Directional detection of earth faults in an electrical distribution network
First Claim
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1. A method implemented by a device for the directional determination of an earth fault in an electric power distribution network, comprising:
- determining, by a module that includes a plurality of current sensors each connected directly to a different respective line phase of the electric power distribution network, a residual current phasor,determining, by a module that includes a plurality of voltage sensors each connected directly to a different respective line phase of the electric power distribution network, a residual voltage phasor,determining an active current by projection of the residual current phasor on the residual voltage phasor,determining of the residual voltage phasor module,comparing, by processing circuitry of the device, the residual voltage phasor module with a threshold,and the method comprises the following steps, as long as the residual voltage phasor module remains higher than the threshold or a fraction of the threshold, and for a predetermined number of iterations starting from the moment when the residual voltage phasor module is greater than the threshold;
determining the integral of the active current and of the sign of the integral of the active current,determining the residual current phasor module,determining, by the processing circuitry, the number of times when the residual current phasor module is greater than a predetermined threshold, during the predetermined number of iterations, andwhen the residual current phasor module is greater than the predetermined threshold at least one time, during the predetermined number of iterations, determining, by the processing circuitry, 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.
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Abstract
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), and
- 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:
- 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.
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Citations
10 Claims
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1. A method implemented by a device for the directional determination of an earth fault in an electric power distribution network, comprising:
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determining, by a module that includes a plurality of current sensors each connected directly to a different respective line phase of the electric power distribution network, a residual current phasor, determining, by a module that includes a plurality of voltage sensors each connected directly to a different respective line phase of the electric power distribution network, a residual voltage phasor, determining an active current by projection of the residual current phasor on the residual voltage phasor, determining of the residual voltage phasor module, comparing, by processing circuitry of the device, the residual voltage phasor module with a threshold, and the method comprises the following steps, as long as the residual voltage phasor module remains higher than the threshold or a fraction of the threshold, and for a predetermined number of iterations starting from the moment when the residual voltage phasor module is greater than the threshold; determining the integral of the active current and of the sign of the integral of the active current, determining the residual current phasor module, determining, by the processing circuitry, the number of times when the residual current phasor module is greater than a predetermined threshold, during the predetermined number of iterations, and when the residual current phasor module is greater than the predetermined threshold at least one time, during the predetermined number of iterations, determining, by the processing circuitry, 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. - View Dependent Claims (2, 3, 4, 5, 10)
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6. A device for the directional determination of an earth fault in an electric power distribution network, comprising:
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a plurality of current sensors, each connected directly to a different respective line phase of the electric power distribution network, for determining a residual current phasor, a plurality of voltage sensors, each connected directly to a different respective line phase of the electric power distribution network, for determining a residual voltage phasor, processing circuitry configured to determine an active current by projection of the residual current phasor on the residual voltage phasor, determine the residual voltage phasor module, compare the residual voltage phasor module with a threshold, when the residual voltage phasor module remains higher than the threshold or a fraction of the threshold, and for a predetermined number of iterations starting from the moment when the residual voltage phasor module is greater than the threshold; determine the integral of the active current and of the sign of the integral of the active current, determine the residual current phasor module, determine the number of times when the residual current phasor module is greater than a predetermined threshold, during the predetermined number of iterations, and determine 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, if the residual current phasor module is greater than the predetermined threshold at least one time, during the predetermined number of iterations. - View Dependent Claims (7, 8)
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9. A non-transitory computer readable medium that stores a program that, when executed, causes a device for the directional determination of an earth fault in an electric power distribution network to perform a method comprising:
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determining, by a module that includes a plurality of current sensors each connected directly to a different respective line phase of the electric power distribution network, a residual current phasor, determining, by a module that includes a plurality of voltage sensors each connected directly to a different respective line phase of the electric power distribution network, a residual voltage phasor, determining an active current by projection of the residual current phasor on the residual voltage phasor, determining of the residual voltage phasor module, comparing, by processing circuitry of the device, the residual voltage phasor module with a threshold, and the method 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 the integral of the active current and of the sign of the integral of the active current, determining the residual current phasor module, determining, by the processing circuitry, the number of times when the residual current phasor module is greater than a predetermined threshold, during the predetermined number of iterations, and when the residual current phasor module is greater than the predetermined threshold at least one time, during the predetermined number of iterations, determining, by the processing circuitry, 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.
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Specification