Preventing transmission distance relays maloperation under unintended bulk DG tripping using SVM-based approach

With high penetration of distributed generation (DG) into distribution systems, an unintended bulk DG tripping as a consequence of severe disturbances such as 3-phase faults in the transmission system is a concern since it can further cause unintended operation of transmission distance relays. To address this matter, this paper presents a novel protection scheme based on support vector machine (SVM) approach. The proposed scheme detects bulk DG tripping following a fault in the power transmission system, and then makes sure there is no follow on distance relay maloperation. It is also able to detect a fault if it happens during the blocking period and hence unblock the relay operation correspondingly. Wide-area (WA) measurements obtained from phasor measurement units (PMUs) are used, in addition to local measurements, to improve the scheme selectivity. The New-England 39 bus system is used to test the proposed scheme. Simulation results are discussed and illustrated.