Model Predictive Control Method for Flying Capacitor Five-Level Commonly-Grounded Photovoltaic Inverter

Abstract

Multilevel grid-tied inverters have been widely introduced for integrating photovoltaic (PV) inverters for several output power ranges. Among the existing multilevel inverters (MIs), the flying capacitor (FC) based topologies are preferred. However, PV systems are subjected to leakage currents due to the existing parasitic capacitance of PV panels and the common mode voltages in PV inverter topologies. Hence, multilevel FC based commonly grounded PV inverters can provide efficient solutions by merging the inherent MIs benefits with total elimination of leakage currents. Therefore, this paper presents model predictive control (MPC) method for commonly-grounded single phase five-level FC PV inverter. The proposed MPC method provides a multi-objective controller for capacitor voltages control in addition to high quality sinusoidal current injection into the grid. The modelling, design, and simulation results of the proposed MPC method are provided in this paper.