MÉTODO PARA OPERAR UM COMUTADOR, E, MÉTODO E SISTEMA PARA OPERAR UM INTERRUPTOR DE REINICIALIZAÇÃO AUTOMÁTICA

Description

/ 12 METHOD FOR OPERATING A SWITCH, AND METHOD AND SYSTEM FOR OPERATING AN AUTOMATIC RESET SWITCH CROSS-REFERENCE TO RELATED REQUEST

[001] This application claims the benefit of priority of the Application United States Provisional Patent No. 63 / 415,185, filed October 11, 2022, the invention of which is expressly incorporated herein by reference for all purposes. FUNDAMENTALS Field

[002] This invention relates generally to a system and method for operating a switch and, more specifically, to a system and method for operating a vacuum switch in an automatic reset switch. Discussion of the Related Technique

[003] An electrical power distribution network, often referred to as a power grid, typically includes a series of power generating plants, each having a series of 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 a series of substations typically located within a community, where the voltage is reduced to a medium voltage for distribution. The substations provide medium-voltage power to several three-phase feeders which include three single-phase feeder lines carrying the same current but separated by 120° in phase.A number of three-phase and single-phase side lines are derived from the feeder that provide the average voltage for. Petition 870250012100, dated 02 / 14 / 2025, page 11 / 29 / 12 several distribution transformers, where the voltage is reduced to low voltage and supplied to a number of loads, such as residences, businesses, etc. Power distribution networks of the type mentioned above typically include a number of switching devices, circuit breakers, reclosers, switches, etc. that control the flow of power throughout the network.

[004] Periodically, leaks occur in the distribution network due to various 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 bolted 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 employed as a primary overload protection device to protect distribution transformers and other devices that have a certain rating so that the fuse operates above a transformer inrush current, but below a transformer external leakage protection resistance or damage curve. However, fuses often arc when operating, which brings obvious safety risks and disadvantages.

[006] It has become increasingly popular to replace the traditional fuse with a self-powered leakage interruption device. Petition 870250012100, dated 02 / 14 / 2025, page 12 / 29 / 12 mounted on a circuit breaker that employs a vacuum switch and a magnetic actuator to operate the vacuum switch. A vacuum switch is a switch that uses opposing contacts, one fixed and one moving, positioned within a vacuum enclosure. When the vacuum switch is opened by the operation of the magnetic actuator to move the moving contact away from the fixed contact to prevent current flow through the switch, a plasma arc is created between the contacts, which is contained and quickly extinguished by the vacuum at the next zero crossing of the current. When leakage current is detected by the device, the vacuum switch is opened and the device can be released or “detached” from its mounting, indicating that it has functioned.Point-on-wave (POW) switching is sometimes employed for these types of devices, which is a microprocessor-based switching technique used to eliminate the random nature of mechanical switching devices. POW switching determines the phase angle of the voltage or current cycle and opens or closes the vacuum switch at a predetermined point in the AC waveform to reduce switching transients and arcing.

[007] These types of self-powered leakage interrupters 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 high leakage current is detected, the interrupter will open in response and, after a short delay, will close to determine if the leakage is temporary. If a high leakage current flows when the interrupter is closed after opening, it will immediately reopen. If the leakage current is detected a second time, or several times, during subsequent opening and closing operations, indicating a persistent leakage, the interrupter will remain open and may trip, in which case the time between detection tests may increase after each test. Petition 870250012100, dated 02 / 14 / 2025, page 13 / 29 / 12

[008] Leakage interruption devices employed for the protection of downstream equipment, where a fuse would normally be used, require release times of one cycle or faster, which necessitates capable energy harvesting systems. Thus, these leakage interruption devices generally employ current transformers that are connected in series with the power line to provide their own power to operate the actuator and the electronic component of the device. Transformer saturation is a magnetization state that is reached when the core flux density stops increasing with increasing primary current through the transformer, and is a well-understood phenomenon.Although saturation of instrument transformers can have a significant detrimental effect on relay protection, current transformers used for power line energy harvesting can be operated partially or temporarily saturated to allow the passage of high-magnitude currents, provided they can supply the desired amount of energy. Releasing a cycle is especially challenging when reclosing in leakage current, because energy harvesting from the system current cannot begin until the closing operation is complete, at which point any energy harvested during that time would be consumed as the actuator is being driven. For one type of device, the actuator is driven approximately 7 ms after the start of current flow, which is almost half the power cycle at 60 Hz.This is compounded by the random closing phase angle and residual flux of the current transformer, which can further limit the energy harvesting capacity of the current transformer.

[009] Often, it is desirable to reduce the size and weight of these types of leakage interruption devices for several reasons, such as reducing the cost and complexity of installation, since it is possible to install and remove the devices from the pole on which they are mounted using a maneuvering rod. Petition 870250012100, dated 02 / 14 / 2025, page 14 / 29 / 12 Since a current transformer is typically a large and heavy device, this is an area where size and weight reduction is being investigated. Because reducing the size of the transformer causes it to become saturated at lower power levels and not operate correctly as a current transformer for energy harvesting purposes, reducing the size of the current transformer creates a number of challenges. SUMMARY

[0010] The following discussion presents and describes a system and method for operating a switch using energy collected from a current transformer. In a non-limiting embodiment, the switch is a magnetically actuated vacuum switch in a self-resetting switch. For this embodiment, the method includes detecting leakage current using energy collected from the current transformer, opening the vacuum switch for the first time, and storing the polarity of the last current half-cycle.The method then determines a near polarity and phase angle so that reclosing occurs in the same polarity half-cycle as the polarity that was stored when the vacuum switch was opened, and that the closing actuation of the vacuum switch ends in a zero crossing of the first current half-cycle, closes the vacuum switch, and opens the vacuum switch a second time after the vacuum switch is closed using the energy collected from the current transformer.

[0011] Additional features of the invention will become apparent from the following description and the appended claims, considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is an isometric view of a switch assembly connected to an insulator mounted on a pole and including a magnetically actuated switching device with a switch. Petition 870250012100, dated 02 / 14 / 2025, page 15 / 29 / 12 vacuum; Figure 2 is a timeline illustrating a POW closing operation and polarity detection of the switching device; and Figure 3 is a timeline illustrating a known random closing operation of the switching device. DESCRIÇÃO DETALHADA DAS MODALIDADES

[0013] The following discussion of embodiments of the invention directed to a system and method for operating a switch is merely illustrative in nature and is not intended to limit the invention or its applications or uses. More specifically, the system and method are discussed below in connection with the operation of a vacuum switch in an automatic reset switch. However, the system and method will have other applications.

[0014] Figure 1 is an isometric view of a pole-mounted switch assembly 10, which includes a magnetically actuated, self-powered, single-phase switching device 12, intended to represent any switching device operating as a self-resetting switch suitable for the purposes discussed in this document. The switching device 12 is coupled to an upper coupling assembly 14 at an upper end and to a lower coupling assembly 16 at a lower end. The upper assembly 14 is fixed to one end of an insulator 18 with skirts 20, and the lower assembly 16 is fixed to an opposite end of the insulator 18, wherein the insulator 18 is mounted on a bracket 24 which may be fixed to a public pole (not shown).The lower assembly 16 includes a capture channel 26 that accepts a hinge rod 28 associated with a trunnion assembly 30 with a trunnion 32 coupled to the device 12 and which is electrically coupled to a lower contact of the unit (not shown). A connector 34 accepts a wire (not shown) on a load side of the device 12 which is... Petition 870250012100, dated 02 / 14 / 2025, page 16 / 29 / 12 electrically coupled to the lower contact of the unit. The upper assembly 14 includes an upper mounting tab 40, an extension tab 42, and a spring 44 positioned between tabs 40 and 42. The upper assembly 14 also includes a support tab 46 attached to the mounting tab 40 and a pair of mounting horns 48 coupled to and extending from the support tab 46 opposite the extension tab 42. An upper unit contact 50 is positioned between the horns 48 and engages the tab 42 against the spring polarization 44 to hold the switching device 12 in the upper assembly 14. A connector 52 accepts a wire (not shown) on one side of the device 12 source which is electrically coupled to the upper unit contact 50 of the device 12 via the upper assembly 14.A guide pull ring member 54 is coupled to an upper part of the device 12 and allows a worker to easily remove the device 12 from the public pole by pulling the ring member 54 to disengage the contact 50 from the upper assembly 14, rotating the device 12 outward on the articulation rod 28 and then lifting the device 12 out of the clamp 26.

[0015] The switching device 12 includes a vacuum switch 60 with an external housing 62, wherein the vacuum switch 60 is representative of any vacuum switch known in the art suitable for the purposes discussed in this document. The vacuum switch 60 includes a vacuum chamber enclosing a fixed contact that is electrically coupled to the upper contact of the unit 50 and a moving contact that is electrically coupled to the lower contact of the unit, wherein the fixed and moving contacts are in contact with each other within the vacuum chamber when the vacuum switch 60 is closed. When the vacuum switch 60 is opened by moving the moving contact away from the fixed contact, the arc that is created between the contacts is extinguished by the vacuum in a zero crossing of the current. The switching device 12 also includes a magnetic actuator 64 that is coupled to the vacuum switch 60 by a linkage of Petition 870250012100, dated 02 / 14 / 2025, page 17 / 29 / 12 actuation (not shown) to open and close the vacuum switch 60. The switching device 12 additionally includes a current transformer 66 that collects energy to operate the switching device 12 and open the vacuum switch 60 when a leakage current is detected in a manner well understood by those skilled in the art. The switching device 12 also includes a control system 68 that is representative of all devices and algorithms necessary to detect and process current and voltage measurements, provide command signals, etc. for the purposes of the discussion in this document, and includes at least one processor and one memory device that stores data and executable code.

[0016] This invention proposes a point-on-wave (POW) and polarity detection technique that increases the energy harvesting capacity of the current transformer 66. In other words, the described technique allows the current transformer 66 to saturate, but still provide the desired amount of energy to open the vacuum switch 60. Therefore, a smaller and lighter current transformer can be employed.

[0017] The energy harvesting capacity of current transformer 66 depends, among other things, on the remanent flux level and its polarity. These values ​​are determined by the magnitude and polarity of the last half-cycle of the primary current. It follows that, when closing on a leakage, the energy harvesting capacity of transformer 66 depends on the magnitude and polarity of the last current cycle associated with the previous leakage. From the relation V = NdΦ / dt = Ldi / dt, it follows that current transformer 66 is most effective at harvesting energy when di / dt is at its highest level, which occurs near the zero crossings of the current. Combining all the above, current transformer 66 is most effective at harvesting energy near a zero crossing of the current when the current transitions to the opposite polarity of the last half-cycle of current. Petition 870250012100, dated 02 / 14 / 2025, page 18 / 29 / 12

[0018] When leakage current is detected and vacuum switch 60 opens in response, the polarity of the last leakage current cycle is stored in memory and used in determining the closing polarity. The closing angle of the POW is adjusted so that the first current half-cycle has a duration equivalent to the time the actuator 64 is activated after the start of the leakage current. In this way, after the closing operation is complete, the current transformer 66 is presented with a zero-crossing transition of the current in the opposite polarity, which allows the device to collect energy more quickly and eliminate leakage in one energy cycle.

[0019] Figure 2 is a timeline showing a POW closing and polarity detection operation of the switching device 12 illustrating the technique described above, wherein line 70 is the detected leakage current, line 72 is the voltage at the output on the secondary winding of the current transformer 66, and line 74 is the actuation of the magnetic actuator 64 for opening and closing operations. When the leakage current becomes present at time 76, voltage becomes available at the output of the current transformer 66 and energy is stored, for example, in a capacitor (not shown) at time 78 until the current transformer 66 becomes saturated near a current peak and the voltage drops at time 80. The stored energy is now available to open the vacuum switch 60, wherein the opening sequence of the switching device 12 begins at time 82 after about a quarter of a power cycle after the onset of the leakage current.At the next zero crossing of the current, the transformer 66 is no longer saturated and energy is again available to be stored, which generally coincides with the moment when the contacts in the vacuum switch 60 separate at around time 86. The opening sequence is completed at time 88, and the arc is extinguished at the next zero crossing at time 90. The control system 68 records the polarity of the current cycle. Petition 870250012100, dated 02 / 14 / 2025, page 19 / 29 / 12 here positive, when the opening sequence of the vacuum switch 60 is completed. This determines the polarization of the magnetic domains in the core of the current transformer 66.

[0020] For the reclosing operation, and assuming that leakage current is still present, the vacuum switch 60 is commanded closed in a calculated time 94 based on the measured phase of the voltage across the switching device 12, so that when the vacuum switch contacts are actuated, the leakage current is of the same polarity as when the vacuum switch 60 was last opened. The energy collected and stored in the capacitor from the last time energy was collected from the current transformer 66 was previously used to open the vacuum switch 60; therefore, the closing operation uses energy from another source, such as the voltage potential across the vacuum switch 60. The actuator 64 moves the moving contact, which engages the fixed contact in time 96, and the current begins to rise. The electrical contact between the fixed and moving contacts of the vacuum switch 60 occurs at a point in the wave that produces a small asymmetrical half-cycle of current.Furthermore, during the closing operation, the secondary winding of the current transformer 66 is short-circuited so that it does not become saturated, which prevents the transformer 66 from collecting energy during the closing operation, as shown by line 72. The actuator 64 is still actuating the moving contact after time 96 against the polarization of a compliance spring until time 98. The closing operation time is set so that time 98 coincides with the zero crossing of the smaller current cycle. As the current polarity and the polarity of the magnetic domain in the core of the transformer 66 are changing from positive to negative at time 98, the current transformer 66 exits saturation and significant energy collection occurs after time 100. Sufficient energy is collected within a quarter cycle to initiate the opening operation of the switch. Petition 870250012100, dated 02 / 14 / 2025, page 20 / 29 / 12 vacuum 60 at time 102, in which the fixed and moving contacts in the vacuum switch 60 separate at time 104, and the opening operation ends at time 106, which is a quick closing-opening operation.

[0021] Figure 3 is a timeline showing a known random closing operation of the switching device 12 to illustrate the longer time between the closing and opening of the switching device 12 during the reclosing operation, where similar elements are identified by the same reference number. Leakage detection and opening of the vacuum switch 60 when leakage current is detected are the same; however, the polarity of the current cycle when the opening operation of the vacuum switch 60 is completed is not recorded. The closing of the vacuum switch 60 at time 94 is random with respect to the phase angle of the current, and for this example, the contact point between the fixed and moving contacts at time 96 occurs during a negative polarity of the current cycle.The end of the closing operation at time 98 occurs near a current peak in the power cycle, where the current transformer 66 is still saturated and the system 68 cannot collect enough energy to perform an opening operation. Most of the energy required for the opening operation of the vacuum switch 60 is collected after the next zero crossing of the current at time 110, where it takes until time 112 to provide enough energy to open the vacuum switch 60. From an energy harvesting perspective, the time from the end of the closing operation at time 98 of the switching device 12 until the next zero crossing at time 110 is lost time and results in a longer release time for the switching device 12. This illustrates how polarity detection and POW techniques can be used to improve the energy harvesting capabilities and interruption performance of the switching device 12.Thus, the use of the POW closure technique and polarity detection discussed above allows for the undersizing of the... Petition 870250012100, dated 02 / 14 / 2025, page 21 / 29 / 12 current transformer 66, which translates into a reduction in the size, weight and cost of the switching device 12. More specifically, to release a leakage during the reclosing operation in the desired time period, as shown in Figure 2, a larger current transformer would be required to achieve the same release time for the operation shown in Figure 3.

[0022] As will be well understood by those skilled in the art, the various and diverse steps and processes discussed in this document to describe the invention may refer to operations performed by a computer, a processor, or other electronic computing device that manipulates and / or transforms data using electrical phenomena. These computers and electronic devices may employ various volatile and / or non-volatile memories, including non-transient computer-readable media with an executable program stored thereon, including various executable codes or instructions capable of being executed by the computer or processor, where the memory and / or computer-readable media may include all forms and types of memory and other computer-readable media.

[0023] The preceding discussion details and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion and the accompanying drawings and claims that various changes, modifications, and variations can be made thereto without departing from the spirit and scope of the invention as defined in the following claims. Petition 870250012100, dated 02 / 14 / 2025, pp. 22-29

Claims

1 / 5 CLAIMS 1. Method for operating a switch (12), characterized in that the method comprises: detecting current; opening the switch (12) for the first time using energy collected from a current transformer (66); storing a polarity of a half-cycle of current from the current detected when the switch (12) is opened; determining a closing time to close the switch (12), such that the polarity of a first half-cycle of current has the same polarity as that which was stored when the switch (12) was opened; and closing the switch (12) at the closing time.

2. Method according to claim 1, characterized in that determining a closing time includes determining the closing time based on a phase angle of a voltage potential across the switch (12).

3. Method according to claim 1, characterized in that determining a closing time includes determining the closing time such that the actuation of the switch (12) closing ends in a zero crossing of the current.

4. Method according to claim 3, characterized in that it further comprises opening the switch (12) a second time after the switch (12) has been closed using energy collected from the current transformer (66).

5. Method according to claim 4, characterized in that opening the switch (12) a second time includes opening the switch (12) as soon as the current transformer (66) has generated sufficient energy to open the switch (12). Petition 870260060167, dated 19 / 06 / 2026, page 12 / 22 2 / 5 6. Method according to claim 5, characterized in that it further comprises causing a short circuit in a secondary winding of the current transformer (66) while the switch (12) is closing to prevent the current transformer (66) from becoming saturated.

7. Method according to claim 1, characterized in that the switch (12) is actuated open and closed by a magnetic actuator (64).

8. Method according to claim 1, characterized in that the switch (12) is a vacuum switch (60).

9. Method according to claim 1, characterized in that the current is a leakage current, and the switch (12) is part of a self-resetting switch.

10. Method according to claim 9, characterized in that the self-reset switch is a self-reset switch mounted on a circuit breaker (10).

11. Method for operating a self-reset switch, wherein the self-reset switch includes a vacuum switch (60), a magnetic actuator (64) for opening and closing the vacuum switch (60) and a current transformer (66) that provides power to open the vacuum switch (60), characterized in that the method comprises: detecting leakage current; opening the vacuum switch (60) for the first time using power collected from the current transformer (66) when leakage current is detected; storing a polarity of a half-cycle current of the leakage current detected when the vacuum switch (60) is opened; determining a closing time to close the switch. Petition 870260060167, dated 06 / 19 / 2026, p.13 / 22 3 / 5 vacuum (60), so that the polarity of a first half cycle of current has the same polarity as that which was stored when the vacuum switch (60) was opened, and that the closing actuation of the vacuum switch (60) ends in a zero crossing of the current; close the vacuum switch (60) at the closing time; and open the vacuum switch (60) for the second time after the vacuum switch (60) is closed using energy collected from the current transformer (66).

12. Method according to claim 11, characterized in that determining a closing time includes determining the closing time based on a phase angle of a voltage potential across the vacuum switch (60).

13. Method according to claim 11, characterized in that opening the vacuum switch (60) a second time includes opening the vacuum switch (60) as soon as the current transformer (66) has generated sufficient energy to open the vacuum switch (60).

14. Method according to claim 13, characterized in that it further comprises causing a short circuit in a secondary winding of the current transformer (66) while the vacuum switch (60) is closing to prevent the current transformer (66) from becoming saturated.

15. Method according to claim 11, characterized in that the self-reset switch is a self-reset switch mounted on a circuit breaker (10).

16. System for operating an automatic reset switch, wherein the automatic reset switch includes a vacuum switch (60), a magnetic actuator (64) for opening and closing the vacuum switch (60) and a current transformer (66) that provides power to open the vacuum switch (60), characterized in that the Petition 870260060167, dated 06 / 19 / 2026, page 14 / 22 4 / 5 system comprises: a controller (68) that includes at least one processor and a memory device that stores computer-readable instructions that, when executed, cause the at least one processor to: detect leakage current; open the vacuum switch (60) for the first time using power collected from the current transformer (66) when leakage current is detected; store a polarity of a half-cycle current of the leakage current detected when the vacuum switch (60) is opened;Determine a closing time to close the vacuum switch (60) such that the polarity of a first half-cycle of current has the same polarity as that which was stored when the vacuum switch (60) was opened, and that the closing action of the vacuum switch (60) ends on a zero crossing of the current cycle; close the vacuum switch (60) at the closing time; and open the vacuum switch (60) for the second time after the vacuum switch (60) is closed using energy collected from the current transformer (66).

17. System according to claim 16, characterized in that determining a closing time includes determining the closing time based on a phase angle of a voltage potential across the vacuum switch (60).

18. System according to claim 16, characterized in that opening the vacuum switch (60) a second time includes opening the vacuum switch (60) as soon as the current transformer (66) has generated sufficient energy to open the vacuum switch (60).

19. System according to claim 18, characterized in that the electronic control component (68) causes a short circuit in a secondary winding of the current transformer (66) while the vacuum switch (60) is closing to prevent the current transformer (66) from becoming saturated.

20. System according to claim 16, characterized in that the automatic reset switch is an automatic reset switch mounted on a circuit breaker (10). Petition 870260060167, dated 06 / 19 / 2026, pp. 16 / 22

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