Renewable energy sources, especially PV systems, which become more significant sources of energy, are attracting considerable commercial interest. Nonetheless, the integration of the PV power plants to the utility grids may cause several operational problems for distribution networks. The severity of these problems directly depends on the percentage of PV penetration and the geography of the installation. Hence, knowing the possible impact of small grid-connected PV systems on distribution networks can provide feasible solutions before practical implementations in real-time. The electrical power generated from photovoltaic (PV) array depends mainly on the weather conditions. So, the PV solar grid-connected inverters should equip with the control system to meet a fast response of solar irradiance change. This study includes performance analysis for data and measurements which real-time from the PV grid-connected system site according to Egyptian PV-LV code-2014, simulation by using MATLAB/Simulink, and cost analysis for connecting small-scale 39.78 kW photovoltaic (SSPV) system to LV distribution networks. Power quality parameters are measured for the output of the installed PV system at the Holy Family School in Helwan, Egypt. The proposed system model is built on MATLAB/Simulink and simulated under daily weather conditions to test its operating performance. The power quality indices at the inverter output side have been measured using PA-9-plus power quality analyzer. The cost analysis of SSPV generator based on the weather conditions will lead to new investments. The system has been installed in October 2016, produces 68.966MWh/year annual energy yield, and reaches its initial cost in 6.2198 years. The produced electricity by the system is injected directly into the grid without storage devices (On-grid Plant).