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CA-3174600-C - SYSTEMS AND METHODS FOR HIGH-SPEED FALLING CONDUCTOR PROTECTION IN ELECTRIC TRANSMISSION SYSTEMS

CA3174600CCA 3174600 CCA3174600 CCA 3174600CCA-3174600-C

Abstract

Systems, methods, and computer-readable media are disclosed for high-speed falling conductor protection in electric distribution systems. An example method may include calculating, by a processor, at a first time, and for each phase, one or more first impedance values associated with one or more terminals of a transmission line. The example method may also include calculating, by the processor, at a second time, and for each phase, one or more second impedance values associated with the one or more terminals. The example method may also include determining, by the processor, that a rate of change of an impedance of the one or more terminals is greater than a threshold rate of change. The example method may also include determining, by the processor and based on the determination that the rate of change of the one or more terminals is greater than the threshold rate of change, that the transmission line has broken. The example method may also include sending, by the processor and based on the determination that the transmission line has broken, a signal to de-energize the transmission line before a broken conductor reaches a ground surface.

Inventors

  • Yujie YIN
  • Mohammad Amin ZAMANI
  • Johannes KRUGER
  • Hasan BAYAT
  • STEPHAN D. PICARD

Assignees

  • GENERAL ELECTRIC TECHNOLOGY GMBH

Dates

Publication Date
20260505
Application Date
20220914
Priority Date
20210914

Claims (17)

  1. CLAIMS TuAT WHICH IS CLAIMED IS: 1. A method comprising: calculating, by a processor, at a first time, and for each phase, one or more first impedance values associated with one or more terminals of a transmission line; calculating, by the processor, at a second time, and for each phase, one or more second impedance values associated with the one or more terminals; determining, by the processor, using the one or more first impedance values and the one or more second impedance values, a current rate of change of an impedance of a first phase of the transmission line; determining, by the processor, a first rate of increase of the impedance of the first phase based on a ratio between the current rate of change of the impedance and a prior rate of change of the impedance; determining, by the processor, that the first rate of increase of the impedance of the first phase and a second rate of increase of a second impedance of a second phase of the transmission line are both greater than a threshold rate of change; comparing, by the processor, the first rate of increase of the impedance of the first phase to the second rate of increase of the second impedance of the second phase; determining, by the processor, based on the comparison of the first rate of increase of the impedance of the first phase to the second rate of increase of the second impedance of the second phase, that the first rate of increase is greater than the second rate of increase; determining, by the processor and based on the determination that the first rate of increase of the first phase is greater than the threshold rate of change, that the transmission line has broken; selecting, by the processor, based on determining that the first rate of increase is greater than the second rate of increase, the first phase instead of the second phase as a broken phase of the transmission line; and sending, by the processor and based on selecting the first phase as the broken phase, a signal to de-energize the first phase of the transmission line, instead of the second phase of the transmission line, before the broken phase of the transmission line reaches a ground surface.
  2. 2. The method of claim 1, wherein determining the current rate of change of the impedance Date re~ue/Date recieved 2024-04-30 26 is based on a ratio of a difference between a voltage of the one or more terminals and a difference between a current of the one or more terminals.
  3. 3. The method of claim 1, wherein determining that the first rate of increase and the second rate of increase are both greater than the threshold rate of change is based on a moving buffer.
  4. 4. The method of claim 1, wherein the one or more terminals includes either two terminals or three terminals.
  5. 5. The method of claim 1, wherein calculating the one or more first impedance values is based on data received from one or more intelligent electronic devices (IEDs) of the transmission line.
  6. 6. The method of claim 5, wherein the data includes at least one of: a Clarke voltage, a positive-sequence voltage, or synchrophasor data.
  7. 7. A system comprising: a computer processor operable to execute a set of computer-executable instructions; and memory operable to store the set of computer-executable instructions operable to: calculate, at a first time, for each phase, and based on a Clarke voltages, one or more first impedance values associated with one or more terminals of a transmission line; calculate, at a second time and for each phase, one or more second impedance values associated with the one or more terminals; determine, using the one or more first impedance values and the one or more second impedance values, a current rate of change of an impedance of a first phase of the transmission line; determine a first rate of increase of the impedance of the first phase based on a ratio between the current rate of change of the impedance and a prior rate of change of the impedance; determine, that the first rate of increase of the impedance of the first phase and a second rate of increase of a second impedance of a second phase of the transmission line are both greater than a threshold rate of change; compare the first rate of increase of the impedance of the first phase to the second rate of Date re~ue/Date recieved 2024-04-30 27 increase of the second impedance of the second phase; determine, based on the comparison of the first rate of increase of the impedance of the first phase to the second rate of increase of the second impedance of the second phase, that the first rate of increase is greater than the second rate of increase; determine, based on the determination that the first rate of increase of the first phase is greater than the threshold rate of change, that the transmission line has broken; select, based on determining that the first rate of increase is greater than the second rate of increase, the first phase instead of the second phase as a broken phase of the transmission line; and send, based on selecting the first phase as the broken phase, a signal to de-energize the first phase of the transmission line, instead of the second phase of the transmission line, before the broken phase of the transmission line reaches a ground surface.
  8. 8. The system of claim 7, wherein determining the current rate of change of the impedance is based on a ratio of a difference between a voltage of the one or more terminals and a difference between a current of the one or more terminals.
  9. 9. The system of claim 7, wherein determining that the first rate of increase and the second rate of increase are both greater than the threshold rate of change is based on a moving buffer.
  10. 10. The system of claim 7, wherein the one or more terminals includes either two terminals or three terminals.
  11. 11. The system of claim 7, wherein calculating the one or more first impedance values is based on data received from one or more intelligent electronic devices (IEDs) of the transmission line.
  12. 12. The system of claim 11, wherein the data includes at least one of: a positive-sequence voltage, or synchrophasor data.
  13. 13. A non-transitory computer-readable medium storing computer-executable instructions, that when executed by at least one processor, cause the at least one processor to: calculate, at a first time and for each phase, one or more first impedance values associated Date re~ue/Date recieved 2024-04-30 28 with one or more terminals of a transmission line; calculate, at a second time and for each phase, one or more second impedance values associated with the one or more terminals; determine, using the one or more first impedance values and the one or more second impedance values, a current rate of change of an impedance of a first phase of the transmission line; determine a first rate of increase of the impedance of the first phase based on a ratio between the current rate of change of the impedance and a prior rate of change of the impedance; determine, that the first rate of increase of the impedance of the first phase and a second rate of increase of a second impedance of a second phase of the transmission line are both greater than a threshold rate of change; compare the first rate of increase of the impedance of the first phase to the second rate of increase of the second impedance of the second phase; determine, based on the comparison of the first rate of increase of the impedance of the first phase to the second rate of increase of the second impedance of the second phase, that the first rate of increase is greater than the second rate of increase; determine, based on the determination that the first rate of increase of the first phase is greater than the threshold rate of change, that the transmission line has broken; determine select, based on determining that the first rate of increase is greater than the second rate of increase, the first phase instead of the second phase as a broken phase of the transmission line; and send, based on selecting the first phase as the broken phase, a signal to de-energize the first phase of the transmission line, instead of the second phase of the transmission line, before the broken phase of the transmission line reaches a ground surface.
  14. 14. The non-transitory computer-readable medium of claim 13, wherein determining the current rate of change of the impedance is based on a ratio of a difference between a voltage of the one or more terminals and a difference between a current of the one or more terminals.
  15. 15. The non-transitory computer-readable medium of claim 13, wherein determining that the first rate of increase and the second rate of increase are both greater than the threshold rate of Date re~ue/Date recieved 2024-04-30 29 change is based on a moving buffer.
  16. 16. The non-transitory computer-readable medium of claim 13, wherein the one or more terminals includes either two terminals or three terminals.
  17. 17. The non-transitory computer-readable medium of claim 13, wherein calculating the one or more first impedance values is based on data received from one or more intelligent electronic devices (IEDs) of the transmission line. Date re~ue/Date recieved 2024-04-30

Description

1 SYSTEMS AND METHODS FOR HIGH-SPEED FALLING CONDUCTOR PROTECTION IN ELECTRIC TRANSMISSION SYSTEMS FIELD OF DISCLOSURE [0001] The present disclosure is related to power transmission, and more particularly to systems and methods for high-speed falling conductor detection (FCD) or falling conductor protection (FCP) in electric transmission systems. BACKGROUND [0002] An energized overhead power line can break and fall to the ground or other objects for a variety of reasons such as severe weather conditions, natural disasters, conductor clamp failures, tree fall and/or pole knock-overs. When the falling conductor touches the earth or other grounded objects, it may cause a high-impedance (Hi-Z) fault which may not be reliably detected by conventional overcurrent protection schemes. Moreover, as the live conductor contacts the ground, the conductor may produce electrical arcing, which can ignite flammable materials or vegetation and start a fire. An undetected Hi-Z fault is a risk to people and their properties as well as having a potential to evolve into a full-blown fault. Most of the conventional methods are not able to detect all Hi-Z faults, and operation of the relay for downed conductor faults is not guaranteed. In addition, for the broken or falling conductors, it is expected to detect the condition and trip the corresponding breaker(s) before the conductor touches the ground. BRIEF DESCRIPTION OF THE DRAWINGS [0003] The detailed description is set forth with reference to the accompanying drawings. The drawings are provided for purposes of illustration only and merely depict example embodiments of the disclosure. The drawings are provided to facilitate understanding of the disclosure and shall not be deemed to limit the breadth, scope, or applicability of the disclosure. In the drawings, the left-most digit(s) of a reference numeral may identify the drawing in which the reference numeral first appears. The use of the same reference numerals indicates similar, but not necessarily the same or identical components. However, different reference numerals may be used to identify similar components as well. Various embodiments may utilize elements or components other than those illustrated in the drawings, and some elements and/or components may not be present in 46550773.1 Date Re9ue/Date Received 2022-09-14 2 various embodiments. The use of singular terminology to describe a component or element may, depending on the context, encompass a plural number of such components or elements and vice versa. [0004] FIG. 1 is a schematic diagram of an example system, in accordance with one or more example embodiments of the disclosure. [0005] FIG. 2 is a schematic illustration of another example system, in accordance with one or more example embodiments of the disclosure. [0006] FIG. 3 is a schematic illustration of another example system, in accordance with one or more example embodiments of the disclosure. [0007] FIG. 4 is a schematic diagram of an example flow diagram, in accordance with one or more example embodiments of the disclosure. [0008] FIG. 5 is a schematic diagram of an example flow diagram, in accordance with one or more example embodiments of the disclosure. [0009] FIG. 6 is a schematic diagram of an example system, in accordance with one or more example embodiments of the disclosure. [0010] FIG. 7 is a schematic diagram of an example system, in accordance with one or more example embodiments of the disclosure. [0011] FIG. 8 is a block diagram of an example method, in accordance with one or more example embodiments of the disclosure. [0012] FIG. 9 is a block diagram of an example of a machine or system for high impedance detection, in accordance with one or more example embodiments of the disclosure. DETAILED DESCRIPTION OVERVIEW [0013] This disclosure relates to, among other things, systems, methods, computer-readable media, techniques, and methodologies for high-speed falling conductor detection in electric transmission systems. The algorithm described herein may address the challenges associated with broken conductor detection for two- and three-terminal transmission lines using data received from other end(s) of the transmission line (for example, data, such as voltage and/or current data exchanged between intelligent relays associated with the transmission line). While the descriptions provided herein may be specific to two- and three-terminal transmission lines, similar methods 46550773.1 Date Re9ue/Date Received 2022-09-14 3 may be applicable to transmission lines with any other number of terminals as well. To ensure that the most updated data is used for detection purposes, the algorithm described herein may also ensure that the data exchanged between relays and/or a centralized controller (described in further detail below) is time synchronized and up-to-date. Additionally, since during a broken conductor scenario a transmission line conductor may typically only take between one and two seconds to