公开(公告)号：US3593124A

公开(公告)日：1971-07-13

申请号：US3593124D

申请日：1968-06-03

Applicant: COMPTEURS COMP D

Inventor： CAHEN GILBERT MOISE ,  GUYARD HENRI GEORGES ,  SOUILLARD MICHEL HENRY PIERRE

IPC: G01R31/08 ,  H02H3/08 ,  H02H3/40

CPC classification number: H02H3/40 ,  G01R31/08 ,  H02H3/081

Abstract: A method for detection of faults in a polyphase alternating current transmission line system includes the steps of measuring the voltage, current and derivative of the latter for each phase, formulating the equations for the relationship between the measured values of different phases in accordance with Ohm''s law, transforming these equations into forms having straight line characteristics by application of numerical coefficients, and repeating the foregoing steps at regular intervals to obtain successive straight lines which intersect in a single point and the coordinates of which characterize the operation of the system thus to show line operation in either a normal manner or the existence of a phase-to-phase or phase-to-earth fault. The related apparatus for carrying out the method includes various instruments for measuring the voltage, current and derivative of the current at regular intervals, instruments for recording the data and a computer for processing the data thus obtained.