Enhancement of Power Quality in a Grid-Connected Photovoltaic System using Robust Modified Champernowne Function Adaptive Filter and DSOGI-FLL

Integrating renewable sources into the weak distribution grid is challenging owing to voltage and current distortions present in weak grid. This article implements a dual second-order generalized integrator frequency locked loop (DSOGI-FLL) and a robust modified Champernowne function-based adaptive filter (MCAF) based control scheme to a grid-connected photovoltaic system (GCPVS). The control scheme utilizes DSOGI-FLL to extract fundamental positive sequence components (FPSC) of distorted grid voltages to further use in synchronization. The MCAF filters the distorted load currents to improve the grid power quality (PQ). The photovoltaic (PV) system is integrated into the weak grid while the grid PQ obeys the limits defined by the IEEE-519-2022 standard. The behavior of GCPVS is analyzed at distorted grid voltages, load variation, and solar irradiance variation. The MATLAB simulation results are observed to understand the behavior of GCPVS.