Photovoltaic System Performance Under Partial Shading Conditions: Insight into the Roles of Bypass Diode Numbers and Inverter Efficiency Curve

Partial shading is a common challenge influencing the performance of photovoltaic (PV) systems, particularly in urban and residential applications. A practical solution to mitigate hotspot formation due to shading is the use of bypass diodes. Increasing the number of bypass diodes further enhances PV system performance but alters the global maximum power points (MPPs), shifting their voltage locations and power magnitudes, consequently resulting in a change in the operating points in the efficiency curve of the inverters. This study investigates the impact of bypass diode numbers and inverter efficiency curves on PV system performance under various partial shading conditions. The analysis systematically deals with three inverters with different efficiency characteristics in terms of loading and input voltage, as well as module configurations with different numbers of bypass diodes. Additionally, three more factors—ambient temperature, inverter loading ratio by varying the number of series-connected PV modules, and shading intensity—are considered in the context of bypass diodes and inverter characteristics through the efficiency curve. The global MPPs of PV modules under different cases are simulated using a Simscape/Simulink-based circuit model with random irradiance samples. The results indicate the formation of bands according to the voltage that vary with bypass diode configurations. In this manner, utilizing the probabilities of these bands and inverter efficiency curves, the average PV system performance is determined for each case. The findings reveal the effects of the relationship between bypass diode configurations and inverter efficiency on PV system performance. As partial shading is especially common in dense urban areas, the results are of interest for the development of resilient and sustainable PV installations.