A long-term condition monitoring and performance assessment of grid connected PV power plant with high power sizing factor under partial shading conditions

Abstract

Partial shading conditions of photovoltaic (PV) modules often occurs in urban areas leading to losses in electricity power generation of the PV power plant. The purpose of this study is to present how the PV power plant with high value of inverter power sizing factor (Kinv) can achieve high performance and power production under partial shading conditions with high shading losses. In this paper the results of long-term monitoring, performance analysis and experimental results are presented, while the results are compared to the estimated values calculated using PVsyst software. The study focused on the PV power plant at the Faculty of Technical Sciences (FTS) in Novi Sad, Republic of Serbia, for the period between the years 2012 and 2019. It has been shown that the values of PV power plant performance parameters are better than expected (very high), and resemble the power plants operating without shading. The high value of the inverter power sizing factor may lead to occasional saturation of the inverter when certain conditions are met, but most of the times it allows the inverter to operate at a more optimal power level. PV module soiling and power degradation is within the limits mentioned in the literature. The increase in Kinv in the partial shading conditions favorably affects the performance, does not degrade the efficiency of the inverter at saturation, reduces the effect of soiling and aging of PV modules, leading to higher power production.