Analysis on Static Voltage Stability Using SVC, STATCOM, TCSC & UPFC

Modern electric power utilities are facing many challenges due to ever increasing complexity in their operation and structure. One problem that received wide attention is voltage instability. One of the major causes of voltage instability in the power system is with its reactive power limit. Voltage instability is the cause of the system voltage collapse, in which the power system voltage decays to a level, from which point, it is unable to recover. Voltage collapse may lead to partial or full power interruption in the system. Providing adequate reactive power support at the appropriate location solves voltage instability problems. Improving the systems reactive power handling capacity with Flexible AC Transmission System (FACTS) devices is one remedy for prevention of the voltage instability and voltage collapse. In this paper the effect of four FACTS controllers SVC, STATCOM, TCSC and UPFC on voltage stability are studied. The IEEE-14 bus system is simulated with continuation power flow feature of PSAT and accurate model of these controllers for Voltage stability of a test system is investigated.