Performance Improvement of a Photovoltaic System Using a Programmable Microcontroller

It is well known that solar radiation can vary considerably over the course of a day or from one day to the next. In this paper we are presenting the design of a simple MPPT (Maximum Power Point Tracker) charge controller based on perturb and observe algorithm embedded into Atmega 2560 microcontroller. The voltage of the solar cell that operates at its maximum power point at 25C°, which is the standard temperature for testing, is higher than the voltage of battery. While solar panel temperature goes down, the voltage goes up. Therefore, the microcontroller with the MPP algorithm is able to capture the surplus energy and inject it into the accumulator. So, during the colder periods of the year (or the day), a MPPT controlled solar panel can generate up to 30% more energy than during warmer periods. The charge controller will use the microcontroller, DC-DC buck boost circuit, sensors that will read the electrical information from the photovoltaic panel and the battery.