Transient Stability Enhancement of Power System Using UPFC (Unified Power Flow Controller)

In the power grid system, the prime subjects are to transmit power with supreme power factor and high power quality, supreme transient stability, economical and minimum risk of system failure. The constantly growth of electrical power demands and loads, particularly non-linear loads making the power system network become more obscure to operate and the system becomes unstable with large power flows without proper control and operation. The development in power system with time have brings new challenges and sometimes it is tough to operate system in stable condition due to complex system network. Though, on the other side there is vast development been made in power electronics, which helps the power system to continue in stable condition during most horrible condition occurred due to fault. One of the creation of power electronics is FACTS technology. FACTS (Flexible Alternating Current Transmission Systems) devices are created on power electronics and other dynamic controllers that provide control of one or more AC transmission system parameters to enhance controllability and growth power transfer capability. One way to enhance the power system control is by applying FACTS controller such UPFC (Unified Power Flow Controller). UPFC can control voltage, impedance and phase at alike time. The UPFC control scheme for the grid connected power system is simulated by MATLAB/PSAT in power system block set. By means of IEEE 9 bus power system network, the effectiveness of UPFC are tested by applying the 3-phase fault at dissimilar buses and evaluated the performance of FACTS devices in IEEE nine bus power system during fault conditio