Abstract: Since 1985, many Photovoltaic (PV) systems have been sited in Batna Region (Algeria). They are used to supply energy to isolated schools, nurseries and for water pumping. In addition to this; the grid connected photovoltaic system study was investigated for domestic applications. The progressive tendency, in the Photovoltaic (PV) system connected to the electrical grid, is establishing new applications, in such a way that, the grid connected PV system has to be optimally used. Nowadays many optimised configurations starting to bring benefits into the electrical network, such as: export/import of real and reactive power, quick fix to shortages in power when used with storage equipment, active power mains harmonics filtering and reduction of greenhouse emission and environment friendly power generation source. Thus, within this context, this study deals with the optimisation model for the grid connected PV systems, targeting their optimum performing. Maximising the daily inverter path efficiency model is used to make a continuous matching operation between the PV array generator and the utility grid-load, leading to an adequate control law which can transfer the maximum available power. This technique provides the designer with a useful tool that optimises different functional control parameters as well as sizes the system components efficacy. Simulation results show the system performance prediction and the corresponding optimised parameters.