. Simulation and experimental results are provided to validate the proposed topology.