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EP-4741858-A2 - SYSTEMS AND METHODS FOR IMPEDANCE-BASED BROKEN CONDUCTOR DETECTION IN ELECTRIC DISTRIBUTION SYSTEMS

EP4741858A2EP 4741858 A2EP4741858 A2EP 4741858A2EP-4741858-A2

Abstract

Systems, methods, and computer-readable media are disclosed for impedance-based broken conductor detection in electric distribution systems. Upon the detection of a broken conductor, the affected overhead line will be de-energized before it hits the ground. An example method may include determining, during a first time period, a first impedance value measured by a first IED, and may further include determining, during a second time period that after the first time period, a second impedance value measured by the first IED. The method may further include determining a first ratio based on dividing a difference between the first impedance value and the second impedance value by the first impedance value, and may further include determining that the first ratio deviates from a threshold setpoint, and determining that a broken conductor condition occurs based on the first ratio deviating from the threshold setpoint.

Inventors

  • YIN, YUJIE
  • ZAMANI, MOHAMMAD AMIN
  • KRUGER, JOHANNES
  • BAYAT, HASAN

Assignees

  • GE Vernova Technology GmbH

Dates

Publication Date
20260513
Application Date
20220124

Claims (15)

  1. A method (700) comprising: determining, by a processor (242), during a first time period, a first impedance value measured by a first IED 105, wherein the first IED (105) is located at a feeder head (102) of a feeder associated with a distribution substation; determining, by the processor (242), during a second time period, a second impedance value measured by the first IED (105), wherein the second time period is after the first time period; determining, by the processor (242), a first ratio based on dividing a difference between the first impedance value and the second impedance value by the first impedance value; determining, by the processor (242), that the first ratio deviates from a threshold setpoint; and determining, by the processor (242), that a broken conductor condition occurs based on the first ratio deviating from the threshold setpoint; wherein the threshold setpoint is a first threshold setpoint associated with a first feeder load current of a distribution overhead line (110) associated with the feeder, the method (700) further comprising: determining, by the processor (242), that the first feeder load current is changed with time to a second feeder load current; determining, by the processor (242), a second threshold setpoint based on the second feeder load current; and adjusting, by the processor (242), the first threshold setpoint to the second threshold setpoint.
  2. The method (700) of claim 1, wherein the first impedance value and the second impedance value are with respect to a ground and are associated with a first phase of a distribution overhead line (110) associated with the feeder, the method (700) further comprising: determining, by the processor (242), during the second time period, a third impedance value measured by the first IED (105), wherein the third impedance value is associated with a second phase of the distribution overhead line (110) with respect to the ground; determining, by the processor (242), a second ratio based on dividing a difference between the second impedance value and the third impedance value by the third impedance value; and determining, by the processor (242), that the second ratio derives from the threshold setpoint, wherein determining that the broken conductor condition occurs is further based on the second ratio deviating from the threshold setpoint.
  3. The method (700) of any one of the preceding claims, further comprising: determining, by the processor (242), during the first time period, a fourth impedance value measured by the first IED (105), wherein the fourth impedance value is associated with the second phase relative to a third phase of a distribution overhead line (110) associated with the feeder; determining, by the processor (242), during the second time period, a fifth impedance value measured by the first IED, wherein the fifth impedance value is associated with the second phase relative to the third phase; determining, by the processor (242), a third ratio based on dividing a difference between the fourth impedance value and the fifth impedance value by the fourth impedance value; determining, by the processor (242), that the third ratio is less than the threshold setpoint; and determining, by the processor (242), that the broken conductor condition relative to the first phase occurs based on the third ratio being less than threshold setpoint.
  4. The method (700) of any one of the preceding claims, wherein the second feeder load current is greater than the first feeder load current, and wherein the second threshold setpoint is less than the first threshold setpoint.
  5. The method (700) of any one of the preceding claims, further comprising: storing, by the processor (242), two or more impedance values prior to receiving the second impedance value, wherein the two or more impedance values comprise the first impedance value; determining, by the processor (242), a time interval between the first time period and the second time period based on a sampling rate of an output of the IED (105), wherein the time interval is associated with a number of cycles of time of the output of the IED (105); and retrieving, by the processor (242), the first impedance value based on the time interval.
  6. The method (700) of any one of the preceding claims, wherein the broken conductor condition is a first broken conductor condition, wherein the first IED (105) is associated with a feeder main (102) of the feeder, the method (700) further comprising: determining, by the processor (242), during the first time period, a third impedance value measured by a second IED (105), wherein the second IED (106) is located at a downstream location of the feeder, and the second IED (106) is associated with a first branch of the feeder; determining, by the processor (242), during the second time period, a fourth impedance value measured by the second IED; determining, by the processor (242), a second ratio based on dividing a difference between the third impedance value and the fourth impedance value by the third impedance value; determining, by the processor (242), that the second ratio deviates from the threshold setpoint; determining, by the processor (242), that a second broken conductor condition occurs in the first branch based on the second ratio deviating from the threshold setpoint; and determining trip time for the second IED (106) associated with the second broken condition in coordination with the first IED (105) associated with the first broken condition.
  7. The method (700) of any one of the preceding claims, further comprising: sending an alarm signal indicative of the occurrence of the broken conductor condition to one or more monitoring and computing devices (280); and performing one or more corrective actions in response to the occurrence of the broken conductor condition, wherein the one or more corrective actions comprise sending a trip signal to the first IED (105).
  8. The method (700) of any one of the preceding claims, further comprising: storing, by the processor, prior to receiving the first impedance value, one or more previous impedance values and/or phasors measured and/or calculated by the first IED.
  9. The method (700) of claim 8, further comprising: determining, by the processor, prior the receiving the first impedance value, the threshold setpoint based at least in part on the one or more previous impedance values and/or phasors measured and/or calculated by the first IED.
  10. The method (700) of any one of the preceding claims, comprising: storing, by the processor, the first ratio for a plurality of phases; and updating, by the processor, the threshold setpoint, based at least in part on the stored first ratios for the plurality of phases.
  11. A system (100) comprising: a feeder; a first IED (105) configured to measure one or more impedance values, wherein the first IED (105) is located at a feeder head (102) of the feeder associated with a distribution substation; a memory (250) coupled to at least one processor (242); the at least one processor (242) configured to: determine, during a second time period, a second impedance value measured by the first IED (105), wherein the second time period is after the first time period; determine a first ratio based on dividing a difference between the first impedance value and the second impedance value by the first impedance value; determine that the first ratio deviates from a threshold setpoint; and determine that a broken conductor condition occurs based on the first ratio deviating from the threshold setpoint; wherein the threshold setpoint is a first threshold setpoint associated with a first feeder load current of a distribution overhead line (110) associated with the feeder, wherein the at least one processor (242) is further configured to: determine that the first feeder load current is changed with time to a second feeder load current; determine a second threshold setpoint based on the second feeder load current; and adjust the first threshold setpoint to the second threshold setpoint.
  12. The system (100) of claim 11, wherein the first impedance value and the second impedance value are with respect to a ground and are associated with a first phase of a distribution overhead line (110) associated with the feeder, wherein the at least one processor (242) is further configured to: determine, during the second time period, a third impedance value measured by the first IED (105), wherein the third impedance value is associated with a second phase of the distribution overhead line (110) with respect to the ground; determine a second ratio based on dividing a difference between the second impedance value and the third impedance value by the third impedance value; and determine that the second ratio derives from the threshold setpoint, wherein determining that the broken conductor condition occurs is further based on the second ratio deviating from the threshold setpoint.
  13. The system (100) of claim 12, wherein the at least one processor (242) is further configured to: determine, during the first time period, a fourth impedance value measured by the first IED (105), wherein the fourth impedance value is associated with the second phase relative to a third phase of a distribution overhead line (110) associated with the feeder; determine, during the second time period, a fifth impedance value measured by the first IED (105), wherein the fifth impedance value is associated with the second phase relative to the third phase; determine, a third ratio based on dividing a difference between the fourth impedance value and the fifth impedance value by the fourth impedance value; determine that the third ratio is less than the threshold setpoint; and determine that the broken conductor condition relative to the first phase occurs based on the third ratio being less than threshold setpoint.
  14. The system (100) of any one of claims 11-13, wherein the second feeder load current is greater than the first feeder load current, and wherein the second threshold setpoint is less than the first threshold setpoint.
  15. A computer program comprising instructions which when executed by at least once processor causes the at least one processor to perform the method of any one of claims 1-10.

Description

FIELD OF DISCLOSURE The present disclosure related to power distribution, and more particularly to systems and methods for impedance-based broken conductor detection. BACKGROUND An energized overhead power distribution line, also known as a conductor, may break and fall to the ground for a variety of reasons such as severe weather conditions, natural disasters, conductor clamp failures, tree fall, and/or fallen poles. When a 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, it produces electrical arcing which may 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 conventional methods may not detect all Hi-Z faults, and operation of an associated relay for downed conductor faults is not guaranteed. In addition, for such broken or falling conductors, conventional solutions may not be capable of detecting the condition and tripping the corresponding breaker(s) before the conductor touches the ground. DISCLOSURE OF INVENTION An aspect of the invention is to provide a method as defined in the claims. According to another aspect, the invention provides a system as defined in the claims. BRIEF DESCRIPTION OF THE DRAWINGS 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 leftmost 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 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. FIG. 1 is a schematic diagram of an example system and method illustrating impedance-based broken conductor detection in accordance with one or more example embodiments of the disclosure.FIG. 2 is a schematic illustration of another example system and method for impedance-based broken conductor detection in accordance with one or more example embodiments of the disclosure.FIG. 3 is a schematic diagram of an example impedance calculation with a moving window in accordance with one or more example embodiments of the disclosure.FIG. 4 is a schematic diagram illustrating an example relationship between adaptive threshold setpoints and feeder load in accordance with one or more example embodiments of the disclosure.FIG. 5 is a schematic diagram illustrating system parameter variation for an example single-phase fuse blown condition in accordance with one or more example embodiments of the disclosure.FIG. 6 is a schematic diagram illustrating an example logic diagram for broken conductor detection in accordance with one or more example embodiments of the disclosure.FIG. 7 is an example process flow diagram of an illustrative method for impedance-based broken conductor detection in accordance with one or more example embodiments of the disclosure.FIG. 8 is a schematic illustration of an example system and method illustrating multiple feeders controlled by a single controller for broken conductor detections in distribution systems in accordance with one or more example embodiments of the disclosure.FIG. 9 is a block diagram of an example of a machine or system for broken conductor detection in accordance with one or more example embodiments of the disclosure. DETAILED DESCRIPTION OVERVIEW This disclosure relates to, among other things, systems, methods, computer-readable media, techniques, and methodologies for impedance-based broken conductor detection to effectively detect broken or falling conductors and improve the performance of overhead distribution power lines. When an overhead power line, known as a conductor, breaks, an energized conductor falls to the ground causing a high-impedance fault and arcing, which may be difficult to detect via conventional protection elements. This may potentially cause wildfires if a protection system does not operate adequately fast. Conventional systems and methods may detect broken conductors in transmission systems, but the efficiency of the conventional systems and methods may be compromised in distribut