METHOD FOR ISOLATING A LEAKAGE IN AN ELECTRICAL POWER DISTRIBUTION NETWORK

Abstract

A system and method for providing fault isolation in a power distribution network. The network includes a power line, a recloser coupled to the power line and a plurality of switching devices coupled to the power line downstream of the recloser, where each switching device is capable of detecting fault current in response to the fault and detecting presence of voltage. In one non-limiting embodiment, the method includes detecting overcurrent, loss of voltage and return of voltage by the switching devices and includes sequentially opening and closing switching devices from the recloser to a switching device immediately upstream of the fault in response to detecting overcurrent, loss of voltage and return of voltage.

Description

METHOD FOR ISOLATING A LEAKAGE IN AN ELECTRICAL POWER DISTRIBUTION NETWORK CROSS-REFERENCE TO RELATED REQUEST

[001] This application claims the benefit of priority under U.S. Provisional Application No. 63 / 588,845, filed October 9, 2023, the description of which is hereby incorporated by reference for all purposes. FUNDAMENTALS FIELD

[002] The present description refers, in general, to a system and method for providing leakage isolation in an electrical power distribution network. DISCUSSION OF THE RELATED TECHNIQUE

[003] An electrical power distribution network, often referred to as the power grid, typically includes power generation plants, each having power generators such as gas turbines, nuclear reactors, coal-fired generators, hydroelectric dams, etc. The power plants provide power at a variety of medium voltages which are then stepped up by transformers to a high-voltage AC signal to be connected to high-voltage transmission lines that supply electrical power to substations, usually located within a community, where the voltage is reduced to a medium voltage for distribution. The substations supply medium-voltage power to three-phase feeders, including three single-phase feeder lines that carry the same current but are separated by 120° in phase.Three-phase and single-phase branch lines are derived from the feeder that provides the medium voltage to several distribution transformers, where the voltage is reduced to low voltage and supplied to loads such as homes and businesses.

[004] Periodically, leaks occur in the distribution network in Petition 870260025984, dated 03 / 20 / 2026, page 13 / 35 2 / 13 Consequences include reasons such as animals touching the lines, lightning strikes, tree branches falling on the cables, vehicle collisions with light poles, etc. Leaks can create a short circuit that increases the voltage in the network, which can cause the current flow to increase significantly, for example, many times above the normal current, along the path of the leak. This amount of current causes the power lines to heat up significantly and possibly melt, and can also cause mechanical damage to various network components. These leaks are often transient or intermittent leaks, as opposed to a persistent or zero-impedance leak, in which the thing that caused the leak is removed shortly after the leak occurs, for example, a lightning strike. In these cases, the distribution network will begin to function normally almost immediately after a brief disconnection from the power source.

[005] Traditionally, a fuse is installed as a primary overload protection device for distribution transformers and other devices, and the type and rating are selected so that the fuse does not operate at normally expected current magnitudes, such as transformer inrush current, but operates at faster times compared to the transformer through resistance curve protection against external transformer leakage or damage. However, expulsion fuses often create byproducts during operation, which presents obvious disadvantages in some circumstances.

[006] Reclosers and other related leakage interruption devices are often applied by distribution motors as protective devices on power line transmission poles and other locations. These reclosers typically sense the current and / or voltage on the line to monitor current flow and have controls that indicate problems with the network circuit, such as the detection of a high leakage current event. If such a leakage current is detected, the recloser is opened. Petition 870260025984, dated 03 / 20 / 2026, page 14 / 35 3 / 13 in response to this, and then, after a short delay, it is closed to determine if the leakage is a transient leakage. If a high leakage current flows when the recloser is closed after opening, it will be immediately reopened. If the leakage current is detected a second time or multiple times during subsequent opening and closing operations, indicating a persistent leakage, then the recloser remains open and may come out of its assembly or may provide another form of indication that it is locked in the open position, in which the time between detection tests may increase after each test.

[007] When a leakage is detected, it is desirable that the first leakage interruption device upstream of the leakage be opened as soon as possible so that the leakage is quickly removed from the network to prevent damage to equipment, personal injury, fire, etc., and so that loads upstream of that leakage interruption device are not disconnected from the power supply and service to them is not interrupted. It is also desirable that if the first leakage interruption device upstream of the leakage does not open for any reason, then a subsequent leakage interruption device upstream of the leakage be opened, and so on. For this objective to be achieved, it is necessary that some type of communications protection or coordination scheme be employed in the network so that the desired leakage interruption device is opened in response to the leakage.

[008] A known protection scheme for this purpose is called a time-current characteristic curve (TCC) coordination scheme in engineering. In general, for a TCC coordination scheme, each leakage interrupter in a particular series of leakage interrupters is assigned a TCC curve that defines how quickly the leakage interrupter will open in response to the detected current, where the timing value of the TCC curve is more Petition 870260025984, dated 03 / 20 / 2026, page 15 / 35 4 / 13 long for lower currents and shorter for higher currents, and the settings entered in the specific recloser control define the TCC curve. Devices with dual TCC curves (fast and slow) are typically used in systems where protection consists of both fuses and leakage interruption devices with relays and / or reclosers. In fuse-free systems, a single TCC curve is more commonly used. As they are supplied further downstream from the source, leakage interruption devices are typically configured with faster TCC curves so that the first leakage interruption device upstream of a detected leakage will open before a subsequent upstream interruption device, where the particular leakage interruption device will stop timing on its TCC curve once the downstream leakage interruption device opens and the leakage is removed.However, traditional TCC coordination schemes are limited in the number of leakage interruption devices a feeder can have, as the TCC curves cannot be too close to each other for coordination to be effective. In other words, the number of TCC curves that can actually be applied is limited. Furthermore, when multiple leakage interruption devices are applied to a feeder, it is necessary that the devices installed near the source operate relatively slowly to coordinate properly with the multiple devices along the line. SUMMARY

[009] The following discussion reveals and describes a system and method for isolating a leakage current in an electrical power distribution network. The network includes an electrical power line, a recloser coupled to the electrical power line, and a plurality of switching devices coupled to the electrical power line downstream of the recloser, wherein each switching device has the capability to detect leakage current in response to the leakage and to Petition 870260025984, dated 03 / 20 / 2026, page 16 / 35 5 / 13 detect the presence of voltage. The method includes detecting overcurrent in the network due to leakage by the recloser and all switching devices positioned along a leakage path between the recloser and the leakage location, interrupting the overcurrent by opening the recloser based on an initial tripping profile TCC curve, and detecting voltage loss or absence of current when the recloser is opened by the switching devices along the leakage path.The method additionally includes recording a leakage count for each switching device that detected the overcurrent and then voltage loss or absence of current, opening each switching device that recorded a predetermined number of leakage counts, and changing the initial tripping profile TCC curve of the recloser to an operational tripping profile TCC curve that is slower than the initial tripping profile TCC curve and is coordinated with the interruption and leakage tripping profile TCC curves of the switching devices along the leakage path when the recloser is opened and the predetermined number of leakage counts has been reached.The method also includes closing a first downstream switching device after a predetermined closing time period when the recloser closes, activating a TCC (Threaded Circuit Breaker) profile of the first switching device during a waiting time before the predetermined closing time period has ended, and closing a subsequent downstream switching device after the predetermined closing time period when the first switching device closes. The method further includes activating a TCC profile of the next switching device during a waiting time before the predetermined closing time period has ended, and deactivating the TCC profile of the first switching device before the next device closes. Petition 870260025984, dated 03 / 20 / 2026, page 17 / 35 6 / 13 Switching is closed and the switching devices sequentially close along the leakage path until a switching device immediately upstream of the leakage is closed and detects leakage overcurrent and then opens due to its fast TCC curve, where that switching device remains open.

[0010] Additional features of the description will become apparent from the following description and the appended claims, considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a simplified schematic diagram of an electrical power distribution network that includes leakage interruption devices; Figure 2 is a simplified schematic block diagram of a leakage interruption device; Figure 3 is a logarithmic graph with current in amperes on the horizontal geometric axis and time in seconds on the vertical geometric axis, showing an initial trip profile TCC curve for the recloser shown in Figure 1; and Figure 4 is a logarithmic graph with current in amperes on the horizontal geometric axis and time in seconds on the vertical geometric axis, showing a TCC (Transmission Control Chart) profile curve for the recloser shown in Figure 1 and a TCC profile curve for the leakage interruption tripping of the disconnectors shown in Figure 1. DETAILED DESCRIPTION OF THE MODALITIES

[0012] The following discussion of the description modalities refers to a system and method for providing leakage isolation in an electrical power distribution network, wherein the method includes sequentially opening and closing line switching devices installed downstream of Petition 870260025984, dated 03 / 20 / 2026, p. 18 / 35 7 / 13 A recloser that results in the opening of only the switching device immediately upstream of the fault in response to the detection of overcurrent, voltage loss and voltage return is of an illustrative nature only and should in no way limit the invention or its applications or uses.

[0013] Figure 1 is a simplified schematic diagram of an electrical power distribution network 10. The network 10 includes an AC power source 12, such as a substation that provides power on a three-phase feeder 14, where a circuit breaker 16 is provided on the feeder 14 near the source 12. A single-phase main branch 18 is served by the feeder 14, and single-phase sub-branches 20 and 22 are served by the branch 18. In other embodiments, branches 18, 20, and 22 may be two-phase or three-phase branches. A recloser 24 is provided on branch 18 near the connection location to the feeder 14.A leakage disconnector 26 is provided on branch 18 between sub-branches 20 and 22, a leakage disconnector 28 is provided on branch 18 downstream of sub-branch 22, a leakage disconnector 30 is provided on sub-branch 20 near the connection location to branch 18, and a leakage disconnector 32 is provided on sub-branch 22 near the connection location to branch 18, wherein the disconnectors 26-32 include contacts 34 and a suitable device 36 for detecting voltage loss and return. The recloser 24 and the disconnectors 26-32 are shown in their closed position.

[0014] This description provides a leakage isolation scheme for an electrical power distribution network. If a leakage 38 occurs, for example, in sub-branch 22, the protection scheme will operate so that the disconnector 32 opens, removing power from the loads served by sub-branch 22, but power will be maintained for the rest of the network 10. The recloser 24 has reclosing capabilities, but the disconnectors 26-32, although designed and built to close on a leakage, do not function in the same way as the recloser 24. The leakage disconnectors 26-32 have the capacity to identify a leakage event by detecting the overcurrent followed by Petition 870260025984, dated 03 / 20 / 2026, page 19 / 35 8 / 13 loss of voltage or absence of current as a result of recloser 24 opening in a reclosing operation to clear the leakage, whereas disconnectors 26-32 register each leakage event as a leakage count. Each disconnector 26-32 is programmed to open its contacts 34 if it registers a predetermined number of leakage counts after a certain delay. Each disconnector 26-32 is also programmed to open after a certain number of leakage counts that would be less than the number of overcurrent detections by recloser 24, so that all disconnectors upstream of the leakage and downstream of the recloser in the leakage path current open before recloser 24 locks in the open position. Disconnectors 26-32 have the capability to detect or measure current, but are not required to measure voltage; they only determine the presence of voltage in the specific mode under discussion.In other configurations, the 26-32 disconnectors can operate in the manner discussed in this document only by detecting overcurrent and absence of current, and not by detecting the presence of voltage.

[0015] Figure 2 is a simplified schematic block diagram of a leakage interruption device 50 intended to be a general, non-limiting representation of either the recloser 24 or one of the leakage disconnectors 26-32. The device 50 includes a switch 52, for example, a vacuum switch, voltage / current sensors 54, a controller 56, a memory 58, and an optional communications device 60, for example, a cellular radio or other communications technology device, wherein the memory 58 stores executable code for performing the various calculations and operations discussed in this document.

[0016] Figure 3 is a logarithmic graph with current in amperes on the horizontal geometric axis and time in seconds on the vertical geometric axis showing a TCC curve with an initial tripping profile of 70 for recloser 24. The 70 curve has a certain width where one side Petition 870260025984, dated 03 / 20 / 2026, page 20 / 35 9 / 13 of the left side of curve 70 is the minimum tripping time of recloser 24, and the right side of curve 70 is the maximum clearing time of recloser 24 when all tolerances are applied. As will be discussed in more detail below, when tripping open in response to leakage current detection based on curve TCC 70, recloser 24 will then change its TCC curve tripping profile so that it is coordinated with downstream disconnectors 26-32 to allow disconnectors 26-32 to clear the leakage before recloser 24 operates again.

[0017] Figure 4 is a logarithmic graph with current in amperes on the horizontal geometric axis and time in seconds on the vertical geometric axis showing an example of a TCC curve with an operational tripping profile 72 for recloser 24 and disconnectors 26-32 after leakage 38 is detected and interrupted by recloser 24, wherein TCC curve 72 replaces TCC curve 70 for recloser 24 and a TCC curve with a leakage interruption tripping profile 74 is used by all disconnectors along the leakage path. As will be evident from Figure 4, disconnectors 26-32 will operate before recloser 24 and thus recloser 24 will only be opened and closed once for any leakage downstream of any of the disconnectors 26-32.

[0018] When leakage 38 occurs in branch 22 downstream of disconnector 32, recloser 24 and disconnectors 26 and 32 along the leakage path detect the overcurrent, and recloser 24 opens by tripping based on the initial trip profile TCC curve 70, thus removing the voltage in branch 18. Disconnectors 26 and 32 register a leakage count because they detected overcurrent followed by voltage loss when recloser 24 opens. Alternatively, as mentioned above, disconnectors 26 and 32 may not have voltage detection capability and will instead register a leakage count due to the detected overcurrent followed by the absence of current when the recloser Petition 870260025984, dated 03 / 20 / 2026, page 21 / 35 10 / 13 is open. Disconnectors 28 and 30 are not in the leakage path current, so they do not detect sufficient overcurrent and therefore do not register a leakage count when they lose voltage. In this example, disconnectors 26 and 32 are programmed to open on a leakage count of 1, so they open after recloser 24 opens. Recloser 24 switches to the TCC 72 curve when it opens to be coordinated with the TCC 74 curve for disconnectors 26 and 32 when they operate as leakage interruption devices when open, as discussed below.

[0019] Next, recloser 24 opens and supplies voltage to branch 18, which is detected by disconnector 26 and which supplies power to loads along branch 18 upstream of disconnector 26 and in sub-branch 20. When recloser 24 is switched on and disconnector 26 detects voltage return, disconnector 26 prepares to switch on after a predetermined period of time, for example, forty-five seconds.Disconnector 26 operates as a leakage current interruption device with a tripping profile TCC curve of 74 during this waiting time to close. When disconnector 26 closes after the waiting time expires, disconnector 32 detects voltage return and prepares to close when its predetermined time period has elapsed. Disconnector 26 does not observe any leakage current upon reclosing since leakage 38 is downstream of disconnector 32, which is still in the open state. Disconnector 32 is now operating as a leakage current interruption device with a tripping profile TCC curve of 74. However, when disconnector 26 does not detect leakage current during a predetermined time interval, the tripping profile TCC curve of 74 for disconnector 26 is deactivated before disconnector 32 closes to reduce the number of leakage current interruption devices along the leakage path that require time-current coordination.After a predetermined period of time, the disconnector 32 closes and detects overcurrent from the leakage current 38 and opens again. The disconnector 32 can close on leakage current 38 and reopen on... Petition 870260025984, dated 20 / 03 / 2026, page 22 / 35 / 13 a reclosing operation a predetermined number of times and then it can come out of its cutout assembly to provide a visual indication that it has been opened to eliminate leakage 38. If they cannot detect voltage, disconnectors 26 and 32 can be programmed to close at the end of the predetermined waiting time without detecting voltage return.

[0020] After a predetermined period of time in which recloser 24 does not detect overcurrent, it will be reset to the TCC curve of tripping profile 70. If there were other disconnectors along the leakage path between disconnectors 26 and 32, then they would operate sequentially from upstream to downstream as disconnector 26 did, as discussed above. In other words, each disconnector upstream of disconnector 32 detects voltage and no overcurrent, and temporarily functions as a leakage interruption device.

[0021] Because only one disconnector is operating as a leakage interruption device with the leakage interruption profile TCC curve 74 at a specific instant in time during leakage elimination operation, more disconnectors can be provided along a given leakage path compared to what was previously possible.

[0022] A second method of leakage elimination is described that uses leakage production instead of leakage interruption, as described above. In this method, and using the example discussed above, the sequential closing of leakage disconnectors 26 and 32 along the leakage path that were opened when their leakage count was reached depends on recloser 24 interrupting the leakage current after disconnector 32 immediately upstream of the leakage 38 closed on the leakage, instead of disconnectors 26 and 32 operating as leakage interruption devices. In this method, recloser 24 does not switch from the TCC 70 curve to the TCC 72 curve when it first operates, and disconnectors 26 and 32 do not use the Petition 870260025984, dated 03 / 20 / 2026, page 23 / 35 12 / 13 TCC curve 74.

[0023] More specifically, disconnectors 26 and 32 are opened when the leakage count is reached in the same manner described above. When recloser 24 then recloses, disconnector 26 detects the return voltage and closes, but does not detect overcurrent and no further action is taken by disconnector 26. When disconnector 26 closes, disconnector 32 detects return voltage and closes, and this action re-establishes a detectable overcurrent from leakage 38, so the control logic indicates that it needs to be the first disconnector upstream of leakage 38. However, instead of opening in response to the overcurrent detection, disconnector 32 remains closed and recloser 24 detects the overcurrent and opens a second time using its normal TCC 70 curve. Since the logic of disconnector 32 concludes that it was closed on fault 38, it opens, or exits, after detecting a voltage loss resulting from recloser 24 opening a second time.Recloser 24 recloses a second time, and since disconnector 26 remained closed and disconnector 32 is open, or exits, recloser 24 does not detect leakage current and remains closed. If another reclosing operation is desired, then disconnector 32 can close when it detects voltage return the second time, at which point recloser 24 detects the overcurrent again and opens and then closes again. Furthermore, if the disconnectors were operating with a higher leakage count, recloser 24 would open the number of times required by that count.

[0024] The main advantage of the second method over the first is that TCC curve coordination is not required between recloser 24 and downstream leakage disconnectors. Recloser 24 trips and recloses at least twice before a disconnector isolates a permanent leak and the leak-free branch sections are reconnected. Temporary leaks that disappear after a reclosing operation would produce an operation Petition 870260025984, dated 03 / 20 / 2026, p. 24 / 35 13 / 13 closing of the disconnectors 26 and 32.

[0025] The preceding discussion details and describes merely illustrative embodiments of the present description. One skilled in the art will readily recognize from such discussion and the accompanying drawings and claims that various changes, modifications, and variations may be made thereto without departing from the spirit and scope of the description as defined in the following claims.

Claims

CLAIMS 1. A method for isolating a leakage current in an electrical power distribution network, the network including a power line, a recloser coupled to the power line and a plurality of switching devices coupled to the power line downstream of the recloser, each switching device having the capability to detect leakage current in response to the leakage and to detect the presence of voltage, characterized in that the method comprises: detecting overcurrent in the leakage network by means of the recloser and all switching devices positioned along a leakage path between the recloser and the leakage; interrupting the overcurrent by opening the recloser based on a time-current characteristic curve (TCC) of initial tripping profile; detecting voltage loss and / or absence of current when the recloser is opened by the switching devices along the leakage path;record a leakage count through each switching device that detected the overcurrent and then the voltage loss and / or absence of current; open each switching device that recorded a predetermined number of leakage counts; change the initial tripping profile TCC curve of the recloser to an operational tripping profile TCC curve that is slower than the initial tripping profile TCC curve and is coordinated with the interruption and leakage tripping profile TCC curves of the switching devices along the leakage path when the recloser opens and the predetermined number of leakage counts has been reached; close the recloser; Petition 870260025984, dated 03 / 20 / 2026, page 26 / 35 2 / Ί close a first downstream switching device of the recloser after a predetermined closing time period when the recloser closes;Activate a TCC (Triggering Control Profile) curve for the first switching device during a waiting time before the predetermined closing time period ends; close a subsequent switching device downstream of the first switching device after the predetermined closing time period when the first switching device closes; activate a TCC (Triggering Control Profile) curve for the next switching device during a waiting time before the predetermined closing time period ends; deactivate the TCC (Triggering Control Profile) curve for the first switching device before the next switching device closes;and to close, sequentially, the switching devices along the leakage path in this manner until a switching device immediately upstream of the leakage closes and detects the leakage overcurrent, at which point this switching device remains open.

2. Method according to claim 1, characterized in that the closing of a first switching device downstream of the recloser, the closing of a subsequent switching device downstream of the first switching device, and the sequential closing of subsequent switching devices also include detecting the return voltage.

3. Method according to claim 1, characterized in that the switching device immediately upstream of the leakage closes and opens several times before remaining open.

4. Method according to claim 3, characterized by the fact that the switching device immediately upstream of the leakage exits from a cutout assembly when it remains open.

5. Method according to claim 1, characterized in that the switching devices include vacuum switches.

6. Method according to claim 1, characterized in that the power line is a single-phase branch line coupled to a three-phase feeder.

7. Method according to claim 1, characterized in that the TCC curve of the leakage interruption tripping profile of all switching devices is the same.

8. Method according to claim 1, characterized in that it further comprises returning the recloser to the initial trip profile TCC curve after a certain period of time during which the recloser does not detect overcurrent.

9. Method for isolating a leakage in an electrical power distribution network, the network including an electrical power line, a recloser coupled to the electrical power line and a plurality of switching devices coupled to the electrical power line downstream of the recloser, each switching device having the capability to detect leakage current in response to the leakage and to detect the presence of voltage, characterized in that the method comprises: detecting overcurrent in the leakage network by means of the recloser and all switching devices positioned along a leakage path between the recloser and the leakage; interrupting the overcurrent by opening the recloser; detecting voltage loss and / or absence of current when the recloser is opened by the switching devices along the leakage path; recording a leakage count by means of each device. Petition 870260025984, dated 03 / 20 / 2026, p.28 / 35 4 / 7 switching device that detected the overcurrent and then the voltage drop and / or the absence of current; open each switching device that recorded a predetermined number of leakage counts; close the recloser; close a first switching device downstream of the recloser after a predetermined closing time period when the recloser closes; close a next switching device downstream of the first switching device after the predetermined closing time period when the first switching device closes; and close, sequentially, the next switching devices along the leakage path in this manner until a switching device, immediately upstream of the leakage, closes and detects the leakage overcurrent, at which point this switching device remains open.

10. Method according to claim 9, characterized in that the closing of a first switching device downstream of the recloser, the closing of a subsequent switching device downstream of the first switching device, and the sequential closing of subsequent switching devices also include detecting the return voltage.

11. Method according to claim 9, characterized in that the interruption of the overcurrent by means of opening the recloser includes using a time-current characteristic curve (TCC) of the initial tripping profile.

12. Method according to claim 11, characterized in that it further comprises changing the initial tripping profile TCC curve of the recloser to an operational tripping profile TCC curve that is slower than the initial tripping profile TCC curve and is coordinated with the interruption and leakage tripping profile TCC curves of the switching devices along the leakage path when the recloser opens and the predetermined number of leakage counts has been reached.

13. Method according to claim 12, characterized in that it further comprises activating a TCC curve of leakage interruption tripping profile of the first switching device that detected voltage return during a hold time before the predetermined closing time period has ended.

14. Method according to claim 13, characterized in that it further comprises activating a TCC curve of leakage interruption tripping profile of the next switching device that detected voltage return during a hold time before the predetermined closing time period has ended.

15. Method according to claim 14, characterized in that it further comprises disabling the TCC curve of the leakage interruption tripping profile of the first switching device that detected voltage return before the next switching device closes.

16. Method according to claim 11, characterized in that it further comprises returning the recloser to the initial trip profile TCC curve after a certain period of time during which the recloser does not detect overcurrent.

17. Method for isolating a leakage in an electric power distribution network, the network including an electric power line, a recloser coupled to the electric power line and a plurality of switching devices coupled to the electric power line downstream of the recloser, each switching device having the capability to detect leakage current in response to the leakage and to detect the presence of voltage, Petition 870260025984, dated 03 / 20 / 2026, page 30 / 35 6 / 7 characterized in that the method comprises: detecting overcurrent in the leakage network by means of the recloser and all switching devices positioned along a leakage path between the recloser and the leakage; interrupting the overcurrent by opening the recloser; detecting voltage loss and / or absence of current when the recloser is opened by the switching devices along the leakage path;Record a leakage count through each switching device that detected the overcurrent and then the voltage drop and / or absence of current; open each switching device that recorded a predetermined number of leakage counts; close the recloser; close a first switching device downstream of the recloser after a predetermined closing time period when the recloser closes; close a subsequent switching device downstream of the first switching device after the predetermined closing time period when the first switching device closes; close, sequentially, the next switching devices along the leakage path until a switching device immediately upstream of the leakage closes and causes overcurrent on the leakage path; interrupt the overcurrent again by operating the recloser; open the switching device immediately upstream of the leakage;and close the recloser again. Petition 870260025984, dated 03 / 20 / 2026, pp. 31 / 35 7 / 7; 18. Method according to claim 17, characterized in that the closing of a first switching device downstream of the recloser, the closing of a subsequent switching device downstream of the first switching device, and the sequential closing of subsequent switching devices also include detecting the return voltage.

19. Method according to claim 17, characterized in that the switching device immediately upstream of the leakage exits from a cutout assembly when it remains open.

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