Control, implementation, and analysis of a dual two-level photovoltaic inverter based on modified proportional–resonant controller

This study presents a modified proportional–resonant (M-PR) control topology for single-stage photovoltaic (PV) system, operating both in grid-connected and stand-alone modes. Dual two-level voltage source inverter fed three-phase open-end winding transformer is used to supply the load in this scheme. The M-PR controller is developed for the inner current control loop of the system. The M-PR controller has the ability to track ac current with zero steady-state error. The outer dc-link voltage control loop is developed through the indirect vector control method at synchronously rotating reference frame. The control scheme ensures improved performance of the system at variable solar irradiance and load disturbances. The performance analysis of the dual two-level PV inverter is carried out for different operating conditions. The control scheme is implemented in MATLAB–SIMULINK environment. The theoretical results are verified through experiments in a laboratory prototype. The experimental results show close match with their theoretical counterparts.