A multilevel current-source inverter based grid-connected photovoltaic system

Abstract

This paper proposes a grid-connected Photovoltaic (PV) system based on a multilevel Current Source Inverter (CSI) topology. The topology proposed here consists of parallel-connected CSI modules operating at a very low switching frequency. For n number of inverter modules, 2n+1 current levels are resulted in the output. In the multilevel inverter topology, each inverter module has its own PV source, Maximum Power Point Tracking (MPPT) unit, and DC-link current controller. Unlike earlier proposed multilevel CSI topologies, the proposed topology has a single AC-side current controllers, lowering the requirements for AC-side sensors and filters. To demonstrate the performance of the multilevel inverter based on CSI, two inverter units are considered in this study. The simulation studies are carried out in PSCAD/EMTDC environment.