ABSTRACT
The performance of photovoltaic (PV) module is dependent on shading conditions of the cells. This research work is aimed at developing an improved PV-model considering the various degree of shading on PV-cells connected in a PV-module. This is based on modelling the different degrees of shading of cells in a module into the general model by introducing degree of shading parameter. A MATLAB-based graphical user interface (GUI) is developed using Artificial Fish Swarm Algorithm (AFSA). This is used to accurately predict current-voltage (i-v) curves, power-voltage (p-v) curves, maximum power point values, short-circuit current and open-circuit voltage. A set of simulation scenarios involving uniform and non-uniform shading across PV-modules with/without bypass diodes were carried out in order to demonstrate the effectiveness of the developed models and their accuracy. The developed AFSA based model was compared with the conventional dynamic programming (DP) based model, using the output parameters of the PV-system presented in the work of El-Saady et al. (2013) to evaluate the performance of the proposed approach using three performance metrics (open circuit voltage, short-circuit current and maximum power point). Results from AFSA based model showed 59.7303W, 3.8A and 21.0897V for maximum power point, short-circuit current and open circuit voltage respectively. This showed that AFSA based model produced increase in accuracy improvement of 5.1%, 0.03% and 0.22% over DP based model. Even though the developed AFSA based approach possessed some degree of truncation error, it has been shown to outperform the conventional DP based approach.