Real-Time Experimental Assessment of a New MPPT Algorithm Based on the Direct Detection of the Short-Circuit Current for a PV System

Abstract

To substantially increase the efficiency of photovoltaic (PV) systems, it is important that the Maximum Power Point Tracking (MPPT) system has an output close to 100%.This process is handled by 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) controllers. The FSCC algorithm is simple to be implemented and uses only one current sensor. This method is based on the unique existence of the linear approximation between the Maximum Power Point (MPP) current and the short-circuit current in standard conditions. The speed of this MPPT optimization technic is fast, however this algorithm needs to short-circuit the PV panel each time in order to obtain the short circuit current. This process leads to energy losses and high oscillations. In order to improve the FSCC algorithm, we propose a method based on the direct detection of the shortcircuit current by simply reading the output current of the PV panel. This value allows directly calculating the short circuit current by incrementing or decrementing the solar irradiation. Experimental results show time response attenuation, little oscillations, power losses reduction and better MPPT accuracy of the enhanced algorithm compared to the conventional FSCC method.