Solar Photovoltaic Array Reconfiguration for Reducing Partial Shading Effect

Abstract

In the photovoltaic (PV) system some problems happen causes a substantial reduction in power generation, one of these problems are Partial shading (PS), and (PS) happen when some obstacles block the sun's rays on the photovoltaic (PV) cells in a PV array, panel, or module in the PV system. Therefore, this paper suggests a method for reducing the effects of partial shading and increasing output power by reconfiguring a solar photovoltaic array using a new shade dispersion strategy (NSDS). The improvements achieved in maximum power point MPP when the shadows are angled or have a significant size, NSDS is also suitable for any photovoltaic array size. The simulation in this study was done by using MATLAB-software Simulink. Different shapes for shades were taken like Short and Wide (SW), Short and Narrow (SN), Long and Wide (LW), and Long and Narrow (LN) partial shading in addition to diagonal shade (DI). The suggested method was used on 6x3 photovoltaic panels to solve the partial shadow problem that cannot be solved by some previous shadow dispersion methods like so du Ku and stepwise. Also, it is applied to a 4x2 PV array which is considered difficult to spread the shadows to all PV panels because of its small size. Analysis and comparisons of the output characteristic were done using Cadmium telluride (CdTe) F-4112-3 PV panels and it was found that the increment in the generated power is more than 30% in comparison with the typical series-parallel (SP) for the SW and LW shades while it is more than 30% and 20% in comparison with the Total-Cross-Tied (TCT) configuration for the SW and LW shades respectively.

Enhancing PV Power Extraction Under Partial Shading Condition with Shade Dispersion Strategy

“…Solar power systems fall into two basic categories: standalone systems, which are typically utilized in rural and remote regions and have a power output of a few kilowatts, and grid-connected systems, which can provide the grid with many megawatts of power [14]. To meet the voltage and current requirements of the electrical network or the power requirements of the loads, solar panels must be assembled and connected to a photovoltaic (PV) array [5], [13].…”

“…Another method to lessen the effect of partial shadowing is to disperse the shadow uniformly throughout the displayed array. As long as the array's shadow pattern doesn't change, dispersion can be accomplished by moving PV modules around without breaking their connections [14]. Various algorithms are used to disperse partial shade in photovoltaic energy systems.…”

Optimal PV array configurations for partial shading conditions

“…Solar energy systems are designed either to be independent of the electrical network by a few kilowatts (which is used in villages, rural areas and remote areas that are not connected to the national electrical network) or to be connected to the electrical network to supply it with several megawatts [17]. Solar panels are assembled and connected to form a PV array to suit the voltage and current of the electrical network or the requirements of the loads, and this is done in several ways; Figure 3 is a diagrammatic representation of the many configurations of PV arrays [8], [18].…”

“…Besides the by-pass diode, reconfiguring a PV array is a low-cost way to increase a PV array's maximum achievable power in PSCs. Installing semiconductor switches and power electronic converters doesn't cost any more with this method [17], [18]. Some researchers have tried the following methods to maximize power by using reconfiguration techniques.…”