Five-level multilevel power conditioning system for grid-tie photovoltaic applications with novel model predictive control

This paper claims to propose a very high gain grid connected system with its control strategy. The proposed system consists of two stages. The first stage is a very high gain Switched Inductor with Voltage Multiplication Converter (SIVMC) to provide high gain and also it can provides the two dc sources required by the multilevel inverter. The second stage is a five-level multilevel inverter. The construction of the multilevel inverter consists of two voltage sources and six switches. It has five levels: 0, ±V_dc and ±2V_dc. The harmonic profile of the proposed system is better than two level h-bridge inverter. The proposed multilevel inverter required two dc voltage sources with equal amplitude. Novel finite-set model predictive control strategy is claimed to be proposed in this paper. The proposed control technique is designed to do the following functions: extract maximum power from the PV module and inject a sinusoidal current into the grid with low Total Harmonic Distortion (THD) and in phase with the grid voltage.