Control of Low Voltage Grid-Tied Solar PV System

A low voltage grid-tied solar PV (GSPV) system suffers from poor power quality (PQ) due to the distorted currents drawn by the loads affixed at the point of common coupling (PCC). Moreover, during the peak PV (Photovoltaic) array generation and low load condition, the PCC voltages rise beyond the prescribed limit as par the IEEE std. 1547. Hence, this work presents the control and operation of the GSPV system to satisfy the IEEE-519 and IEEE-1547 standards by improving the PQ at the PCC and to limit the rise in PCC voltages as par the specified limit, respectively. The system either works at unity power factor (UPF) mode or voltage regulation (VR) mode depending upon the PCC voltage variation. It maintains the grid currents distortionfree and balanced during its operation. Here, an in-loop filter based second-order generalized integrator (ILF-SOGI) algorithm is used to control the GSPV system. The proportional-integral (PI) based perturb and observe (P&O) algorithm is used to maximize the efficiency of the GSPV system. A simulation study is carried out in MATLAB environment for performance validation of the presented GSPV system.