Impact analysis of SVC on stepped distance protection modeling and simulation using PSCAD/EMTDC

Static VAr compensators (SVCs) are one of the types of FACTs devices which can control the transmission line voltages. A SVC generally regulates and controls voltage to the required set point under the normal steady-state conditions as well as abnormal conditions. In addition, a SVC can also reduce losses, increase transfer capability and maintain a constant voltage. The stepped distance protection is used for the protection of long transmission line. The distance relay continuously measured the impedance of transmission line in terms of distance. The apparent impedance measured by the distance relay is also affected due to presence of static VAr compensator. This paper represents the modeling and simulation analysis of stepped distance protection along with static VAr compensator. A detailed model of SVC is proposed which is integrated into 230kV and 300km long transmission line system. Simulation results show the effect of SVC on stepped distance protection operation during the different kind of abnormal condition. In this paper represents the impact of SVC on relay load ability limit; the setting of SVC control parameter and mode of operation for SVC is taken in to consideration.