Modelling and Simulation of a 330 kV Power Transmission Network with FACTS Devices

The increasing demand for electrical energy, coupled with constrained expansion of physical transmission infrastructure, has placed significant operational stress on high-voltage power transmission networks. In Zambia, the 330 kV transmission system serves as the backbone of bulk power transfer, interconnecting major generation stations with critical load centres. Under rising load demand and contingency conditions, this network is increasingly exposed to voltage instability, reactive power deficiencies, and transmission congestion, which threaten system reliability and operational security. This study presents the modelling and simulation of a 330 kV power transmission network with the integration of Flexible AC Transmission System (FACTS) devices. A detailed steady-state and dynamic model of the transmission network was developed to evaluate baseline system performance in terms of voltage profiles, power flows, and transmission losses. FACTS devices, specifically the Static Var Compensator (SVC) and the Static Synchronous Compensator (STATCOM), were incorporated to assess their effectiveness in enhancing voltage stability and controlling real and reactive power flows. Load flow and voltage stability analyses were conducted under normal, stressed, and contingency operating conditions using simulation platforms including MATLAB/Simulink, ETAP, and Power World Simulator. Quantitative results show that without FACTS compensation, heavily loaded receiving end buses suffer severe voltage degradation, with system voltage efficiencies falling between 86% and 92% (0.86–0.92 pu). Upon integrating 100 MVA SVC and STATCOM devices at critical weak buses, receiving-end voltage efficiencies were restored to 94–98% (0.94–0.98 pu), and dynamic bus voltages stabilised at approximately 0.97 pu following step-load variations. Furthermore, reactive power injection responses reached -0.54 pu and -0.31 pu to arrest voltage drops. The study concludes that FACTS devices offer a technically effective and economically practical alternative to traditional transmission expansion, contributing to improved use, reliability, and stability of high-voltage transmission infrastructure.