Investigation of the effects of FACTS devices on the voltage stability of power systems

In parallel with the technological advances, the electrical power demand is constantly increasing and this makes the voltage stability difficult for the electrical power systems. At this point, FACTS (Flexible AC Transmission System) devices come into prominence in order to provide the voltage stability and increase the power transfer capacity. In this study, the most critical buses are determined by making the continuous power flow analysis on the IEEE 14-bus power system. Then, the FACTS devices SVC (static VAr compensator), UPFC (unified power flow controller), STATCOM (static synchronous compensator) and SSSC (static synchronous series compensator) are used to provide the voltage stability. For the cases with/without FACTS devices, the maximum loading limits of the most critical buses are compared by utilizing the bus voltage and bus angle values, and the X-V curves. In consequene, many comparative assessments are made related to the voltage stability enhancement in power systems.