Implementação e validação de um protótipo de traçador de curva IV para módulos fotovoltaicos

Abstract

Due to the increasing demand for renewable energy sources worldwide, the use of photovoltaic generators is becoming more common. Therefore, it is essential to assess and diagnose the performance and lifespan of photovoltaic modules. Concerning solar panels, one of the primary methods for analyzing the functionality of this equipment is the IV curve, which represents the relationship between module current and voltage under constant temperature and irradiance conditions. Module manufacturers provide this curve in their catalogs and datasheets under standard test conditions (STC). However, obtaining the IV curve under real operating conditions remains challenging due to the high cost of measurement equipment and the numerous variables involved in constructing this curve. This work demonstrates the implementation of a low-cost IV curve tracer. The designed prototype uses a capacitive load to obtain the points that form the curve, with these points being recorded by ARDUINO and saved in a text file processed later by MATLAB, chosen as the graphical interface software. The prototype's validation involves comparing results with a commercial tracer. In this analysis, the prototype shows good performance compared to the commercial tracer under full sunlight conditions, with a maximum error of 6.9% in temperature and only 6.6% in irradiance. The maximum voltages and currents of the photovoltaic module exhibited errors of less than 3% in all tests. However, under shading conditions, the prototype exhibits greater current fluctuations and fails to capture the complete curve due to interactions between the load and the module's internal parameters. Nevertheless, even incomplete, the IV curve measured in this situation proved useful for graphical analysis.