Experimental assessment of malfunction events in photovoltaic modules from IR thermal maps

This paper presents an innovative diagnostic technique to be adopted for the smart maintenance of photovoltaic plants. The proposed technique is able to relate the temperature distribution over PV modules, achievable by means of thermographic images, with the electrical produced/dissipated power of each single cell in the modules. This goal is achieved by applying the power balance equation at individual cell level in the modules under test with respect to a reference module; the approach does not require irradiance and ambient temperature sensors, thus ensuring low complexity and costs. Experiments have been performed to investigate the effectiveness of the proposed technique in describing the behavior of modules subject to malfunction events leading to the occurrence of hot-spots.