Experimental Study of the Cloud Influence on PV Grid Connected System

Abstract

In recent years, PV panels witnessed a vigorous gross, as their performance and the leverage of large-scale industrial production steadily decreased costs. Factors such as solar irradiance, insolation, mismatch of modules/arrays characteristic, aging, partial shading situation have a major effect on the harvested power. Evidence suggests that partial shading situation is the most critical factor and causes a significant reduction in PV system output. In this paper, a method based on two degrees of freedom, namely upper and lower was proposed in order to address the partial shading losses that due to cloud movement. Moreover, an extensive simulation of voltage, current indicators, bypassed modules, fault string, and DC output power was presented to analyze the PV system. The validation of experimental data analysis was carried out on two different days with different amounts of solar irradiance in Minqin County, Gansu Province, China. The results indicated that the power losses were 18.989 W and 127.629 W according to the minimum and the maximum irradiations (1.88 MW/m2) and (2.104 MW/m2) respectively. By considering the minimum irradiance, the upper and the lower degrees of freedom of the losses were 22.17 W/d, and 15.8 W/d respectively. On the other hand, by considering the maximum irradiance, the upper and the lower degrees of freedom were 130.49 W/d, 125.78 W/d respectively.