METHOD AND DEVICE FOR LOCATING FAILURE POINT

PROBLEM TO BE SOLVED: To simplify the location of failure points and improve accuracy based on normal phase, reverse phase and zero phase equivalent circuit by the method of symmetrical component coordinates. SOLUTION: During an accident of three-phase alternating current transmission line 3, a failure point locating device 100 periodically samples the voltage and current of each phase measuring with data collection terminals 10A and 10B at electric sites A and B with a data acquisition part 101, which are maintained during the accident. A symmetrical component signal converter 103 converts the voltage and current of each phase into symmetrical component voltage and symmetrical component current in each circuit of normal phase, reverse phase and zero phase of a symmetrical component equivalent circuit. An accident kind judgment par 104 selects the phase of symmetrical component equivalent circuit used in failure point locating operation according to the accident scheme judged by the symmetrical component current and the like. A failure point location operation part 105 calculates failure point of the symmetrical component equivalent circuit of selected phase by utilizing the fact that the symmetrical component voltage of the failure point become the same value in both sides of electric sites A and B.