Maximum Power Point Tracker Based on Digital OCC Applied in PV Systems
MPPT, OCC, PV Systems, Digital Controllers
Photovoltaic systems have been highlighting among the renewable energies by converting sunlight directly into electricity, low maintenance, good production of electricity and not produce greenhouse effect gases. Due to the climatic changes of temperature and radiation, besides the shading of the cells, all this causes a decrease in the production of electricity and affects the efficiency of photovoltaic panels, therefore, they need a control system that makes it operate at the point of maximum power, are the so-called MPPT algorithms. The final objective of this work is to develop a photovoltaic system controlled by a microcontroller and a Boost converter, so that the system does the tracking of the maximum power of the photovoltaic panel, maximizing its efficiency. A control scheme based on the panel temperature measurement will be implemented to provide the reference voltage equivalent to the maximum power point in non-STC conditions. According to the temperature read by the MCP9808 sensor, the microcontroller will adjust the reference voltage of the internal PI controller, resulting in a duty cycle value of the Boost converter. Switching the work cycle to the Boost converter will be done using the one-cycle control (OCC) instead of the PWM, because the OCC provides a rapid response to change of reference, null error in regime and rejection of perturbations. The simulations will show that this scheme presents some advantages over the conventional MPPT method. Will be described the principles of photovoltaic panels, their types of associations, the main MPPT tracking techniques, the design of converters and controllers, as well as the simulations to justify the use of the method.