Analysis of the SVC impact on distance relays performance

Modern energy transmission systems suffer from great voltage dropping due to enormous loads. Therefore, appropriate schemes should be devised to regulate the voltage. FACTS devices such as SVC are often used for this purpose. However, FACTS devised may leads to deteriorate of distance relays operation resulting in inaccurate estimation of faults locations. In this paper the effects of SVC on the distance relays operation and their origins are investigated. The location of SVC installation and fault occurrence on the distance relays operation are also studied. The simulation results show that as the SVC is closer to distance relays the impedance measured by the relay is more erroneous. Also the distance between the fault location and the relay is greater the impedance measured by the relay is more erroneous.