In modern power system utilities, increased power demand often lead to the
situation where the system no longer remains in secure operating region. Flexible AC
Transmission Systems (FACTS) controllers can play an important roll in power
system security enhancement. The goal of FACTS devices study is to measure their
impact on the state of the electrical networks into which they are introduced. Their
principal function is to improve the static and dynamic properties of the electrical
networks and that by increasing the margins of static and dynamic stability. In this
paper the modeling of Static Synchronous Compensator (STATCOM) within
Newton-Raphson power flow equations has been presented, discussed, implemented
and the transient stability of a power system was tested when three phase fault is
applied at a certain branch of the power system. Case studies are carried out on a 5-
bus and a 30-bus test systems to demonstrate the effectiveness of the proposed model.