A New Five-Level Inverter Topology with Voltage Controller for Grid-Connected PV System

Photovoltaic (PV) systems are growing in demand due to the recent drop in prices of the solid state components. However, the quality of the output of the PV systems are still lacking behind and this is a major problem while connecting the system to the grid. Inverters being the brains of a solar PV system need to be made smarter and better. Multi-level inverters are one of the most popular types of inverters for grid-connected PV systems due to the higher quality output they can produce than other inverters. One of the key features they provide is the minimization of total harmonic distortion (THD) and electromagnetic interference which tackles leakage current issue. So, in this paper a new five-level inverter topology for grid-tie PV is proposed which is controlled using a new voltage controller that ensures higher efficiency while enhancing the stability of the system. The suggested closed loop voltage controller method additionally provides the ability to provide constant or adjustable voltage to the grid. In this proposed topology the voltage controller enables the PV system to provide high quality power to the grid which is vastly important. To validate the accuracy of the theoretical analysis, the control technique was applied to the existing multi-level inverter topology and then has been simulated in MATLAB/Simulink software. Moreover the five-level output provides a much better output and better PF then other existing topologies.