A novel protection scheme for shunt reactors

It is essential to protect the shunt reactors of EHV/UHV transmission line in the power system. The conventional protection of shunt reactors is not sufficiently sensitive to detect the turn-to-turn fault. In this paper, by analyzing the characters of negative sequence power direction in various fault cases, a novel protection scheme for shunt reactors is proposed. The presented technique is valid to distinguish internal faults of shunt reactors from external faults and some other operation states. EMTP simulations and tests show that the negative sequence power direction relay is valid and sensitive to detect different kinds of faults.