Gas circuit breaker

Abstract

Provided is a gas circuit breaker that allows for easy miniaturization and reduction of driving force. In the gas circuit breaker according to an embodiment, an insulation nozzle is a tubular body that includes a nozzle large diameter portion, a nozzle small diameter portion, and a nozzle inclination portion, and is disposed coaxially with an opposite-side arc contact in an axial direction. The nozzle small diameter portion is positioned closer to the opposite-side contact portion than the nozzle large diameter portion, and has a smaller outer diameter than that of the nozzle large diameter portion. The nozzle inclination portion is positioned closer to the opposite-side contact portion than the nozzle small diameter portion, and the outer peripheral surface thereof is inclined with respect to the axial direction so that the outer diameter increases from the nozzle small diameter portion toward the opposite-side contact portion side. Here, a deformation ring is provided so as to surround at least one of the nozzle small diameter portion and the nozzle inclination portion, such that an electric field that is generated around the tip of the opposite-side arc contact during a separation process is relaxed by the deformation ring.

Description

Gas circuit breaker

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

[0002] The gas circuit breaker is, for example, a puffer type, and is configured to blow arc-extinguishing gas, pressurized in a puffer chamber in conjunction with the current interruption operation, onto the arc discharge in order to extinguish the arc discharge that occurs during the current interruption operation. The arc-extinguishing gas is, for example, sulfur hexafluoride (SF ６ In addition to sulfur hexafluoride gas, carbon dioxide (CO ２ ) is being promoted.

[0003] When a gas circuit breaker performs a breaking operation, it 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 contact inserted into a tubular opposing contact outside the tubular insulating nozzle, so that the opposing and driving contacts are in contact with each other, and a rod-shaped opposing arcing contact inserted into a tubular driving contact inside the tubular insulating nozzle, so that the opposing and driving arcing contacts are in contact with each other.

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

[0006] Thereafter, in the completely open state, the opposing conductive contact and the driving conductive contact are at their farthest apart, and the opposing arc contact and the driving arc contact are at their farthest apart.

[0007] WO-A1-2019 / 150655 JP 2016-213146 A

[0008] Gas circuit breakers are required to be smaller in size and to have a lower driving force for increasing 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 arcing contact may become high. That is, 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 arcing contact may become high. As a result, the possibility of dielectric breakdown occurring between the opposing arcing contact and the driving arcing contact increases.

[0010] In order to prevent the occurrence of dielectric breakdown, it is necessary to ensure a sufficient amount of arc-extinguishing gas is blown, and since it is not easy to reduce the amount of blown gas, it may be difficult to downsize 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 that can improve current interruption performance and insulation performance, and can easily be made smaller and require a reduced driving force.

[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 enter a closed state by contacting the opposing contact portion and to enter an open state by separating from the opposing contact portion. The insulating nozzle is provided inside the sealed container and moves together with the driving contact portion during a separation process in which the driving contact portion and the opposing contact portion change from a closed state to an open state. The insulating nozzle includes a nozzle internal space from which the arc-extinguishing gas is released when an arc discharge occurs between the opposing contact portion and the driving contact portion during the separation process. The opposing contact portion has an opposing arc contact and an opposing current-carrying contact. The opposing arc contact is a rod-shaped body extending axially and includes a portion accommodated in the nozzle internal space. The opposing arc contactor is a tubular body arranged coaxially with the opposing arc contactor in the axial direction and includes a portion that accommodates the opposing arc contactor therein via an insulating nozzle. The drive contactor portion has a drive arc contactor and a drive contactor. The drive arc contactor is a tubular body arranged coaxially with the opposing arc contactor in the axial direction and is accommodated in the nozzle internal space, the opposing arc contactor is inserted therein in a closed state, and an arc discharge occurs between the drive contactor and the opposing arc contactor in a breaking process. The drive contactor is a tubular body arranged coaxially with the opposing arc contactor in the axial direction and includes a portion that accommodates the driving arc contactor therein via an insulating nozzle, and is inserted into the opposing arc contactor 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 arc contactor in the axial direction. The nozzle large diameter portion is interposed between the drive arc contactor and the drive contactor. 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 so that the outer diameter increases as the nozzle goes from the nozzle small diameter portion to 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 variable strain ring reduces the electric field that occurs around the tip of the opposing arc contact during the separation process.

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

[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 a puffer type, and as shown in FIG. 1, an opposing unit 3 and a driving unit 4 are housed inside a sealed container 2 .

[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 electrical circuits in a power system, and the interruption operation to interrupt 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 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 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 details of each component of the gas circuit breaker 1 will be explained in order.

[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 inside of the sealed container 2 is filled with an arc-extinguishing gas. The arc-extinguishing gas is a gas that has excellent arc-extinguishing and insulating properties, and is, for example, sulfur hexafluoride gas (SF ６ The arc-extinguishing gas may be a gas having a global warming potential smaller than that of sulfur hexafluoride gas. The arc-extinguishing gas having a global warming potential smaller than that of sulfur hexafluoride gas may be, for example, air, carbon dioxide, oxygen, nitrogen, or a mixed gas of the above-mentioned gases.

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

[0024] [A-2-1] Cooling cylinder 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 Portion 302 The support portion 302 includes a support ring portion 321 and a support protrusion portion 322 .

[0026] The support ring portion 321 is, for example, a circular ring-shaped body, and is installed on the end face of the cooling cylinder 301 that is located on the drive side DS, coaxially with the sealed container 2. Here, the outer diameter of the support ring portion 321 is, for example, the same as the outer diameter of the cooling cylinder 301, and the inner diameter of the support ring portion 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 from 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 Contactor Portion 303 The opposing contactor portion 303 includes an opposing arcing contactor 331 and an opposing current-carrying contactor 335 , and is provided inside the sealed container 2 .

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

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

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

[0032] [A-3] Driving 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 are each 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. The operating rod 401 is configured to move 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 its end located on the drive 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 is formed radially through the end of the operating rod hollow portion 412 located on the drive side DS.

[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 drive 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-like body, and is provided at the 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 with the operating rod 401 passing through the rod through-hole H422a, the operating rod 401 is fixed to the puffer cylinder 402, and the two are electrically connected.

[0042] 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 housed 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 ring-shaped 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 able to slide 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 the cylinder cylindrical portion 421 that constitutes the puffer cylinder 402, and the puffer cylinder 402 is able to slide in the axial direction relative to the puffer piston 403.

[0045] The puffer piston 403 defines the interior of the puffer cylinder 402 in the axial direction. Within the puffer cylinder 402, the space located closer to the drive side DS than the puffer piston 403 is the puffer chamber PR. The volume of the puffer chamber PR changes as the puffer cylinder 402 moves axially together with the operating rod 401. As the volume of the puffer chamber PR decreases, the pressure of the arc-extinguishing gas inside the puffer chamber PR increases. 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 portion 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), thereby varying the distance between the driving-side contact portion 405 and the opposing-side contact portion 303. As will be described in detail later, when energizing 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 separates from the opposing-side contact portion 303, and enters an open state, and when the interruption operation is completed, it enters a completely open state.

[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 installed coaxially with the sealed container 2 and the opposing side arc contact 331, etc.

[0049] Here, the driving-side arcing contact 451 has approximately the same outer diameter and inner diameter as the operating rod hollow portion 412 that constitutes the operating rod 401. The driving-side arcing contact 451 is connected to an end portion of the operating rod hollow portion 412 that is located on the opposite side OS, and is electrically connected to the operating rod 401. The driving-side arcing contact 451 is configured to slide axially 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 radially inward, and the inner diameter of the end 451 a is the same as the outer diameter of the opposing-side arcing contact 331 .

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

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

[0053] Here, the inner diameter of the driving-side conductive contact 455 is larger than the outer diameter of the driving-side arc contact 451. The outer diameter of the driving-side conductive contact 455 is the same as the inner diameter of the end 335a of the opposing-side conductive contact 335. The driving-side conductive contact 455 is fixed to the cylinder bottom plate 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 conductive contact 455 is configured to slide axially together with the operating rod 401 by a driving device (not shown).

[0054] An end 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 installed coaxially with the sealed container 2 and the opposing-side arc contact 331, etc. The cylinder support annular portion 462 is provided at the end 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 that constitutes 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 end of the piston support cylindrical portion 471 located on the opposing side OS is 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 the end of the piston support cylindrical portion 471 located on the drive 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 installed inside the sealed container 2 coaxially with the sealed container 2 and the opposing arc contact 331.

[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 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 arcing contact 331 and the driving side arcing contact 451. The insulating nozzle 500 is also configured so 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, arc-extinguishing gas is released from the puffer chamber PR into the nozzle internal space S500.

[0069] [A-3-8] Variable strain ring 600 The variable strain ring 600 is made of an insulating material. The variable strain ring 600 is a cylindrical tubular body that 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 strain ring 600 is formed using a dielectric material having a higher dielectric constant than the insulating nozzle 500. For example, if the insulating nozzle 500 is formed from polytetrafluoroethylene (PTFE), the variable strain ring 600 is formed from 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 arcing contact 331 during the separation process.

[0072] [B] Detailed Configuration of the Insulating Nozzle 500 and the Variable Distortion Ring 600 FIG. 2 is an enlarged cross-sectional view showing the configuration of the insulating nozzle 500 and the variable distortion 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 portion 510 The large-diameter nozzle portion 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 large-diameter nozzle portion 510 includes a portion whose outer peripheral surface extends along the axial direction. Here, the outer diameter R510 (the maximum outer diameter of the large-diameter nozzle portion 510) of the portion whose outer peripheral surface extends along the axial direction of the large-diameter nozzle portion 510 is the same as the inner diameter of the driving-side current-carrying contact 455, and the outer peripheral surface of the large-diameter nozzle portion 510 and the inner peripheral surface of the driving-side current-carrying contact 455 are in close contact with each other.

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

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

[0077] [B-1-3] Nozzle Sloped Section 530 The nozzle sloped section 530 is located on the opposing side OS of the insulating nozzle 500 relative to the nozzle small diameter section 520. The nozzle sloped section 530 includes a portion whose outer peripheral surface slopes with respect to the axial direction so that the outer diameter increases from the nozzle small diameter section 520 toward the opposing side OS. The slope angle of the nozzle sloped section 530 with respect to the axial direction is, for example, 10° or less.

[0078] An end 530 a 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 530 a is smaller than the inner diameter of the opposing side conductive contact 335 .

[0079] [B-2] Details of the nozzle internal space S500 As shown in FIG. 2, the nozzle internal space S500 provided inside the insulating nozzle 500 comprises 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] Large-diameter nozzle internal space portion S510 The large-diameter nozzle internal space portion S510 is a portion of the nozzle internal space S500 that is located on the driving side DS and accommodates the driving-side arcing contact 451 therein. The large-diameter nozzle internal space portion S510 includes a portion whose circumferential surface extends along the axial direction. Here, the diameter of the portion of the large-diameter nozzle internal space portion S510 whose circumferential surface extends 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 is configured so that the diameter of the portion located on the opposing side OS decreases from the driving side DS toward the opposing side OS.

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

[0083] [B-2-3] Nozzle internal space expanded diameter portion 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 small 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 small 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 distortion 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 of the nozzle internal space expansion portion S530 located on the side of the driving side arc contact 451 (the boundary portion between the nozzle internal space expansion portion S530 and the nozzle internal space small diameter portion S520).

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

[0087] [C] Breaking Operation of Gas Circuit Breaker 1 The breaking operation of the gas circuit breaker 1 will 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 unit 3 and a part of the driving 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, it transitions from a closed state to an open state in an opening process and reaches a completely open state. Here, the interruption operation is performed through the states shown in Figures 3A, 3B, 3C, and 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 arcing contact 331 and the driving side arcing contact 451 are separated from each other during the opening process when the gas circuit breaker 1 transitions from a closed state to a fully open state. Fig. 3C shows a state in which the opposing side arcing contact 331 and the driving side arcing contact 451 are separated from each other during the opening process when the gas circuit breaker 1 transitions from a closed state to a fully open state. Fig. 3D shows the state when the gas circuit breaker 1 is in a fully open state.

[0092] [C-1] Closed state In the closed state, as shown in FIG. 3A, the gas circuit breaker 1 is in contact between 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.

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

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

[0095] As a result, in the closed state, the opposing unit 3 and the driving 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) In the opening process, as shown in Fig. 3B, 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. As the operating rod 401 moves, the puffer cylinder 402, driving side contact portion 405, insulating nozzle 500, and variable strain ring 600 of the driving side unit 4 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 energized contact 455 moves from the inside to the outside of the opposing side energized contact 335. As a result, the opposing side energized contact 335 and the driving side energized 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, causing the opposing-side arcing contact 331 to move 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 arcing contact 331 and the driving-side arcing 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. Furthermore, the volume of the puffer chamber PR decreases as the puffer cylinder 402 slides relative to the puffer piston 403 as the operating rod 401 moves. This causes the pressure of the arc-extinguishing gas to increase 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 further 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 increases further, the inflow of the arc-extinguishing gas from the inside of the insulating nozzle 500 into the puffer chamber PR stops. Then, high-pressure arc-extinguishing gas is released from the puffer chamber PR into the insulating nozzle 500. The arc-extinguishing gas released 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 is interrupted between the first conductor 11 and the second conductor 12 (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 conductive contact 335 and the driving conductive contact 455 are at their farthest apart, and the opposing arc contact 331 and the driving 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 further decreases as the operating rod 401 moves, and more arc-extinguishing gas is released from the inside of the puffer chamber PR into the inside of the insulating nozzle 500. Here, the arc-extinguishing gas flows from the inside of the insulating nozzle 500 sequentially through the inside of the opposing-side conductive contact 335 and the inside of the cooling cylinder 301, and then is released 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 sequentially through the inside of the driving-side arcing contact 451, the inside of the operating rod hollow portion 412, and the inside of the piston support cylindrical portion 471, and then is released from the inside of the piston support cylindrical portion 471 to the outside. The arc-extinguishing gas released from the piston support cylindrical portion 471 to the outside is released from the inside of the cylinder support 406 (see FIG. 1 ).

[0105] [D] Functions and Effects FIG. 4 is a diagram schematically showing the 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 in this embodiment in which the variable strain ring 600 is provided on the insulating nozzle 500. In Fig. 4, the dashed lines are equipotential lines L2 showing the potential distribution in a comparative example in which, unlike this embodiment, the variable strain 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 using the surface charge method.

[0107] 4 , in the vicinity of the opposing-side 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 331 a of the opposing-side arc contact 331 is lower than in the comparative example. In this embodiment, even if a voltage is applied between the opposing-side arc contact 331 and the driving-side 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 and lowered by the action of the variable-strain ring 600.

[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 when breaking a small to medium current.

[0109] As a result, in this embodiment, during the period of transition to the fully open state, dielectric breakdown between the opposing contact portion 303 and the driving contact portion 405 is suppressed, thereby improving the current interruption performance of the gas circuit breaker 1. Furthermore, in this embodiment, as the current interruption performance of the gas circuit breaker 1 is improved, the amount of arc-extinguishing gas blown can be reduced, making it easy to reduce the size of the puffer chamber PR. Furthermore, in this embodiment, the pressure of the arc-extinguishing gas in the puffer chamber PR can be reduced, making it easy to reduce the driving force for moving the puffer cylinder 402. Therefore, the gas circuit breaker 1 of this embodiment is easy to reduce in size, and can achieve improved 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 of the nozzle internal space expansion portion S530 located on the side of the driving-side arcing contact 451. In other words, the variable strain ring 600 surrounds the nozzle throat end. During the transition to the fully open state, when the end 331a of the opposing-side arcing contact 331 moves to the nozzle throat end, a significant decrease in density occurs around the end 331a of the opposing-side arcing contact 331, making it easy for a high electric field to be generated. However, in this embodiment, because the variable strain ring 600 surrounds the nozzle throat end, it can effectively reduce the electric field generated around the end 331a of the opposing-side arcing contact 331.

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

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

[0113] [E] Modification In the above embodiment, the variable strain ring 600 is formed using a dielectric material with a higher dielectric constant than the insulating nozzle 500, but this is not limited to this. The variable strain ring 600 may be formed using the same dielectric material as the insulating nozzle 500. In other words, the variable strain ring 600 and the insulating nozzle 500 may be configured to be integrated. In this modification, the effect of alleviating the electric field is reduced compared to the above embodiment, but the effect of the above embodiment can still be fully obtained in this modification.

[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 a gas circuit breaker 1 according to a second embodiment.

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

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

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

[0118] Here, as shown in Figure 6, the variable strain ring 600 is provided on the insulating nozzle 500 so that when in a 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 strain ring 600.

[0119] [B] Function and Effect 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 tip of the opposing arc contact 331 during the opening process is alleviated 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 alleviated, 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] Modification In the above embodiment, the variable strain ring 600 is provided on the outer peripheral surface of the nozzle inclined portion 530, but this is not limited to this. The variable strain 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 strain 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 modification, the effects of the above embodiment can be fully obtained.

[0122] <Others> Although several 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 embodied 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 intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as set forth in the claims.

[0123] 1: gas circuit breaker, 2: sealed container, 3: opposing side unit, 4: driving side unit, 11: first conductor, 12: second conductor, 301: cooling cylinder, 302: support portion, 303: opposing side contact portion, 321: support ring portion, 322: support protrusion portion, 331: opposing side arcing contact, 331a: end portion, 335: opposing side current-carrying contact, 335a: end portion, 401: operating rod, 402: puffer cylinder, 403: puffer piston, 405: driving side 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 side arcing 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: strain-varying 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 gas circuit breaker comprising: 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 and moving to be in a closed state by contacting the opposing contact portion and to be in an open state by separating from the opposing contact portion; and an insulating nozzle provided inside the sealed container and moving 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 the closed state to the open state, wherein the insulating nozzle includes a nozzle internal space from which the arc-extinguishing gas is released when an arc discharge occurs between the opposing contact portion and the driving contact portion in the separation process, wherein the opposing contact portion comprises: an opposing arc contact which is a rod-shaped body extending in the axial direction and includes a portion which is accommodated in the nozzle internal space; and an opposing side current-carrying contact which is a tubular body arranged coaxially with the opposing side arc contact in the axial direction and includes a portion for accommodating the opposing side arc contact therein via the insulating nozzle, wherein the driving side contact portion comprises: a driving side arc contact which is a tubular body arranged coaxially with the opposing side arc contact in the axial direction and accommodated in the nozzle internal space, into which the opposing side arc contact is inserted in the closed state and into which the arc discharge occurs between the opposing side arc contact and the opposing side arc contact in the opening process; and a driving side current-carrying contact which is a tubular body arranged coaxially with the opposing side arc contact in the axial direction and includes a portion for accommodating the driving side arc contact therein via the insulating nozzle, and which is inserted into the opposing side current-carrying contact in the closed state, wherein the insulating nozzle comprises: a nozzle large diameter portion interposed between the driving side arc contact and the driving side current-carrying contact; and a nozzle small diameter portion which is located on the opposing side contact portion side of the nozzle large diameter portion and has 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 said opposing arc contact in the axial direction, wherein a variable strain ring is provided so as to surround at least one of said nozzle small diameter portion and said nozzle inclined portion, and an electric field generated around the tip of said opposing arc contact during said opening process is relaxed by said variable strain ring.

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

3. A gas circuit breaker as described in claim 1, wherein the nozzle internal space is provided with a nozzle internal space expansion portion configured so that its inner diameter expands with increasing distance in the axial direction from an end portion located on the side of the driving side arc contact, and the variable strain ring is provided in the insulating nozzle so as to surround at least the end portion located on the side of the driving side arc contact in the nozzle internal space expansion portion.

4. A gas circuit breaker as described in claim 1, wherein the variable strain ring is provided on the insulating nozzle so that, when the driving side contact portion is in a completely open state where it is farthest from the opposing side contact portion, the end portion of the opposing side current-carrying contact portion that is located on the side of the driving side contact portion surrounds the variable strain ring.

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

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