Single stage three-level MPPT inverter for solar supplied systems

In this study, a single stage, three-phase, three-level neutral point clamped inverter is designed for grid connected renewable energy systems. The proposed voltage source inverter is operated in current controlled mode and a PI current controller is used for the production of switching pattern. Also the proposed inverter is operated in parallel with public grid by using phase locked loop method. Maximum power point tracking process which is aimed to obtain maximum energy from the supply is performed via the proposed inverter without using any additional DC-DC converter. Maximum power point tracking algorithm generates the current reference for the current controller. Results of experimental studies show that inverter output current is in phase with line and unity power factor operation is obtained. Also inverter output current total harmonic distortion is measured as 3.95%. This value is in the limits of international standards (5%).