A Fast and Accurate Analytical Method for Parameter Determination of a Photovoltaic System Based on Manufacturer's Data. (15th May 2020)

• Record Type: Journal Article
• Authors: Ndegwa, Robinson; Simiyu, Justus; Ayieta, Elijah; Odero, Nicodemus
• Other Names: Li Shuhui Academic Editor.
• Is Part Of: Journal of renewable energy. Volume 2020(2020)
• Publication Date: 2020-05-15
• Subjects: Renewable energy sources -- Periodicals; Renewable energy sources; Electronic journals; Periodicals; Electronic journals; 621.042
• DOI: 10.1155/2020/7580279
• Languages: English
• ISSNs: 2314-4386

Abstract

Abstract : Modeling and simulation of a photovoltaic solar system play a significant role in understanding its behavior in various environmental conditions. Utilization of the datasheet information in modeling and simulation of the PV system correlates the experimental data and the theory that instigate the mathematical predictions of an actual system. A single-diode model gives a simple, fast, and straightforward way of depicting the PV system performance. We have developed a new approach of determining the five unknown parameters of a single-diode model using manufacturer's data at three main points: the open circuit point (OCP), short circuit point (SCP), and the maximum power point (MPP) of the IV and PV curves. The ideality factor ( A ) and the diode saturation current ( I o ) are the key unknown parameters that greatly affect the reduplication of the three main points. The purpose of this study is to evaluate the ideality factor using simple calculation procedure starting from its optimal value ( A o ) and other values within the proximity of A o . The optimal value is obtained by assumptions of negligible series resistance ( R s ) and very large shunt resistance ( R sh ). Therefore, the choice of the other ideality factors in the neighborhood of its optimal value gives rise to different values of R s, R sh, and I ph that are more realistic in an experimental setup. Positive values of R sh and R s have been iteratively obtained by utilizing data at maximum power point combined with open and short circuit data. The five unknown parameters have been determined in the proximity of A o and have been used to plot the PV curve with accuracy and precision of less than 0.5% error of maximum power and less than 0.1% error of V oc of manufacturer's data. The proposed method has been implemented using fast, simple, and accurate procedures using GNU Octave programming software to calculate A o, I o, R s, R sh, and I ph and to execute both R s - R sh and PV characteristic equations of BP3235T, KC200GT, BP-SX 150, and MSX60 PV modules. The reduced steps employed in the algorithm improve execution speed, thereby reducing the computation time.