Circuit breaker matching capacitor power taking fault isolation blocking protection device and method

Abstract

This invention relates to the field of power equipment technology, and provides a circuit breaker-compatible capacitor-powered fault isolation and interlocking protection device and method. The device includes a disconnecting switch located on one side of the circuit breaker body. The disconnecting switch includes an isolating blade holder, an isolating blade, a magnetic control mechanism, and a capacitor-powered device. A magnetic control coil is mounted on the stationary end of the magnetic control mechanism, and the output terminal of the capacitor-powered device is electrically connected to the magnetic control coil. When the arc-extinguishing chamber within the circuit breaker body fails to open and the circuit breaker body is tripped, voltage still exists on the disconnecting switch. The capacitor-powered device outputs electrical energy to the magnetic control coil, causing the stationary end and moving end of the capacitor-powered device to attract each other, preventing the isolating blade from tripping and achieving line-on-line interlocking. The device detects the residual voltage at the lower end of the circuit breaker body using a passive capacitor-powered method, offering rapid response and high reliability. It effectively prevents the disconnecting switch from tripping with residual voltage and, during forced tripping, utilizes the magnetic field generated by the magnetic control mechanism to drive arc rotation and cooling, reducing the risk of arcing.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, and in particular to a circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device and method. Background Technology

[0002] Overhead power distribution lines are a crucial link in the transmission and distribution of electrical energy in power systems. During the operation of overhead lines, single-phase grounding faults are one of the most common types of faults. To achieve rapid isolation of the fault point, a multi-stage switching mechanism is typically used: when a single-phase grounding fault occurs at a point on the line, the downstream switch at the fault point trips due to the corresponding phase loss of voltage, and the upstream switch at the fault point also trips accordingly after detecting the downstream tripping signal or fault signal, thereby isolating the faulty section from the power grid.

[0003] In the aforementioned fault isolation scheme, the circuit breaker body, with its arc-extinguishing chamber, undertakes the tasks of normal line interruption and fault current isolation; the disconnecting switch, due to its simple structure and low cost, is used to create a clear disconnection point after the circuit breaker is opened, facilitating maintenance personnel to confirm the line status. However, in actual operation, the arc-extinguishing chamber of the circuit breaker body may fail to function due to contact erosion, mechanism jamming, insulation medium deterioration, or insufficient operating energy. In this case, even if the circuit breaker body has performed an opening operation, residual line voltage may still remain at its lower end (i.e., the disconnecting switch side).

[0004] In existing technologies, disconnect switches themselves do not have arc-extinguishing capabilities; their safe operation relies on the circuit breaker reliably interrupting the line current and creating a de-energized state. When the arc-extinguishing chamber fails to interrupt the circuit, if maintenance personnel open the disconnect switch according to normal operating procedures, an electric arc will be generated between the disconnecting blade and the disconnecting blade holder, causing a load-bearing disconnect switch opening accident, resulting in equipment burnout, personal injury, or even escalating into a phase-to-phase short circuit or regional power outage.

[0005] To prevent the aforementioned accidents, existing solutions mostly rely on external voltage transformers, current sensors, and secondary control circuits to detect the voltage on the disconnector side, and to prohibit the operation of the disconnector through an electrical interlocking circuit when residual voltage is detected. However, this approach has significant shortcomings: First, the secondary circuit has a large number of components and complex wiring, and a failure in any part will lead to interlocking failure; second, it requires a continuous external control power supply, and the interlocking function is lost when the control power supply fails; third, the voltage transformers, sensors, and other electronic components have poor adaptability to harsh environments such as outdoor temperature, humidity, pollution, and electromagnetic interference, resulting in insufficient long-term operational reliability; fourth, additional electrical isolation and insulation coordination are required between the secondary circuit and the primary equipment, increasing equipment costs and installation and maintenance workload.

[0006] Therefore, how to achieve live state detection and mechanical interlocking on the disconnector side in a simple, passive, and highly reliable manner, and effectively suppress arc hazards during abnormal forced operation, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] To address the aforementioned technical problems, embodiments of the present invention provide a circuit breaker-compatible capacitor-powered fault isolation and interlocking protection device and method. This device detects the residual voltage at the lower port of the circuit breaker body through a passive capacitor-powered method, offering rapid response and high reliability. It effectively prevents the disconnecting switch from tripping with residual voltage and, during forced tripping, utilizes the magnetic field generated by the magnetic control mechanism to drive the arc rotation for cooling, thereby reducing the risk of arcing.

[0008] According to one aspect, to achieve the above objective, embodiments of the present invention provide a circuit breaker-compatible capacitor-powered fault isolation and interlocking protection device, comprising a circuit breaker body and a disconnecting switch disposed on one side of the circuit breaker body, wherein the circuit breaker body is provided with an arc-extinguishing chamber, and the disconnecting switch includes an isolation blade holder and an isolation blade cooperating with the isolation blade holder, and the disconnecting switch further includes: A magnetic control mechanism includes a stationary end seat and a moving end seat. The stationary end seat is disposed on the isolation knife holder, and the moving end seat is disposed on the isolation knife. A magnetic control coil is provided on the stationary end seat. A capacitor power-taking device is disposed on the stationary end base. The power-taking end of the capacitor power-taking device is electrically connected to the isolation knife holder, and the output end of the capacitor power-taking device is electrically connected to the magnetic control coil. When the circuit breaker body is tripped and the arc-extinguishing chamber fails to break, there is still voltage on the disconnecting switch side. The capacitor power-taking device draws power from the disconnecting knife holder and outputs voltage to the magnetic control coil, so that there is a magnetic force between the stationary end seat and the moving end seat and they attract each other, thereby preventing the disconnecting knife from tripping with the disconnecting knife holder and putting the disconnecting switch in a energized and locked state.

[0009] In one possible implementation, both the stationary end seat and the moving end seat are provided with a magnetic conductor. The magnetic control coil is located in the stationary end seat and is arranged around the magnetic conductor. When the magnetic control coil is energized, a closed magnetic circuit is formed between the stationary end seat and the moving end seat under the magnetic guidance of the magnetic conductor, and they attract each other.

[0010] In one possible implementation, the circuit breaker body is provided with an outwardly extending conductive rod, one end of the isolating blade is hinged to the outer end of the conductive rod and electrically connected to the conductive rod.

[0011] In one possible implementation, the capacitor power-taking device is located at the bottom of the stationary end seat. The capacitor power-taking device includes a power-taking capacitor, a rectifier and voltage regulator circuit, and a power output terminal connected in sequence. The power-taking capacitor is electrically connected to the isolation knife holder, and the power output terminal is electrically connected to the magnetic control coil. When the circuit breaker body is tripped and the arc-extinguishing chamber fails to open, the capacitor power-taking device can obtain the voltage at the isolation knife holder.

[0012] In one possible implementation, an insulating layer is provided between the moving end seat and the isolating blade, and between the stationary end seat and the isolating blade holder, so as to electrically isolate the magnetic control mechanism from the conductive parts of the isolating blade and the isolating blade holder.

[0013] In one possible implementation, when the circuit breaker body is tripped and the arc-extinguishing chamber's breaking function is only partially ineffective, the stationary end seat and the moving end seat are in an attracted state but the attracting force is insufficient. When the isolating knife is forced to rotate in the tripping direction and separates from the isolating knife seat, and an arc is formed between them, the stationary end seat and the moving end seat separate synchronously. The magnetic field drives the arc generated at the separation point between the isolating knife and the isolating knife seat to rotate in order to cool the arc.

[0014] In one possible implementation, the circuit breaker body has a housing at its bottom, a rotating shaft is rotatably mounted on the housing, an operating handle is mounted at the end of the rotating shaft, an insulating connecting rod is mounted between the rotating shaft and the isolating blade, the two ends of the insulating connecting rod are respectively hinged to the isolating blade and the rotating shaft, and the rotation of the operating handle drives the isolating blade to rotate through the rotating shaft and the insulating connecting rod.

[0015] In one possible implementation, an elastic element is provided between the housing and the rotating shaft. The elastic element is used to apply torque to the rotating shaft so that the isolating knife rotates away from the isolating knife seat along with the rotating shaft. This causes the isolating knife to open when there is no attraction between the stationary end seat and the moving end seat, and separates the moving end seat from the stationary end seat.

[0016] According to another aspect, to achieve the above objective, embodiments of the present invention provide a method for live-line interlocking of capacitor-powered fault isolation, applied to a circuit breaker-compatible capacitor-powered fault isolation interlocking protection device, comprising: After the circuit breaker body is tripped, if the arc-extinguishing chamber's breaking function is not ineffective, the capacitor power supply device will have no voltage output, the magnetic control coil will not be energized, there will be no magnetism between the stationary end seat and the moving end seat, and the isolating switch will trip normally. After the circuit breaker body trips, if the arc-extinguishing chamber fails to break, there is still voltage on the disconnecting switch side. The capacitor power-taking device draws power from the disconnecting knife holder and outputs voltage to the magnetic control coil, so that the stationary end seat and the moving end seat attract each other, thereby locking the disconnecting knife and the disconnecting knife holder to prevent tripping, and putting the disconnecting switch in a energized locked state.

[0017] One possible implementation also includes: After the circuit breaker body is tripped, if the arc-extinguishing chamber's breaking function is only partially ineffective, when the isolating knife is forcibly tripped in the attracted state of the stationary end seat and the moving end seat and an arc is generated between the isolating knife and the isolating knife seat, the magnetic field between the stationary end seat and the moving end seat drives the arc to rotate and cool the arc.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: First, this invention directly integrates the magnetic control mechanism onto the isolating knife holder and isolating knife of the disconnecting switch, and draws power from the lower end of the circuit breaker body through a capacitor power extraction device set on the stationary end seat. It can achieve passive detection of residual voltage on the disconnecting switch side without additional secondary control power supply, voltage transformer and complex logic judgment circuit. When the arc-extinguishing chamber fails to open, the residual voltage automatically drives the magnetic control coil to excite, causing the stationary end seat and the moving end seat to be attracted together, preventing the isolating knife from opening from the mechanical structure. The live blocking action is directly related to the status of the primary line, with rapid response and high reliability, which significantly improves the safety of operation and maintenance of outdoor overhead lines.

[0019] Secondly, the present invention utilizes the magnetic field generated by the magnetic control mechanism in the engaged state to apply Lorentz force to the electric arc generated during forced opening, driving the electric arc to rotate, lengthening the arc diameter and accelerating cooling. This can reduce the arcing energy in the event of energized interlock failure or being broken by violent operation, reduce the erosion of the isolation blade and isolation blade seat by the electric arc, and prevent the accident from escalating further.

[0020] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are merely some exemplary embodiments of this application. For those skilled in the art, other drawings can be obtained based on the content of the exemplary embodiments of this application and these drawings without any creative effort.

[0022] Figure 1 This is a schematic diagram of the open state of the capacitor power supply fault isolation and interlocking protection device in one embodiment of the present invention; Figure 2 This is a schematic diagram of the closed state of the capacitor power supply fault isolation and interlocking protection device in one embodiment of the present invention; Figure 3 This is a schematic diagram of the capacitor power supply fault isolation and interlocking protection device in the open state from another perspective in one embodiment of the present invention; Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0023] In the diagram: 1. Circuit breaker body, 2. Disconnecting switch, 21. Disconnecting blade, 22. Disconnecting blade holder, 3. Magnetic control mechanism, 31. Stationary end seat, 32. Moving end seat, 33. Magnetic control coil, 34. Capacitor power extraction device, 341. Power extraction capacitor, 342. Power output terminal, 35. Magnetic conductor, 4. Conductive rod, 5. Operating handle, 6. Insulating connecting rod, 7. Housing, 8. Rotating shaft. Detailed Implementation

[0024] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0025] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, components with the same structure or function are shown only schematically, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0026] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] It should be noted that when an element is referred to as being "set on" another element, it can be directly set on the other element or indirectly set on the other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0029] Existing disconnector operation interlocking schemes mainly rely on secondary electrical interlocking circuits: voltage transformers or sensors detect the voltage on the disconnector side, the control unit judges the signal and outputs an interlocking signal, and then an electromagnetic lock or electric operating mechanism prevents the disconnector from opening. The secondary circuit has numerous components and complex wiring; a failure in any part will lead to interlocking failure. Furthermore, it requires a continuous external control power supply; when the control power is lost, the interlocking function is lost. Secondly, voltage transformers, sensors, and other electronic components have poor adaptability to harsh environments such as outdoor temperature, humidity, pollution, electromagnetic interference, and UV aging, resulting in insufficient long-term operational reliability. In addition, the secondary circuit requires additional electrical isolation and insulation between the secondary circuit and the primary equipment, increasing equipment costs and installation and maintenance workload.

[0030] The present invention aims to provide a passive live-line interlocking device integrated into the body of the disconnecting switch. Through the organic cooperation of the magnetic control mechanism and the capacitor power supply device, the energization status of the disconnecting switch side is directly converted into the mechanical state of whether the magnetic control mechanism is engaged or not, thereby realizing live-line interlocking in a simple and reliable manner.

[0031] Please see Figures 1 to 4 An embodiment of the present invention provides a circuit breaker-equipped capacitor-powered fault isolation and interlocking protection device, including a circuit breaker body 1 and a disconnecting switch 2 disposed on one side of the circuit breaker body 1. The circuit breaker body 1 contains an arc-extinguishing chamber for normal interruption of line current. The disconnecting switch 2 includes an isolating blade holder 22 and an isolating blade 21 cooperating with the isolating blade holder 22. The isolating blade 21 can rotate around its end opposite to the isolating blade holder 22 to achieve closing and opening. The disconnecting switch 2 also includes a magnetic control mechanism 3 and a capacitor-powered device 34.

[0032] Specifically, the magnetic control mechanism 3 includes a stationary end seat 31 and a moving end seat 32. The stationary end seat 31 is mounted on the isolating knife holder 22, and the moving end seat 32 is mounted on the isolating knife 21. When the disconnecting switch 2 is closed, the isolating knife 21 is in electrical contact with the isolating knife holder 22, and the moving end seat 32 is positioned opposite the stationary end seat 31 with a small working air gap between them. During the disconnecting switch 2 opening process, the isolating knife 21 rotates around the hinge point, and the moving end seat 32 moves away from the stationary end seat 31 along with the isolating knife 21.

[0033] Furthermore, a magnetic control coil 33 is provided on the stationary end base 31. A capacitor power extraction device 34 is disposed on the stationary end base 31, and the output terminal of the capacitor power extraction device 34 is electrically connected to the magnetic control coil 33. The capacitor power extraction device 34 draws power from the isolating knife holder 22. When there is voltage on the isolating switch 2 side, the capacitor power extraction device 34 outputs electrical energy to the magnetic control coil 33, energizing the magnetic control coil 33; when there is no voltage on the isolating switch 2 side, the capacitor power extraction device 34 has no output, and the magnetic control coil 33 is de-energized.

[0034] In this embodiment, the circuit breaker body 1 is provided with a conductive rod 4, and one end of the isolating blade 21 is hinged to the conductive rod 4 of the circuit breaker body 1 and electrically connected to the conductive rod 4. In this way, when the circuit breaker body 1 is closed, the line voltage is transmitted to the isolating blade 21 through the arc-extinguishing chamber of the circuit breaker body 1 and the conductive rod 4; when the circuit breaker body 1 is opened and the arc-extinguishing chamber is reliably interrupted, the electrical connection between the conductive rod 4 and the isolating blade 21 is cut off, and there is no residual voltage on the isolating blade 21 side.

[0035] Please refer to the following: Figure 3 and Figure 4 A capacitor-driven power extraction device 34 is disposed at the bottom of the stationary base 31. The device includes a capacitor 341, a rectifier and voltage regulator circuit, and a power output terminal 342, all connected in sequence. The capacitor 341 is electrically connected to the isolation blade holder 22, and the power output terminal 342 is electrically connected to the magnetic control coil 33. When the circuit breaker body 1 is tripped and the arc-extinguishing chamber fails to open, the voltage at the isolation blade holder 22 can be obtained by the capacitor-driven power extraction device 34.

[0036] The capacity of the power-taking capacitor 341 can be selected based on the line's rated voltage, the excitation power of the magnetron coil 33, and the required response time. Taking a 10kV overhead line as an example, the capacity of the power-taking capacitor 341 can be set to tens of picofarads to several nanofarads, coupling sufficient electrical energy to drive the magnetron coil 33 from the line-to-ground voltage through the capacitive voltage divider principle. The rectifier and voltage regulator circuit converts the AC power output from the power-taking capacitor 341 into DC power and regulates it to the rated operating voltage range of the magnetron coil 33. The power output terminal 342 can be a terminal block, a conductive spring, or other reliable electrical connection structure, used to deliver the rectified and regulated electrical energy to the magnetron coil 33.

[0037] In a preferred embodiment, both the stationary end seat 31 and the moving end seat 32 are provided with a magnetic conductor 35, and a magnetic control coil 33 is disposed within the stationary end seat 31 and surrounds the magnetic conductor 35. When the magnetic control coil 33 is energized, the magnetic conductor 35 is magnetized, and a closed magnetic circuit is formed between the stationary end seat 31 and the moving end seat 32, causing them to attract each other. The magnetic conductor 35 can be made of electrical pure iron, silicon steel sheet, iron-nickel alloy, or other high-permeability soft magnetic materials to reduce magnetic resistance and increase the attraction force of the magnetic control mechanism 3.

[0038] Insulating layers are provided between the moving end seat 32 and the isolating blade 21, and between the stationary end seat 31 and the isolating blade seat 22, to electrically isolate the conductive parts of the magnetic control mechanism 3 from the disconnecting switch 2. The insulating layers can be made of insulating materials such as epoxy resin, ceramic, polytetrafluoroethylene, or silicone rubber, which ensures the insulation strength between the magnetic control mechanism 3 and the primary conductive circuit without hindering the effective passage of the magnetic field.

[0039] The working principle of this embodiment is as follows: When the circuit breaker body 1 is closed, the disconnector switch 2 is also in the closed state. The line voltage forms a circuit through the circuit breaker body 1, the conductive rod 4, the disconnector switch 21, and the disconnector switch holder 22. The capacitor power extraction device 34 obtains electrical energy from the line and outputs it to the magnetic control coil 33. The stationary end holder 31 and the moving end holder 32 are attracted together. Since the disconnector switch 2 is in the closed position at this time, the attraction force does not affect the normal state of the disconnector switch 2.

[0040] When a line fault occurs or maintenance is required, the circuit breaker body 1 performs a tripping operation. If the arc-extinguishing chamber's breaking function is normal, the circuit breaker body 1 reliably disconnects the electrical connection between the conductive rod 4 and the isolating blade 21. There is no voltage on both the isolating blade 21 side and the isolating blade holder 22 side, the capacitor power supply device 34 has no voltage output, the magnetic control coil 33 is de-energized, and there is no magnetism between the stationary end holder 31 and the moving end holder 32. At this time, maintenance personnel can normally operate the isolating switch 2 to trip. Under the action of the operating force, the isolating blade 21 rotates around the hinge point and moves away from the isolating blade holder 22, completing the formation of a clear disconnection point.

[0041] If the arc-extinguishing chamber fails to open, although the circuit breaker body 1 performs a tripping action, its internal contacts fail to disconnect effectively, and an electrical connection remains between the conductive rod 4 and the isolating blade 21. Line voltage remains on the isolating blade holder 22 and the isolating blade 21. At this time, the capacitor-driven power extraction device 34 couples power from the remaining voltage and outputs it to the magnetic control coil 33. After the magnetic control coil 33 is energized, a magnetic force is generated between the stationary end holder 31 and the moving end holder 32, causing them to attract each other. Since the stationary end holder 31 is fixed to the isolating blade holder 22, and the moving end holder 32 is set with the isolating blade 21, the attraction between them directly resists the tripping operation force of the isolating blade 21, preventing the isolating blade 21 from tripping, thus achieving line-energized interlocking.

[0042] The magnetic control mechanism 3 should have a greater pulling force than the opening force applied to the isolating blade 21 during normal operation of the disconnecting switch 2, with an appropriate safety margin. Taking a disconnecting switch with a rated current of 630A and a rated voltage of 12kV as an example, the pulling force of the magnetic control mechanism 3 under the power supply conditions of the capacitor power take-off device 34 can be set to hundreds to thousands of Newtons to ensure that a reliable locking force can be provided under the action of single-phase grounding residual voltage or normal phase voltage.

[0043] Furthermore, when the isolating knife 21 is forcibly disconnected while the stationary end seat 31 and the moving end seat 32 are in the attracted state, and an arc is generated between the isolating knife 21 and the isolating knife seat 22, the magnetic field between the stationary end seat 31 and the moving end seat 32 acts on the arc generated at the separation point of the isolating knife 21 and the isolating knife seat 22, driving the arc to rotate and cool the arc.

[0044] Specifically, the electric arc, as a conductive plasma, is subjected to the Lorentz force within the magnetic field generated by the magnetic control mechanism 3. Since the arc channel between the isolation blade 21 and the isolation blade holder 22 is approximately horizontal, and the magnetic field direction of the magnetic control mechanism 3 is approximately perpendicular to the contact surface between the isolation blade 21 and the isolation blade holder 22, the Lorentz force is directed circumferentially along the arc, driving the arc to rotate around the center of the magnetic poles of the magnetic control mechanism 3. During rotation, the arc is elongated and expanded, increasing its contact area with the surrounding cold air, rapidly carrying away heat, increasing arc resistance, and decreasing current, thereby accelerating arc extinguishing, reducing the degree of arc erosion on the isolation blade 21 and the isolation blade holder 22, and preventing further escalation of the accident.

[0045] In one possible implementation, a housing 7 is provided at the bottom of the circuit breaker body 1, and a rotating shaft 8 is rotatably mounted on the housing 7. An operating handle 5 is provided at the end of the rotating shaft 8, and an insulating connecting rod 6 is provided between the rotating shaft 8 and the isolating switch 21. The two ends of the insulating connecting rod 6 are respectively hinged to the isolating switch 21 and the rotating shaft 8. The maintenance personnel drive the rotating shaft 8 to rotate through the operating handle 5, and the rotating shaft 8 drives the isolating switch 21 to rotate around the hinge point through the insulating connecting rod 6, thereby realizing the closing and opening of the isolating switch 2.

[0046] Furthermore, an elastic element is provided between the housing 7 and the rotating shaft 8. This elastic element applies torque to the rotating shaft 8 to rotate the isolating blade 21 away from the isolating blade seat 22. This allows the isolating blade 21 to open when there is no attraction between the stationary end seat 31 and the moving end seat 32, thus separating the moving end seat 32 from the stationary end seat 31. The elastic element can be an energy storage component such as a torsion spring, tension spring, or disc spring. When the isolating switch 2 is closed, the elastic element is compressed or twisted to store energy. When the magnetic control coil 33 is de-energized and the magnetic control mechanism 3 is not engaged, the elastic element releases energy to assist the isolating blade 21 in rotating in the opening direction, achieving automatic or semi-automatic opening of the isolating switch 2.

[0047] According to another aspect, this embodiment also provides a method for live-line interlocking of capacitor-powered fault isolation, applied to the above-mentioned circuit breaker-equipped capacitor-powered fault isolation interlocking protection device, including the following steps: Step S1: Power is coupled from the isolation knife holder 22 through the capacitor power supply device 34; Step S2: After the circuit breaker body 1 is tripped, determine whether the arc-extinguishing chamber's breaking function has failed based on whether there is voltage output from the capacitor power supply device 34. When the capacitor power supply device 34 has no voltage output, it is determined that the arc-extinguishing chamber has normal breaking function, there is no voltage on the two sides of the isolating switch, the magnetic control coil 33 is not energized, there is no magnetism between the stationary end seat 31 and the moving end seat 32, and the isolating knife 21 is normally opened. When the capacitor power supply device 34 has a voltage output, it is determined that the arc-extinguishing chamber's breaking function is failed and the isolating switch 2 has residual voltage. The capacitor power supply device 34 outputs voltage to the magnetic control coil 33, the stationary end seat 31 and the moving end seat 32 are energized and attract each other, and the blocking isolating knife 21 is blocked from opening, so that the line is energized and locked.

[0048] In one possible implementation, the above method further includes: when the isolating knife 21 is forcibly disconnected in the attracted state of the stationary end seat 31 and the moving end seat 32, and an arc is generated between the isolating knife 21 and the isolating knife seat 22, the magnetic field between the stationary end seat 31 and the moving end seat 32 drives the arc to rotate and cool the arc.

[0049] It should be noted that in this embodiment, "failure of arc-extinguishing chamber interruption function" refers to a situation where, after the circuit breaker body 1 performs a tripping operation, its internal conductive circuit fails to completely disconnect as intended, resulting in a state where line voltage still exists at the lower end of the circuit breaker body 1. This state may be caused by various reasons such as arc-extinguishing chamber contact welding, improper operation mechanism, or insulation medium failure.

[0050] It should also be noted that the capacitor power-taking device 34 of the present invention can be integrated inside the stationary end holder 31 or installed outside the stationary end holder 31, as long as its power-taking terminal can reliably couple the line voltage at the isolation blade holder 22 and its output terminal can reliably supply power to the magnetic control coil 33. The specific circuit topology and parameters of the power-taking capacitor 341 and the rectifier and voltage regulator circuit can be conventionally designed according to the line voltage level, the parameters of the magnetic control coil 33 and the environmental conditions, and the present invention does not limit them.

[0051] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the invention. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary technical means not disclosed in this application. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0052] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, but various modifications can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A circuit breaker-equipped capacitor-powered fault isolation and interlocking protection device, comprising a circuit breaker body (1) and a disconnecting switch (2) disposed on one side of the circuit breaker body (1), wherein the circuit breaker body (1) is provided with an arc-extinguishing chamber, and the disconnecting switch (2) comprises an isolation blade holder (22) and an isolation blade (21) cooperating with the isolation blade holder (22), characterized in that, The disconnecting switch (2) also includes: The magnetic control mechanism (3) includes a stationary end seat (31) and a moving end seat (32). The stationary end seat (31) is disposed on the isolation knife seat (22), and the moving end seat (32) is disposed on the isolation knife (21). The stationary end seat (31) is provided with a magnetic control coil (33). A capacitor power-taking device (34) is disposed on the stationary end seat (31). The power-taking end of the capacitor power-taking device (34) is electrically connected to the isolation knife seat (22), and the output end of the capacitor power-taking device (34) is electrically connected to the magnetic control coil (33). When the circuit breaker body (1) is open and the arc-extinguishing chamber fails to open, there is still voltage on the side of the disconnecting switch (2). The capacitor power-taking device (34) takes power from the disconnecting knife holder (22) and outputs voltage to the magnetic control coil (33) so that there is a magnetic force between the stationary end seat (31) and the moving end seat (32) and they attract each other, thereby preventing the disconnecting knife (21) from opening with the disconnecting knife holder (22) and putting the disconnecting switch (2) in a energized locked state.

2. The circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device according to claim 1, characterized in that, Both the stationary end seat (31) and the moving end seat (32) are provided with magnetic conductors (35). The magnetic control coil (33) is located in the stationary end seat (31) and is arranged around the magnetic conductors (35). When the magnetic control coil (33) is energized, under the magnetic guidance of the magnetic conductors (35), a closed magnetic circuit is formed between the stationary end seat (31) and the moving end seat (32) and they attract each other.

3. The circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device according to claim 1, characterized in that, The circuit breaker body (1) is provided with a conductive rod (4) extending outward. One end of the isolation blade (21) is hinged to the outer end of the conductive rod (4) and electrically connected to the conductive rod (4).

4. The circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device according to claim 1, characterized in that, The capacitor power extraction device (34) is located at the bottom of the stationary end seat (31). The capacitor power extraction device (34) includes a power extraction capacitor (341), a rectifier voltage regulator circuit and a power output terminal connected in sequence. The power extraction capacitor (341) is electrically connected to the isolation knife seat (22), and the power output terminal is electrically connected to the magnetic control coil (33). When the circuit breaker body (1) is tripped and the arc extinguishing chamber fails to open, the capacitor power extraction device (34) can obtain the voltage at the isolation knife seat (22).

5. The circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device according to claim 1, characterized in that, An insulating layer is provided between the moving end seat (32) and the isolation knife (21), and between the stationary end seat (31) and the isolation knife seat (22), so as to electrically isolate the magnetic control mechanism (3) from the conductive parts of the isolation knife (21) and the isolation knife seat (22).

6. The circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device according to claim 1, characterized in that, When the circuit breaker body (1) is open and the interruption function of the arc-extinguishing chamber is only partially ineffective, the stationary end seat (31) and the moving end seat (32) are in a state of attraction but the attraction force is insufficient. When the isolating knife (21) is forced to rotate in the opening direction and separates from the isolating knife seat (22), and an arc is formed between them, the stationary end seat (31) and the moving end seat (32) separate synchronously. The magnetic field drives the arc generated at the separation point of the isolating knife (21) and the isolating knife seat (22) to rotate to cool the arc.

7. The circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device according to claim 1, characterized in that, The circuit breaker body (1) has a housing (7) at its bottom. A rotating shaft (8) is rotatably mounted on the housing (7). An operating handle (5) is mounted at the end of the rotating shaft (8). An insulating connecting rod (6) is mounted between the rotating shaft (8) and the isolating blade (21). The two ends of the insulating connecting rod (6) are respectively hinged to the isolating blade (21) and the rotating shaft (8). The rotation of the operating handle (5) drives the isolating blade (21) to rotate through the rotating shaft (8) and the insulating connecting rod (6).

8. The circuit breaker-equipped capacitor power supply fault isolation and interlocking protection device according to claim 7, characterized in that, An elastic element is provided between the housing (7) and the rotating shaft (8). The elastic element is used to apply torque to the rotating shaft (8) so that the isolation knife (21) rotates away from the isolation knife seat (22) along with the rotating shaft (8). Then, when there is no attraction between the stationary end seat (31) and the moving end seat (32), the isolation knife (21) is opened and the moving end seat (32) is separated from the stationary end seat (31).

9. A method for live-line interlocking of capacitor-powered fault isolation, applied to the circuit breaker-equipped capacitor-powered fault isolation interlocking protection device according to any one of claims 1 to 8, characterized in that, include: After the circuit breaker body (1) is opened, if the arc-extinguishing chamber's breaking function is not ineffective, the capacitor power supply device (34) has no voltage output, the magnetic control coil (33) is not energized, the stationary end seat (31) and the moving end seat (32) do not exhibit magnetism, and the isolating knife (21) is opened normally. After the circuit breaker body (1) is tripped, if the arc-extinguishing chamber fails to break, there is still voltage on the side of the disconnecting switch (2). The capacitor power-taking device (34) takes power from the disconnecting knife holder (22) and outputs voltage to the magnetic control coil (33) so that the stationary end seat (31) and the moving end seat (32) attract each other, thereby locking the disconnecting knife (21) and the disconnecting knife holder (22) to prevent tripping, so that the disconnecting switch (2) is in a energized locked state.

10. A method for isolating and locking live capacitor power supply faults according to claim 9, characterized in that, Also includes: After the circuit breaker body (1) is opened, if the arc-extinguishing chamber's breaking function is only partially ineffective, when the isolating knife (21) is forcibly opened in the state of the static end seat (31) and the moving end seat (32) being attracted together and an arc is generated between the isolating knife (21) and the isolating knife seat (22), the magnetic field between the static end seat (31) and the moving end seat (32) drives the arc to rotate and cool the arc.

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