Method for photovoltaic parameter extraction according to a modified double‐diode model

Abstract

The variables presented in the current–voltage equation of a photovoltaic (PV) device are usually called PV parameters. There are several different methods for PV parameter extraction from measured data according to different models. However, many of these methods provide results that do not represent I–V curves of thin films devices correctly. This can occur because either the applied model or the PV parameter extraction methods are not suitable. It is also possible that the extracted parameters provide a good mathematical representation of the curves but without physical meaning (e.g. negative series resistance). This work presents a method for PV parameter extraction based on a modified double‐diode model. In this model, the ideality factor related to the recombination of the charge carriers in the space‐charge region is assumed as a variable. This method has been tested for different I–V curves of different PV module technologies providing very good results and parameters with physical meaning in all the cases. Copyright © 2012 John Wiley & Sons, Ltd.

Changes of solar cell parameters during damp-heat exposure

“…A modified double‐diode model is used to represent PV module's equivalent circuit parameters of which can be extracted from measured I‐V characteristics. There are a number of extraction methods, for example, . The optimum extraction is normally assessed by the quality of re‐built I‐V curves.…”

“…The A and B type modules were used for this study. The solar cell equivalent circuit parameters, including photocurrent (I ph ), series resistance (R s ), parallel resistance (R p ), diode recombination current (I r0 ) and diode ideality factor (n), were extracted from I‐V curves measured at Standard Testing Conditions over the course of ageing for the modules that were aged under different temperature and humidity levels. The degradation behaviours of each parameter are plotted versus the derived humidity dose as shown in Figure .…”