Simulation and dSPACE Hardware Implementation of an Improved Fractional Short-Circuit Current MPPT Algorithm for Photovoltaic System

The main weakness of photovoltaic (PV) systems is the fact that their energy production depend on solar irradiation and temperature variations. In this paper, a new follow-up approach to the Maximum Power Point Tracking (MPPT) of the photovoltaic system has been proposed and implemented. To increase the efficiency of a photovoltaic (PV) system, it must be able to operate at its maximum power, in other words it must have efficiency close to 100%. Efficiency of PV systems can thus be increased with MPPT algorithms such as Fractional Open Circuit Voltage (FOCV), Perturb and Observe (P&O), Fractional Short-Circuit Current (FSCC), Incremental Conductance (INC), Fuzzy Logic Controller (FLC) and Neural Network (NN) just to name a few. The FSCC algorithm which only requires a single current sensor, is very simple to implement, and is fast (has good execution speed). This approach is based on the unique existence under standard conditions of the linear approximation between Maximum Power Point (MPP) current and short circuit current. The disadvantage of this technique lies in the fact that each time you have to short-circuit the solar panel to obtain the short-circuit current value; there are strong oscillations and power losses by the Joule effect. To overcome these weaknesses, we propose a new approach based on the direct detection of the short-circuit current by simple regular reading of the output current of the solar panel. This value is used to calculate the short-circuit current by increasing or decreasing the global solar irradiance. Experimental results reveal reduced energy losses, temporal response attenuation, low oscillations and better accuracy of the improved algorithm compared to the classic FSCC algorithm.