Optimized Parameter Extraction Method for Photovoltaic Devices Model

Abstract

A model that accurately reproduces the electrical behavior of photovoltaic (PV) devices becomes relevant, not only for cell, panel, array and system simulation, but also as an analysis tool that provides an insight of the internal physical mechanisms of PV devices. Consequently, a method based on genetic algorithms is proposed in this paper to obtain the parameters of the one-diode model of PV cells. The proposed method is applicable to I-V curves at several irradiation and temperature levels. Moreover, it simplifies the computation by adjusting the real data to the modeled one, without solving the transcendental equation that describes the current-voltage (I-V) characteristic. Additionally, the presented method combines two approaches; on the one hand, one that relies on the use of fitting algorithms that minimize the error for the entire set of data, and on the other, one that seeks minimization in selected I-V points (open-circuit, short-circuit and maximum power points ). In order to verify the validity of the method, an I-V curve is obtained out of the parameters previously determined and later compared with that offered by the panel manufacturer.