Modelling and experimental verification of the operating current of mono-crystalline photovoltaic modules using four- and five-parameter models

This article presents the modelling and experimental verification of the operating current of a 120 W of mono-crystalline photovoltaic module using four- and five-parameter analytical models. The southern part of Turkey, where the experimental system is mounted, is particularly well suited to photovoltaic installations. The operating current of the photovoltaic module, calculated from the models, is validated based on a series of experimental measurements. As well as the current and voltage of the photovoltaic module, the environmental variables such as ambient temperature and solar irradiance were measured and used for validation of the operating current. The photovoltaic cell models considered in this article are drawn from the equivalent electrical circuit that includes light-generated current, diode reverse saturation current, and series and shunt resistances. The simplified four-parameter model assumes the shunt resistance as infinite and thus neglects it. After determining the model parameters, the operating current is calculated using both models and compared to the measured current produced by the photovoltaic module. It is shown that the complete five-parameter model predicts the operating current better than the simplified four-parameter model, especially around solar noon, when most of the power is produced. (c) 2006 Elsevier Ltd. All rights reserved.