A Novel PV Array Reconfiguration Algorithm Approach to Optimising Power Generation across Non-Uniformly Aged PV Arrays by Merely Repositioning

Abstract

Photovoltaic (PV) module working conditions lack consistency and PV array power outputs fluctuate due to the non-uniform impact that aging has on various PV modules in a PV array. No assessment has been conducted on the energy potential of a non-uniform PV array, despite the fact that the maximum power point (MPP) can be tracked by global maximum power point tracking (GMPPT). Therefore, the present work undertakes such an assessment by devising an algorithm to optimise the PV array electrical structure as the PV modules undergo aging in a non-uniform way. To enable PV arrays with non-uniform aging to produce as much power as possible and to make maintenance more cost-effective, the work puts forward a novel approach for reconfiguring PV arrays, where the PV modules are repositioned by retaining the aged PV modules. By this approach, the selection of the best reconfiguration topology necessitates the information on the electrical parameters associated with the PV modules in an array. Furthermore, the non-uniform aging of the PV modules can engender an incompatibility effect, which can be diminished in the proposed algorithm through iterative sorting of the modules in a hierarchical pattern. To determine how effective the method is for PV arrays with non-uniform aging and of different sizes, such as 3 × 4, 5 × 8 and 7 × 8 arrays, computer simulation and analysis have been conducted, with findings indicating that, irrespective of dimensions, PV arrays with non-uniform aging can have improved power yield.

Gene Evaluation Algorithm for Reconfiguration of Medium and Large Size Photovoltaic Arrays Exhibiting Non-Uniform Aging

“…Equivalent circuit models represent the entire I-V curve of a cell/array/module using a continuous function for a specific series of functioning circuit variables. In Figure 3, an overview of the corresponding of a single-diode circuit of the PV cell and the PV modules or array is given [2]. P-V features of several PV modules.…”

“…This enables the production of the required current and voltage, and constitutes a PV array. In Figure 2, an illustration is given of the equivalent circuit linked to the PV module with NP parallel-connected cell and NS series-connected cell configuration [2]. For a single diode, where I DO is the loss diode current modelled using the Shockley equation for an ideal diode, this can be defined by Equation (1).…”

“…The electrical behaviour of a PV module is modelled using Equation (3), where the ohm's losses are R s and R sh , I SC represents the photo-induced current depending on the irradiance, I D represents the saturation current, nV T represents the thermal voltage depending on the module temperature, I PV is the current generated by the module. The parameters can be calculated from datasheet values or experimental measurements by solving the expressions given in [2,24].…”

“…This enables the production of the required current and voltage, and constitutes a PV array. In Figure 2, an illustration is given of the equivalent circuit linked to the PV Energies 2020, 13,1921 6 of 19 module with NP parallel-connected cell and NS series-connected cell configuration [2]. Hence, in the case of the PV array, as indicated in Figure 2, it is possible to express the output current equation in the following way:…”

“…Furthermore, non-sustainable fossil fuels constitute a finite resource, and there is an inverse relationship between stock availability (which is declining) and stock price. Consequently, there is an urgent requirement for all energy suppliers to promote energy efficiency and cost-effectiveness to ensure competitiveness in a changing world [1,2].…”