A power electronic compensator to extract maximum power from partially shaded PV module

This paper presents a power electronic compensator to extract the maximum power from a partially shaded PV module connected in a series PV string. The power electronic compensator comprises of a dedicated DC-DC converter with voltage mode control. The compensator compensates the deviation from the maximum power during mismatch conditions of PV modules. The compensator enables each PV module in the string to operate at its maximum power point (MPP) under given atmospheric conditions and flow of maximum possible string current corresponding to highly illuminated module of the string. The flyback DC-DC converters with voltage mode control are employed to process the compensation power during mismatch conditions. A prototype of flyback DC-DC converters for two PV modules is designed and developed. A digital voltage mode controller and MPPT control are implemented on PIC18F452 microcontroller to control each flyback DC-DC converter. The experimental results and performance of the system are presented.