Application of grey relational analysis to fault type identification on power transmission line

The speed and accuracy of digital relays of transmission lines can be improved by accurate and fast fault type identification, and this also allows single pole tripping and auto-reclosure to be employed. Conventional selection schemes, however, have defects. A fault phase selector, based on grey relational analysis (GRA), is proposed in this paper. Experiments are given in this paper, the actual fault data of transmission line is compared with all kinds of fault types got by RTDS (real time digital simulation), the type of fault-phase is found lastly. The experiments´ result is accuracy, so the GRA based fault type identification method proposed in this paper is reliable and feasible.