US-12618887-B2 - Parameter independent traveling wave-based fault location using unsynchronized measurements

Abstract

Examples of fault location in a power transmission line connecting a first and a second terminal is described. In an example, arrival times of a first peak, a second peak, and a third peak of a travelling wave detected from measurements carried out at the first and second terminals is detected. A rise time associated with the first peak of the travelling wave is calculated. One of a first half and a second half of the power transmission line is identified, as having a fault, based on a comparison of the rise time. One of a first segment, a second segment, a third segment, and a fourth segment of the power transmission line is identified as having the fault. Length of the power transmission line is estimated. The fault location is estimated based on identification of one of the first, second, third, and fourth segments as having the fault.

Inventors

• OD NAIDU
• Preetham Venkat Yalla
• Neethu GEORGE

Assignees

• HITACHI ENERGY LTD

Dates

Publication Date

20260505

Application Date

20231009

Priority Date

20200130

Claims (20)

1. 1 . A method for fault location in a power transmission line connecting a first terminal with a second terminal, the method comprising: obtaining arrival times of a first peak, a second peak, and a third peak of a travelling wave detected from measurements carried out at each of the first and second terminals; calculating a rise time associated with the first peak of the travelling wave detected from the measurements carried out at the first and second terminals; identifying one of a first half and a second half of the power transmission line as having a fault, based on a comparison of the rise time estimated for the first peak of the travelling wave at the first and second terminals; identifying a segment of the power transmission line as having the fault, based on the identification of one of the first and the second half as having the fault, and a comparison of the arrival times of the first, second, and third peaks of the travelling wave at the first terminal or the second terminal; estimating a length of the power transmission line based on the identified segment, the arrival time of the first peak of the travelling wave reflected from the second terminal detected from the measurements carried out at the first terminal, and the arrival time of the first peak of the travelling wave reflected from the first terminal detected from the measurements carried out at the second terminal; and estimating the fault location based on the identified segment, the arrival times of the first, second, and third peaks of the travelling wave detected from measurements carried out at the first and second terminals, and the estimated length of the power transmission line.
2. 2 . The method as claimed in claim 1 , wherein the fault is identified in the first half of the power transmission line if T ART is less than T BRT , and the fault is identified in the second half of the power transmission line if T ART is greater than T BRT , wherein T ART is the rise time of the first peak of the travelling wave detected from the measurements carried out at the first terminal, and T BRT is the rise time of the first peak of the travelling wave detected from the measurements carried out at the second terminal.
3. 3 . The method as claimed in claim 1 , wherein identifying a segment of the power transmission line as having the fault comprises: in response to identifying the first half of the power transmission line as having the fault, determining a first difference between the arrival times, wherein the first difference is an absolute difference between arrival times of two consecutive peaks among the first, second, and third peaks of the travelling wave detected from the measurements carried out at the second terminal, and identifying one of a plurality of segments within the first half of the power transmission line as having the fault, based on the first difference; and in response to identifying the second half of the power transmission line as having the fault, determining a second difference between the arrival times, wherein the second difference is an absolute difference between arrival times of two consecutive peaks among the first, second, and third peaks of the travelling wave detected from the measurements carried out at the second terminal, and identifying one of a plurality of segments within the second half of the power transmission line as having the fault, based on the second difference.
4. 4 . The method as claimed in claim 1 , wherein estimating the length of the power transmission line comprises: when the identified segment is in a first range from the first terminal to one-third of the length of the power transmission line, calculating a first estimated length of the power transmission line proportional to a sum of a difference between the arrival times of the first and second peaks of the travelling wave detected from the measurements carried out at the first terminal and a difference between the arrival times of the first peak of the travelling wave reflected from the second terminal and the second peak of the travelling wave detected from the measurements carried out at the first terminal; when the identified segment is in a second range that is a middle one-third of the length of the power transmission line, calculating a second estimated length of the power transmission line proportional to a difference between a sum of the arrival times of the second and third peaks of the travelling wave detected from the measurements carried out at the first terminal and twice the arrival time of the first peak detected from the measurements carried out at the first terminal; and when the identified segment is in a third range from the second terminal to one-third of the length of the power transmission line, calculating a third estimated length of the power transmission line proportional to the sum of a difference between the arrival times of the first and second peaks of the travelling wave detected from the measurements carried out at the second terminal and a difference between the arrival times of the first peak of the travelling wave reflected from the first terminal and the second peak of the travelling wave detected from the measurements carried out at the second terminal.
5. 5 . The method as claimed in claim 4 , wherein the fault location in the first range of the power transmission line is estimated from a ratio of a difference between the arrival times of the second and first peaks of the travelling wave detected from measurements carried out at the first terminal to the first estimated length and expressed in terms of fault location per unit length.
6. 6 . The method as claimed in claim 4 , wherein the fault location in a first half of the second range of the power transmission line, closest to the first terminal, is estimated from a ratio of a difference between the arrival times of the second and first peaks of the travelling wave detected from measurements carried out at the first terminal to the second estimated length and expressed in terms of fault location per unit length.
7. 7 . The method as claimed in claim 4 , wherein the fault location in a second half of the second range of the power transmission line, closest to the second terminal, is estimated from a ratio of a difference between the arrival times of the third and first peaks of the travelling wave detected from measurements carried out at the first terminal to the second estimated length and expressed in terms of fault location per unit length.
8. 8 . The method as claimed in claim 4 , wherein the fault location in the third range of the power transmission line is estimated from a ratio of a sum of the difference between the arrival times of the first and second peaks of the travelling wave detected from the measurements carried out at the second terminal and a difference between the arrival times of the first peak of the travelling wave reflected from the first terminal and the second peak of the travelling wave detected from the measurements carried out at the second terminal to the third estimated length and expressed in terms of fault location per unit length.
9. 9 . A device for fault location in a power transmission line connecting a first terminal with a second terminal, the device comprising: a travelling wave detector to detect a first peak, a second peak, and a third peak of a travelling wave detected from measurements carried out at the first and second terminals, obtain arrival times of the first peak, the second peak, and the third peak of the travelling wave detected from measurements carried out at the first and second terminals, and calculate a rise time associated with the first peak of the travelling wave detected from the measurements carried out at the first and second terminals; a fault localization module configured to identify one of a first half and a second half of the power transmission line, as having a fault, based on a comparison of the calculated rise time associated with the first peak of the travelling wave; identify a segment of the power transmission line as having the fault, based on the identification of one of the first and the second half as having the fault, and a comparison of the arrival times of the first, second, and third peaks of the travelling wave; and a fault location module coupled to a processor to estimate a length of the power transmission line based on the identified segment, the arrival time of the first peak of the travelling wave reflected from the second terminal detected from the measurements carried out at the first terminal, and the arrival time of the first peak of the travelling wave reflected from the first terminal detected from the measurements carried out at the second terminal, and estimate the fault location based on the identified segment, the arrival times of the first, second, and third peaks of the travelling wave detected from measurements carried out at the first and second terminals, and the estimated length of the power transmission line.
10. 10 . The device as claimed in claim 9 , wherein the device is an intelligent electronic device associated with one of the first and the second terminal, and wherein the device receives the measurements carried out at each of the first and second terminals from at least one of a measurement equipment and communication interface associated with each of the first and second terminals.
11. 11 . The device as claimed in claim 9 , wherein the fault is identified in the first half of the power transmission line if T ART is less than T BRT , and the fault is identified in the second half of the power transmission line if T ART is greater than T BRT , wherein T ART is the rise time of the first peak of the travelling wave detected from the measurements carried out at the first terminal, and T BRT is the rise time of the first peak of the travelling wave detected from the measurements carried out at the second terminal.
12. 12 . The device as claimed in claim 9 , wherein identifying a segment of the power transmission line as having the fault comprises: in response to identifying the first half of the power transmission line as having the fault, determining a first difference between the arrival times, wherein the first difference is an absolute difference between arrival times of two consecutive peaks among the first, second, and third peaks of the travelling wave detected from the measurements carried out at the second terminal, and identifying one of a plurality of segments within the first half of the power transmission line as having the fault, based on the first difference; and in response to identifying the second half of the power transmission line as having the fault, determining a second difference between the arrival times, wherein the second difference is an absolute difference between arrival times of two consecutive peaks among the first, second, and third peaks of the travelling wave detected from the measurements carried out at the second terminal, and identifying one of a plurality of segments within the second half of the power transmission line as having the fault, based on the second difference.
13. 13 . The device as claimed in claim 9 , wherein estimating the length of the power transmission line comprises: when the identified segment is in a first range from the first terminal to one-third of the length of the power transmission line, calculating a first estimated length of the power transmission line proportional to a sum of a difference between the arrival times of the first and second peaks of the travelling wave detected from the measurements carried out at the first terminal and a difference between the arrival times of the first peak of the travelling wave reflected from the second terminal and the second peak of the travelling wave detected from the measurements carried out at the first terminal; when the identified segment is in a second range that is a middle one-third of the length of the power transmission line, calculating a second estimated length of the power transmission line proportional to a difference between a sum of the arrival times of the second and third peaks of the travelling wave detected from the measurements carried out at the first terminal and twice the arrival time of the first peak detected from the measurements carried out at the first terminal; and when the identified segment is in a third range from the second terminal to one-third of the length of the power transmission line, calculating a third estimated length of the power transmission line proportional to the sum of a difference between the arrival times of the first and second peaks of the travelling wave detected from the measurements carried out at the second terminal and a difference between the arrival times of the first peak of the travelling wave reflected from the first terminal and the second peak of the travelling wave detected from the measurements carried out at the second terminal.
14. 14 . The device as claimed in claim 13 , wherein the fault location in the first range of the power transmission line is estimated from a ratio of a difference between the arrival times of the second and first peaks of the travelling wave detected from measurements carried out at the first terminal to the first estimated length and expressed in terms of fault location per unit length.
15. 15 . The device as claimed in claim 13 , wherein the fault location in a first half of the second range of the power transmission line, closest to the first terminal, is estimated from a ratio of a difference between the arrival times of the second and first peaks of the travelling wave detected from measurements carried out at the first terminal to the second estimated length and expressed in terms of fault location per unit length.
16. 16 . The device as claimed in claim 13 , wherein the fault location in a second half of the second range of the power transmission line, closest to the second terminal, is estimated from a ratio of a difference between the arrival times of the third and first peaks of the travelling wave detected from measurements carried out at the first terminal to the second estimated length and expressed in terms of fault location per unit length.
17. 17 . The device as claimed in claim 13 , wherein the fault location in the third range of the power transmission line is estimated from a ratio of a sum of the difference between the arrival times of the first and second peaks of the travelling wave detected from the measurements carried out at the second terminal and a difference between the arrival times of the first peak of the travelling wave reflected from the first terminal and the second peak of the travelling wave detected from the measurements carried out at the second terminal to the third estimated length and expressed in terms of fault location per unit length.
18. 18 . A non-transitory computer-readable medium having instructions stored thereon, wherein the instructions, when executed by a processor, cause the processor to perform a method comprising: obtaining arrival times of a first peak, a second peak, and a third peak of a travelling wave detected from measurements carried out at each of the first and second terminals; calculating a rise time associated with the first peak of the travelling wave detected from the measurements carried out at the first and second terminals; identifying one of a first half and a second half of the power transmission line as having a fault, based on a comparison of the rise time estimated for the first peak of the travelling wave at the first and second terminals; identifying a segment of the power transmission line as having the fault, based on the identification of one of the first and the second half as having the fault, and a comparison of the arrival times of the first, second, and third peaks of the travelling wave at the first terminal or the second terminal; estimating a length of the power transmission line based on the identified segment, the arrival time of the first peak of the travelling wave reflected from the second terminal detected from the measurements carried out at the first terminal, and the arrival time of the first peak of the travelling wave reflected from the first terminal detected from the measurements carried out at the second terminal; and estimating the fault location based on the identified segment, the arrival times of the first, second, and third peaks of the travelling wave detected from measurements carried out at the first and second terminals, and the estimated length of the power transmission line.
19. 19 . The non-transitory computer-readable medium as claimed in claim 18 , wherein the fault is identified in the first half of the power transmission line if T ART is less than T BRT , and the fault is identified in the second half of the power transmission line if T ART is greater than T BRT , wherein T ART is the rise time of the first peak of the travelling wave detected from the measurements carried out at the first terminal, and T BRT is the rise time of the first peak of the travelling wave detected from the measurements carried out at the second terminal.
20. 20 . The non-transitory computer-readable medium as claimed in claim 18 , wherein identifying a segment of the power transmission line as having the fault comprises: in response to identifying the first half of the power transmission line as having the fault, determining a first difference between the arrival times, wherein the first difference is an absolute difference between arrival times of two consecutive peaks among the first, second, and third peaks of the travelling wave detected from the measurements carried out at the second terminal, and identifying one of a plurality of segments within the first half of the power transmission line as having the fault, based on the first difference; and in response to identifying the second half of the power transmission line as having the fault, determining a second difference between the arrival times, wherein the second difference is an absolute difference between arrival times of two consecutive peaks among the first, second, and third peaks of the travelling wave detected from the measurements carried out at the second terminal, and identifying one of a plurality of segments within the second half of the power transmission line as having the fault, based on the second difference.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of U.S. application Ser. No. 17/795,300, filed on Jul. 26, 2022, which is a national stage entry of International Application No. PCT/EP2021/052221, filed on Jan. 29, 2021, which claims priority to Indian Application No. 202041004115, filed on Jan. 30, 2020, which are all hereby incorporated herein by reference as if set forth in full. TECHNICAL FIELD The present disclosure relates, in general, to fault location in power transmission lines. In particular, the present disclosure relates to traveling wave-based fault location independent of line parameters and using unsynchronized measurements. BACKGROUND An electric power transmission system is a large and complex network that consists of transmission and distribution lines and numerous electrical components such as generators, transformers, relays, Intelligent electronic devices (IEDs), etc. Transmission lines are often subjected to faults due to storms, lightning, snow, freezing rain, insulation breakdown, and short circuit faults caused by birds, tree branches, and other external objects. Generally, fault is defined as an abnormal condition of the electrical system causing disruption in the normal flow of electric current. This deviated flow of electric current causes change in voltage and/or current flow, which interrupts power transmission. Restoration of power supply after faults can be done only after the maintenance team finishes the repair of the damage caused by the fault. Thus, accurate fault location in transmission lines is important, so that the maintenance crew can reach the fault location and undertake repair to restore the power transmission. Quick identification of fault location improves the reliability, restoration of power supply and reduce the revenue loss for the utilities. SUMMARY The present disclosure relates to a method for fault location in a power transmission line connecting a first terminal with a second terminal, the method comprising obtaining arrival times of a first peak, a second peak, and a third peak of a travelling wave detected from measurements carried out at each of the first and second terminals; calculating a rise time associated with the first peak of the travelling wave detected from the measurements carried out at the first and second terminals; identifying one of a first half and a second half of the power transmission line, as having a fault, based on a comparison of the rise time estimated for the first peak of the travelling wave at the first and second terminals; identifying one of a first segment, a second segment, a third segment, and a fourth segment of the power transmission line as having the fault, based on the identification of one of the first and the second half as having the fault, and a comparison of the arrival times of the first, second, and third peaks of the travelling wave at the first and second terminals; estimating lengths of the power transmission line based on identification of one of the first, second, third, and fourth segments as having the fault, a comparison of the arrival times of the first, second, and third peaks of the travelling wave, arrival time of a first peak of a travelling wave reflected from the second terminal detected from the measurements carried out at the first terminal, and arrival time of a first peak of a travelling wave reflected from the first terminal detected from the measurements carried out at the second terminal; and estimating the fault location based on the identification of one of the first, second, third, and fourth segments as having the fault, the arrival times of the first, second, and third peaks of the travelling wave detected from measurements carried out at the first and second terminals, and estimated lengths of the power transmission line. The present disclosure also relates to a device for fault location in a power transmission line connecting a first terminal with a second terminal, the device comprising: a travelling wave detector to detect a first peak, a second peak, and a third peak of a travelling wave detected from measurements carried out at the first and second terminals; obtain arrival times of the first peak, the second peak, and the third peak of the travelling wave detected from measurements carried out at the first and second terminals; and calculate a rise time associated with the first peak of the travelling wave detected from the measurements carried out at the first and second terminals; a fault localization module configured to: identify one of a first half and a second half of the power transmission line, as having a fault, based on a comparison of the calculated rise time associated with the first peak of the travelling wave; identify one of a first segment, a second segment, a third segment, and a fourth segment of the power transmission line as having the fault, based on the identification of one of the first and the second half as having