Selection of Most Favourable FACTS device in Transmission Systems

Abstract

Voltage stability is the most important challenge in today’s ever-changing power transmission systems and Flexible AC transmission system (FACTS) devices help to maintain and improve voltage stability. But, choosing the suitable FACTS device and its most beneficial location in the network is a matter of consideration under practical limitations. In the context of the voltage profile (VP) improvement, active and reactive power losses reduction, cost of device, and relative environmental aspects (RECDI), static VAR compensator (SVC), the combination of SVC and thyristor controlled series compensator (TCSC) and the unified power flow controller (UPFC) are compared to determine the most preferable FACTS device. The standard IEEE 30-bus test system with randomly increased load is used for this purpose. A new online voltage stability index (OLVSI), Relative Environmental Contamination Decay Index (RECDI) is proposed. The multiple objective functions (MOFs) are normalized and converted by proposed weighted combined objective function (COF) and evaluated. The results show that in presence of system’s security constraints, the combination of SVC and TCSC is the most suitable device.