A model for the series–parallel association of photovoltaic devices

Abstract

This work presents a method to obtain the one-exponential model parameters of a series-parallel association of photovoltaic (PV) devices. From the linear expressions of the I-V characteristic in short-circuit and open-circuit zones, simple equations for association model parameters are obtained based on cell parameters. In order to validate the model, measurements have been performed in the 33 cells of a conventional PV module previously modified to have access to its cells, either individually or associated. Series and parallel proposed models have been applied to measurements, supposing all module cells are connected either in series or in parallel. Good approximations have been found in both cases. The method here proposed supplies a useful formulation that can be used in simulation programmes and array calculations.

Irradiance sensitivity of the model parameters of photovoltaic cells

“…In order to facilitate the mathematical analysis and provide an accurate numerical set of values for the first-order sensitivity a Matlab application is implemented In relation (26) the theoretical value of open-circuit voltage is obtained by using the first order sensitivity of these parameter results from relation (19), when the irradiance level changes with ∆G=400 W/m 2 and the sensitivity calculation is related to the STC conditions.…”

New approach of PV cell efficiency

“…In terms of studying the energy transferred from the "solar source" to PV cell the 2-terminal of the current source can be considered 1-port for the equivalent circuit, or an input port, as in [10], [11], and [12]. From this theoretically premise it is possible to consider that the input current and voltage of PV cell are I ph , respectively V d .…”

Analytical Model for a Mixed Association of Photovoltaic Cells

“…The number of cells in a branch and the number of branches on a ECS Transactions, 14 (1) 529-537 (2008) module depend on the type of cell used, on the desired current-voltage-power specifications for the load and on environmental conditions. Since the output characteristic of a module resembles that of a single cell, Alonso-Garcia et al (6) suggested that Equation 1 be also used for an association of photovoltaic cells, where its parameters must be derived from a combination of the parameters of the individual cells employing the linearized equations [Eq. 2 and 3].…”

“…Studies of the association of photovoltaic (PV) cells contemplate several different approaches: Kirchoff rules; numerical methods, mostly based on SPICE; MPP analysis; and module-parameter extraction from individual-cell parameters (1,2,3,4,5). Alonso-Garcia et al (6) developed a simple analytical method to attain the aggregation model of either series or parallel associations of PV cells, being valid for the complete I-V range under uniform irradiation. In this paper we recur to the latter approach and propose a model for the mixed association, more commonly found in practical PV modules, where non-uniform irradiation can be considered.…”