Granted Patent B2

US 12,650,454 · App. 18/188,219 · Granted Jun 9, 2026

Inventors: Hengxu Ha (Stafford, GB); Xiaoming Li (Stafford, GB)

Assignee: GE VERNOVA INFRASTRUCTURE TECHNOLOGY LLC

G01R31/088G01R31/086

Abstract

Claims (98)

1 . A method for determining a distance to a fault in a power systems network, comprising:

collecting a set of measured voltage samples and a set of measured current samples over a first time window;

determining, based at least in part on the set of measured voltage samples, a set of processed voltage samples;

determining, based at least in part on the set of measured current samples, a set of processed reactive current samples and a set of processed resistive current samples;

determining, based at least in part on the set of measured current samples, a set of processed negative sequence current samples and a set of processed zero sequence current samples;

selecting, based at least in part on an indication from a faulty phase indicator, a selected processed voltage sample of the set of processed voltage samples, a selected processed reactive current sample of the set of processed reactive current samples, a selected processed resistive current sample of the set of processed resistive current samples, and a selected processed negative or zero sequence current sample of the set of processed negative current samples or the set of processed zero sequence current samples;

determining, based at least in part on the selected processed reactive current sample, that no distortion has occurred during the first time window on the set of measured voltage samples and the set of measured current samples due to current transformer (CT) saturation;

detecting, based at least in part on a second set of measured voltage samples and a second set of measured current samples collected over a second time window, that CT saturation distortion is present during the second time window; and

calculating, based at least in part on the determination that no distortion has occurred, the selected processed voltage sample, the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample, the distance to the fault, wherein the calculating of the distance to the fault excludes the use of voltage and current samples collected from time windows in which the CT saturation distortion was detected.

2 . The method of claim 1 , wherein calculating the distance to the fault based at least in part on the determination that no distortion has occurred further comprises:

formulating a set of equations for calculating the distance to the fault, wherein the set of equations is based at least in part on the set of measured voltage samples and the set of measured current samples; and

calculating, based at least in part on the set of equations, the determination that no distortion has occurred, the selected processed voltage sample, the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample, the distance to the fault.

3 . The method of claim 2 , wherein calculating the distance to the fault based at least in part on the determination that no distortion has occurred further comprises:

formulating a first matrix based at least in part on the selected processed voltage sample;

formulating a second matrix based at least in part on the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample; and

calculating, based at least in part on the first matrix and the second matrix, the distance to the fault.

4 . The method of claim 1 , wherein determining that no distortion has occurred due to current transformer (CT) saturation based at least in part on the selected processed reactive current sample further comprises:

calculating, based at least in part on the selected processed reactive current sample, a full-cycle Fourier phasor current in a fraction of a full-cycle;

calculating a magnitude of the full-cycle Fourier phasor current;

calculating an average of the magnitude of the full-cycle Fourier phasor current for one-eighth of a cycle; and

determining a difference between the average of the magnitude of the full-cycle Fourier phasor current for one-eighth of the cycle and a constant, wherein the constant is determined based at least in part on the magnitude of the full-cycle Fourier phasor current in the fraction of the full-cycle after an occurrence of the fault.

5 . The method of claim 4 , wherein determining that no distortion has occurred due to CT saturation based at least in part on the selected processed reactive current sample further comprises:

determining that the difference is less than a predetermined error threshold;

responsive to the determination that the difference is less than the predetermined error threshold, determining that no distortion has occurred due to the CT saturation; and

outputting an output of “1” based on the determination that no distortion has occurred on the set of measured voltage samples and the set of measured current samples due to the CT saturation.

6 . The method of claim 1 , wherein determining the set of processed voltage samples based at least in part on the set of measured voltage samples further comprises:

receiving the set of measured voltage samples;

applying an averaging function to the set of measured voltage samples; and

determining the set of processed voltage samples, wherein the set of processed voltage samples comprises an output of the averaging function.

7 . The method of claim 1 , wherein determining the set of processed reactive current samples and the set of processed resistive current samples based at least in part on the set of measured current samples further comprises:

receiving the set of measured current samples;

determining a set of processed resistive currents based at least in part on the set of measured current samples;

applying an averaging function to the set of processed resistive currents; and

determining the set of processed resistive current samples, wherein the set of processed resistive current samples comprises an output of the averaging function.

8 . The method of claim 7 , wherein determining the set of processed reactive current samples and the set of processed resistive current samples based at least in part on the set of measured current samples further comprises:

receiving the set of measured current samples;

determining a set of processed reactive currents based at least in part on the set of measured current samples;

applying a differential function to the set of processed reactive currents; and

determining the set of processed reactive current samples, wherein the set of processed reactive current samples comprises an output of the differential function.

9 . The method of claim 1 , wherein the indication from the faulty phase indicator is indicative of a type of fault associated with the fault.

10 . A method for determining a distance to a fault in a power systems network, comprising:

collecting a set of measured voltage samples and a set of measured current samples over a first time window;

determining, based at least in part on the set of measured voltage samples, a set of processed voltage samples;

determining, based at least in part on the set of measured current samples, a set of processed reactive current samples and a set of processed resistive current samples;

determining, based at least in part on the set of measured current samples, a set of processed negative current samples and a set of processed zero sequence current samples;

receiving an indication from a faulty phase indicator;

selecting, based at least in part on the indication, a selected processed voltage sample of the set of processed voltage samples, a selected processed reactive current sample of the set of processed reactive current samples, a selected processed resistive current sample of the set of processed resistive current samples, and a selected processed negative or zero sequence current sample of the set of processed negative sequence current samples or the set of processed zero sequence current samples;

determining, based at least in part on the selected processed reactive current sample, that no distortion has occurred during the first time window on the set of measured voltage samples and the set of measured current samples due to current transformer (CT) saturation;

determining, based at least in part on a second set of measured voltage samples and a second set of measured current samples collected over a second time window, that CT saturation distortion is present during the second time window; and

calculating, based at least in part on the determination that no distortion has occurred, the selected processed voltage sample, the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample, the distance to the fault, wherein the calculating of the distance to the fault excludes the use of voltage and current samples collected from time windows in which the CT saturation distortion was detected.

11 . The method of claim 10 , wherein calculating the distance to the fault based at least in part on the determination that no distortion has occurred further comprises:

formulating a set of equations for calculating the distance to the fault, wherein the set of equations is based at least in part on the set of measured voltage samples and the set of measured current samples; and

calculating, based at least in part on the set of equations, the determination that no distortion has occurred, the selected processed voltage sample, the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample, the distance to the fault.

12 . The method of claim 11 , wherein calculating the distance to the fault based at least in part on the determination that no distortion has occurred further comprises:

formulating a first matrix based at least in part on the selected processed voltage sample;

formulating a second matrix based at least in part on the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample; and

calculating, based at least in part on the first matrix and the second matrix, the distance to the fault.

13 . The method of claim 10 , wherein determining that no distortion has occurred due to current transformer (CT) saturation based at least in part on the selected processed reactive current sample further comprises:

calculating, based at least in part on the selected processed reactive current sample, a full-cycle Fourier phasor current in a fraction of a full-cycle;

calculating a magnitude of the full-cycle Fourier phasor current;

calculating an average of the magnitude of the full-cycle Fourier phasor current for one-eighth of a cycle; and

determining a difference between the average of the magnitude of the full-cycle Fourier phasor current for one-eighth of the cycle and a constant, wherein the constant is determined based at least in part on the magnitude of the full-cycle Fourier phasor current in the fraction of the full-cycle after an occurrence of the fault.

14 . The method of claim 13 , wherein determining that no distortion has occurred due to CT saturation based at least in part on the selected processed reactive current sample further comprises:

determining that the difference is less than a predetermined error threshold;

responsive to the determination that the difference is less than the predetermined error threshold, determining that no distortion has occurred due to the CT saturation; and

outputting an output of “1” based on the determination that no distortion has occurred on the set of measured voltage samples and the set of measured current samples due to the CT saturation.

15 . The method of claim 10 , wherein determining the set of processed voltage samples based at least in part on the set of measured voltage samples further comprises:

receiving the set of measured voltage samples;

applying an averaging function to the set of measured voltage samples; and

determining the set of processed voltage samples, wherein the set of processed voltage samples comprises an output of the averaging function.

16 . The method of claim 10 , wherein determining the set of processed reactive current samples and the set of processed resistive current samples based at least in part on the set of measured current samples further comprises:

receiving the set of measured current samples;

determining a set of processed resistive currents based at least in part on the set of measured current samples;

applying an averaging function to the set of processed resistive currents; and

determining the set of processed resistive current samples, wherein the set of processed resistive current samples comprises an output of the averaging function.

17 . The method of claim 16 , wherein determining the set of processed reactive current samples and the set of processed resistive current samples based at least in part on the set of measured current samples further comprises:

receiving the set of measured current samples;

determining a set of processed reactive currents based at least in part on the set of measured current samples;

applying a differential function to the set of processed reactive currents; and

determining the set of processed reactive current samples, wherein the set of processed reactive current samples comprises an output of the differential function.

18 . A power systems network, comprising:

a power line, wherein a set of measured voltage samples and a set of measured current samples are associated with a section of the power line and collected over a first time window; and

a fault located on the power line,

wherein a set of processed voltage samples are determined based at least in part on the set of measured voltage samples,

wherein a set of processed reactive current samples, a set of processed resistive current samples, a set of processed negative sequence current samples, and a set of processed zero sequence current samples are determined based at least in part on the set of measured current samples,

wherein a selected processed voltage sample of the set of processed voltage samples, a selected processed reactive current sample of the set of processed reactive current samples, a selected processed resistive current sample of the set of processed resistive current samples, and a selected processed negative or zero sequence current sample of the set of processed negative current samples or the set of processed zero sequence current samples are selected based at least in part on an indication from a faulty phase indicator,

wherein a determination that no distortion has occurred on the set of measured voltage samples and the set of measured current samples due to current transformer (CT) saturation is made based at least in part on the selected processed reactive current sample,

detecting, based at least in part on a second set of measured voltage samples and a second set of measured current samples collected over a second time window, that CT saturation distortion is present during the second time window, and

wherein a distance to the fault is calculated based at least in part on the determination that no distortion has occurred, the selected processed voltage sample, the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample, further wherein the distance of the fault is calculated without use of voltage and current samples collected from time windows in which the CT saturation distortion was detected.

19 . The power systems network of claim 18 , wherein the distance to the fault is calculated further based at least in part on a set of equations based at least in part on the set of measured voltage samples and the set of measured current samples, the selected processed voltage sample, the selected processed reactive current sample, the selected processed resistive current sample, and the selected processed negative or zero sequence current sample, the distance to the fault.

20 . The power systems network of claim 18 , wherein the determination that no distortion has occurred due to current transformer (CT) saturation based at least in part on the selected processed reactive current sample further comprises:

calculating, based at least in part on the selected processed reactive current sample, a full-cycle Fourier phasor current in a fraction of a full-cycle;

calculating a magnitude of the full-cycle Fourier phasor current;

calculating an average of the magnitude of the full-cycle Fourier phasor current for one-eighth of a cycle;

determining a difference between the average of the magnitude of the full-cycle Fourier phasor current for one-eighth of the cycle and a constant, wherein the constant is determined based at least in part on the magnitude of the full-cycle Fourier phasor current in the fraction of the full-cycle after an occurrence of the fault;

determining that the difference is less than a predetermined error threshold;

responsive to the determination that the difference is less than the predetermined error threshold, determining that no distortion has occurred due to the CT saturation; and

outputting an output of “1” based on the determination that no distortion has occurred on the set of measured voltage samples and the set of measured current samples due to the CT saturation.

Assignments (2)

Continuity (1)

References Cited (9)