The Effect of Temperature and Partial Shading on P–V and I–V Characteristics of the Solar Photovoltaic System Using NgSpice-Based Model

Photovoltaic (PV) systems are becoming increasingly popular sustainable energy sources, as the natural resources such as fossil and nuclear fuels are expected to diminish dramatically. Before installing a PV system at any location, modeling, simulation, and analysis of these solar PV systems is essential, which aids in understanding the PV system's behavior, characteristics, and features under the local climatic conditions. Researchers, manufacturing companies, and consumers can thoroughly understand solar PV modules by examining their I–V and P–V plots. This paper uses NgSpice software to simulate PV cells and arrays under various operating conditions using single-diode and two-diode equivalent models. The effect of series resistance, temperature and partial shading on the I–V and P–V characteristics are demonstrated using diode equivalent models at cell and array level. The results show that the two-diode equivalent PV cell model provides better results than the single one. A significant change is observed in I–V & P–V characteristics as temperature & non-ideality resistors are varied. The performance of the cell and overall panel decreases with an increase in series resistance, while the open circuit voltage of the panel has been hampered with an increase in temperature. The results also show that the output current decreases by 41.18% with 15% of partial shading.