Gas circuit breaker

Abstract

To provide a gas circuit breaker that can easily be made compact and has a reduced driving force.SOLUTION: In a gas circuit breaker according to an embodiment, an insulating nozzle is a tubular body including a large nozzle diameter portion, a nozzle small diameter portion, and a nozzle inclined portion, and is arranged coaxially with the opposing arc contact in the axial direction. The nozzle small diameter portion is located closer to the opposing contact portion than the nozzle large diameter portion, and has a smaller outer diameter than the nozzle large diameter portion. The nozzle inclined portion is located closer to the opposing contact portion than the nozzle small diameter portion, and the outer circumferential surface is inclined with respect to the axial direction such that the outer diameter increases from the nozzle small diameter portion toward the opposing contact portion. A variable strain ring is provided so as to surround at least one of the nozzle small diameter portion and the nozzle inclined portion, and the electric field generated around the tip of the opposing arc contact during the opening process is alleviated by the variable strain ring.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a gas circuit breaker. [Background technology]

[0002] The gas circuit breaker is, for example, of a puffer type, and is configured to blow arc-extinguishing gas pressurized in a puffer chamber in conjunction with the current interruption operation to the arc discharge in order to extinguish the arc discharge that occurs during the current interruption operation. For example, sulfur hexafluoride (SF6) gas is mainly used as the arc-extinguishing gas. In addition, due to restrictions on the use of fluorine-based gases, it is being promoted to use a mixed gas mainly containing carbon dioxide (CO2) in addition to sulfur hexafluoride gas as the arc-extinguishing gas.

[0003] When performing a breaking operation, the gas circuit breaker transitions from a closed state to an open state in the opening process, and then reaches a completely open state.

[0004] Specifically, in the closed state, the gas circuit breaker has a tubular driving-side current contact inserted into a tubular opposing-side current contact outside the tubular insulating nozzle, so that the opposing-side current contact and the driving-side current contact are in contact with each other, and a rod-shaped opposing-side arc contact inserted into a tubular driving-side arc contact inside the tubular insulating nozzle, so that the opposing-side arc contact and the driving-side arc contact are in contact with each other.

[0005] In the opening process from the closed state to the open state, first, the opposing arc contact and the driving side arc contact are maintained in contact with each other, while the opposing arc contact and the driving side arc contact are separated from each other. Next, the opposing arc contact and the driving side arc contact are separated from each other. At this time, an arc discharge occurs between the opposing arc contact and the driving side arc contact inside the insulating nozzle. As the opening process progresses, the arc discharge is extinguished by the blowing of the arc-extinguishing gas pressurized in the puffer chamber.

[0006] Thereafter, in the completely open state, the opposing current-carrying contact and the driving current-carrying contact are at their farthest apart positions, and the opposing arcing contact and the driving arcing contact are at their farthest apart positions. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] WO-A1-2019 / 150655 [Patent Document 2] JP 2016-213146 A Summary of the Invention [Problem to be solved by the invention]

[0008] Gas circuit breakers are required to be smaller in size and to reduce the driving force required to increase the pressure of the arc-extinguishing gas, but it is not easy to meet these demands.

[0009] Specifically, during the period of transition to a completely open state after the arc discharge is extinguished, the electric field around the tip of the opposing arc contact may become high. In other words, during the opening process when switching a small leading current or breaking a small to medium current, the electric field around the tip of the opposing arc contact may become high. As a result, the possibility of dielectric breakdown occurring between the opposing arc contact and the driving arc contact increases.

[0010] In order to prevent the occurrence of dielectric breakdown, it is necessary to ensure a sufficient amount of arc-extinguishing gas blown, and since it is not easy to reduce the blown amount, it may be difficult to reduce the size of the puffer chamber. Also, in order to prevent the occurrence of dielectric breakdown, it is necessary to maintain a high pressure of the arc-extinguishing gas in the puffer chamber, and since it is not easy to reduce the pressure, it may be difficult to reduce the driving force for pressurizing the arc-extinguishing gas in the puffer chamber.

[0011] Due to the above circumstances, it is difficult to improve the current interruption performance and insulation performance of the gas circuit breaker, and therefore it is not easy to reduce the size of the gas circuit breaker and the driving force.

[0012] Therefore, the problem to be solved by the present invention is to provide a gas circuit breaker which enables improvement in current interruption performance and insulation performance, and which can easily be made smaller and has a reduced driving force. [Means for solving the problem]

[0013] A gas circuit breaker according to an embodiment includes a sealed container, an opposing contact portion, a driving contact portion, and an insulating nozzle. The sealed container is filled with an arc-extinguishing gas. The opposing contact portion is provided inside the sealed container. The driving contact portion is provided inside the sealed container, and moves so as to come into contact with the opposing contact portion to enter a closed state, and to move away from the opposing contact portion to enter an open state. The insulating nozzle is provided inside the sealed container, and moves together with the driving contact portion in a separation process in which the state between the driving contact portion and the opposing contact portion changes from a closed state to an open state. The insulating nozzle includes a nozzle internal space from which an arc-extinguishing gas is released when an arc discharge occurs between the opposing contact portion and the driving contact portion in the separation process. The opposing contact portion has an opposing arc contact and an opposing current contact. The opposing arc contact is a rod-shaped body extending in the axial direction, and includes a portion accommodated in the nozzle internal space. The opposing side current-carrying contact is a tubular body arranged coaxially with the opposing side arc contact in the axial direction, and includes a portion that accommodates the opposing side arc contact therein via an insulating nozzle. The driving side contact portion has a driving side arc contact and a driving side current-carrying contact. The driving side arc contact is a tubular body arranged coaxially with the opposing side arc contact in the axial direction, and is accommodated in the nozzle internal space, the opposing side arc contact is inserted therein in a closed state, and an arc discharge occurs between the driving side arc contact and the opposing side arc contact in a breaking process. The driving side current-carrying contact is a tubular body arranged coaxially with the opposing side arc contact in the axial direction, and includes a portion that accommodates the driving side arc contact therein via an insulating nozzle, and is inserted into the opposing side current-carrying contact in a closed state. The insulating nozzle is a tubular body that includes a nozzle large diameter portion, a nozzle small diameter portion, and a nozzle inclined portion, and is arranged coaxially with the opposing side arc contact in the axial direction. The nozzle large diameter portion is interposed between the driving side arc contact and the driving side current-carrying contact. The nozzle small diameter portion is located closer to the opposing contact portion than the nozzle large diameter portion and has a smaller outer diameter than the nozzle large diameter portion. The nozzle inclined portion is located closer to the opposing contact portion than the nozzle small diameter portion and has an outer peripheral surface inclined with respect to the axial direction such that the outer diameter increases from the nozzle small diameter portion toward the opposing contact portion.Here, a variable strain ring is provided to surround at least one of the nozzle small diameter portion and the nozzle inclined portion, and the electric field generated around the tip of the opposing arc contact during the separation process is alleviated by the variable strain ring. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing the overall configuration of a gas circuit breaker 1 according to a first embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing the configuration of the insulating nozzle 500 and the variable strain ring 600 in the gas circuit breaker 1 according to the first embodiment. [Figure 3A] FIG. 3A is a cross-sectional view for explaining an interrupting operation in the gas circuit breaker 1 according to the first embodiment (closed state). [Figure 3B] FIG. 3B is a cross-sectional view for explaining the interrupting operation in the gas circuit breaker 1 according to the first embodiment (opening process). [Figure 3C] FIG. 3C is a cross-sectional view for explaining the interrupting operation (opening process) in the gas circuit breaker 1 according to the first embodiment. [Figure 3D] FIG. 3D is a cross-sectional view for explaining the interrupting operation in the gas circuit breaker 1 according to the first embodiment (completely open contact state). [Figure 4] FIG. 4 is a diagram showing a schematic diagram of the electric potential distribution around the insulating nozzle 500 and the variable strain ring 600 in the gas circuit breaker 1 according to the first embodiment. [Diagram 5] FIG. 5 is an enlarged cross-sectional view showing the configuration of an insulating nozzle 500 and a variable strain ring 600 in the gas circuit breaker 1 according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view for explaining the interrupting operation in the gas circuit breaker 1 according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] First Embodiment [A] Overall configuration of gas circuit breaker 1 FIG. 1 is a cross-sectional view showing the overall configuration of a gas circuit breaker 1 according to a first embodiment.

[0016] The gas circuit breaker 1 is of a puffer type, and has an opposed side unit 3 and a driving side unit 4 housed inside a sealed container 2, as shown in FIG.

[0017] In the gas circuit breaker 1, a first conductor 11 and a second conductor 12 are installed so as to penetrate from the inside to the outside of the sealed container 2. The first conductor 11 is provided on the opposing side OS where the opposing side unit 3 is located in the sealed container 2, and is connected to the opposing side unit 3. The second conductor 12 is provided inside the sealed container 2 on the driving side DS where the driving side unit 4 is located, and is connected to the driving side unit 4.

[0018] The gas circuit breaker 1 is a switching device that opens and closes an electrical circuit in an electric power system, and the interrupting operation for interrupting the current flowing between the first conductor 11 and the second conductor 12 is performed by the opposing side unit 3 and the driving side unit 4.

[0019] In the gas circuit breaker 1, the opposing unit 3 and the driving side unit 4 are electrically connected to each other, so that a current flows between the first conductor 11 and the second conductor 12. In the gas circuit breaker 1, the opposing unit 3 and the driving side unit 4 are electrically separated from each other, so that the current flowing between the first conductor 11 and the second conductor 12 is interrupted.

[0020] The individual components of the gas circuit breaker 1 will now be described in detail.

[0021] [A-1] Sealed container 2 The sealed container 2 is made of a metal material and is grounded (not shown). The sealed container 2 is, for example, a cylindrical tubular body, and the opposing unit 3 and the driving unit 4 are provided inside the sealed container 2 so as to be aligned in the axial direction along the tube axis (dotted line).

[0022] The sealed container 2 is filled with an arc-extinguishing gas. The arc-extinguishing gas is a gas with excellent arc-extinguishing and insulating properties, such as sulfur hexafluoride gas (SF6 gas). The arc-extinguishing gas may be a gas with a smaller global warming potential than sulfur hexafluoride gas. The arc-extinguishing gas with a smaller global warming potential than sulfur hexafluoride gas is, for example, air, carbon dioxide, oxygen, nitrogen, or other gas, or may be a mixed gas of the above gases.

[0023] [A-2] Opposite unit 3 The opposing side unit 3 includes a cooling cylinder 301, a support portion 302, and an opposing side contact portion 303. The cooling cylinder 301, the support portion 302, and the opposing side contact portion 303 are each formed of, for example, a metal material, and each is electrically connected to the first conductor 11.

[0024] [A-2-1] Cooling tube 301 The cooling cylinder 301 is, for example, a cylindrical tubular body, and is arranged coaxially with the sealed container 2 etc. In other words, the cooling cylinder 301 is installed so that its central axis coincides with that of the sealed container 2. The cooling cylinder 301 is connected to the first conductor 11. Although not shown in the figure, the cooling cylinder 301 is fixed to the sealed container 2.

[0025] [A-2-2] Support Department 302 The support portion 302 includes a support ring portion 321 and a support protrusion portion 322 .

[0026] The support ring part 321 is, for example, a circular ring-shaped body, and is installed coaxially with the sealed container 2 on the end face of the cooling cylinder 301 located on the driving side DS. Here, the outer diameter of the support ring part 321 is, for example, the same as the outer diameter of the cooling cylinder 301, and the inner diameter of the support ring part 321 is, for example, the same as the inner diameter of the cooling cylinder 301.

[0027] The support protrusion 322 is, for example, a rod-shaped body, and is provided so as to protrude radially inward on the inner circumferential surface of the support ring portion 321. Here, the support protrusion 322 is, for example, formed integrally with the support ring portion 321.

[0028] [A-2-3] Opposing contact part 303 The opposing contact portion 303 includes an opposing arc contact 331 and an opposing current-carrying contact 335 , and is provided inside the sealed container 2 .

[0029] [A-2-3-1] Opposing arc contact 331 The opposing arc contact 331 is, for example, a cylindrical rod-like body extending in the axial direction. The opposing arc contact 331 is installed coaxially with the sealed container 2, etc., on a surface of the support protrusion 322 located on the driving side DS. An end 331a of the opposing arc contact 331 located on the driving side DS has a curved surface.

[0030] [A-2-3-2] Opposing conductive contact 335 The opposing side current-carrying contact 335 is, for example, a cylindrical tubular body, and is installed coaxially with the sealed container 2 and the opposing side arc contact 331, etc., via a support part 302 on an end face located on the driving side DS of the cooling cylinder 301. The opposing side current-carrying contact 335 includes a portion that houses the opposing side arc contact 331 therein.

[0031] Here, the outer diameter of the opposing side electric contact 335 is, for example, the same as the outer diameter of the cooling cylinder 301, and the inner diameter of the opposing side electric contact 335 includes, for example, a portion that is the same as the inner diameter of the cooling cylinder 301. In the opposing side electric contact 335, an end 335a located on the driving side DS protrudes radially inward.

[0032] [A-3] Drive side unit 4 The driving side unit 4 includes an operating rod 401, a puffer cylinder 402, a puffer piston 403, a driving side contact portion 405, a cylinder support 406, a piston support 407, an insulating nozzle 500, and a variable strain ring 600. The operating rod 401, the puffer cylinder 402, the puffer piston 403, the driving side contact portion 405, the cylinder support 406, and the piston support 407 are each formed of, for example, a metal material, and each is electrically connected to the second conductor 12.

[0033] [A-3-1] Operating rod 401 The operating rod 401 is a rod-shaped body, and is installed coaxially with the sealed container 2 and the opposing arc contact 331, etc. The operating rod 401 is configured to be moved in the axial direction by a driving device (not shown).

[0034] Here, the operating rod 401 has an operating rod solid portion 411 and an operating rod hollow portion 412 .

[0035] The operating rod solid portion 411 is, for example, cylindrical.

[0036] The operating rod hollow portion 412 is, for example, cylindrical, and an end portion located on the driving side DS is connected to the operating rod solid portion 411. The outer diameter of the operating rod hollow portion 412 is, for example, the same as the outer diameter of the operating rod solid portion 411. The inner diameter of the operating rod hollow portion 412 is larger than the outer diameter of the opposing side arc contact 331. A first ventilation hole H412 penetrating in the radial direction is formed in the end portion located on the driving side DS in the operating rod hollow portion 412.

[0037] [A-3-2] Puffer Cylinder 402 The puffer cylinder 402, together with the operating rod 401, is configured to slide in the axial direction by a driving device (not shown).

[0038] Here, the puffer cylinder 402 includes a cylinder cylindrical portion 421 and a cylinder bottom plate portion 422 .

[0039] The cylinder cylindrical portion 421 is, for example, a cylindrical tubular body, and is installed coaxially with the sealed container 2 and the opposing arc contact 331, etc. The inner diameter of the cylinder cylindrical portion 421 is larger than the outer diameter of the operating rod 401, and the operating rod 401 is housed inside the cylinder cylindrical portion 421.

[0040] The cylinder bottom plate portion 422 is, for example, a disk-shaped plate body, and is provided at an end portion of the cylinder cylindrical portion 421 that is located on the driving side DS.

[0041] A rod through hole H422a through which the operating rod 401 passes is formed in the center of the cylinder bottom plate portion 422. The inner diameter of the rod through hole H422a is approximately the same as the outer diameter of the operating rod 401, and in a state in which the operating rod 401 passes through the rod through hole H422a, the operating rod 401 is fixed to the puffer cylinder 402, and the two are electrically connected.

[0042] Further, an exhaust hole H422b is formed in the cylinder bottom plate portion 422. The exhaust hole H422b is formed around the rod through-hole H422a so as to penetrate in the axial direction. Here, the exhaust hole H422b is configured to communicate with, for example, the rod through-hole H422a.

[0043] [A-3-3] Puffer Piston 403 The puffer piston 403 is accommodated inside the puffer cylinder 402. The puffer piston 403 is fixed to the sealed container 2 via a cylinder support 406 and a piston support 407. The puffer piston 403 is, for example, an annular body, and is installed coaxially with the sealed container 2 and the opposing arc contact 331, etc. An operating rod 401 passes through the inside of the puffer piston 403.

[0044] Here, the inner diameter of the puffer piston 403 is approximately the same as the outer diameter of the operating rod 401, and the operating rod 401 is capable of sliding in the axial direction relative to the puffer piston 403. In addition, the outer diameter of the puffer piston 403 is approximately the same as the inner diameter of a cylinder cylindrical portion 421 constituting the puffer cylinder 402, and the puffer cylinder 402 is capable of sliding in the axial direction relative to the puffer piston 403.

[0045] The puffer piston 403 divides the inside of the puffer cylinder 402 in the axial direction. Inside the puffer cylinder 402, a space located on the driving side DS of the puffer piston 403 is a puffer chamber PR. The volume of the puffer chamber PR changes as the puffer cylinder 402 moves in the axial direction together with the operating rod 401. As the volume of the puffer chamber PR decreases, the pressure of the arc-extinguishing gas increases inside the puffer chamber PR. Then, as will be described in detail later, the arc-extinguishing gas whose pressure has increased in the puffer chamber PR is released from the puffer chamber PR via the exhaust hole H422b of the puffer cylinder 402.

[0046] [A-3-4] Driving side contact part 405 The driving side contact portion 405, together with the operating rod 401, is configured to slide in the axial direction by a driving device (not shown), and the distance between the driving side contact portion 405 and the opposing side contact portion 303 varies. Although details will be described later, when the driving side contact portion 405 is brought into a conductive state between the first conductor 11 and the second conductor 12, the driving side contact portion 405 comes into contact with the opposing side contact portion 303 to enter a closed state (closed state). When performing an interruption operation to interrupt the current between the first conductor 11 and the second conductor 12, the driving side contact portion 405 goes through an opening process in which it is separated from the opposing side contact portion 303 to enter an open state, and enters a completely open state when the interruption operation is completed.

[0047] Here, the drive side contact portion 405 includes a drive side arc contact 451 and a drive side current-carrying contact 455 .

[0048] [A-3-4-1] Driving side arc contact 451 The driving side arc contact 451 is, for example, a cylindrical tubular body, and is disposed coaxially with the sealed container 2 and the opposing side arc contact 331 and the like.

[0049] Here, the driving side arc contact 451 has approximately the same outer diameter and inner diameter as those of the operating rod hollow portion 412 constituting the operating rod 401. The driving side arc contact 451 is connected to an end portion located on the opposing side OS in the operating rod hollow portion 412, and is electrically connected to the operating rod 401. The driving side arc contact 451 is configured to slide in the axial direction together with the operating rod 401 by a driving device (not shown).

[0050] An end 451 a of the driving side arcing contact 451 located on the opposing side OS protrudes inward in the radial direction, and the inner diameter of the end 451 a is the same as the outer diameter of the opposing side arcing contact 331 .

[0051] Although details will be described later, the driving side arc contact 451 is configured so that the opposing side arc contact 331 is inserted inside in the closed state, and an arc discharge occurs between the driving side arc contact 451 and the opposing side arc contact 331 during the opening process.

[0052] [A-3-4-2] Driving side conductive contact 455 The driving side current-carrying contact 455 is, for example, a circular ring-shaped body, and is installed coaxially with the sealed container 2 and the opposing side arc contact 331. The driving side current-carrying contact 455 includes a portion that houses the driving side arc contact 451 therein.

[0053] Here, the inner diameter of the driving side energized contact 455 is larger than the outer diameter of the driving side arc contact 451. The outer diameter of the driving side energized contact 455 is the same as the inner diameter of the end 335a of the counter side energized contact 335. The driving side energized contact 455 is fixed to the cylinder bottom plate portion 422 of the puffer cylinder 402 so as to surround the driving side arc contact 451, and is electrically connected to the puffer cylinder 402. The driving side energized contact 455 is configured to slide in the axial direction together with the operating rod 401 by a driving device (not shown).

[0054] An end portion 455a of the driving-side conductive contact 455 located on the opposing side OS has, for example, a curved surface.

[0055] Although details will be described later, the driving-side conductive contact 455 is configured to be inserted into the opposing-side conductive contact 335 in the closed state.

[0056] [A-3-5] Cylinder Support 406 The cylinder support 406 is electrically connected to the puffer cylinder 402 and the second conductor 12. Although not shown in the figure, the cylinder support 406 is fixed to the sealed container 2 and supports the puffer cylinder 402 so that the puffer cylinder 402 slides in the axial direction.

[0057] Here, the cylinder support 406 includes a cylinder support cylindrical portion 461 and a cylinder support annular portion 462 .

[0058] The cylinder support cylindrical portion 461 is a cylindrical tubular body, and is installed coaxially with the sealed container 2 and the opposing arc contact 331, etc. The inner diameter of the cylinder support cylindrical portion 461 is larger than the outer diameter of the cylinder cylindrical portion 421 that constitutes the puffer cylinder 402.

[0059] The cylinder support annular portion 462 is an annular ring-shaped body, and is disposed coaxially with the sealed container 2 and the opposing side arc contact 331. The cylinder support annular portion 462 is provided at an end portion of the cylinder support cylindrical portion 461 located on the opposing side OS, and is configured to protrude radially inward from the cylinder support cylindrical portion 461. Here, the cylinder support annular portion 462 is formed integrally with the cylinder support cylindrical portion 461. The inner diameter of the cylinder support annular portion 462 is the same as the outer diameter of the cylinder cylindrical portion 421 constituting the puffer cylinder 402.

[0060] A second ventilation hole H461 is formed in the cylinder support cylindrical portion 461. The second ventilation hole H461 is configured to penetrate the cylinder support cylindrical portion 461 in the radial direction.

[0061] [A-3-6] Piston Support 407 The piston support 407 is fixed to the cylinder support 406, and supports the puffer piston 403. The operating rod 401 passes through the inside of the piston support 407.

[0062] Here, the piston support 407 includes a piston support cylindrical portion 471 and a piston support annular portion 472 .

[0063] The piston support cylindrical portion 471 is a cylindrical tubular body, and is installed coaxially with the sealed container 2 and the opposing side arc contact 331, etc. The outer diameter of the piston support cylindrical portion 471 is smaller than the outer diameter of the puffer piston 403, and the inner diameter of the piston support cylindrical portion 471 is larger than the outer diameter of the operating rod 401. The piston support cylindrical portion 471 has an end portion located on the opposing side OS connected to the puffer piston 403.

[0064] The piston support annular portion 472 is an annular ring-shaped body, and is disposed coaxially with the sealed container 2 and the opposing arc contact 331. The piston support annular portion 472 is provided at an end portion of the piston support cylindrical portion 471 located on the driving side DS. The outer diameter of the piston support annular portion 472 is smaller than the outer diameter of the piston support cylindrical portion 471, and the inner diameter of the piston support annular portion 472 is larger than the outer diameter of the operating rod 401. The outer diameter of the piston support annular portion 472 is the same as the inner diameter of the cylinder support cylindrical portion 461, and the piston support annular portion 472 is fixed to the cylinder support cylindrical portion 461. Here, the piston support annular portion 472 is formed integrally with the piston support cylindrical portion 471.

[0065] A third ventilation hole H471 is formed in the piston support cylindrical portion 471. The third ventilation hole H471 is configured to penetrate the piston support cylindrical portion 471 in the radial direction.

[0066] [A-3-7] Insulating nozzle 500 The insulating nozzle 500 is made of an insulating material. The insulating nozzle 500 is a cylindrical tubular body, and is disposed inside the sealed container 2 coaxially with the sealed container 2 and the opposing arc contact 331, etc.

[0067] The insulating nozzle 500 is fixed to the puffer cylinder 402, and is configured to move together with the puffer cylinder 402 and the driving side contact portion 405, etc., during the separation process from the closed state to the open state.

[0068] The insulating nozzle 500 has a nozzle internal space S500 formed therein, and the nozzle internal space S500 accommodates the opposing side arc contact 331 and the driving side arc contact 451. The insulating nozzle 500 is also configured such that, when an arc discharge (not shown in FIG. 1) occurs between the opposing side contact portion 303 and the driving side contact portion 405 during the separation process, an arc-extinguishing gas is released from the puffer chamber PR into the nozzle internal space S500.

[0069] [A-3-8] Variable distortion ring 600 The variable strain ring 600 is made of an insulating material. The variable strain ring 600 is a cylindrical tubular body, and is provided on the outer circumferential surface of the insulating nozzle 500 so as to surround the insulating nozzle 500 in the circumferential direction. In other words, the variable strain ring 600 is provided so as to protrude radially from the outer circumferential surface of the insulating nozzle 500.

[0070] In this embodiment, the variable distortion ring 600 is formed using a dielectric material having a higher dielectric constant than the insulating nozzle 500. For example, when the insulating nozzle 500 is formed of polytetrafluoroethylene (PTFE), the variable distortion ring 600 is formed of epoxy resin.

[0071] Although details will be described later, the variable strain ring 600 is provided on the outer circumferential surface of the insulating nozzle 500 in order to reduce the electric field generated around the tip of the opposing arc contact 331 during the separation process.

[0072] [B] Detailed configuration of the insulating nozzle 500 and the variable strain ring 600 FIG. 2 is an enlarged cross-sectional view showing the configuration of the insulating nozzle 500 and the variable strain ring 600 in the gas circuit breaker 1 according to the first embodiment.

[0073] [B-1] Details of the insulating nozzle 500 As shown in FIG. 2, the insulating nozzle 500 has a large diameter nozzle portion 510, a small diameter nozzle portion 520, and an inclined nozzle portion 530.

[0074] [B-1-1] Large diameter nozzle part 510 The nozzle large diameter section 510 is a portion of the insulating nozzle 500 located on the driving side DS, and is interposed between the driving side arcing contact 451 and the driving side current-carrying contact 455. The nozzle large diameter section 510 includes a portion whose outer circumferential surface runs along the axial direction. Here, the outer diameter R510 (maximum outer diameter of the nozzle large diameter section 510) of the portion of the nozzle large diameter section 510 whose outer circumferential surface runs along the axial direction is the same as the inner diameter of the driving side current-carrying contact 455, and the outer circumferential surface of the nozzle large diameter section 510 and the inner circumferential surface of the driving side current-carrying contact 455 are in close contact with each other.

[0075] The end of the nozzle large diameter portion 510 located on the opposing side OS is configured so that the outer diameter becomes smaller from the driving side DS toward the opposing side OS.

[0076] [B-1-2] Nozzle small diameter part 520 The nozzle small diameter portion 520 is located on the opposing side OS of the nozzle large diameter portion 510 in the insulating nozzle 500. The nozzle small diameter portion 520 includes a portion whose outer circumferential surface runs along the axial direction. An outer diameter R520 of the portion of the nozzle small diameter portion 520 whose outer circumferential surface runs along the axial direction is smaller than an outer diameter R510 of the nozzle large diameter portion 510.

[0077] [B-1-3] Nozzle inclined portion 530 The nozzle inclined portion 530 is located on the opposing side OS of the insulating nozzle 500 relative to the nozzle small diameter portion 520. The nozzle inclined portion 530 includes a portion whose outer circumferential surface inclines with respect to the axial direction such that the outer diameter increases from the nozzle small diameter portion 520 toward the opposing side OS. The inclination angle of the nozzle inclined portion 530 with respect to the axial direction is, for example, 10° or less.

[0078] An end 530a of the nozzle inclined portion 530 located on the opposing side OS protrudes outward in the radial direction, and the outer diameter of the end 530a is smaller than the inner diameter of the opposing side electric contact 335.

[0079] [B-2] Details of the nozzle internal space S500 As shown in FIG. 2, a nozzle internal space S500 provided inside the insulating nozzle 500 includes a nozzle internal space large diameter portion S510, a nozzle internal space small diameter portion S520, and a nozzle internal space expanded diameter portion S530.

[0080] [B-2-1] Nozzle internal space large diameter section S510 The nozzle internal space large diameter portion S510 is a portion located on the driving side DS in the nozzle internal space S500, and accommodates the driving side arcing contact 451 therein. The nozzle internal space large diameter portion S510 includes a portion whose peripheral surface runs along the axial direction. Here, the diameter of the portion of the nozzle internal space large diameter portion S510 whose peripheral surface runs along the axial direction is larger than the outer diameter of the driving side arcing contact 451.

[0081] The nozzle internal space large diameter portion S510 at the portion located on the opposing side OS is configured so that the diameter becomes smaller from the driving side DS toward the opposing side OS.

[0082] [B-2-2] Nozzle internal space small diameter section S520 The nozzle internal space small diameter portion S520 is located on the opposite side OS of the nozzle internal space large diameter portion S510 in the nozzle internal space S500. The nozzle internal space small diameter portion S520 includes a portion whose peripheral surface runs along the axial direction. The diameter of the portion whose peripheral surface runs along the axial direction in the nozzle internal space small diameter portion S520 is smaller than the diameter of the portion whose peripheral surface runs along the axial direction in the nozzle internal space large diameter portion S510.

[0083] [B-2-3] Nozzle internal space expansion section S530 The nozzle internal space expanded diameter portion S530 is located on the opposing side OS of the nozzle internal space S500 relative to the nozzle internal space narrow diameter portion S520. The nozzle internal space expanded diameter portion S530 includes a portion whose circumferential surface is inclined with respect to the axial direction so that the diameter increases from the nozzle internal space narrow diameter portion S520 toward the opposing side OS.

[0084] [B-3] Details of the variable distortion ring 600 As shown in FIG. 2, the variable strain ring 600 is provided on the outer circumferential surface of the insulating nozzle 500 so as to surround a part of the nozzle small diameter portion 520 .

[0085] In this embodiment, the variable strain ring 600 is provided on the insulating nozzle 500 so as to surround the end portion (the boundary portion between the nozzle internal space expansion portion S530 and the nozzle internal space small diameter portion S520) located on the side of the driving side arc contact 451 in the nozzle internal space expansion portion S530.

[0086] In this embodiment, the diameter R600 of the outer circumferential surface of the variable distortion ring 600 is larger than the diameter R520 of the outer circumferential surface of the nozzle inclined portion 530 and is smaller than the diameter R455 of the inner circumferential surface of the driving side conductive contactor 455.

[0087] [C] Gas circuit breaker 1 interruption operation The interrupting operation of the gas circuit breaker 1 will now be described.

[0088] 3A, 3B, 3C, and 3D are cross-sectional views for explaining the interrupting operation of the gas circuit breaker 1 according to the first embodiment.

[0089] 3A, 3B, 3C, and 3D show the entire opposing side unit 3 and a part of the driving side unit 4 of the gas circuit breaker 1, and components such as the sealed container 2 are not shown.

[0090] When the gas circuit breaker 1 performs an interruption operation, the state transitions from a closed state to an open state in an opening process, and the state becomes a completely open state. Here, the interruption operation is performed through the states shown in Fig. 3A, Fig. 3B, Fig. 3C, and Fig. 3D in order.

[0091] Fig. 3A shows the state when the gas circuit breaker 1 is in a closed state (closed state). Fig. 3B shows a state in which the opposing side arc contact 331 and the driving side arc contact 451 are separated from each other during the opening process when the gas circuit breaker 1 transitions from a closed state to a completely open state. Fig. 3C shows a state in which the opposing side arc contact 331 and the driving side arc contact 451 are separated from each other during the opening process when the gas circuit breaker 1 transitions from a closed state to a completely open state. Fig. 3D shows the state when the gas circuit breaker 1 is in a completely open state.

[0092] [C-1] Closed state In the closed state, as shown in FIG. 3A, in the gas circuit breaker 1, the opposing side contact portion 303 constituting the opposing side unit 3 and the driving side contact portion 405 constituting the driving side unit 4 are in contact with each other.

[0093] Specifically, the driving side electric contact 455 constituting the driving side contact portion 405 is inserted into the opposing side electric contact 335 constituting the opposing side contact portion 303. As a result, the outer periphery of the driving side electric contact 455 contacts the inner periphery of the end portion 335a of the opposing side electric contact 335.

[0094] At the same time, the opposing side arc contact 331 constituting the opposing side contact portion 303 is inserted inside the driving side arc contact 451 constituting the driving side contact portion 405. As a result, the outer peripheral surface of the end portion 331a of the opposing side arc contact 331 contacts the inner peripheral portion of the end portion 451a of the driving side arc contact 451.

[0095] As a result, in the closed state, the opposing side unit 3 and the driving side unit 4 are electrically connected, and an electrical path is formed between the first conductor 11 and the second conductor 12 (see Figure 1).

[0096] [C-2] Opening process (transition from closed state to open state) 3B, in the opening process, the operating rod 401 of the driving side unit 4 constituting the gas circuit breaker 1 moves in the axial direction toward the driving side DS. With the movement of the operating rod 401, in the driving side unit 4, the puffer cylinder 402, the driving side contact part 405, the insulating nozzle 500, and the variable strain ring 600 move in the axial direction toward the driving side DS.

[0097] Specifically, in the gas circuit breaker 1, first, the operating rod 401 moves to the driving side DS, whereby the driving side current-carrying contact 455 moves from inside to outside the opposing side current-carrying contact 335. As a result, the opposing side current-carrying contact 335 and the driving side current-carrying contact 455 change from a contact state to a separated state while the opposing side arc contact 331 and the driving side arc contact 451 maintain their contact state.

[0098] 3C, the operating rod 401 moves further toward the driving side DS, whereby the opposing side arcing contact 331 moves from the inside to the outside of the driving side arcing contact 451. As a result, the opposing side arcing contact 331 and the driving side arcing contact 451 change from a contact state to a separated state.

[0099] At this time, an arc discharge AR occurs between the opposing side arc contact 331 and the driving side arc contact 451 inside the insulating nozzle 500. Inside the insulating nozzle 500, the arc discharge AR heats and expands the arc-extinguishing gas, causing the arc-extinguishing gas to flow from inside the insulating nozzle 500 into the puffer chamber PR. In addition, the volume of the puffer chamber PR decreases as the puffer cylinder 402 slides against the puffer piston 403 in accordance with the movement of the operating rod 401. As a result, the pressure of the arc-extinguishing gas increases in the puffer chamber PR.

[0100] Then, as the distance between the opposing side arcing contact 331 and the driving side arcing contact 451 becomes longer, the arc discharge AR decreases. When the arc discharge AR decreases and the pressure of the arc-extinguishing gas in the puffer chamber PR becomes higher, the inflow of the arc-extinguishing gas from the inside of the insulating nozzle 500 to the puffer chamber PR stops. After that, the high-pressure arc-extinguishing gas is discharged from the puffer chamber PR to the inside of the insulating nozzle 500. The arc-extinguishing gas discharged from the puffer chamber PR flows between the insulating nozzle 500 and the driving side arcing contact 451 and is sprayed onto the arc discharge AR. As a result, the arc discharge AR is extinguished at the current zero point.

[0101] As a result, an open state is established in which the electrical path between first conductor 11 and second conductor 12 is interrupted (see FIG. 1).

[0102] [C-3] Completely open state The completely open state is a state in which the operating rod 401 has moved further axially toward the driving side DS, as shown in FIG. 3D.

[0103] In the completely open state, the opposing side conductive contact 335 and the driving side conductive contact 455 are at their farthest apart, and the opposing side arc contact 331 and the driving side arc contact 451 are at their farthest apart.

[0104] When the state is shifted to the completely open state, the volume of the puffer chamber PR is further reduced with the movement of the operating rod 401, and the arc-extinguishing gas is further discharged from the inside of the puffer chamber PR to the inside of the insulating nozzle 500. Here, the arc-extinguishing gas flows from the inside of the insulating nozzle 500 through the inside of the opposing side conductive contact 335 and the inside of the cooling cylinder 301 in sequence, and is then discharged from the inside of the cooling cylinder 301 to the outside. In addition, the arc-extinguishing gas flows from the inside of the insulating nozzle 500 through the inside of the driving side arc contact 451, the inside of the operating rod hollow portion 412, and the inside of the piston support cylindrical portion 471 in sequence, and is then discharged from the inside of the piston support cylindrical portion 471 to the outside. The arc-extinguishing gas discharged from the piston support cylindrical portion 471 to the outside is discharged from the inside of the cylinder support 406 (see FIG. 1) to the outside.

[0105] [D] Actions and Effects FIG. 4 is a diagram showing a schematic diagram of a potential distribution inside the insulating nozzle 500 in the gas circuit breaker 1 according to the first embodiment.

[0106] Fig. 4 shows an example of the potential distribution during the period when the state transitions to a completely open state after the arc discharge AR is extinguished. In Fig. 4, the solid lines are equipotential lines L1 showing the potential distribution of this embodiment in which the variable distortion ring 600 is provided on the insulating nozzle 500. In Fig. 4, the dashed lines are equipotential lines L2 showing the potential distribution of a comparative example in which, unlike this embodiment, the variable distortion ring 600 is not provided on the insulating nozzle 500. The potential distribution is obtained by grounding the side of the driving side arc contact 451 and applying a potential to the side of the opposing side arc contact 331, and calculating the electric field by the surface charge method.

[0107] 4, in the vicinity of the opposing arc contact 331 inside the insulating nozzle 500, the interval between the equipotential lines L1 showing the potential distribution in this embodiment is wider than the interval between the equipotential lines L2 showing the potential distribution in the comparative example. Therefore, in this embodiment, the electric field around the tip 331a of the opposing arc contact 331 is lower than that in the comparative example. In this embodiment, even if a voltage is applied between the opposing arc contact 331 and the driving arc contact 451 during the period when the state transitions to the completely open state after the arc discharge AR is extinguished, the electric field is distorted by the action of the distortion ring 600, and the electric field is lowered.

[0108] In this manner, in this embodiment, the variable strain ring 600 is provided so as to surround the nozzle small diameter portion 520, and the electric field generated around the tip of the opposing arc contact 331 during the opening process is alleviated by the variable strain ring 600. Specifically, in this embodiment, it is possible to alleviate the electric field generated around the tip of the opposing arc contact 331 during the opening process when switching a small leading current or breaking a small or medium current.

[0109] As a result, in this embodiment, during the period of transition to the completely open state, dielectric breakdown between the opposing contact portion 303 and the driving contact portion 405 is suppressed, and the current interruption performance of the gas circuit breaker 1 can be improved. In this embodiment, the amount of arc-extinguishing gas blown can be reduced with the improvement in the current interruption performance of the gas circuit breaker 1, so that the puffer chamber PR can be easily downsized. In addition, in this embodiment, the pressure of the arc-extinguishing gas in the puffer chamber PR can be reduced, so that the driving force for moving the puffer cylinder 402 can be easily reduced. Therefore, the gas circuit breaker 1 of this embodiment is easy to downsize, and can achieve improvement in current interruption performance and insulation performance even with a small driving force.

[0110] In this embodiment, the variable strain ring 600 is provided on the insulating nozzle 500 so as to surround the end located on the driving side arc contact 451 side in the nozzle internal space expansion portion S530. That is, the variable strain ring 600 surrounds the nozzle throat end. During the period when the nozzle moves to the completely open state, when the end 331a of the opposing side arc contact 331 moves to the nozzle throat end, a significant decrease in density occurs around the end 331a of the opposing side arc contact 331, and a high electric field is likely to occur. However, in this embodiment, since the variable strain ring 600 surrounds the nozzle throat end, the electric field generated around the end 331a of the opposing side arc contact 331 can be effectively alleviated.

[0111] In this embodiment, the variable distortion ring 600 is formed using a dielectric material having a higher dielectric constant than the insulating nozzle 500. Therefore, in this embodiment, the electric field generated around the end 331a of the opposing arc contact 331 can be more effectively reduced.

[0112] In this embodiment, the diameter R600 of the outer circumferential surface of the variable distortion ring 600 is larger than the diameter R520 of the outer circumferential surface of the nozzle small diameter portion 520, and is smaller than the diameter R455 of the inner circumferential surface of the driving side conductive contact 455. Therefore, in the gas circuit breaker 1 of this embodiment, the overall weight can be reduced.

[0113] [E] Variation In the above embodiment, the variable distortion ring 600 is formed using a dielectric material having a higher dielectric constant than the insulating nozzle 500, but this is not limited to the above. The variable distortion ring 600 may be formed using the same dielectric material as the insulating nozzle 500. In other words, the variable distortion ring 600 and the insulating nozzle 500 may be configured to be integrated. In this modified example, the effect of mitigating the electric field is lower than in the above embodiment, but the effect of the above embodiment can be sufficiently obtained even in this modified example.

[0114] <Second embodiment> [A] Configuration FIG. 5 is an enlarged cross-sectional view showing the configuration of an insulating nozzle 500 and a variable strain ring 600 in the gas circuit breaker 1 according to the second embodiment.

[0115] Fig. 6 is a cross-sectional view for explaining the interrupting operation in the gas circuit breaker 1 according to the second embodiment. Fig. 6 shows the state when the gas circuit breaker 1 is in a completely open state, similar to Fig. 3D.

[0116] As shown in Fig. 5 and Fig. 6, the gas circuit breaker 1 of this embodiment differs from the first embodiment (see Fig. 2, Fig. 3D, etc.) in the position where the variable strain ring 600 is provided in the insulating nozzle 500. This embodiment is similar to the first embodiment except for this point and related points. Therefore, explanations of overlapping points will be omitted as appropriate.

[0117] In this embodiment, the variable strain ring 600 is provided on the outer circumferential surface of the nozzle inclined portion 530 of the insulating nozzle 500 as shown in FIG.

[0118] Here, as shown in FIG. 6, the variable distortion ring 600 is provided on the insulating nozzle 500 so that, when in the fully open state, the end 335a of the opposing side conductive contact 335 located on the side of the driving side contact portion 405 surrounds the variable distortion ring 600.

[0119] [B] Actions and Effects In this embodiment, a variable strain ring 600 is provided so as to surround the nozzle inclined portion 530, and the electric field generated around the tip of the opposing arc contact 331 during the opening process is relaxed by the variable strain ring 600, as in the first embodiment. In this embodiment, the variable strain ring 600 is provided so as to surround the nozzle inclined portion 530, and the electric field generated around the end 331a of the opposing arc contact 331 in the completely open state can be effectively relaxed, so that the stroke length for moving the operating rod 401 in the gas circuit breaker 1 can be shortened.

[0120] Therefore, the gas circuit breaker 1 of this embodiment can also be easily miniaturized, and even with a small driving force, it is possible to achieve improved current interruption performance and insulation performance.

[0121] [C] Variation In the above embodiment, the variable distortion ring 600 is provided on the outer peripheral surface of the nozzle inclined portion 530, but this is not limited thereto. The variable distortion ring 600 may be provided so as to cover both the outer peripheral surface of the nozzle inclined portion 530 and the outer peripheral surface of the nozzle small diameter portion 520. In other words, it is sufficient that the variable distortion ring 600 is provided so as to surround at least one of the nozzle small diameter portion 520 and the nozzle inclined portion 530. Even in the case of this modified example, the effects of the above embodiment can be sufficiently obtained.

[0122] <Other> Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0123] 1: gas circuit breaker, 2: sealed container, 3: opposing unit, 4: driving unit, 11: first conductor, 12: second conductor, 301: cooling cylinder, 302: support portion, 303: opposing contact portion, 321: support ring portion, 322: support protrusion portion, 331: opposing arc contact, 331a: end portion, 335: opposing current-carrying contact, 335a: end portion, 401: operating rod, 402: puffer cylinder, 403: puffer piston, 405: driving contact portion, 406: cylinder support, 407: piston support, 411: operating rod solid portion, 412: operating rod hollow portion, 421: cylinder cylindrical portion, 422: cylinder bottom plate portion, 451: driving arc contact, 451a: end portion , 455: driving side conductive contact, 455a: end, 461: cylinder support cylindrical portion, 462: cylinder support annular portion, 471: piston support cylindrical portion, 472: piston support annular portion, 500: insulating nozzle, 510: nozzle large diameter portion, 520: nozzle small diameter portion, 530: nozzle inclined portion, 530a: end, 600: variable distortion ring, AR: arc discharge, DS: driving side, H412: first ventilation hole, H422a: rod through hole, H422b: exhaust hole, H461: second ventilation hole, H471: third ventilation hole, OS: opposing side, PR: puffer chamber, S500: nozzle internal space, S510: nozzle internal space large diameter portion, S520: nozzle internal space small diameter portion, S530: nozzle internal space enlarged diameter portion

Claims

1. a sealed container filled with an arc-extinguishing gas; An opposing contact portion provided inside the sealed container; a driving contact portion provided inside the sealed container, the driving contact portion being brought into a closed state by contacting the opposing contact portion, and being moved away from the opposing contact portion to be brought into an open state; an insulating nozzle provided inside the sealed container and moving together with the driving contact portion during a separation process in which the driving contact portion and the opposing contact portion change from the closed state to the open state; a nozzle internal space into which the arc-extinguishing gas is discharged when an arc discharge occurs between the opposing contact portion and the driving contact portion during the separation process, The opposing contact portion is an opposing arc contact that is a rod-shaped body extending in an axial direction and includes a portion that is accommodated in the nozzle internal space; an opposing current-carrying contact, the opposing current-carrying contact being a tubular body arranged coaxially with the opposing arcing contact in the axial direction, the opposing current-carrying contact including a portion for accommodating the opposing arcing contact therein through the insulating nozzle; having The driving side contact portion is a driving-side arc contact which is a tubular body arranged coaxially with the opposing-side arc contact in the axial direction, the driving-side arc contact being accommodated in the nozzle internal space, the opposing-side arc contact being inserted therein in the closed state, and the arc discharge being generated between the driving-side arc contact and the opposing-side arc contact in the opening process; a driving-side current-carrying contact that is inserted into the opposing-side current-carrying contact in the closed state via the insulating nozzle, the driving-side current-carrying contact being a tubular body that is arranged coaxially with the opposing-side arcing contact in the axial direction, the driving-side current-carrying contact including a portion that accommodates the driving-side arcing contact therein; having The insulating nozzle is a nozzle large diameter portion interposed between the driving side arc contact and the driving side current-carrying contact; a nozzle small diameter portion located closer to the opposing contact portion than the nozzle large diameter portion and having an outer diameter smaller than that of the nozzle large diameter portion; a nozzle inclined portion located closer to the opposing contact portion than the nozzle small diameter portion, and having an outer peripheral surface inclined with respect to the axial direction such that an outer diameter increases from the nozzle small diameter portion toward the opposing contact portion; a tubular body arranged coaxially with the opposing arc contact in the axial direction, a variable strain ring is provided so as to surround at least one of the nozzle small diameter portion and the nozzle inclined portion, and an electric field generated around the tip of the opposing arc contact during the separation process is relaxed by the variable strain ring; Gas circuit breaker.

2. The diameter of the outer peripheral surface of the variable strain ring is larger than the diameter of the outer peripheral surface of the nozzle small diameter portion and smaller than the diameter of the inner peripheral surface of the driving side conductive contact. The gas circuit breaker according to claim 1.

3. The nozzle internal space is a nozzle internal space expanding diameter portion configured such that an inner diameter expands with increasing distance in the axial direction from an end portion located on the driving side arc contact; Equipped with The variable strain ring is provided on the insulating nozzle so as to surround at least an end portion of the nozzle internal space expansion portion located on the driving side arc contact. The gas circuit breaker according to claim 1.

4. The variable strain ring is provided on the insulating nozzle such that, when the driving side contact portion is in a completely open state in which the driving side contact portion is farthest from the opposing side contact portion, an end portion of the opposing side conductive contact portion that is located on the driving side contact portion side surrounds the variable strain ring. The gas circuit breaker according to claim 1.

5. The variable strain ring is formed using a dielectric material having a higher dielectric constant than the insulating nozzle. The gas circuit breaker according to claim 1.

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