SAIAH Zenagui MohammedKHELIFI LahcenADJOUDJ Labiba2026-09-092026-09-092026https://dspace.univ-temouchent.edu.dz/handle/123456789/7485This thesis focuses on the optimization of electrical power systems using Optimal Power Flow (OPF) and FACTS devices, particularly the Static Var Compensator (SVC). The main objective is to improve the technical and economic performance of the power network by reducing active power losses, enhancing the voltage profile, and satisfying operational constraints. After presenting the fundamentals of power systems and FACTS technologies, an SVC model and a mathematical formulation of the OPF problem were developed. The proposed methodology was applied to the IEEE 9-bus and IEEE 14-bus test systems using the PSAT/MATLAB environment. The obtained results demonstrate that the optimal integration of the SVC significantly improves voltage profiles, reduces transmission losses, and enhances system stability. The study confirms the effectiveness of combining FACTS devices with OPF techniques to improve the performance of modern electrical power networks.frPower SystemOptimal Power Flow (OPF)FACTSSVCVoltage ProfilePower LossesPSAT.Thesis