Improved single-diode modeling approach for photovoltaic modules using data sheet

This paper proposed an improved single diode photovoltaic module model over the Rp-model (single-diode, five parameter model) based on datasheet values. Rp-model is widely in use being a compromise among other diode models in simplicity and accuracy. However, the model has major drawback at low irradiance level that is deviation from experimental data in the vicinity of open circuit voltage. And this drawback was improved using two diode model at the expense of increased complexity, parameters, and computation time. The main contribution of this paper is an improved single diode model partly using empirically determined points. Like the Rp-model it has simplicity and improved accuracy, unlike the Rp-model showed a significant reduction in absolute error from the experimental data especially at low irradiance level in the vicinity of open circuit voltage. The performance of model was verified against the experimental data for three common PV module technologies: Mono-crystalline silicon, multi-crystalline silicon, and Thin-film (CIS). The performance of three module types using Rp-model and proposed model was compared against the experimental data. The I-V characteristic and absolute relative error plots of module current revealed the significant improvement of the proposed model over the Rp model.