Transient Stability Enhancement of SMIB (Single Machine Infinite Bus) System using UPFC

The focus of this paper is to improve transient stability of Single Machine Infinite Bus (SMIB) system with the help of Unified Power Flow Controller (UPFC). UPFC has a capability to control simultaneously real and reactive power flows in a transmission line and also to regulate voltage at the bus where it is connected. A proportional integral (PI) controller has been used for the Unified Power Flow Controller (UPFC). In this paper, two simulation models of Single Machine Infinite Bus (SMIB) system with and without Unified Power Flow Controller (UPFC) have been developed. The Flexible Alternating Current Transmission (FACTS) devices such as UPFC are the most important in suppressing power system oscillations and improving damping. We can study the transient stability using the waveform of fault current, real power, reactive power at receiving end, shunt injected voltage and its angle, series injected voltage and its angle and excitation voltage. Therefore we can conclude that transient stability of Single Machine Infinite Bus (SMIB) system is improved with the use of Unified Power Flow Controller (UPFC).