Novel Optimized Method for Maximum Power Point Tracking in PV Systems Using Fractional Open Circuit Voltage Technique

The paper proposes new improved MPPT measurement method based on the conventional Fractional Open Circuit Voltage (FOCV) method, where the maximum power point voltage is estimated by continuous measuring of PV panel's open circuit voltage and calculation of the voltage factor. In the proposed Semi-Pilot Cell (SPC-FOCV) the measurements of the open circuit voltage are performed on one PV cell which is located at the edge of PV panel. When there is no measurement of the open circuit voltage, the PV panel configuration is unchanged and all PV cells inside the panel supply power to the load. During the measurement, the semi-pilot cell is disconnected from the panel by a pair of transistors and bypassed by the bypass diode in order to ensure proper operation of other cells in the panel. This method is intended for application in small PV systems. The proposed method was analyzed and validated by extensive simulation results. It was proved that it can precisely estimate maximum power point voltage. The SPC-FOCV method overcomes the disadvantages of the conventional FOCV and pilot cell FOCV methods. By implementing the proposed method, more power can be supplied to the load with higher efficiency than by the conventional FOCV and pilot cell methods.