This paper presents a modeling and simulation, in Matlab/Simulink environment, of a stand-alone solar PV system in order to analyse its performance under irradiation and load variations. Indeed, to supply an alternative load with a sinusoidal line without harmonic distortion under weather conditions, a MPPT (Maximum Power Point Tracking) algorithm has used to control a DC-DC boost converter to generate the MPP (Maximum Power Point) of the photovoltaic generator to alternative load via a PWM (Pulse Width Modulation) three phase inverter. The computer simulation results presented in this paper, developed in MATLAB/Simulink environment, validate the full PV system components.