**4. Conclusion**

In this chapter, we have analyzed the operation of photovoltaic (PV) panels around their maximum power points (MPP). We recalled the equations and electrical models that govern the operation of these panels and showed that knowledge of their electrical quantities, over the sun, is essential to design the different blocks of the PV system, which control their operation in a PV application. As part of our experiment, when the intensity of the illumination varies from 300 to 900 W, the optimum voltages, currents, powers, and resistances of a PV panel (300 Wp), vary, respectively, from 25.4 to 25, 5 V; 2.87 to 8.61 A; 72.9 to 218.7 W and 8.85 to 2.95 Ω. Then, we showed that these electrical quantities are fixed through a power block (DC/DC converter), controlled by an MPPT command, which generates a variable duty cycle PWM signal. We specified that the most established MPPT command is that of perturb and observe since it presents the stability and the precision of convergence toward the MPP. In the case of a solar photovoltaic application (solar cooker), we have followed the role of this control in the optimization of the operation of the 600 Wp PV panels (two PV panels in series). We have shown that, during a sunny day, where the intensity of the illumination varies from 950 to 1000 W/m<sup>2</sup> , the duty cycle of the PWM signal varies from 0.42 to 0.45, and the operation of the PV panels converges toward their optimum electrical quantities (voltage, current, optimum resistance, and power of the order of: 51.17 V, 9.2 A, 5.56 Ω, and 470 W), and the temperature of a liter of water has reached the boiling temperature of 90°C after 23 min of heating. All the results obtained show the role of the power unit and its perturb and observe type command to optimize the operation of PV panels, in a PV application, over the sun.
