# US 10,483,747 B2 · Detection of an electric power system fault direction using traveling waves

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- Number: US 10,483,747 B2
- Document ID: US10483747B2
- Status: Granted
- Kind: B2
- Application number: 15/291,295
- Filed: 2016-10-12
- Published: 2017-04-13
- Granted: 2019-11-19
- Earliest claimed: 2015-10-12
- Assignees: Schweitzer Engineering Laboratories, Inc.
- Applicants: Schweitzer Engineering Laboratories, Inc.
- Inventors: Edmund O. Schweitzer, III; Armando Guzman-Casillas; Bogdan Z. Kasztenny; Mangapathirao Venkata Mynam
- Web page: https://patentgrep.com/patent/US10483747B2

## CPC

- H02H 1/0007: {concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445)}
- G01R 31/085: {in power transmission or distribution lines, e.g. overhead}
- G01R 31/086: {in power transmission or distribution networks, i.e. with interconnected conductors}
- G01R 31/11: using pulse reflection methods
- H02H 3/38: responsive to both voltage and current; responsive to phase angle between voltage and current
- H02H 7/265: {making use of travelling wave theory}
- H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H)
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

The present disclosure relates to a fault in an electric power delivery system. In one embodiment, a system may include a data acquisition subsystem configured to receive a plurality of representations of electrical conditions associated with at least a portion of the electric power delivery system. A traveling wave detector may be configured to detect a traveling wave event based on the plurality of representations of electrical conditions. A traveling wave directional subsystem may be configured to calculate an energy value of the traveling wave event during an accumulation period based on the detection of the traveling wave by the traveling wave disturbance detector. A maximum and a minimum energy value may be determined during the accumulation period. A fault direction may be determined based on the maximum energy value and the minimum energy value. A fault detector subsystem configured to declare a fault based on the determined fault direction.

## Claims

### Claim 1

A system configured to detect a fault in an electric power delivery system, comprising:
a data acquisition subsystem configured to receive a plurality of representations of electrical conditions associated with at least a portion of the electric power delivery system;
a traveling wave detector configured to detect a traveling wave event based on the plurality of representations of electrical conditions;
a traveling wave directional subsystem configured to:
calculate an energy value of the traveling wave event during an accumulation period based on the detection of the traveling wave by the traveling wave detector;
determine a maximum energy value and a minimum energy value of the energy value during the accumulation period; and
determine a fault direction based on the maximum energy value and the minimum energy value;
a fault detector subsystem configured to declare the fault based on the determined fault direction; and
a protective action subsystem configured to implement a protective action based on the declaration of the fault.

### Claim 2 (depends on 1)

The system of claim 1, wherein each of the data acquisition subsystem, traveling wave detector, and traveling wave directional subsystem are configured to monitor a plurality of phases of the electric power delivery subsystem.

### Claim 3 (depends on 2)

The system of claim 2, wherein the fault detector subsystem is further configured to determine a faulted phase based on the fault direction for each phase.

### Claim 4 (depends on 2)

The system of claim 2, wherein the traveling wave directional subsystem is further configured to receive an indication of which phase among the plurality of phases corresponds to the maximum energy value and assert a signal corresponding with that phase.

### Claim 5 (depends on 4)

The system of claim 4, wherein the protective action subsystem is further configured to activate a trip signal depending on the declaration of the fault.

### Claim 6 (depends on 1)

The system of claim 1, wherein the traveling wave directional subsystem is further configured to determine the fault direction as forward or reverse based on a comparison of one of the maximum energy value and the minimum energy value to an energy threshold.

### Claim 7 (depends on 6)

The system of claim 6, wherein the energy threshold value comprises a function of traveling wave directional element settings.

### Claim 8 (depends on 1)

The system of claim 1, wherein the protective action subsystem further comprises a directional comparison permissive overreaching transfer trip scheme activated by the determined fault direction.

### Claim 9 (depends on 1)

The system of claim 1, wherein the data acquisition system comprises one of a sensor component configured to determine electrical conditions on an electrical transmission line and a communication interface configured to receive the plurality of representations of electrical conditions.

### Claim 10 (depends on 1)

The system of claim 1, wherein the accumulation period is determined by a timer initiated when a plurality of traveling wave voltage measurements comprised in the plurality of representations of electrical conditions exceed a first threshold and a plurality of traveling wave current measurements comprised in the plurality of representations of electrical conditions exceed a second threshold.

### Claim 11 (depends on 1)

The system of claim 1, wherein the accumulation period comprises a duration between 30 μs and 50 μs.

### Claim 12 (depends on 1)

The system of claim 1, wherein the data acquisition subsystem further comprises a differentiator-smoother configured to determine traveling wave phase currents and voltages.

### Claim 13

A method for detecting a fault in an electric power delivery system, comprising:
receiving a plurality of representations of electrical conditions associated with at least a portion of the electric power delivery system;
detecting a traveling wave event based on the plurality of representations of electrical conditions;
calculating an energy value of the traveling wave event during an accumulation period based on the detection of the traveling wave;
determining a maximum energy value and a minimum energy value of the energy value during the accumulation period;
determining a fault direction based on the maximum energy value and the minimum energy value;
declaring the fault based on the determined fault direction; and
implementing a protective action based on the declaration of the fault.

### Claim 14 (depends on 13)

The method of claim 13, further comprising monitoring each of a plurality of phases of the electric power delivery subsystem to detect the fault.

### Claim 15 (depends on 14)

The method of claim 14, further comprising determining a faulted phase based on the fault direction for each phase.

### Claim 16 (depends on 13)

The method of claim 13, further comprising calculating the energy value as a sign-inverted product of a plurality of traveling wave voltage and a plurality of traveling wave currents.

### Claim 17 (depends on 13)

The method of claim 13, further comprising determining the fault direction by comparing each of the maximum energy value and the minimum energy value to an energy threshold.

### Claim 18 (depends on 17)

The method of claim 17, wherein the energy threshold value comprises a function of traveling wave directional element settings.

### Claim 19 (depends on 13)

The method of claim 13, wherein the protective action subsystem further comprises a directional comparison permissive overreaching transfer trip scheme activated by the determined fault direction.

### Claim 20 (depends on 13)

The method of claim 13, further comprising determining the accumulation period using a timer initiated when a plurality of traveling wave voltage measurements comprised in the plurality of representations of electrical conditions exceed a first threshold and a plurality of traveling wave current measurements comprised in the plurality of representations of electrical conditions exceed a second threshold.

### Claim 21 (depends on 13)

The method of claim 13, further comprising processing the plurality of representations of electrical conditions using a differentiator-smoother.