Impact of an SVC device on voltage and transient stability in power systems

Abstract

The increasing complexity of modern electrical networks, driven by the expansion of transmission networks along with the increasing penetration of renewable-based generation, has intensified concerns regarding voltage control performance and rotor-angle stability. Flexible AC transmission system (FACTS) technology, particularly the shunt-connected static var compensator (SVC), offers effective solutions for enhancing system performance through dynamic reactive power support. This study examines the effect of SVC integration on voltage regulation performance as well as rotor-angle stability within electrical transmission networks. The study is conducted using MATLAB and the electrical network analysis toolbox (PSAT) on IEEE 5-bus, 14-bus, and 9-bus benchmark systems. Voltage stability performance is evaluated under transmission line outage conditions, while rotor-angle stability is assessed through critical clearing time (CCT) analysis during balanced three-phase faults. The simulation results demonstrate that the incorporation of an SVC considerably improves voltage profiles, reduces active and reactive power losses, and enhances system resilience under disturbed operating conditions. Furthermore, the SVC increases the critical clearing time and improves post-fault dynamic behavior, contributing to better preservation of generator synchronism. The presented results confirm that SVC-based compensation provides an effective and practical solution for strengthening both voltage control performance and rotor-angle stability reserves in power transmission systems.