Shading on photovoltaic (PV) modules induces disproportionate impacts on power production. This paper presents a fault detection method able to identify anomalies on PV systems such as shading problems. The presence of localized shading on PV modules leads to an overheating of the shaded PV cells despite the activation of bypass diodes. The temperature increase reduces considerably PV module performances and its lifetime. The presented method uses a simple equation, which corresponds to the normalized error (DE) of the comparison between the I-V curve in normal operation and the I-V curve in shading condition. The first derivative calculation gives the area of the detection in function of the PV voltage of the module (DE/DV). This defines whether one or several PV cells dissipate power. This phenomenon essentially occurs in the case of non-uniform irradiance received on PV modules and could impact PV modules performances. The detection method is explained in detail through the study of specific shadows simulations on PV modules. The results are validated through experimental tests on PV modules.

This paper presents the study of a simplified approach to model and analyze the performance of partially shaded photovoltaic modules using the shading ratio. This approach integrates the characteristics of shaded area and shadow opacity into the photovoltaic cell model. The studied methodology is intended to improve the description of shaded photovoltaic systems by specifying an experimental procedure to quantify the shadow impact. Furthermore, with the help of image processing, the analysis of the shading ratio provides a set of rules useful for predicting the current-voltage behavior and the maximum power points of shaded photovoltaic modules. This correlation of the shading ratio and shading patterns can contribute to the supervision of actual photovoltaic installations. The experimental results validate the proposed approach in monocrystalline and polycrystalline technologies of solar panels.