Power System Stability and Load Flow Analysis for a Grid-Tied Photovoltaic System: Lebanon Case Study

Recently, due to the economic crisis in Lebanon and the low reliability of the National Grid, more customers are utilizing renewable energy sources (RES), especially the photovoltaic (PV) system, where cases of residential users who are going toward off-grid systems have rapidly increased. This paper enters the future with the assumption that the utility power of Lebanon is performing well and supposes that there will be a transition to on-grid systems to facilitate power sharing. For that, a Lebanon case study analyzing the interactive integration of PV systems ahead of time, stability analysis, load flow, and short circuit analysis are performed using ETAP software, and PVsyst software for assessing PV system performance. By examining these critical factors in the context of a potential transition to on-grid systems, this research aims to highlight the challenges that grid operators may encounter. The results reveal that a radial system with PV setup exhibits instability, whereas in the two feeders with PV scenario, following a three-phase fault, the frequency fluctuates between 49.9 and 52.1 hertz for 5.5 seconds with no voltage increase observed, then returns to its stable value of 50 Hz. The findings will assist future researchers and engineers address instability and other abnormal conditions in their designs, offering solutions before the widespread adoption of on-grid PV systems.