Simulation Model of Photovoltaic and Photovoltaic/Thermal Module/String Under Nonuniform Distribution of Irradiance and Temperature

The modern concepts of sustainable cities and smart grids have caused an increase in the installation of solar systems in urban and suburban areas, where, due to the presence of many obstacles or design constraints, photovoltaic (PV) modules can operate in operating conditions that are very different from the optimal ones (e.g., standard test conditions, STC). Shading and reflection are the main phenomena that cause uneven distribution of irradiance on PV cells; in turn, they create a nonuniform distribution of PV cell temperatures. The latter problem can also be caused by different ventilation regimes in various parts of the PV array. On the other hand, due to the need to exploit different solar technologies (solar thermal and photovoltaic), problems related to the availability of a useful surface can arise. In this context, there is a technology that produces heat end electrical energy at the same time, such a technology is referred to as a solar hybrid photovoltaic/thermal (PV/T). Here, the uneven distribution of temperature is a design input and its effect depends on both path of the water flow and the PV cell connections. To study the electrical behavior of a PV array under mismatching conditions, a suitable matlab/simulink model has been developed. The model has been tested both numerically and experimentally. Finally, an application of this model in the electrical analysis of a PV/T module is reported, and the results are discussed.