Optimal Power Flow in Distribution Network Considering DG Penetration and Isolated Grid Operation.

Abstract

This research investigates the optimal power flow (OPF) in a Libyan 30 kV distribution network with a case study focused on the Bir-Alganm substation. The search addresses critical operational challenges such as voltage instability, high system losses, and reduced efficiency, which threaten the reliability of power supply. To overcome these issues, both conventional methods such as re-planning an expansion and advanced approaches through distributed generation (DG) penetration are examined. Using the NEPLAN software and the extended Newton–Raphson method, simulations are performed to determine system weaknesses, evaluate DG placement and sizing, and compare network performance under grid-connected and isolated operation. The results demonstrate that integrating DG significantly reduces losses, enhances voltage stability, and provides a flexible and cost-effective alternative to traditional expansion. Moreover, load growth analysis over a ten-year horizon highlights the sustainability advantages of DG compared to conventional solutions. The findings underscore the practical role of DG in improving reliability, efficiency, and resilience of Libya’s distribution networks.