University of Tasmania, Australia

Microcontroller Based Control of Solar Power Converter with Maximum Power Point Tracking in Changing Environmental Conditions

The power generated by a photovoltaic (PV) module depends on several factors such as solar insolation levels, temperature, shading conditions, PV cell aging and load conditions. The electrical power output of the photovoltaic module usually increases linearly with the insolation. Moreover, the PV module has a single operating point, where the values of the current and voltage of the cell result in a maximum power output. There are many maximum power point tracking (MPPT) methods proposed in the literature. Each of these methods has its own advantages and limitations. Generally, the MPPT controller drives a dc-dc converter, whose duty-cycle is modulated in order to track the instantaneous MPP of the PV module. Studies show that converter topology alters the performance of MPPT techniques. As both the PV module and converter show non-linear and time-varying characteristics, perfect matching between them is necessary for the optimum performance of the whole system. It is well known that the change in solar irradiation largely influences the true MPP. The change in temperature also reallocates the operating point of the MPP. The problem of finding the MPP becomes severe during rapidly changing environmental conditions

In this project, the problem associated with maximum power point tracking will be investigated in details. A control strategy will be developed that can track the maximum power point under stable and changing weather conditions. The project work include: Computer simulation and hardware implementation using microcontroller.