DIRECTIONAL DETECTION OF EARTH FAULTS IN AN ELECTRICAL DISTRIBUTION NETWORK

摘要

Method for the directional determination of an earth fault in an electric power distribution network, characterised in that it comprises the steps of:
Determining (E2) a residual current phasor and a residual voltage phasor,Determining (E3) an active current,Comparing (E7) the residual voltage phasor module with a threshold (SVR), andas long as the residual voltage phasor module remains higher than the threshold (SVR) or a fraction of the threshold (SVR), and for a predetermined number of iterations:Determining (E9, E12) the integral of the active current and of its sign,Determining the number of times when the residual current phasor module is greater than a predetermined threshold (SIR), during the predetermined number of iterations,If the residual current phasor module is greater than the predetermined threshold (SIR) at least one time, during the predetermined number of iterations,Determining (E16) the location upstream or downstream of the fault according to the number of times when the sign of the integral of the active current was positive or negative during the predetermined number of iterations.

主权项

1. Method for the directional determination of an earth fault in an electric power distribution network, characterised in that it comprises the steps of:
Determining (E2) a residual current phasor, Determining (E2) a residual voltage phasor, Determining (E3) an active current by projection of the residual current phasor on the residual voltage phasor, Determining (E7) of the residual voltage phasor module, Comparing (E7) the residual voltage phasor module with a threshold (SVR), and in that it comprises the following steps, as long as the residual voltage phasor module remains higher than the threshold (SVR) or a fraction of the threshold (SVR), and for a predetermined number of iterations starting from the moment when the residual voltage phasor module is greater than the threshold (SVR): Determining (E9, E12) the integral of the active current and of the sign of the integral of the active current, Determining (E5) the residual current phasor module, Determining the number of times when the residual current phasor module is greater than a predetermined threshold (SIR), during the predetermined number of iterations, If the residual current phasor module is greater than the predetermined threshold (SIR) at least one time, during the predetermined number of iterations, Determining (E16) the location upstream or downstream of the defect according to the number of times when the sign of the integral of the active current was positive or negative during the predetermined number of iterations.