Gauss-Seidel iteration based parameter estimation for a single diode model of a PV module

Photovoltaic (PV) modeling plays a vital role in the estimation of the expected yield from a PV generation plant. The single diode model of a PV module requires estimation of 5 unknown parameters derived from the equivalent circuit using only the parameters extracted from datasheets as input. These parameters are used to evaluate the current and voltage from the module under varying conditions of temperature and irradiance. This paper presents the Gauss-Seidel method in a step by step manner to extract the 5 unknown STC parameters used in a single diode PV model with series and shunt resistances. These parameters are then used to plot the I-V characteristics of two PV modules, SQ80 and the GEPV110 under varying temperature and irradiance. Algorithm of the Matlab code used for implementation of the model is presented. The results are then verified by simulations using graphs extracted from the datasheet of the GEPV110 as well as plots from experimentally measured values for the SQ80 PV module.