Novel outdoor pillar type three-phase recloser

Abstract

The invention relates to the technical field of three-phase reclosers, and particularly provides a novel outdoor pillar type three-phase recloser, which comprises a solid-sealed polar pole, a shell, three-phase vacuum arc extinguish chambers and an insulating rod piece for connecting contacts of the three-phase vacuum arc extinguish chambers, a single-coil bistable permanent magnet mechanism is adopted, stable static holding magnetic flux is provided at the opening position and the closing position through an annular permanent magnet, opening energy is provided by an opening spring, a transmission mechanism is in a dead point passing self-locking state at the closing end point, and in the state, force needed for maintaining closing is mainly borne by mechanism self-locking; the end point of the opening action is jointly determined by stable permanent magnetic force and accurate spring force, so that the stability and adjustability of the whole device are ensured, and the single-coil bistable permanent magnetic mechanism, the transmission mechanism and the dead point self-locking mechanism are all integrally mounted on the same lining plate to form a standardized module capable of completing all precise assembly and debugging in a factory. And the overall structure is smaller and is convenient for subsequent use.

Description

Technical Field

[0001] This invention relates to the field of three-phase recloser technology, and specifically proposes a novel outdoor pillar-type three-phase recloser. Background Technology

[0002] Outdoor post-mounted three-phase reclosers are core switching devices in smart distribution networks that enable automatic fault detection, isolation, and power restoration. Unlike ordinary circuit breakers, reclosers need to execute multiple preset opening and closing operation sequences (such as "open-delay-close-open") continuously within a very short time. This places extremely stringent requirements on the mechanical endurance, energy recovery speed, action consistency, and final position retention reliability of the operating mechanism. It also imposes extremely stringent requirements on the rebound and overshoot control indicators of the opening process (such as requiring a rebound stabilization time of less than 0.1ms), which directly affects the arc extinguishing effect, contact life, and breaking success rate.

[0003] Most mainstream recloser products in China are upgraded from the spring operating mechanism of outdoor pole-mounted circuit breakers (such as the ZW32 type). Although this solution has a lower cost, it has not been fundamentally optimized for the harsh working conditions of reclosers that require continuous and rapid operation (such as Ot-CO sequence). Because it relies on rubber pads or oil buffers to suppress rebound, the performance of rubber pads or oil buffers is greatly affected by temperature, aging and manufacturing precision, resulting in uncontrollable tripping performance. At the same time, it relies on manual adjustment of pre-pressure and effective number of turns, resulting in a loose structure and low reliability.

[0004] Chinese patent CN202585237U discloses a high-voltage intelligent recloser. This solution introduces permanent magnet drive technology into the recloser, but it is a monostable permanent magnet mechanism. That is, closing is done by electromagnetic force, holding is done by permanent magnet force, and opening is done by spring force. It lacks permanent magnet holding at the opening position, which results in the mechanism being magnetically unstable at the opening end and easily affected by vibration. In addition, the opening spring (elastic body) is simply connected to the moving iron core and the bottom of the cavity, which is an external or semi-external layout. It does not achieve deep integration with the magnetic circuit and occupies a lot of space.

[0005] Therefore, there is an urgent need for a modular and standardized operating mechanism to solve the problems of tripping rebound control, assembly consistency, and miniaturization of a new type of outdoor pillar-type three-phase recloser. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a novel outdoor pillar-type three-phase recloser, which solves the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention employs the following technical solution: a novel outdoor pillar-type three-phase recloser, comprising a solid-sealed pole, a housing, three-phase vacuum interrupters, and insulating rods connecting the vacuum interrupter contacts of each phase; further comprising a single-coil bistable permanent magnet mechanism as a power source for outputting linear motion; a liner fixedly installed inside the housing, the single-coil bistable permanent magnet mechanism fixedly installed on the liner; a transmission mechanism installed on the surface of the liner, the transmission mechanism comprising a connecting rod and a crank arm, the connecting rod being installed on the surface of the single-coil bistable permanent magnet mechanism, one end of the crank arm being hinged to the surface of the connecting rod, the other end of the crank arm being hinged to the end of the insulating rod, and the crank end of the crank arm being movably installed on the surface of the liner; dead point self- The locking mechanism includes a self-locking rod telescopically mounted on the surface of the liner, with the end of the crank arm abutting against the surface of the self-locking rod. A single-coil bistable permanent magnet mechanism drives the connecting rod to move linearly, pulling the insulating rod vertically through the crank arm. The geometric configuration of the transmission mechanism is such that when the recloser is in the closed position, the transmission mechanism is in a mechanical dead-point self-locking state, that is, the driving torque of the transmission mechanism acting on the contact reaction force inside the vacuum interrupter is zero. At this time, the self-locking rod extends out of the surface of the liner, the end of the crank arm abuts against the surface of the self-locking rod, and the contacts inside the vacuum interrupter are closed. When the recloser is in the open position, the single-coil bistable permanent magnet mechanism drives the connecting rod to move linearly in the opposite direction, and the connecting rod pulls the insulating rod downward through the crank arm, separating the contacts of the vacuum interrupter.

[0008] Preferably, the single-coil bistable permanent magnet mechanism includes an inner yoke and an outer yoke arranged coaxially. A ring-shaped permanent magnet is radially arranged between the inner yoke and the outer yoke. A fixed iron core and a movable iron core that can move axially are provided on the inner side of the inner yoke. A tripping spring is provided between the movable iron core and the fixed iron core. A tripping coil is provided on the outside of the movable iron core. A drive rod arranged axially is installed on the surface of the movable iron core. A connecting rod is installed on the surface of the drive rod.

[0009] Preferably, an overtravel adjusting screw is installed between the crank arm and the insulating rod. By turning the screw, the effective length of the overtravel adjusting screw can be changed to finely adjust the contacts of the vacuum interrupter of the corresponding phase and the geometric angle at which the crank arm terminates when the circuit is closed.

[0010] Preferably, an upper magnetic yoke and a lower magnetic yoke are installed inside the outer magnetic yoke. The surface of the lower magnetic yoke is provided with a central boss through which the drive rod passes. One end of the opening spring abuts against the inner end face of the central boss. The annular permanent magnet, the inner magnetic yoke, the opening and closing coil, and the moving iron core are encapsulated inside the outer magnetic yoke.

[0011] Preferably, the dead-point self-locking mechanism further includes an electromagnet and a magnetic block. The electromagnet is fixedly installed inside the liner, and the magnetic block is fixedly installed at the end of the self-locking rod. When the circuit is closed, the electromagnet drives the magnetic block to move the self-locking rod closer to the crank arm.

[0012] Preferably, the end of the self-locking rod is provided with a guide groove, and a guide rod is installed inside the liner, with the guide rod located inside the guide groove.

[0013] Preferably, the end of the self-locking lever is set as a bevel.

[0014] Preferably, the angle of the inclined plane is less than 10°.

[0015] Preferably, the liner is equipped with an anti-detachment block parallel to the inclined surface.

[0016] The above technical solution has the following advantages or beneficial effects: This invention provides a novel outdoor pillar-type three-phase recloser, which replaces the traditional spring operating mechanism with a single-coil bistable permanent magnet mechanism. The annular permanent magnet can provide a stable static holding magnetic flux in both the opening and closing positions. The opening energy is provided by a built-in opening spring with preset parameters. The transmission mechanism is in a "dead-point" self-locking geometric state at the closing end point, and is also in conjunction with a dead-point self-locking mechanism. In this state, the force required to maintain the closing is mainly borne by the mechanism's self-locking, so that the endpoint of the opening action is determined by the stable permanent magnet force and the precise spring force, thereby ensuring the stability and adjustability of the entire device. The single-coil bistable permanent magnet mechanism, the transmission mechanism, and the dead-point self-locking mechanism are all integrated and installed on the same liner, forming a standardized module that can be fully assembled and debugged in the factory. The overall structure is smaller and easier to use later. Attached Figure Description

[0017] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings, which are not intentionally drawn to scale; the focus is on illustrating the spirit of the invention.

[0018] Figure 1 This is a three-dimensional structural diagram of a novel outdoor support-type three-phase recloser provided by the present invention.

[0019] Figure 2 This is a schematic diagram of the location and structure of the transmission mechanism inside the housing.

[0020] Figure 3 This is a schematic diagram of the exploded structure of a single-coil bistable permanent magnet mechanism.

[0021] Figure 4 This is a schematic diagram of the open state structure of a single-coil bistable permanent magnet mechanism.

[0022] Figure 5 This is a schematic diagram of the closed state structure of a single-coil bistable permanent magnet mechanism.

[0023] Figure 6This is a schematic diagram of the dead-point self-locking mechanism in the open circuit state.

[0024] Figure 7 This is a schematic diagram of the dead-point self-locking mechanism in the closed state.

[0025] In the diagram: 1. Solid-sealed pole; 2. Housing; 3. Vacuum interrupter; 4. Insulating rod; 5. Single-coil bistable permanent magnet mechanism; 50. Ring permanent magnet; 51. Inner yoke; 52. Outer yoke; 53. Fixed iron core; 54. Moving iron core; 55. Opening spring; 56. Opening and closing coil; 57. Drive rod; 58. Upper yoke; 59. Lower yoke; 6. Liner plate; 7. Transmission mechanism; 71. Connecting rod; 72. Crank arm; 8. Dead-point self-locking mechanism; 81. Self-locking rod; 82. Electromagnet; 83. Magnetic block; 84. Guide groove; 85. Guide rod; 86. Anti-disengagement block; 9. Overtravel adjusting screw. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Figure 1 and Figure 2 A novel outdoor support-type three-phase recloser is provided. Its main structure includes a three-phase solidified pole 1 made of epoxy resin, a vacuum interrupter 3 encapsulated inside the solidified pole 1, and a metal housing 2 for support and protection. The housing 2 is located below the solidified pole 1 and integrates an operating mechanism inside. The operating mechanism realizes the opening and closing of the solidified pole 1. The operating mechanism includes a single-coil bistable permanent magnet mechanism 5, a high-efficiency transmission mechanism 7, and an active dead-point self-locking mechanism 8.

[0029] like Figures 2-5As shown, the single-coil bistable permanent magnet mechanism 5 is an electromagnetic-mechanical energy conversion unit. Its magnetic circuit adopts an inner and outer yoke opposition structure, including an upper yoke 58 and a lower yoke 59. An outer yoke 52 is provided between the upper yoke 58 and the lower yoke 59. The outer yoke 52 is cylindrical. The two ends of the outer yoke 52 are fastened to the disc-shaped upper yoke 58 and lower yoke 59 by internal hexagonal bolts, thereby forming a closed soft magnetic shell. An inner yoke 51 is installed inside the outer yoke 52. The inner yoke 51 is cylindrical and coaxially suspended inside the outer yoke 52. An annular cavity is formed between the outer yoke 52 and the inner yoke 51. Inside the annular cavity, one or more pairs of axially magnetized annular permanent magnets 50 are placed radially. It should be noted that all the annular permanent magnets 50 are magnetized in the same direction (e.g., the N poles all face the upper yoke 58) to provide static holding magnetic flux in two working positions (open and closed).

[0030] The central part of the lower yoke 59 is a fixed iron core 53. A moving iron core 54 is provided at the relative position of the fixed iron core 53. The moving iron core 54 is a cylinder made of high magnetic permeability material. Its outer diameter and the inner hole of the inner yoke 51 are precisely slidingly fitted. The fit tolerance can be selected as H7 / g6. The purpose is to ensure that the moving iron core 54 can slide freely along the axial direction and with minimal magnetic resistance. A non-magnetic drive rod 57 is fixed in the central axis of the moving iron core 54. The drive rod 57 is a stainless steel rod that passes through the central hole of the inner yoke 51, the opening spring 55, and the central through hole of the upper yoke 58 in sequence before extending out of the outside of the single-coil bistable permanent magnet mechanism 5.

[0031] A tripping spring 55 is housed within the enclosed space formed by the upper yoke 58, the end face of the moving iron core 54, and the drive rod 57. The tripping spring 55 is a helical compression spring. One end of the tripping spring 55 abuts against the stepped surface of the moving iron core 54 facing the lower yoke 59, and the other end abuts against the inner end face of the central boss of the lower yoke 59. This central boss can also be used to guide the tripping spring 55. A tripping coil 56 is installed in the annular space between the moving iron core 54 and the inner yoke 51. The tripping coil 56 is a single coil that is directly wound on a coil frame. The coil frame is coaxially sleeved in the annular space between the moving iron core 54 and the inner yoke 51. The lead wire of the tripping coil 56 is sealed out from the side of the yoke.

[0032] At this point, the pre-compression force, working stroke, and fatigue life of the trip spring 55 have been precisely set and locked once during module assembly using tooling, completely eliminating human error in on-site assembly and thus ensuring the stability of the tripping and closing performance.

[0033] The transmission mechanism 7 is used to synchronously and accurately convert the linear horizontal motion output by the single-coil bistable permanent magnet mechanism 5 into the vertical motion of the contacts inside the vacuum interrupter 3.

[0034] Inside the housing 2, a liner 6 is fixedly installed by anti-vibration bolts. The liner 6 is made of thick steel plate. The transmission mechanism 7 is installed on the surface of the liner 6. The surface of the drive rod 57 is machined with a first pin hole. The first pin hole is hinged to a connecting rod 71 through a first pin shaft. The surface of the connecting rod 71 is machined with a second pin hole. The second pin hole is mounted with a crank arm 72 through a second pin shaft. The middle position of the crank arm 72 is mounted on the surface of the liner 6 through a wear-resistant bushing bearing, thus forming a rotation fulcrum. The other end of the crank arm 72 is machined with a threaded hole. An overtravel adjustment screw 9 is installed inside the threaded hole. The vacuum interrupter 3 is equipped with an insulating rod 4. The other end of the overtravel adjustment screw 9 is connected to the lower end of the insulating rod 4 through a spherical bearing. The upper end of the insulating rod 4 is connected to the conductive rod inside the vacuum interrupter 3 through a spring contact finger assembly (not shown in the figure).

[0035] It should be noted that the lever arm of connecting rod 71 and crank arm 72, as well as the initial installation angle, have been rigorously optimized through kinematic and dynamic simulations. The design goal is that at the closing end position, i.e., when the drive rod 57 is at its left limit, the moving iron core 54 is in contact with the magnetic yoke 58, and the insulating rod 4 is at its upper limit, the force F acting on the output end of crank arm 72, which is equivalent to the reaction force of the spring contact finger assembly, has its line of action passing through or infinitely close to the rotation fulcrum of crank arm 72. Mechanically, at this time, the torque M generated by F on the rotation fulcrum is M=F×d≈0 (d is the lever arm, which approaches 0). The mechanism is at the theoretical dead point. In actual design, the closing end point will be slightly "over the dead point", i.e., d becomes a negative value, so that the contact reaction force generates a small positive torque that makes the mechanism go deeper into the closing state, thereby forming a stable self-locking tendency.

[0036] like Figure 2 , Figure 6 and Figure 7 As shown, the dead-point self-locking mechanism 8 ensures that the closing position is absolutely reliable under any harsh conditions. It includes a self-locking rod 81 with a guide groove 84 in the middle of the rod. A guide rod 85 is pressed into the corresponding hole of the liner 6. The guide rod 85 is embedded in the corresponding hole and is located inside the guide groove 84, so that the self-locking rod 81 can only slide precisely along its axial direction. A magnetic block 83 is fixed at the tail of the self-locking rod 81. A tubular electromagnet 82 is installed inside the liner 6 opposite to the magnetic block 83. The electromagnet 82 is designed with a double coil configuration. When energized, it can generate magnetic fields of opposite polarities by passing in positive or reverse current.

[0037] When the recloser is about to reach the closing end position, the controller sends a positive current to the electromagnet 82, causing the electromagnet 82 to generate a magnetic field with the same polarity as the magnetic block 83. According to the principle of like poles repulsion, the electromagnet 82 generates a strong repulsive force, which quickly pushes the magnetic block 83 at the end of the self-locking rod 81 away, thereby driving the self-locking rod 81 to move quickly along the guide groove 84 in the extension direction until the inclined surface at its end is tightly pressed against the upper surface of the crank arm 72. When it is necessary to perform the opening operation, the controller sends a reverse current to the electromagnet 82, causing the electromagnet 82 to generate a magnetic field with the opposite polarity to the magnetic block 83. According to the principle of opposite poles attracting, the electromagnet 82 generates a strong attractive force, which quickly attracts the magnetic block 83 at the end of the self-locking rod 81, thereby causing the self-locking rod 81 to retract quickly and release the mechanical constraint on the crank arm 72.

[0038] The end of the self-locking rod 81 is optimized. The end of the self-locking rod 81 is a bevel with an acute angle, preferably between 5° and 10°, such as 8°. Under the action of magnetic repulsion, the longer the self-locking rod 81 protrudes outward, the more tightly it will press against the crank arm 72, thus counteracting the force F from the spring contact finger assembly, thereby forming a secondary self-lock. Since the angle is very small, when the electromagnet 82 is no longer energized, the self-locking rod 81 is difficult to be pushed back into the liner 6, thus maintaining stability. To prevent the self-locking rod 81 from falling off, an anti-detachment block 86 is fixedly welded inside the liner 6.

[0039] The overtravel adjusting screw 9 is a screw with oppositely oriented threads at both ends and a locking nut in the middle. Rotating the overtravel adjusting screw 9 can change the effective length between its two hinge points (i.e., the output point of the crank arm 72 and the upper end of the insulating rod 4). Fine adjustment will slightly change the absolute angular position of the crank arm 72 when the closing is terminated. Through this adjustment, the cumulative tolerance of each transmission link can be compensated, and the crank arm 72 is exactly at the optimal "over-dead point" self-locking angle, so that the efficiency of the dead point is optimal.

[0040] The opening and closing process is controlled by a microcontroller. First, the controller receives the closing command and drives the power module to output a positive current of 30A to the opening and closing coil 56 for 80ms. The moving iron core 54 begins to move to the left. The controller starts the internal timer T1, set to the total closing time, such as 120ms. When T1 reaches 110ms (i.e., the closing process is about 92%), the controller synchronously outputs a positive current of 5A to the electromagnet 82 for 100ms. The electromagnet 82 generates a magnetic field with the same polarity as the magnetic block 83. The repulsive force pushes the self-locking rod 81 to extend. The inclined surface of the self-locking rod 81 collides with and abuts the crank arm 72 when it reaches its end point. When the circuit is closed, the moving iron core 54 reaches its left limit. The controller cuts off the current to the opening and closing coil 56, and the current to the electromagnet 82 is cut off after 100ms. The self-locking rod 81 is maintained in position by relying on residual magnetism and friction. When the controller receives the opening command, it first outputs a reverse current to the electromagnet 82 with an amplitude of 5A and a duration of 50ms. The electromagnet 82 generates a magnetic force to pull the self-locking rod 81 back. After a delay of 10ms (to ensure that the unlocking is in place), the controller outputs a reverse current to the opening and closing coil 56 with an amplitude of 25A and a duration of 60ms to weaken the closing holding force. The opening spring 55 releases energy and drives the transmission mechanism 7 to complete the opening. Then all currents are cut off, and the circuit stabilizes in the opening state.

[0041] It should be noted that, for on-site installation and commissioning, the pre-installed operating module is hoisted into the housing 2 and fixed with anti-vibration bolts. The lower end of the insulating rod 4 is connected to the corresponding overtravel adjusting screw 9 through a spherical bearing. The recloser is slowly closed by manual (or electric) operation. The exposed height of the insulating rod 4 is measured with a vernier caliper. The overtravel adjusting screw 9 is adjusted so that the height deviation is less than 0.5mm. The stroke curve of the spring contact finger assembly is monitored using a displacement sensor. The closing operation is performed under the rated operating voltage. The time difference of the closing point is observed. The overtravel adjusting screw 9 is finely adjusted when the response is slow to increase the effective length, so that the phase crank arm 72 reaches the dead point earlier, and the closing time difference is less than 2ms. After adjustment, the locking nut in the middle of the overtravel adjusting screw 9 is tightened with a wrench and marked.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a manner common to the art; any possible variations and modifications made by those skilled in the art without departing from the technical solution of the present invention, or equivalent embodiments with equivalent changes, do not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A novel outdoor pillar-type three-phase recloser, comprising a solid-sealed pole, a housing, three-phase vacuum interrupters, and insulating rods connecting the contacts of the vacuum interrupters of each phase, characterized in that, Also includes: A single-coil bistable permanent magnet mechanism is used as a power source to output linear motion; The liner is fixedly installed inside the housing, and the single-coil bistable permanent magnet mechanism is fixedly installed on the liner. A transmission mechanism is installed on the surface of the liner. The transmission mechanism includes a connecting rod and a crank arm. The connecting rod is installed on the surface of the single-coil bistable permanent magnet mechanism. One end of the crank arm is hinged to the surface of the connecting rod, and the other end of the crank arm is hinged to the end of the insulating rod. The crank end of the crank arm is movably installed on the surface of the liner. The dead-point self-locking mechanism includes a self-locking rod telescopically mounted on the surface of the liner, with the end of the crank arm abutting against the surface of the self-locking rod; The single-coil bistable permanent magnet mechanism drives the connecting rod to move linearly, and pulls the insulating rod to move vertically through the crank arm. The geometric configuration of the transmission mechanism is such that when the recloser is in the closed position, the transmission mechanism is in a mechanical dead-point self-locking state, that is, the reaction force of the contacts inside the vacuum interrupter acts on the driving torque of the transmission mechanism to be zero. At this time, the self-locking rod extends out of the surface of the liner, and the end of the crank arm abuts against the surface of the self-locking rod, and the contacts inside the vacuum interrupter are closed. When the recloser is in the open position, the single-coil bistable permanent magnet mechanism drives the connecting rod to move linearly in the opposite direction. The connecting rod pulls the insulating rod downward through the crank arm, and the contacts of the vacuum interrupter separate.

2. The novel outdoor support-type three-phase recloser according to claim 1, characterized in that: The single-coil bistable permanent magnet mechanism includes an inner yoke and an outer yoke arranged coaxially. A ring-shaped permanent magnet is radially arranged between the inner yoke and the outer yoke. A fixed iron core and a movable iron core that can move axially are provided on the inner side of the inner yoke. A tripping spring is provided between the movable iron core and the fixed iron core. A tripping coil is provided on the outside of the movable iron core. A drive rod arranged axially is installed on the surface of the movable iron core. The connecting rod is installed on the surface of the drive rod.

3. A novel outdoor support-type three-phase recloser according to claim 2, characterized in that: An overtravel adjusting screw is installed between the crank arm and the insulating rod. By turning the screw, the effective length of the overtravel adjusting screw can be changed to finely adjust the contacts of the vacuum interrupter of the corresponding phase and the geometric angle at which the crank arm terminates when the circuit is closed.

4. A novel outdoor support-type three-phase recloser according to claim 2, characterized in that: The outer magnetic yoke has an upper magnetic yoke and a lower magnetic yoke installed inside. The surface of the lower magnetic yoke has a central boss through which the drive rod passes. One end of the opening spring abuts against the inner end face of the central boss. The annular permanent magnet, the inner magnetic yoke, the opening and closing coil, and the moving iron core are encapsulated inside the outer magnetic yoke.

5. A novel outdoor support-type three-phase recloser according to claim 1, characterized in that: The dead-point self-locking mechanism also includes an electromagnet and a magnetic block. The electromagnet is fixedly installed inside the liner, and the magnetic block is fixedly installed at the end of the self-locking rod. When the circuit is closed, the electromagnet drives the magnetic block to move the self-locking rod closer to the crank arm.

6. A novel outdoor support-type three-phase recloser according to claim 5, characterized in that: The end of the self-locking rod is provided with a guide groove, and a guide rod is installed inside the liner, with the guide rod located inside the guide groove.

7. A novel outdoor support-type three-phase recloser according to claim 5, characterized in that: The end of the self-locking rod is set as an inclined surface.

8. A novel outdoor support-type three-phase recloser according to claim 7, characterized in that: The angle of the inclined plane is less than 10°.

9. A novel outdoor support-type three-phase recloser according to claim 7, characterized in that: The liner is equipped with an anti-detachment block that is parallel to the inclined surface.

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