Temperature Estimation of Partially Shaded Photovoltaic Modules Using a Multiphysics Model

Partial shading is common in both photovoltaic (PV) stations and building integrated PV systems. The temperature increase of partially shaded (PTS) module not only reduces its efficiency but also accelerates its degradation. Therefore, temperature estimation of PTS module is essential for assessment and maintainence of PV systems. In this article, a multiphysics model consisting of an electrical model, an optical model, and a thermal model is developed. Particularly, the parallel circuit is adopted for the PTS cell, making it possible to calculate the electric power and heat generation of shaded region and unshaded region in the PTS cell, respectively. To the best of our knowledge, it is the first attempt to estimate the temperature distribution of PV module with PTS cell. Experiments are conducted on monocrystalline PV modules. One specific cell is partially shaded in various proportions and environmental conditions. The maximum temperature on the front surface of the PTS module is measured with the infrared thermographic camera and also calculated by our method. The root mean square error is 6.14 degrees C, which verifies the effectiveness of the proposed multiphysics model for temperature estimation of PTS modules.