In this paper, we analyze the design, realization and optimization of a photovoltaic (PV) system equipped with a maximum power point tracking (MPPT) command and detection circuit of dysfunction and convergence the system (CDCS) to the new maximum power point (MPP) following a perturbation due to the meteorological variation (solar radiation, temperature, ..) and the load. We have analyzed in depth manner the structure and optimization the operation of the MPPT command realized during this work. The results obtained show very good agreement between simulation and experiment. The experimental system realized during cloudy days or by varying the load, shows that it operates under optimum conditions independently of the meteorological variations. At each perturbation, the CDCS circuit detects it and convergences the system without restart it. The good efficiency of the direct current to direct current (DC-DC) converter used and the low loss (less than 7%) shows that the system realized can be used in a PV system to minimize losses due to connecting the panels to the load and in particularly to minimize the cost of installations. Key words: Panels and photovoltaic system, photovoltaic conversion, maximum power point tracking (MPPT) command, the detection circuit of dysfunction and convergence (CDCS), direct current to direct current (DC-DC) converter, simulator Pspice, optimal functioning, energy losses.