UPFC for Analysis of Relay Performance During Power Swing Condition

Distance relay plays important role in the transmission line as far as protection of the system is concerned. Now a days facts devices has been widely used in transmission line because of their numerous advantages, but its present in transmission line leads to some obstacle in operation of distance protection. Present of FACTS controller causes change in the measured impedance of the distance relay which in turn can cause undesirable tripping or improper operation of relay. So it is a challenge to correct the operation of distance relay in the presence of FACTS devices so that FACTS device can be used properly without any interruption. For this purpose, it is necessary to analyze the impact of these devices on relay under different circumstances so that new reach setting of distance relay can be made accordingly. This study presents effect of series and shunt compensator as well as UPFC on performance of distance relay with both analytic and simulation methods .In this study, its effects have been seen on the relay by comparing R-X characteristic and apparent impedance for different fault condition and location of the fault