An accurate two diode model computation for CIS thin film PV module using the hybrid approach

Abstract

This paper proposes an accurate computation for the parameters of the two diode model for the Copper Indium Diselenide (CIS) thin film PV module. The approach is based on a hybrid solution, i.e. by combining the traditional analytical method with the soft computing technique known as the Differential Evolution (DE). In contrast to conventional modelling methods which rely on keeping several parameters constant (in order to make the model manageable), the proposed model computes all parameters simultaneously at a given irradiance and temperature using only the information available in the datasheet. The photocurrent (IPV) and saturation current for the first diode (Io1) are analytically computed while the rest of the parameters are determined using DE. The accuracy of the new computation technique is verified using the experimental data of two CIS thin film modules, namely the Shell ST36 and ST40. Furthermore, its performance was compared against an established two diode model from the literature. In all cases, the new method is found to exhibit superior accuracy. In particular, it performs very well at low irradiance and high temperature conditions.