Mathematical Model for Regular and Irregular PV Arrays with Improved Calculation Speed

Abstract

Photovoltaic (PV) systems are usually developed by configuring the PV arrays with regular connection schemes, such as series-parallel, total cross-tied, bridge-linked, among others. Such a strategy is aimed at increasing the power that is generated by the PV system under partial shading conditions, since the power production changes depending on the connection scheme. Moreover, irregular and non-common connection schemes could provide higher power production for irregular (but realistic) shading conditions that aere caused by threes or other objects. However, there are few mathematical models that are able to predict the power production of different configurations and reproduce the behavior of both regular and irregular PV arrays. Those general array models are slow due to the large amount of computations that are needed to find the PV current for a given PV voltage. Therefore, this paper proposes a general mathematical model to predict the power production of regular and irregular PV arrays, which provides a faster calculation in comparison with the general models that were reported in the literature, but without reducing the prediction accuracy. The proposed modeling approach is based on detecting the inflection points that are caused by the bypass diodes activation, which enables to narrow the range in which the modules voltages are searched, thus reducing the calculation time. Therefore, this fast model is useful in designing the fixed connections of PV arrays that are subjected to shading conditions, in order to reconfigure the PV array in real-time, depending on the shading pattern, among other applications. The proposed solution is validated by comparing the results with another general model and with a circuital implementation of the PV system.

Implicit Mathematical Model of Photovoltaic Arrays with Improved Calculation Speed Based on Inflection Points of the Current–Voltage Curves

“…The inflection points (IPs) in the current vs. voltage (I-V) curve of an array, independently of its configuration [31], are produced by the activation/deactivation of the bypass diodes in the PV modules. In general, a bypass diode is active while the current flowing through a given module (I i,j ) is higher than its short-circuit current (I sc,i,j ), i.e., I i,j > I sc,i,j ; otherwise, when I i,j < I sc,i,j the bypass diode is inactive because it is reverse-biased.…”

Localization of Disconnection Faults in PV Installations Using the Multiple Frequencies Injection Method

“…A PV array is generally composed by connecting several PV strings, and each PV string connects several PV modules in a series. When PV modules are connected, the overall I-V characteristics are determined by the interactions among the PV modules, and the module or string with the lowest performance has the greatest influence on the overall characteristics [5,31,32].…”

Analysis of Global and Local Maximum Power Points in Pv Arrays Under Partial Shading Condition

“…In addition to being derived from abundant and eco-friendly solar sources, the low costs of operation and maintenance, as well as the ease of construction, render it a promising prospect for future access to renewable electrical energy worldwide [1], [2]. In recent years, solar panel technology has become popular with a total installed power of 627 GW in 2019 and in some reports predicting growth of 46% by 2023 [3], [4]. Solar panel electrical energy is produced from the direct transformation of solar radiation, where this energy conversion is conducted using PV cells based on a physical phenomenon known as the photovoltaic effect [5].…”