Advancements in Photovoltaic Research: Electro-Impedance Spectroscopy for PV Cell Characterization

This article presents a method for characterizing the dynamic behavior of photovoltaic (PV) cells using the Electro-Impedance Spectroscopy (EIS) technique. High-precision laboratory equipment has been used to measure a single PV cell, capturing impedance (Z LB) and voltage-current (I -
$V$
) curve characteristics. We propose a model incorporating variable capacitance and conductance behavior for describing diode impedance dynamics. The experimental IV curve and impedance measurements are used as the reference for model parameters fitting through an evolutionary algorithm. Exploiting data from a single spectral measurement at a specific operating point, the methodology enables the prediction of the IV curve and spectral impedance plot at any operating point, as long as the irradiance conditions remain constant. The experimentation in a PV cell demonstrates a strong match between the obtained real data and the mathematical model. However, it is important to note that these findings are based on controlled simulated environmental conditions in a single cell. Further testing on PV panels is required to reproduce conditions such as mismatch or partial shadowing in order to stress and test the proposed model.