Variable Rate LPPT Based Droop Controlled Operation of Photovoltaic System for Microgrid Frequency Regulation

The objective of this paper is to improve the frequency regulation of an islanded microgrid system consisting of non-battery-backed photovoltaic (PV) systems. Operating the PV system in limited power point tracking (LPPT) mode gives provision for the application of droop control on the PV system active power, which in turn enhances the frequency regulation of the microgrid. The LPPT is a control technique used for extracting the desired amount of power that may be less than the maximum available power from the PV system. Variable rate LPPT is the superior control technique among the available LPPT control techniques, which is employed in the work. The droop controller implemented in this paper provides the required power reference command for the limited power operation of a PV system based on the deviation of bus frequency from its nominal value (50 Hz/60 Hz). A case study is presented to validate the effectiveness of the above-mentioned concept