Electrochemical impedance spectroscopy technique-based internal parameter estimation of a monocrystalline PV cell

Modeling and simulation of photovoltaic systems, in addition to helping in the design phase of the project, can be used to emulate system performance in real time, serving to identify any failures that may occur. In this way, static PV models are widely used in the literature. Among them, the single-diode model is preferred by many authors, due to its simplicity and accuracy. However, some research works prove limitations of this model, especially for low irradiance levels. In this context, a new dynamic two-diode model is proposed in this paper which makes it possible to overcome the drawbacks of the single-diode model on the one hand and to describe PV cell behavior on faulty cases on the other hand. Electrochemical impedance spectroscopy is employed to measure the internal parameters of the studied PV cell model, namely the series resistance, shunt resistance, and junction capacitor for low irradiance levels from 1 to 36 W/m 2 . Experimental results show that although the series resistance remains constant, the shunt resistance and junction capacitance are sensitive to either the operation zone of the PV cell or the irradiance level. An interpolation of capacitor and shunt resistance is then proposed, and the elaborated dynamic two-diode eight-parameter model is validated for both low and high irradiance levels. Experimental results prove the accuracy and effectiveness of the proposed model for monocrystalline PV cells.