Static Voltage Stability Analysis with the Integration of Distributed Generation: An Albanian Case Study

Modern power networks face significant operational uncertainties that can threaten the stability of the power grid, due to the rising integration of distributed generation (DG), particularly from renewable energy sources, such as photovoltaic plants. The integration of distributed generation (DG) into power systems has become a pivotal factor in enhancing the efficiency and sustainability of electricity supply. This paper presents a detailed static voltage stability analysis of the Albanian power grid, focused on the effects of the Karavasta Photovoltaic Park, one of Albania’s largest renewable energy projects. Using a combination of P-V and Q-V curves, V-Q sensitivity analysis, and modal analysis, the study reveals significant improvements in the system’s voltage stability following the integration of the PV plant. The NEPLAN software is used for voltage stability analysis. Particularly, the reactive power margin at the critical node Nst. Babice increased considerably from -82.009 MVAr to -1061.2 MVAr, while the system’s loading margin improved from 99.08% to 101.97%, demonstrating that the integration of large-scale PV generation enhances voltage stability by providing additional reactive power support and improving the grid’s resilience to voltage collapse. Furthermore, the modal analysis identified the Bistrice-Delvine-Sarande buses as the system’s weakest points, highlighting areas where additional reinforcement is required. As more renewable energy has to be integrated into the grid, the study also emphasizes the importance of making targeted interventions at critical buses and branches to ensure long-term stability. The results of this research are essential for Albania’s energy transition as the country seeks to diversify its energy sources, especially solar power. More generally, the methodologies and results in this paper provide a suggestion for maintaining power system voltage stability with increased renewable energy penetration.