Systems and methods to improve distance protection in transmission lines

Patent metadata

Field	Value
Publication number	US-11480601-B2
Application number	US-201916584723-A
Country	US
Kind code	B2
Filing date	Sep 26, 2019
Priority date	Sep 26, 2019
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

Systems and methods are provided herein for improving distance protection in transmission lines. Such systems and methods may involve receiving one or more current and voltage inputs, and determining, based on the one or more current and voltage inputs, one or more current and voltage phasors, wherein the one or more current and voltage phasors are determined using a short window phasor estimation. Such systems and methods may also involve determining, within a single power cycle and based on the one or more current and voltage phasors, a fault in a transmission line. Such systems and methods may also involve sending, to a distance protection element and based on the determination that the fault exists, a signal to clear the fault in the transmission line, and clearing the fault in the transmission line.

First claim

That which is claimed is:

1. A transmission line protection method comprising:
receiving one or more current and voltage inputs;
determining, based on the one or more current and voltage inputs, one or more sets of current and voltage phasors, wherein the one or more current and voltage phasors are determined using a short window phasor estimation with different window lengths;
determining, within a single power cycle and based on the one or more sets of current and voltage phasors, wherein the sets of voltage phasors are used to adapt to a particular type of voltage transformer and to different time after a fault occurs, a fault in a transmission line;
sending, to a distance protection element and based on the determination that the fault exists, a signal to clear the fault in the transmission line; and
clearing the fault in the transmission line.

2. The method of claim 1 , wherein short-window phasor estimation comprises:
determining a decaying Direct Current (DC) time constant;
determining poles of a decaying DC component using the decaying DC time constant;
determining poles of a fundamental frequency using a number of samples per power cycle;
determining, using the poles of the decaying DC component and the poles of the fundamental frequency, a matrix;
determining, based on the matrix, a coefficient matrix; and
determining coefficients of the one or more current and voltage phasors using the coefficient matrix.

3. The method of claim 1 , further comprising:
determining that the transmission line comprises a magnetic voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first number of samples is less than or equal to a number of samples associated with one cycle; and
determining, based on the determination that the first number of samples is less than or equal to a number of samples associated with one cycle, that the one or more current and voltage phasors are determined using a window size of 16 with respect to 64 samples per-cycle.

4. The method of claim 1 , further comprising:
determining that the transmission line comprises a magnetic voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first number of samples is greater than a number of samples associated with one cycle; and
determining, based on the determination that the first number of samples is greater than a number of samples associated with one cycle, that the one or more current and voltage phasors comprise a current phasor determined using a window size of 64 with respect to 64 samples per-cycle and a voltage phasor determined by a combination of a phasor determined using a window size of 64 with respect to 64 samples per-cycle and a phasor determined using half-cycle Fourier.

5. The method of claim 1 , further comprising:
determining that the transmission line comprises a passive capacitor voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first number of samples is less than or equal to a number of samples associated with one cycle; and
determining, based on the determination that the first number of samples is less than or equal to a number of samples associated with one cycle, that the one or more current and voltage phasors are determined using a window size of 6 with respect to 64 samples per-cycle.

6. The method of claim 1 , further comprising:
determining that the transmission line comprises a passive capacitor voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first number of samples is greater than a number of samples associated with one cycle; and
determining, based on the determination that the first number of samples is greater than a number of samples associated with one cycle, that the one or more current and voltage phasors comprise a current phasor determined using a window size of 64 with respect to 64 samples per-cycle and a voltage phasor voltage phasor determined by a combination of a phasor determined using a window size of 64 with respect to 64 samples per-cycle and a phasor determined using half-cycle Fourier.

7. The method of claim 1 , further comprising:
determining that the transmission line comprises an active capacitor voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first number of samples is less than or equal to a number of samples associated with one half of a cycle; and
determining, based on the determination that the first number of samples is greater than a number of samples associated with one half of a cycle, that the one or more current and voltage phasors are determined using a window size of 6 with respect to 64 samples per-cycle.

8. The method of claim 1 , further comprising:
determining that the transmission line comprises an active capacitor voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first number of samples is greater than to a number of samples associated with one half of a cycle and is less than or equal to a number of samples associated with one cycle; and
determining, based on the determination that first number of samples is greater than to a number of samples associated with one half of a cycle and is less than or equal to a number of samples associated with one cycle, that the one or more current and voltage phasors comprise a current phasor determined using a window size of 6 with respect to 64 samples per-cycle and a voltage phasor determined by a combination of a phasor determined using a window size of 6 with respect to 64 samples per-cycle and a phasor determined using half-cycle Fourier.

9. The method of claim 1 , further comprising:
determining that the transmission line comprises an active capacitor voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first number of samples is less than or equal to a number of samples associated with two cycles; and
determining, based on the determination that the first number of samples is less than or equal to a number of samples associated with two cycles, that the one or more current and voltage phasors comprise a current phasor determined using a window size of 64 with respect to 64 samples per-cycle and a voltage phasor determined by a combination of a phasor determined using a window size of 6 with respect to 64 samples per-cycle and a phasor determined using half-cycle Fourier.

10. The method of claim 1 , further comprising:
determining that the transmission line comprises an active capacitor voltage transformer;
determining a first number of samples, the first number of samples comprising a number of samples after a fault disturbance detector is triggered and an arming event takes place;
determining that the first numb

Assignees

• General Electric Technology Gmbh

Inventors

• Ha Hengxu
• Zhang Zhiying

Classifications

• H02H7/261 Primary

  involving signal transmission between at least two stations (transmission of signals in general H02H1/0061) · CPC title

• H02H7/263 Primary

  involving transmissions of measured values (comparison of currents or voltages using pilot wires H02H3/30) · CPC title

• G01R31/085

  in power transmission or distribution lines, e.g. overhead · CPC title

• G01R19/00

  Arrangements for measuring currents or voltages or for indicating presence or sign thereof (G01R5/00 takes precedence; for measuring bioelectric currents or voltages A61B5/24) · CPC title

• G01R31/088 Primary

  Aspects of digital computing · CPC title