Cutoff device

Abstract

Provided is a cutoff device capable of improving the stability of a power system. A cutoff device (100) according to an embodiment comprises: an energization contact (101); a first cutoff contact (111) connected in parallel with the energization contact; and a second cutoff contact (112) connected in parallel with the energization contact and connected in series to the first cutoff contact. The first cutoff contact is composed of a vacuum circuit breaker (211), and the second cutoff contact and the energization contact are composed of a gas breaker (251). A time point (t112b) at which the second cutoff contact enters a closed state from an open state in a second cutoff contact turn-on operation (CM112) is before a time point (t111b) at which the first cutoff contact enters the closed state from the open state in a first cutoff contact turn-on operation (CM111). A time point (t101b) at which the energization contact enters the closed state from the open state in an energization contact turn-on operation is after the time point (t111b) at which the first cutoff contact enters the closed state from the open state in the first cutoff contact turn-on operation.

Description

Circuit breaker

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to a shutoff device.

[0002] 2. Description of the Related Art When an accident occurs in a power system, a circuit breaker such as a vacuum circuit breaker or a gas circuit breaker is used to switch an electric circuit through which current flows from a conducting state to a cut-off state.

[0003] A vacuum circuit breaker is configured to perform opening and closing operations of a pair of contacts (electrodes) inside a vacuum vessel that is in a vacuum state. Specifically, when the vacuum circuit breaker is to energize an electric circuit, the pair of contacts approach each other in a vacuum atmosphere, becoming a closed state and electrically connected. When the vacuum circuit breaker is to interrupt the electric circuit, the pair of contacts move apart in a vacuum atmosphere, becoming an open state and electrically insulated.

[0004] The gas circuit breaker is configured to perform a switching operation with a pair of contacts inside a grounded container filled with insulating gas. Specifically, when the gas circuit breaker is placed in a conducting state, the pair of contacts approach each other in an atmosphere filled with insulating gas, thereby achieving a closed state and an electrically connected state. When the gas circuit breaker is placed in a disconnected state, the pair of contacts move apart in an atmosphere filled with insulating gas, thereby achieving an open state and an electrically isolated state. When the gas circuit breaker performs a disconnecting operation to switch from a closed state to an open state, for example, insulating gas is sprayed onto the arc discharge that occurs during the disconnecting operation in order to extinguish the arc discharge.

[0005] In gas circuit breakers, the insulating gas is mainly SF6 in order to obtain sufficient insulation performance, arc extinguishing performance, etc. ６ Gas circuit breakers use sulfur hexafluoride gas. Gas circuit breakers have excellent insulation and arc extinguishing properties, making them suitable for use in circuits that are subject to higher voltages than those that vacuum circuit breakers interrupt (electrical circuits of the power transmission class, etc.).

[0006] SF is the main insulating gas used in gas circuit breakers. ６ Gas has a high greenhouse effect potential. ６Although techniques using insulating gases other than SF6 have been proposed, it is not easy to obtain sufficient performance. ６ When a gas circuit breaker uses a naturally occurring gas such as dry air as the insulating gas instead of gas, the arc-extinguishing ability of the gas circuit breaker is low, which may result in a decrease in interruption performance. For this reason, a circuit breaker constructed by combining a gas circuit breaker with a vacuum circuit breaker is being considered.

[0007] Patent No. 6057887

[0008] The circuit breaker is required to improve the stability of the power system. For example, when an electric circuit interruption operation is performed due to an accident such as a short circuit occurring in the power system including the electric circuit EC during an electric circuit closing operation, the stability of the power system is reduced due to the fault current flowing through the circuit breaker. However, improving the stability of the power system is not easy.

[0009] Therefore, an object of the present invention is to provide a circuit breaker capable of improving the stability of a power system.

[0010] The circuit breaker of the embodiment includes a current-carrying contact, a first breaking contact connected in parallel with the current-carrying contact, and a second breaking contact connected in parallel with the current-carrying contact and in series with the first breaking contact. The first breaking contact is configured as a vacuum circuit breaker that switches between a closed state and an open state inside a vacuum container. The second breaking contact and the current-carrying contact are configured as gas circuit breakers that switch between a closed state and an open state inside an insulating gas container filled with insulating gas. When performing an electric circuit closing operation to change an electric circuit from an interrupted state to an energized state, the circuit breaker performs a first breaking contact closing operation to change the first breaking contact from an open state to a closed state, a second breaking contact closing operation to change the second breaking contact from an open state to a closed state, and an energized contact closing operation to change the current-carrying contact from an open state to a closed state. The second breaking contact changes from an open state to a closed state in the second breaking contact closing operation before the first breaking contact changes from an open state to a closed state in the first breaking contact closing operation. The time when the current-carrying contact changes from an open state to a closed state in the current-carrying contact closing operation occurs later than the time when the first breaking contact changes from an open state to a closed state in the first breaking contact closing operation.When the first breaking contact closes due to the occurrence of an arc discharge in the first breaking contact closing operation after the second breaking contact closes in the second breaking contact closing operation, a current flows through the first breaking contact and the second breaking contact.When the current-carrying contact closes in the current-carrying contact closing operation, a larger current flows through the current-carrying contact than through the first breaking contact and the second breaking contact.

[0011] FIG. 1 is a circuit diagram of a circuit breaker 100 according to the first embodiment. FIG. 2A is a cross-sectional view schematically showing the configuration of the circuit breaker 100 according to the first embodiment. FIG. 2B is a cross-sectional view showing a detailed configuration of a gas circuit breaker 251 in the circuit breaker 100 according to the first embodiment. FIG. 3A is a circuit diagram showing an overview of an electric circuit closing operation performed in the circuit breaker 100 according to the first embodiment. FIG. 3B is a circuit diagram showing an overview of an electric circuit closing operation performed in the circuit breaker 100 according to the first embodiment. FIG. 3C is a circuit diagram showing an overview of an electric circuit closing operation performed in the circuit breaker 100 according to the first embodiment. FIG. 4A is a cross-sectional view showing a state when a second circuit breaker contact closing operation CM112 is performed in a gas circuit breaker 251 including a second circuit breaker contact 112 in the circuit breaker 100 according to the first embodiment. FIG. 4B is a cross-sectional view showing a state when a first circuit breaker contact closing operation CM111 is performed in a vacuum circuit breaker 211 including a first circuit breaker contact 111 in the circuit breaker 100 according to the first embodiment. FIG. 4C is a cross-sectional view showing a state when an energizing contact closing operation CM101 is performed in a gas circuit breaker 251 including an energizing contact 101 in the circuit breaking device 100 according to the first embodiment. FIG. 5A is a circuit diagram showing an overview of an electric circuit breaking operation performed in the circuit breaking device 100 according to the first embodiment. FIG. 5B is a circuit diagram showing an overview of an electric circuit breaking operation performed in the circuit breaking device 100 according to the first embodiment. FIG. 6 is a timing chart showing, in time series, each operation performed in the circuit breaking device 100 according to the first embodiment. FIG. 7A is a circuit diagram showing an overview of an electric circuit closing operation performed in a comparative example. FIG. 7B is a circuit diagram showing an overview of an electric circuit closing operation performed in a comparative example. FIG. 8 is a timing chart showing, in time series, each operation performed in the comparative example. FIG. 9A is a timing chart showing, in time series, each operation performed in the circuit breaking device 100 according to the second embodiment. FIG. 9B is a timing chart showing, in time series, each operation performed in the circuit breaking device 100 according to the second embodiment. FIG. 10A is a cross-sectional view schematically showing a configuration of a circuit breaking device 100 according to a third embodiment. FIG. 10B is a timing chart showing, in chronological order, the operations executed in the circuit breaking device 100 according to the third embodiment.

[0012] First Embodiment [A] Circuit of Breaker Device 100 FIG. 1 is a circuit diagram of a breaker device 100 according to a first embodiment.

[0013] 1, the circuit breaker 100 of this embodiment is a device having an energizing contact 101, a first breaking contact 111, and a second breaking contact 112, and is installed on an electric circuit EC, and is configured to switch the electric circuit EC from an energized state to a broken state. Here, the circuit breaker 100 includes an energizing electric circuit EC1 and a breaking electric circuit EC2 as the electric circuits EC, and the breaking electric circuit EC2 is connected in parallel to the energizing electric circuit EC1 so as to bypass the energizing contact 101.

[0014] The following describes each component of the circuit breaker 100. Note that Fig. 1 shows a state in which the circuit breaker 100 switches the electrical circuit EC to an interrupted state (completely open state).

[0015] [A-1] Current-carrying contact 101 The current-carrying contact 101 is installed in the current-carrying electric circuit EC1. The current-carrying contact 101 is configured to have a lower resistance than the first breaking contact 111 and the second breaking contact 112. For example, the current-carrying contact 101 has a larger current-carrying cross-sectional area than the first breaking contact 111 and the second breaking contact 112, and is configured using a conductive material with a higher conductivity than the first breaking contact 111 and the second breaking contact 112.

[0016] [A-2] First Breaker Contact 111 The first breaker contact 111 is installed in the breaking electric circuit EC2 so as to be connected in parallel with the conducting contact 101.

[0017] [A-3] Second Breaker Contact 112 The second breaker contact 112 is connected in parallel with the energizing contact 101 and is also installed in the breaking electrical circuit EC2 so as to be connected in series with the first breaker contact 111.

[0018] [B] Detailed Configuration of the Circuit Breaker 100 Fig. 2A is a cross-sectional view schematically illustrating the configuration of the circuit breaker 100 according to the first embodiment. Fig. 2A illustrates the circuit breaker 100 in a circuit breaker state.

[0019] 2A, the circuit breaker 100 of this embodiment accommodates a vacuum circuit breaker 211 and a gas circuit breaker 251 inside a grounded tank 200. Each part constituting the circuit breaker 100 will be described in order.

[0020] [B-1] Grounded Tank 200 The grounded tank 200 is made of a metal material and is electrically connected to a reference potential point (such as the earth). The inside of the grounded tank 200 is filled with insulating gas.

[0021] Here, the insulating gas is, for example, SF ６ It has a lower greenhouse effect potential than SF gas, but ６ It may also be a gas. ６ The insulating gas having a greenhouse effect coefficient smaller than that of the gas is, for example, carbon dioxide, oxygen, nitrogen, or the like, and may be a mixed gas of the above-mentioned gases.

[0022] [B-2] Vacuum circuit breaker 211 (first interrupting contact 111) The vacuum circuit breaker 211 is a vacuum valve, and accommodates a movable electrode 111A and a fixed electrode 111B as the first interrupting contact 111 inside a vacuum container 212. The vacuum circuit breaker 211 is configured so that the first interrupting contact 111 switches between a closed state and an open state inside the vacuum container 212.

[0023] Here, the vacuum vessel 212 includes a porcelain tube 212a and a pair of flanges 212b, and for example, the pair of flanges 212b are provided at both ends of the cylindrical porcelain tube 212a. The porcelain tube 212a is made of an insulating material (ceramic, etc.), and the pair of flanges 212b are made of, for example, a metal material. The interior of the vacuum vessel 212 is in a vacuum state, and the pressure inside the vacuum vessel 212 is lower than the pressure inside the grounded tank 200.

[0024] The movable electrode 111A and the fixed electrode 111B are, for example, disk-shaped and made of a metal material, and are installed inside the vacuum vessel 212 so that their ends face each other. In this example, the movable electrode 111A is installed at the end of the vacuum circuit breaker movable current-carrying shaft 214. The fixed electrode 111B is installed at the end of the vacuum circuit breaker fixed current-carrying shaft 213. The vacuum circuit breaker fixed current-carrying shaft 213 is installed so as to be aligned coaxially with the vacuum circuit breaker movable current-carrying shaft 214. The vacuum circuit breaker fixed current-carrying shaft 213 is supported by a support part SP made of an insulating material.

[0025] Furthermore, the vacuum circuit breaker movable current-carrying shaft 214 is connected to an operation mechanism 217 (vacuum circuit breaker operation mechanism) via an insulating rod 216. The operation mechanism 217 is configured to operate the vacuum circuit breaker movable current-carrying shaft 214, for example, by using an electric spring or an electromagnetic repulsion mechanism. The operation of the operation mechanism 217 causes the movable electrode 111A and the fixed electrode 111B to come into contact with each other, thereby bringing the vacuum circuit breaker 211 into a closed state, and causes the movable electrode 111A and the fixed electrode 111B to come into a separated state, thereby bringing the vacuum circuit breaker 211 into an open state.

[0026] The vacuum circuit breaker movable current-carrying shaft 214 is slidably supported by a sliding portion SL214. The sliding portion SL214 is made of a metal material and is electrically connected to the electric wire EC1a via the electric wire EC2a. The electric wire EC2a constitutes the interrupting electric circuit EC2 (see FIG. 1).

[0027] The vacuum vessel 212 further contains a bellows 215 and an arc shield 218 .

[0028] The bellows 215 is cylindrical, and the vacuum circuit breaker movable current-carrying shaft 214 passes through it. The internal space of the bellows 215 communicates with the internal space of the grounded tank 200. The bellows 215 is configured to expand and contract in the direction of movement when the movable electrode 111A moves in accordance with the sliding of the vacuum circuit breaker movable current-carrying shaft 214.

[0029] The arc shield 218 is disposed so as to surround the movable electrode 111A and the fixed electrode 111B in the circumferential direction.

[0030] [B-3] Gas circuit breaker 251 (current-carrying contact 101, second breaker contact 112) As shown in Fig. 2A, the gas circuit breaker 251 includes a gas circuit breaker movable current-carrying shaft 401 and a gas circuit breaker fixed current-carrying shaft 253. The gas circuit breaker movable current-carrying shaft 401 is provided with a driving-side arcing contact 451 and a driving-side current-carrying contact 455. The gas circuit breaker fixed current-carrying shaft 253 is aligned coaxially with the gas circuit breaker movable current-carrying shaft 401, and is provided with an opposing-side arcing contact 331 and an opposing-side current-carrying contact 335. The gas circuit breaker fixed current-carrying shaft 253 is configured integrally with the vacuum circuit breaker fixed current-carrying shaft 213, and is supported by a support part SP.

[0031] In the gas circuit breaker 251, the driving side conductive contact 455 and the opposing side conductive contact 335 function as the conductive contacts 101. In the gas circuit breaker 251, the driving side arcing contact 451 and the opposing side arcing contact 331 function as the second breaking contact 112.

[0032] 2B is a cross-sectional view showing a detailed configuration of the gas circuit breaker 251 in the circuit breaker device 100 according to the first embodiment. Hereinafter, the detailed configuration of the gas circuit breaker 251 will be described using FIG. 2B in addition to FIG. 2A.

[0033] The gas circuit breaker 251 is a puffer type, and includes an opposing side unit 3 and a driving side unit 4 as shown in FIG. 2B.

[0034] [B-3-1] Opposing Unit 3 In the gas circuit breaker 251, 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 electric wire EC1a (see FIG. 2A).

[0035] [B-3-1-1] Cooling Cylinder 301 The cooling cylinder 301 is, for example, a cylindrical tubular body and is connected to the electric wire EC1a. The cooling cylinder 301 is supported on the grounded tank 200 by a support part SP (see FIG. 2A).

[0036] [B-3-1-2] Support Portion 302 The support portion 302 includes a support ring portion 321 and a support protrusion portion 322 .

[0037] The support ring portion 321 is, for example, a circular ring-shaped body, and is installed coaxially with the cooling cylinder 301 on the end face of the cooling cylinder 301 that is located on the drive side DS. 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.

[0038] The support protrusion 322 is, for example, a rod-shaped body, and is provided on the inner peripheral surface of the support ring portion 321 so as to protrude radially inward. In the support portion 302, the support ring portion 321 is formed using a conductive material such as metal. In contrast, the support protrusion 322 is formed using an insulating material so that the opposing arc contact 331 and the opposing current-carrying contact 335 are electrically insulated by the support protrusion 322. However, a portion of the support protrusion 322 is formed using a conductive material so as to electrically connect the gas circuit breaker fixed current-carrying shaft 253 and the opposing arc contact 331 (see FIG. 1 ).

[0039] [B-3-1-3] Opposing Contactor Section 303 The opposing contactor section 303 includes an opposing arcing contactor 331 and an opposing current-carrying contactor 335 , and is provided inside the grounded tank 200 .

[0040] [B-3-1-3-1] 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 cooling cylinder 301 and the like on the surface of the support protrusion 322 located on the driving side DS. An end 331a of the opposing arc contactor 331 located on the driving side DS has a curved surface.

[0041] [B-3-1-3-2] Opposing side current-carrying contact 335 The opposing side current-carrying contact 335 is, for example, a cylindrical tubular body, and is installed coaxially with the opposing side arc contact 331, etc., via a support part 302 on the end face of the cooling cylinder 301 located on the driving side DS. The opposing side current-carrying contact 335 includes a portion that houses the opposing side arc contact 331 inside.

[0042] 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.

[0043] [B-3-2] Driving Side Unit 4 The driving side unit 4 includes a gas circuit breaker movable conducting shaft 401 (movable conducting shaft), a puffer cylinder 402, a puffer piston 403, a driving side contact portion 405, a cylinder support 406, a piston support 407, and an insulating nozzle 500. The gas circuit breaker movable conducting shaft 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 electric wire EC1b.

[0044] [B-3-2-1] Gas circuit breaker movable current-carrying shaft 401 The gas circuit breaker movable current-carrying shaft 401 is a rod-shaped body, and is installed coaxially with the opposing arc contact 331, etc. The gas circuit breaker movable current-carrying shaft 401 is connected to an operation mechanism 257 (gas circuit breaker operation mechanism) via an insulating rod 256. The operation mechanism 257 is configured to operate the gas circuit breaker movable current-carrying shaft 401 using, for example, an electric spring or an electromagnetic repulsion mechanism, and the gas circuit breaker movable current-carrying shaft 401 moves in the axial direction by the operation mechanism 257.

[0045] Here, the gas circuit breaker movable current-carrying shaft 401 has a movable current-carrying shaft solid portion 411 and a movable current-carrying shaft hollow portion 412 .

[0046] The movable current-carrying shaft solid portion 411 is, for example, cylindrical.

[0047] The movable current-carrying shaft hollow portion 412 is, for example, cylindrical, and its end portion located on the driving side DS is connected to the movable current-carrying shaft solid portion 411. The outer diameter of the movable current-carrying shaft hollow portion 412 is, for example, the same as the outer diameter of the movable current-carrying shaft solid portion 411. The inner diameter of the movable current-carrying shaft 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 portion of the movable current-carrying shaft hollow portion 412 located on the driving side DS.

[0048] [B-3-2-2] Puffer Cylinder 402 The puffer cylinder 402 is configured to slide in the axial direction together with the gas circuit breaker movable current-carrying shaft 401 by the operation mechanism 257 .

[0049] Here, the puffer cylinder 402 includes a cylinder cylindrical portion 421 and a cylinder bottom plate portion 422 .

[0050] The cylinder cylindrical portion 421 is, for example, a cylindrical tubular body, and is installed coaxially with the opposing arc contact 331, etc. The inner diameter of the cylinder cylindrical portion 421 is larger than the outer diameter of the gas circuit breaker movable current-carrying shaft 401, and the gas circuit breaker movable current-carrying shaft 401 is accommodated inside the cylinder cylindrical portion 421.

[0051] 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.

[0052] A rod through hole H422a through which the gas circuit breaker movable current-carrying shaft 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 gas circuit breaker movable current-carrying shaft 401, and the gas circuit breaker movable current-carrying shaft 401 is fixed to the puffer cylinder 402 in a state where it passes through the rod through hole H422a. The cylinder bottom plate portion 422 and the gas circuit breaker movable current-carrying shaft 401 are electrically connected.

[0053] 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.

[0054] [B-3-2-3] Puffer Piston 403 The puffer piston 403 is housed inside the puffer cylinder 402. The puffer piston 403 is fixed to the grounded tank 200 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 opposing arc contact 331, etc. The gas circuit breaker movable current-carrying shaft 401 passes through the inside of the puffer piston 403.

[0055] Here, the inner diameter of the puffer piston 403 is approximately the same as the outer diameter of the gas circuit breaker movable current-carrying shaft 401, and the gas circuit breaker movable current-carrying shaft 401 can 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 can slide in the axial direction relative to the puffer piston 403.

[0056] The puffer piston 403 defines the interior of the puffer cylinder 402 in the axial direction. Within the puffer cylinder 402, the space located on the drive side DS from 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 gas circuit breaker movable current-carrying shaft 401. As the volume of the puffer chamber PR decreases, the pressure of the insulating gas inside the puffer chamber PR increases. Then, the insulating 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.

[0057] [B-3-2-4] Driving side contact portion 405 The driving side contact portion 405, together with the gas circuit breaker movable current-carrying shaft 401, is configured to slide in the axial direction by the operating mechanism 257, and the distance between it and the opposing side contact portion 303 varies.

[0058] Here, the drive-side contact portion 405 includes a drive-side arc contact 451 and a drive-side current-carrying contact 455 .

[0059] [B-3-2-4-1] Driving Side Arcing Contact 451 The driving side arcing contact 451 is, for example, a cylindrical tubular body, and is installed coaxially with the opposing side arcing contact 331 and the like.

[0060] Here, the driving side arc contactor 451 has approximately the same outer diameter and inner diameter as the movable current-carrying shaft hollow portion 412 constituting the gas circuit breaker moving current-carrying shaft 401. The driving side arc contactor 451 is coupled to an end portion located on the opposing side OS in the movable current-carrying shaft hollow portion 412, and is electrically connected to the gas circuit breaker moving current-carrying shaft 401. The driving side arc contactor 451 is configured to slide in the axial direction together with the gas circuit breaker moving current-carrying shaft 401 by an operating mechanism 257.

[0061] 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 .

[0062] The driving side arc contact 451 is configured so that the opposing side arc contact 331 is inserted inside it when it is in a conducting state, and an arc discharge (pre-arc discharge) occurs between it and the opposing side arc contact 331 during the breaking process.

[0063] [B-3-2-4-2] Driving-side energized contactor 455 The driving-side energized contactor 455 is, for example, an annular ring-shaped body, and is installed coaxially with the opposing-side arcing contactor 331. The driving-side energized contactor 455 includes a portion that houses the driving-side arcing contactor 451 therein.

[0064] 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 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 conductive contact 455 is configured to slide in the axial direction together with the gas circuit breaker movable conductive shaft 401 by the operation mechanism 257.

[0065] An end 455a of the driving-side conductive contact 455 located on the opposing side OS has, for example, a curved surface.

[0066] The driving-side conductive contact 455 is configured to be inserted into the opposing-side conductive contact 335 in a conducting state.

[0067] [B-3-2-5] Cylinder support 406 The cylinder support 406 is electrically connected to the puffer cylinder 402 and the electric wire EC1b. The cylinder support 406 is fixed to the grounded tank 200 and supports the puffer cylinder 402 so that the puffer cylinder 402 can slide in the axial direction.

[0068] Here, the cylinder support 406 includes a cylinder support cylindrical portion 461 and a cylinder support annular portion 462 .

[0069] The cylinder support cylindrical portion 461 is a cylindrical tubular body and is installed coaxially with 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.

[0070] The cylinder support annular portion 462 is an annular ring-shaped body and is installed coaxially with 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.

[0071] 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.

[0072] [B-3-2-6] Piston Support 407 The piston support 407 is fixed to the cylinder support 406 and supports the puffer piston 403. The gas circuit breaker movable conducting shaft 401 passes through the inside of the piston support 407.

[0073] Here, the piston support 407 includes a piston support cylindrical portion 471 and a piston support annular portion 472 .

[0074] The piston support cylindrical portion 471 is a cylindrical tubular body, and is installed coaxially with 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 gas circuit breaker movable current-carrying shaft 401. The piston support cylindrical portion 471 has an end portion located on the opposing side OS connected to the puffer piston 403.

[0075] The piston support annular portion 472 is an annular ring-shaped body and is disposed coaxially with the opposing arc contact 331 and the like. The piston support annular portion 472 is provided at the end 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 gas circuit breaker movable current-carrying shaft 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.

[0076] 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.

[0077] [B-3-2-7] 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 grounded tank 200 coaxially with the opposing arc contact 331, etc.

[0078] 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 interruption process from an energized state (closed state) to an open state (open state).

[0079] 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 occurs between the opposing side contact portion 303 and the driving side contact portion 405 during the interruption process, insulating gas is released from the puffer chamber PR into the nozzle internal space S500.

[0080] The insulating nozzle 500 has a large diameter nozzle portion 510 , a small diameter nozzle portion 520 , and an inclined nozzle portion 530 .

[0081] The nozzle large diameter portion 510 is a portion of the insulating nozzle 500 that is 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 portion 510 includes a portion whose outer circumferential surface extends along the axial direction.

[0082] The small nozzle diameter section 520 is located on the opposing side OS of the large nozzle diameter section 510 in the insulating nozzle 500. The small nozzle diameter section 520 includes a portion whose outer peripheral surface extends along the axial direction. The outer diameter of the portion of the small nozzle diameter section 520 whose outer peripheral surface extends along the axial direction is smaller than the outer diameter of the large nozzle diameter section 510.

[0083] The nozzle inclined portion 530 is located closer to the opposing side OS than the nozzle small diameter portion 520 in the insulating nozzle 500. The nozzle inclined portion 530 includes a portion whose outer peripheral surface is inclined with respect to the axial direction so that the outer diameter increases from the nozzle small diameter portion 520 toward the opposing side OS. An end portion 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 portion 530a is smaller than the inner diameter of the opposing side conductive contact 335.

[0084] [B-4] Control Unit 800 As shown in FIG. 2A, the cutoff device 100 also includes a control unit 800 in addition to the above components.

[0085] The control unit 800 includes an arithmetic unit (not shown) and a memory device (not shown), and is configured to control the operation of each part that constitutes the shutdown device 100, for example, by a high-speed sequence, by the arithmetic unit performing arithmetic processing using a program stored in the memory device.

[0086] In this embodiment, the control unit 800 outputs control signals to the operation mechanisms 217 and 257 based on, for example, commands input from the outside, and controls the operations of the operation mechanisms 217 and 257 .

[0087] When a command to change the electric circuit EC from a disconnected state to a conducting state is input, the control unit 800 executes an electric circuit closing operation. When executing the electric circuit closing operation, the control unit 800 controls the operation of the operation mechanism 217 and the operation mechanism 257 so as to switch the energizing contact 101, the first breaking contact 111, and the second breaking contact 112 from an open state to a closed state.

[0088] On the other hand, when a command to change the electric circuit EC from a conducting state to a cut-off state is input, the control unit 800 executes an electric circuit cut-off operation. When executing the electric circuit cut-off operation, the control unit 800 controls the operation of the operation mechanism 217 and the operation mechanism 257 so as to switch the conducting contact 101, the first cut-off contact 111, and the second cut-off contact 112 from a closed state to an open state.

[0089] [C] Operation of Circuit Breaker 100 [C-1] Circuit Closing Operation FIGS. 3A, 3B, and 3C are circuit diagrams showing an outline of the circuit closing operation performed in the circuit breaker 100 according to the first embodiment.

[0090] 3A, 3B, and 3C, along with Fig. 1, show the state when an electrical circuit closing operation is performed in the circuit breaker 100. In each figure, an electrically insulated state of each contact is shown as an open state (indicated as "Open" in the figures), and an electrically connected state of each contact is shown as a closed state (indicated as "Close" in the figures).

[0091] When the circuit closing operation is performed in the circuit breaker 100 of this embodiment, the circuit EC goes from the interrupted state (completely open state) shown in Fig. 1 through the closing process shown in Fig. 3A, 3B, and 3C in order to enter a conducting state, and current flows through the circuit EC. That is, in the circuit closing operation of this embodiment, a second breaking contact closing operation CM112, a first breaking contact closing operation CM111, and a conducting contact closing operation CM101 are performed, as shown in Fig. 3A, 3B, and 3C.

[0092] The circuit closing operation will be described in detail below.

[0093] [C-1-1] Breaking State In the breaking state before the current circuit closing operation is performed, as shown in FIG. 1, the first breaking contact 111, the second breaking contact 112, and the conducting contact 101 are in the open state.

[0094] Specifically, in the vacuum circuit breaker 211, the movable electrode 111A and the fixed electrode 111B housed inside the vacuum vessel 212 as the first breaking contact 111 are separated from each other and are electrically insulated, thereby bringing the first breaking contact 111 into an open state. Also, in the gas circuit breaker 251, the driving-side conductive contact 455 and the opposing-side conductive contact 335 constituting the current-carrying contact 101 are separated from each other and are electrically insulated, thereby bringing the current-carrying contact 101 into an open state. Furthermore, in the gas circuit breaker 251, the driving-side arcing contact 451 and the opposing-side arcing contact 331 constituting the second breaking contact 112 are separated from each other and are electrically insulated, thereby bringing the second breaking contact 112 into an open state (see FIG. 2A ).

[0095] As a result, as shown in FIG. 1, in the interrupted state, the flow of current is interrupted in both the energizing electric circuit EC1 and the interrupting electric circuit EC2 of the electric circuit EC.

[0096] [C-1-2] Second Breaker Contact Closing Operation CM112 In the electrical circuit closing operation, as shown in FIG. 3A, first, the second breaker contact closing operation CM112 is executed to switch the second breaker contact 112 from an open state to a closed state.

[0097] FIG. 4A is a cross-sectional view showing a state when a second breaking contact closing operation CM112 is performed in a gas circuit breaker 251 including a second breaking contact 112 in the circuit breaker 100 according to the first embodiment.

[0098] As shown in FIG. 4A, in the second breaking contact closing operation CM112, in the gas circuit breaker 251, the driving side arc contact 451 and the opposing side arc contact 331 that constitute the second breaking contact 112 approach each other and are electrically connected.

[0099] Specifically, when the second breaking contact closing operation CM112 is performed, in the gas circuit breaker 251, the gas circuit breaker movable current-carrying shaft 401 moves from the driving side DS to the opposing side OS, causing the driving-side arcing contact 451 to approach the opposing-side arcing contact 331 and come into physical contact with each other. As a result, the opposing-side arcing contact 331 and the driving-side arcing contact 451 are electrically connected to each other, and the second breaking contact 112 is switched to the closed state.

[0100] In addition, the vacuum circuit breaker 211 constituting the first breaking contact 111 is required to have insulation performance equal to or higher than the operating voltage in order to maintain the open state during this operation. As a result, the vacuum circuit breaker 211 constituting the first breaking contact 111 does not experience dielectric breakdown during this operation, and therefore damage is prevented.

[0101] [C-1-3] First Breaker Contact Closing Operation CM111 Next, in the electrical circuit closing operation, as shown in FIG. 3B, the first breaker contact closing operation CM111 is executed, whereby the first breaker contact 111 is switched from the open state to the closed state.

[0102] FIG. 4B is a cross-sectional view showing a state when a first breaking contact closing operation CM111 is performed in a vacuum circuit breaker 211 including a first breaking contact 111 in the circuit breaking device 100 according to the first embodiment.

[0103] 4A , in the first breaking contact closing operation CM111, the movable electrode 111A and the fixed electrode 111B housed inside the vacuum vessel 212 as the first breaking contact 111 approach each other. At this time, an arc discharge ARC occurs between the surfaces of the movable electrode 111A and the fixed electrode 111B inside the vacuum vessel 212. The arc discharge ARC electrically connects the movable electrode 111A and the fixed electrode 111B, and the first breaking contact 111 switches from an open state to a closed state.

[0104] Although not shown in the figure, the movable electrode 111A and the fixed electrode 111B then become even closer inside the vacuum vessel 212. Then, the surfaces of the movable electrode 111A and the fixed electrode 111B come into physical contact with each other, and an electrically connected state (closed state) is maintained (see FIG. 4A).

[0105] As shown in Figure 3B, upon completion of the first breaking contact closing operation CM111 and the second breaking contact closing operation CM112, the first breaking contact 111 is closed and the second breaking contact 112 is closed, causing current to flow through the breaking circuit EC2 in which the first breaking contact 111 and the second breaking contact 112 are installed.

[0106] [C-1-4] Current-Carrying Contact Closing Operation CM101 Next, in the current-circuit closing operation, as shown in FIG. 3C, current-carrying contact closing operation CM101 is executed, whereby the current-carrying contact 101 is switched from the open state to the closed state.

[0107] FIG. 4C is a cross-sectional view showing a state when a current-carrying contact closing operation CM101 is performed in a gas circuit breaker 251 including the current-carrying contact 101 in the circuit breaker 100 according to the first embodiment.

[0108] As shown in Figure 4C, in the energizing contact closing operation CM101, in the gas circuit breaker 251, the driving side energizing contact 455 and the opposing side energizing contact 335 that constitute the energizing contact 101 approach each other and become electrically connected, thereby switching the energizing contact 101 to a closed state.

[0109] Specifically, when the energizing contact closing operation CM101 is performed, in the gas circuit breaker 251, the gas circuit breaker movable energizing shaft 401 moves further from the drive side DS to the opposite side OS, whereby the drive side arcing contact 451 comes into physical contact with the opposite side arcing contact 331, and then the opposite side energizing contact 335 and the drive side energizing contact 455 come closer to each other. Then, the gas circuit breaker movable energizing shaft 401 moves further from the drive side DS to the opposite side OS, whereby the opposite side energizing contact 335 and the drive side energizing contact 455 come into physical contact. As a result, the opposite side energizing contact 335 and the drive side energizing contact 455 are electrically connected to each other, and the energizing contact 101 switches to the closed state.

[0110] As described above, in this embodiment, as shown in FIG. 3C , the energizing contact 101, the first breaking contact 111, and the second breaking contact 112 are switched to a closed state, thereby switching the electric circuit EC to an energized state. As described above, in this embodiment, the energizing contact 101 is configured to have a lower resistance than the first breaking contact 111 and the second breaking contact 112. Therefore, after the energizing contact closing operation CM101 is completed, a larger current flows in the energizing electric circuit EC1 in which the energizing contact 101 is installed than in the breaking electric circuit EC2 in which the first breaking contact 111 and the second breaking contact 112 are installed. In other words, commutation occurs. [C-2] Electric Circuit Interruption Operation FIGS. 5A and 5B are circuit diagrams showing an overview of the electric circuit interruption operation performed by the circuit breaker 100 according to the first embodiment.

[0111] 5A and 5B show how an electrical circuit interruption operation is performed in the circuit breaker 100. In each figure, an electrically insulated state of each contact is indicated as an open state (indicated as "Open" in the figure), and an electrically connected state of each contact is indicated as a closed state (indicated as "Close" in the figure).

[0112] When an electric circuit interruption operation is performed in the circuit breaker 100 of this embodiment, the electric circuit EC goes from the conducting state shown in Fig. 3C through the interruption process shown in Fig. 5A and 5B in sequence to the interruption state (completely open state), and the flow of current is interrupted. That is, in the electric circuit interruption operation of this embodiment, as shown in Fig. 5A and 5B, after an energizing contact interruption operation CM101b is performed, a first breaking contact interruption operation CM111b and a second breaking contact interruption operation CM112b are performed.

[0113] The circuit breaking operation will be described in detail below.

[0114] [C-2-1] Conduction State In the conduction state before the current path interruption operation is performed, the first breaking contact 111, the second breaking contact 112, and the conducting contact 101 are in a closed state, as shown in FIG. 3C.

[0115] Specifically, in the vacuum circuit breaker 211, the movable electrode 111A and the fixed electrode 111B, which are housed inside the vacuum vessel 212 as the first breaking contact 111, are electrically connected to each other, thereby closing the first breaking contact 111. In the gas circuit breaker 251, the driving-side energized contact 455 and the opposing-side energized contact 335, which constitute the energized contact 101, are electrically connected to each other, thereby closing the energized contact 101. In the gas circuit breaker 251, the driving-side arcing contact 451 and the opposing-side arcing contact 331, which constitute the second breaking contact 112, are electrically connected to each other, thereby closing the second breaking contact 112 (see FIG. 2A ).

[0116] As a result, in the energized state, as shown in Figure 3C, a larger current flows in the energizing circuit EC1, in which the energizing contact 101 is installed, than in the interrupting circuit EC2, in which the first interrupting contact 111 and the second interrupting contact 112 are installed.

[0117] [C-2-2] Current-Carrying Contact Breaking Operation CM101b In the electrical circuit breaking operation, as shown in FIG. 5A, first, the current-carrying contact breaking operation CM101b is executed, thereby switching the current-carrying contact 101 from the closed state to the open state.

[0118] Specifically, in the energized contact breaking operation CM101b, in the gas circuit breaker 251, the driving side energized contact 455 and the opposing side energized contact 335 that constitute the energized contact 101 are separated and become electrically insulated, thereby switching the energized contact 101 to an open state (see Figure 2A).

[0119] As a result, in the electrical circuit EC, as shown in Figure 5A, the flow of current in the current-carrying electrical circuit EC1 in which the current-carrying contact 101 is installed is interrupted, and current flows in the interrupting electrical circuit EC2 in which the first interrupting contact 111 and the second interrupting contact 112 are installed.

[0120] [C-2-3] First Breaker Contact Breaking Operation CM111b, Second Breaker Contact Breaking Operation CM112b Next, in the electrical path breaking operation, as shown in Fig. 5B, the first breaker contact 111 is switched from a closed state to an open state by the execution of the first breaker contact breaker operation CM111b, and the second breaker contact 112 is switched from a closed state to an open state by the execution of the second breaker contact breaker operation CM112b. The time when the first breaker contact 111 switches to the open state and the time when the second breaker contact 112 switches to the open state are, for example, simultaneous.

[0121] Specifically, in the first breaking contact breaking operation CM111b, in the vacuum circuit breaker 211, the movable electrode 111A and the fixed electrode 111B, which are housed inside the vacuum vessel 212 as the first breaking contact 111, are separated from each other, becoming electrically insulated, and the first breaking contact 111 switches to the open state (see FIG. 2A ). Here, inside the vacuum vessel 212, an arc discharge ARC occurs between the surface of the movable electrode 111A and the surface of the fixed electrode 111B, and then the first breaking contact 111 switches to the open state.

[0122] Furthermore, when the second breaking contact breaking operation CM112b is executed, in the gas circuit breaker 251, the driving-side arcing contact 451 separates from the opposing-side arcing contact 331, the driving-side arcing contact 451 and the opposing-side arcing contact 331 are electrically insulated from each other, and the second breaking contact 112 switches to the open state (see FIG. 2A ). Here, inside the gas circuit breaker 251, an arc discharge ARC occurs between the driving-side arcing contact 451 and the opposing-side arcing contact 331, and then the second breaking contact 112 switches to the open state.

[0123] As shown in FIG. 5B, in the electrical circuit interruption operation, upon completion of the first interruption contact interruption operation CM111b and the second interruption contact interruption operation CM112b, the first interruption contact 111 is opened and the second interruption contact 112 is opened, thereby interrupting the flow of current in the electrical circuit EC.

[0124] [D] Details of Operation of Circuit Breaker 100 The operation performed by the circuit breaker 100 of this embodiment will be described in further detail.

[0125] FIG. 6 is a timing chart showing, in chronological order, the operations executed in the circuit breaking device 100 according to the first embodiment.

[0126] Figure 6 shows a case where, for example, while the circuit closing operation is being performed in the circuit breaker 100, an accident such as a short circuit occurs in the power system including the circuit EC, and therefore a circuit breaking operation is performed (closing operation + re-breaking operation).

[0127] In Fig. 6, the horizontal axis represents time, and the vertical axis represents the state of each contact (the energizing contact 101, the first breaking contact 111, and the second breaking contact 112). Specifically, in Fig. 6, the vertical axis represents the open state (electrically insulated state) of each contact as "Open," and the closed state (electrically connected state) of each contact as "Close" (the dashed lines indicate a transition from the open state to the closed state). Also, in Fig. 6, the period during which an arc discharge occurs at each contact is represented as "ARC," the period during which sliding occurs at each contact is represented as "SL," and the period during which a fault current flows in the circuit breaker 100 is represented as "FC."

[0128] [D-1] Details of the Electrical Path Closing Operation As shown in FIG. 6, the electrical path closing operation of this embodiment includes a first breaking contact closing operation CM111, a second breaking contact closing operation CM112, and a conducting contact closing operation CM101.

[0129] The first breaking contact closing operation CM111 starts at time t111a and completes at time t111c. In the first breaking contact closing operation CM111, the first breaking contact 111 switches from the open state to the closed state at time t111b during the period from time t111a to time t111c.

[0130] The second breaking contact closing operation CM112 starts at time t112a and completes at time t112c. In the second breaking contact closing operation CM112, the second breaking contact 112 switches from the open state to the closed state at time t112b during the period from time t112a to time t112c.

[0131] The contact closing operation CM101 starts at time t101a and completes at time t101c. In the contact closing operation CM101, the contact 101 switches from the open state to the closed state at time t101b during the period from time t101a to time t101c.

[0132] 6 , in this embodiment, time t111a when the first breaking contact closing operation CM111 starts is later than time t112a when the second breaking contact closing operation CM112 starts and time t101a when the energizing contact closing operation CM101 starts. Time t112a when the second breaking contact closing operation CM112 starts and time t101a when the energizing contact closing operation CM101 starts are the same.

[0133] Time t112b at which the second breaking contact 112 changes from an open state to a closed state in the second breaking contact closing operation CM112 occurs before time t111b at which the first breaking contact 111 changes from an open state to a closed state in the first breaking contact closing operation CM111. Time t101b at which the current-carrying contact 101 changes from an open state to a closed state in the current-carrying contact closing operation CM101 occurs after time t111b at which the first breaking contact 111 changes from an open state to a closed state in the first breaking contact closing operation CM111.

[0134] That is, after time t112b when the second breaking contact 112 is closed during the second breaking contact closing operation CM112, the first breaking contact 111 is closed at time t111b when an arc discharge ARC occurs at the first breaking contact 111 during the first breaking contact closing operation CM111. As a result, a current flows through the first breaking contact 111 and the second breaking contact 112 (see FIG. 3B ). Then, at time t101b when the conducting contact 101 is closed during the conducting contact closing operation CM101, a larger current flows through the conducting contact 101 than through the first breaking contact 111 and the second breaking contact 112 (see FIG. 3C ).

[0135] Time t111c when the first breaking contact closing operation CM111 is completed is before time t112c when the second breaking contact closing operation CM112 is completed and time t101c when the energizing contact closing operation CM101 is completed. At time t111c when the first breaking contact closing operation CM111 is completed, the movable electrode 111A and the fixed electrode 111B that constitute the first breaking contact 111 are in physical contact with each other, and the arc discharge ARC is extinguished. Time t112c when the second breaking contact closing operation CM112 is completed and time t101c when the energizing contact closing operation CM101 are completed are the same.

[0136] Note that time t101a when the current-carrying contact closing operation CM101 starts does not have to be the same as time t112a when the second breaking contact closing operation CM112 starts, and time t101c when the current-carrying contact closing operation CM101 is completed does not have to be the same as time t112c when the second breaking contact closing operation CM112 is completed. In other words, the gas circuit breaker 251 may be configured so that the driving-side arcing contact 451 and the driving-side current-carrying contact 455 move independently of each other.

[0137] [D-2] Details of Electrical Path Breaking Operation As shown in FIG. 6, the electrical path breaking operation of this embodiment includes a first breaking contact breaking operation CM111b, a second breaking contact breaking operation CM112b, and an energizing contact breaking operation CM101b.

[0138] The first breaking contact breaking operation CM111b starts at time t111d and completes at time t111f. In the first breaking contact breaking operation CM111b, the first breaking contact 111 switches from the closed state to the open state at time t111e during the period from time t111d to time t111f. In the first breaking contact breaking operation CM111b, an arc discharge (ARC) occurs at the first breaking contact 111 from time t111d to time t111e, which is before time t111f.

[0139] The second breaking contact breaking operation CM112b starts at time t112c and completes at time t112f. In the second breaking contact breaking operation CM112b, the second breaking contact 112 switches from the closed state to the open state at time t112e, which is within the period from time t112c to time t112f. In the second breaking contact breaking operation CM112b, an arc discharge (ARC) occurs at the second breaking contact 112 between time t112d, which is after time t112c, and time t112e.

[0140] The current-carrying contact breaking operation CM101b starts at time t101c and completes at time t101f. In the current-carrying contact breaking operation CM101b, the current-carrying contact 101 switches from the closed state to the open state at time t101e during the period from time t101c to time t101f.

[0141] 5A , when the current-carrying contact 101 switches from the closed state to the open state in the current-carrying contact breaking operation CM101b, the time t112e occurs before the time t111e when the first breaking contact 111 switches from the closed state to the open state in the first breaking contact breaking operation CM111b and the time t112e when the second breaking contact 112 switches from the closed state to the open state in the second breaking contact breaking operation CM112b. As shown in FIG. 5A , when the current-carrying contact 101 switches to the open state, the current flow in the current-carrying electric circuit EC1 in which the current-carrying contact 101 is installed is interrupted, and current flows in the breaking electric circuit EC2 in which the first breaking contact 111 and the second breaking contact 112 are installed.

[0142] The time t111e when the first breaking contact 111 changes from the closed state to the open state in the first breaking contact breaking operation CM111b and the time t112e when the second breaking contact 112 changes from the closed state to the open state in the second breaking contact breaking operation CM112b are the same. As shown in Fig. 5B , the first breaking contact 111 changes to the open state and the second breaking contact 112 also changes to the open state, thereby interrupting the flow of current in the electrical circuit EC.

[0143] [D-3] Regarding fault current When the circuit-closing operation is being performed in the circuit breaker 100, if an accident such as a short circuit occurs in the power system including the circuit EC and a circuit-breaking operation is performed, a fault current flows in the circuit EC during the period FC shown in Figure 6.

[0144] 6, the fault current starts to flow through the electric circuit EC at time t111b when the first breaking contact 111 switches from the open state to the closed state. The fault current then flows through the electric circuit EC until time t111e when the first breaking contact 111 switches from the closed state to the open state and until time t112e when the second breaking contact 112 switches from the closed state to the open state.

[0145] [E] Details of Operation of Comparative Example The operation of the comparative example of the above embodiment will be described.

[0146] 7A and 7B are circuit diagrams showing an outline of the circuit closing operation executed in the comparative example.

[0147] 7A and 7B, together with FIGS. 1 and 3C, show how the electrical circuit closing operation is performed in the comparative example.

[0148] In the circuit closing operation of the comparative example, the circuit EC is switched from the interrupted state (completely open state) shown in Figure 1 to the closing process shown in Figures 7A and 7B in sequence, and then the closing process shown in Figure 3C is further executed, thereby entering a conducting state.

[0149] Specifically, in the electrical circuit closing operation of the comparative example, as shown in Fig. 7A , first, the first breaking contact 111 is switched from an open state to a closed state by execution of a first breaking contact closing operation CM111. Next, as shown in Fig. 7B , the second breaking contact 112 is switched from an open state to a closed state by execution of a second breaking contact closing operation CM112. After that, as shown in Fig. 3C , the energizing contact 101 is switched from an open state to a closed state by execution of an energizing contact closing operation CM101.

[0150] In other words, in the circuit closing operation of the above embodiment, the second breaking contact 112 switches from the open state to the closed state before the first breaking contact 111 (see Figures 3A and 3B), whereas in the circuit closing operation of the comparative example, the first breaking contact 111 switches from the open state to the closed state before the second breaking contact 112 (see Figures 7A and 7B).

[0151] FIG. 8 is a timing chart showing the operations executed in the comparative example in chronological order.

[0152] As in the case of Figure 6, Figure 8 shows a case where, for example, while the circuit closing operation is being performed in the circuit breaking device 100, an accident such as a short circuit accident occurs in the power system including the circuit EC, and therefore a circuit breaking operation is performed.

[0153] [E-1] Details of the Electrical Circuit Closing Operation As shown in FIG. 8, the electrical circuit closing operation of the comparative example includes a first breaking contact closing operation CM111, a second breaking contact closing operation CM112, and a conducting contact closing operation CM101.

[0154] In the comparative example, time t111a when the first breaking contact closing operation CM111 starts is before time t112a when the second breaking contact closing operation CM112 starts and time t101a when the energizing contact closing operation CM101 starts. Time t112a when the second breaking contact closing operation CM112 starts and time t101a when the energizing contact closing operation CM101 starts are the same.

[0155] In the comparative example, time t112b at which the second breaking contact 112 changes from an open state to a closed state in the second breaking contact closing operation CM112 is later than time t111c at which the first breaking contact 111 changes from an open state to a closed state in the first breaking contact closing operation CM111. Time t101b at which the energizing contact 101 changes from an open state to a closed state in the energizing contact closing operation CM101 is later than time t112b at which the second breaking contact 112 changes from an open state to a closed state in the second breaking contact closing operation CM112.

[0156] In the first breaking contact closing operation CM111, the first breaking contact 111 enters a closed state at time t111c when the movable electrode 111A and the fixed electrode 111B that constitute the first breaking contact 111 come into physical contact, and the first breaking contact closing operation CM111 is completed.

[0157] In the second breaking contact closing operation CM112, the second breaking contact 112 is closed at time t112b when an arc discharge ARC occurs at the second breaking contact 112. This causes a current to flow through the first breaking contact 111 and the second breaking contact 112 (see FIG. 7B ). At the second breaking contact 112, the arc discharge ARC occurs between the opposing side arc contact 331 and the driving side arc contact 451 that constitute the second breaking contact 112, and is extinguished at time t112x when the opposing side arc contact 331 and the driving side arc contact 451 come into physical contact.

[0158] Then, at time t101b when the energizing contact 101 is closed in the energizing contact closing operation CM101, a larger current flows through the energizing contact 101 than through the first breaking contact 111 and the second breaking contact 112 (see FIG. 3C).

[0159] [E-2] Details of the electrical circuit interruption operation In the electrical circuit interruption operation of the comparative example, as shown in Figure 7, the first interruption contact interruption operation CM111b, the second interruption contact interruption operation CM112b, and the energizing contact interruption operation CM101b are performed in the same manner as in the above embodiment (see Figure 6).

[0160] [E-3] Regarding fault current: When a circuit-opening operation is being performed and an accident such as a short circuit occurs in a power system including the circuit EC, a fault current flows in the circuit EC during the period FC shown in Figure 8, even in the comparative example.

[0161] 8 , in the comparative example, the fault current starts to flow through the electric circuit EC at time t112b when the second breaking contact 112 switches from the open state to the closed state. The fault current then flows through the electric circuit EC from time t111e when the first breaking contact 111 switches from the closed state to the open state and from time t112e when the second breaking contact 112 switches from the closed state to the open state.

[0162] [F] Summary As described above, the circuit breaker 100 of this embodiment includes the current-carrying contact 101 (gas current-carrying contact), the first breaking contact 111 (vacuum valve), and the second breaking contact 112 (gas arc contact). The first breaking contact 111 is connected in parallel with the current-carrying contact 101, and the second breaking contact 112 is connected in parallel with the current-carrying contact 101 and in series with the first breaking contact 111. The first breaking contact 111 is configured as a vacuum circuit breaker 211 that switches between a closed state and an open state inside a vacuum vessel 212. The second breaking contact 112 and the current-carrying contact 101 are configured as a gas circuit breaker 251 that switches between a closed state and an open state inside an insulating gas vessel 202 filled with insulating gas.

[0163] In the circuit breaker 100 of this embodiment, sufficient current-carrying performance can be obtained in a current-carrying state because the current-carrying contact 101 is configured as the gas circuit breaker 251. Therefore, in the circuit breaker 100 of this embodiment, the vacuum circuit breaker 211 configuring the first breaking contact 111 does not need to have improved current-carrying performance, so it is possible to switch from a closed state to an open state more quickly and obtain sufficient voltage-resistance performance.

[0164] As described above, in this embodiment, when performing an electrical circuit closing operation to change the electrical circuit EC from a cut-off state to a conductive state, a first breaking contact closing operation CM111 to change the first breaking contact 111 from an open state to a closed state, a second breaking contact closing operation CM112 to change the second breaking contact 112 from an open state to a closed state, and an energizing contact closing operation CM101 to change the energizing contact 101 from an open state to a closed state are performed.

[0165] In this embodiment, time t112b when the second breaking contact 112 changes from an open state to a closed state in the second breaking contact closing operation CM112 occurs before time t111b when the first breaking contact 111 changes from an open state to a closed state in the first breaking contact closing operation CM111. Time t101b when the current-carrying contact 101 changes from an open state to a closed state in the current-carrying contact closing operation CM101 occurs after time t111b when the first breaking contact 111 changes from an open state to a closed state in the first breaking contact closing operation CM111 (see FIG. 6 ).

[0166] In this embodiment, the fault current begins to flow through the electric circuit EC at time t111b when the first breaking contact 111 switches from the open state to the closed state, which is later than time t112b when the second breaking contact 112 switches from the open state to the closed state (see FIG. 6 ). In contrast, in the comparative example, the fault current begins to flow through the electric circuit EC at time t112b when the second breaking contact 112 switches from the open state to the closed state, which is later than time t111b when the first breaking contact 111 switches from the open state to the closed state (see FIG. 8 ).

[0167] In the comparative example, time t112b (see FIG. 8) when the fault current starts to flow through the electric circuit EC is earlier than time t111b (see FIG. 6) when the fault current starts to flow through the electric circuit EC in the above embodiment. Therefore, in the present embodiment, the period FC (see FIG. 6) when the fault current flows through the electric circuit EC is shorter than the period FC (see FIG. 8) when the fault current flows through the electric circuit EC in the comparative example.

[0168] In the first breaking contact closing operation CM111, the movable electrode 111A of the first breaking contact 111 approaches the fixed electrode 111B, and the movable electrode 111A comes into physical contact with the fixed electrode 111B, thereby stopping the movable electrode 111A. In other words, in the first breaking contact closing operation CM111, the movable electrode 111A does not slide after coming into physical contact with the fixed electrode 111B (see FIGS. 2A and 4B ).

[0169] In contrast, in the second breaking contact closing operation CM112, the second breaking contact 112 slides while the driving-side arc contact 451 remains in physical contact with the opposing-side arc contact 331, even after the driving-side arc contact 451 approaches the opposing-side arc contact 331 and physically contacts the opposing-side arc contact 331 (see FIGS. 2B , 4A , and 4C ). In other words, the operation of the second breaking contact 112 includes a period SL during which the driving-side arc contact 451 slides (see FIGS. 6 and 8 ). Therefore, the closing time for switching from the open state to the closed state is longer for the second breaking contact 112 than for the first breaking contact 111.

[0170] In the above embodiment, unlike the comparative example, the first breaking contact 111 switches from the open state to the closed state during the period SL during which the driving-side arcing contact 451 slides in physical contact with the opposing-side arcing contact 331 during the second breaking contact closing operation CM112 (see FIGS. 6 and 8 ). Therefore, as described above, the period FC during which the fault current flows through the electric circuit EC in the embodiment (see FIG. 6 ) is shorter than the period FC during which the fault current flows through the electric circuit EC in the comparative example (see FIG. 8 ).

[0171] <Second embodiment> [A] Operation of the shutoff device 100 In this embodiment, part of the operation of the shutoff device 100 differs from that of the first embodiment (see FIG. 2A). That is, in the shutoff device 100, part of the control of the control unit 800 differs from that of the above embodiment. Except for this point and related matters, the shutoff device 100 of this embodiment is the same as that of the first embodiment. Therefore, explanations of overlapping matters will be omitted as appropriate.

[0172] Unlike the above-described embodiments, in the circuit breaker 100 of this embodiment, current data relating to the current flowing through the electrical circuit EC is input to the control unit 800. The current data is acquired, for example, by a current sensor installed in the electrical circuit EC and output to the control unit 800. Then, the control unit 800 executes an electrical circuit closing operation and an electrical circuit breaking operation in accordance with the current data.

[0173] Here, the control unit 800 controls the circuit closing operation and the circuit breaking operation based on the current data input from time t111b, when the first breaking contact 111 switches from a closed state to an open state after the start of the first breaking contact closing operation CM111 (time t111a), until before the completion of the first breaking contact closing operation CM111 (time t111c) (see Figure 6). In other words, the control unit 800 controls the circuit making operation and the circuit breaking operation according to the value of the current flowing between the movable electrode 111A and the fixed electrode 111B (synonymous with the current flowing through the breaking circuit EC2; see Figure 3B) after time t111b when an arc discharge ARC occurs between the movable electrode 111A and the fixed electrode 111B in the vacuum circuit breaker 211 that constitutes the first breaking contact 111, and the movable electrode 111A and the fixed electrode 111B become electrically connected, but before time t111c when the movable electrode 111A and the fixed electrode 111B come into physical contact with each other.

[0174] [B] Details of Operation of Circuit Breaker 100 FIGS. 9A and 9B are timing charts showing, in chronological order, the operations executed by the circuit breaker 100 according to the second embodiment.

[0175] 9A and 9B, similarly to Fig. 6, the horizontal axis represents time, and the vertical axis represents the state of each contact (the energizing contact 101, the first breaking contact 111, and the second breaking contact 112). Specifically, in Fig. 6, the vertical axis represents "Open" when each contact is in an open state (electrically insulated state), and represents "Close" when each contact is in a closed state (electrically connected state) (the dashed lines indicate a transition from the open state to the closed state).

[0176] 9A shows a case where the value of the current flowing during the period (between time t111b and time t111c) during first breaking contact closing operation CM111 exceeds a predetermined threshold, whereas FIG. 9B shows a case where the value of the current flowing during the period (between time t111b and time t111c) during first breaking contact closing operation CM111 is equal to or less than the threshold.

[0177] [B-1] When the Current Value Exceeds the Threshold Value: If the current value flowing during the above-described period (between time t111b and time t111c) during the first breaking contact closing operation CM111 exceeds the threshold value, the control unit 800 determines that a fault current is flowing. In this case, the control unit 800 stops the first breaking contact closing operation CM111, as shown in FIG. 9A . As a result, in the vacuum circuit breaker 211 constituting the first breaking contact 111, a state in which an arc discharge (ARC) occurs between the movable electrode 111A and the fixed electrode 111B is maintained. In other words, the movable electrode 111A and the fixed electrode 111B are maintained in a state in which they are not in physical contact with each other. FIG. 9A illustrates a state in which the first breaking contact closing operation CM111 is stopped at time t111s during the period from time t111b to time t111c.

[0178] Additionally, if the value of the current flowing during the period (between time t111b and time t111c) during the first breaking contact closing operation CM111 exceeds a threshold, the control unit 800 also stops the second breaking contact closing operation CM112 and the energizing contact closing operation CM101. Here, the first breaking contact closing operation CM111 is stopped at time t111s, and then the second breaking contact closing operation CM112 and the energizing contact closing operation CM101 are stopped at times t112s and t101s, respectively. However, all operations may be stopped simultaneously. Thus, if the current value exceeds the threshold, the control unit 800 completes the electrical circuit closing operation by stopping the first breaking contact closing operation CM111, the second breaking contact closing operation CM112, and the energizing contact closing operation CM101 midway. In other words, the electrical circuit closing operation is completed in the state shown in FIG. 3B .

[0179] After completing the electric circuit closing operation, the control unit 800 executes an electric circuit breaking operation based on the fact that the current value exceeds the threshold. The electric circuit breaking operation is started in a state where the flow of current in the current-carrying electric circuit EC1 where the energizing contact 101 is installed is interrupted (see FIG. 5B ), and then the current is interrupted in the breaking electric circuit EC2 where the first breaking contact 111 and the second breaking contact 112 are installed (see FIG. 5B ). In this embodiment, after the state where an arc discharge ARC is generated between the movable electrode 111A and the fixed electrode 111B is maintained, the first breaking contact breaking operation CM111b is executed in the same manner as in the first embodiment.

[0180] [B-2] When the Current Value is Less than or Equal to the Threshold Value: If the current value during the period (between time t111b and time t111c) during the first breaking contact closing operation CM111 is less than or equal to the threshold value, the control unit 800 determines that a fault current is not flowing and that a normal conducting current is flowing. In this case, the control unit 800 executes the circuit closing operation, as in the first embodiment (see FIG. 6 ). That is, the control unit 800 executes the first breaking contact closing operation CM111, the second breaking contact closing operation CM112, and the conducting contact closing operation CM101, as in the first embodiment, to complete the circuit closing operation. In the vacuum circuit breaker 211 that constitutes the first breaking contact 111, the movable electrode 111A and the fixed electrode 111B come into physical contact with each other upon completion of the first breaking contact closing operation CM111.

[0181] However, in this case, it is determined that no fault current is flowing in the electrical circuit EC, so unlike the first embodiment (see Figure 6), after the electrical circuit closing operation is completed, the electrical circuit closing state is maintained without performing the electrical circuit breaking operation.

[0182] [B] Summary As described above, in the circuit breaker 100 of this embodiment, if the value of the current flowing during the period (between time t111b and time t111c) during the first breaking contact closing operation CM111 exceeds the threshold value, the control unit 800 determines that a fault current is flowing and stops the first breaking contact closing operation CM111. Therefore, in the vacuum circuit breaker 211 that constitutes the first breaking contact 111, the movable electrode 111A and the fixed electrode 111B are not in physical contact with each other and are maintained in a state in which an arc discharge ARC is generated between the movable electrode 111A and the fixed electrode 111B.

[0183] In other words, as shown in Fig. 3B, when both the first breaking contact 111 and the second breaking contact 112 are closed and a large fault current flows through the breaking electrical circuit EC2, in the vacuum circuit breaker 211 that constitutes the first breaking contact 111, the movable electrode 111A and the fixed electrode 111B are not in physical contact with each other but are electrically connected via the arc discharge ARC, as shown in Fig. 4B. Therefore, in this embodiment, the movable electrode 111A and the fixed electrode 111B that constitute the vacuum circuit breaker 211 are not welded together by the arc discharge ARC.

[0184] If the movable electrode 111A and the fixed electrode 111B are welded together by an arc discharge ARC and then the movable electrode 111A and the fixed electrode 111B are separated by the execution of the first breaking contact breaking operation CM111b, the welded surfaces of the movable electrode 111A and the fixed electrode 111B may become rough, which may reduce the voltage resistance performance of the vacuum circuit breaker 211.

[0185] However, in this embodiment, as described above, when a large fault current flows, the movable electrode 111A and the fixed electrode 111B that constitute the vacuum circuit breaker 211 are not welded together, so it is possible to effectively prevent a decrease in the voltage resistance performance of the vacuum circuit breaker 211.

[0186] In this embodiment, as described above, when a normal current flows rather than a fault current, the movable electrode 111A and the fixed electrode 111B that constitute the vacuum circuit breaker 211 may come into physical contact with each other after an arc discharge ARC occurs, and may be welded to each other. However, in this case, the energy of the arc discharge ARC is small, so the degree of welding between the movable electrode 111A and the fixed electrode 111B is low, and the withstand voltage performance of the vacuum circuit breaker 211 is maintained.

[0187] Third Embodiment [A] Detailed Configuration of the Circuit Breaker 100 Fig. 10A is a cross-sectional view schematically illustrating the configuration of the circuit breaker 100 according to the third embodiment. Fig. 10A shows the circuit breaker 100 in a circuit breaker state, similar to Fig. 2A.

[0188] As shown in Fig. 10A, the shutoff device 100 of this embodiment differs from the first embodiment (see Fig. 2A) in that an operation mechanism 257b is provided instead of the operation mechanisms 217 and 257. Except for this point and related matters, the shutoff device 100 of this embodiment is similar to the first embodiment. Therefore, explanations of overlapping matters will be omitted as appropriate.

[0189] 10A , in the circuit breaker 100 of the present embodiment, the operating mechanism 257b is configured to operate the first circuit breaker contact 111 in addition to operating the energizing contact 101 and the second circuit breaker contact 112, similar to the operating mechanism 257 in the first embodiment (see FIG. 2A ). Here, the operating mechanism 257b is connected to the insulating rod 216 via an operating link L216, and is configured to switch the first circuit breaker contact 111 between a closed state and an open state by operating the insulating rod 216.

[0190] [B] Details of the Electrical Circuit Closing Operation FIG. 10B is a timing chart showing, in chronological order, the operations executed by the circuit breaker 100 according to the third embodiment.

[0191] In FIG. 10B, similarly to FIG. 6, the horizontal axis represents time, and the vertical axis represents the state of each contact (the energizing contact 101, the first breaking contact 111, and the second breaking contact 112).

[0192] 10B , in the electrical circuit closing operation of the present embodiment, as in the first embodiment (see FIG. 6 ), time t112b at which the second breaking contact 112 changes from an open state to a closed state in the second breaking contact closing operation CM112 occurs before time t111b at which the first breaking contact 111 changes from an open state to a closed state in the first breaking contact closing operation CM111. Furthermore, time t101b at which the energizing contact 101 changes from an open state to a closed state in the energizing contact closing operation CM101 occurs after time t111b at which the first breaking contact 111 changes from an open state to a closed state in the first breaking contact closing operation CM111.

[0193] 10B , in the electrical circuit closing operation of this embodiment, unlike the first embodiment (see FIG. 6 ), the time t111a at which the first breaking contact closing operation CM111 starts, the time t112a at which the second breaking contact closing operation CM112 starts, and the time t101a at which the energizing contact closing operation CM101 starts are the same. That is, in this embodiment, the first breaking contact closing operation CM111, the second breaking contact closing operation CM112, and the energizing contact closing operation CM101 start simultaneously.

[0194] [C] Summary As described above, in the circuit breaking device 100 of this embodiment, the operating mechanism 257b operates all of the energized contact 101, the first breaking contact 111, and the second breaking contact 112, and is configured so that the first breaking contact closing operation CM111, the second breaking contact closing operation CM112, and the energized contact closing operation CM101 are started simultaneously.

[0195] Therefore, in this embodiment, it is possible to obtain the same effects as those of the first embodiment with a simplified device.

[0196] [D] Modifications In the above embodiment, the first breaking contact closing operation CM111, the second breaking contact closing operation CM112, and the energizing contact closing operation CM101 are simultaneously started by operating the operation mechanism 257b, but this is not limiting. For example, as in the first embodiment (see FIG. 6 ), the operation mechanism 257b may be configured so that the first breaking contact closing operation CM111 is started after the second breaking contact closing operation CM112 and the energizing contact closing operation CM101 have started.

[0197] Additionally, in the above embodiment, the case where the operation mechanism 257b operates all of the energized contact 101, the first breaker contact 111, and the second breaker contact 112 has been described, but this is not limited thereto. As in the first embodiment, when the operation mechanism 217 and the operation mechanism 257 are provided, for example, the first breaker contact closing operation CM111, the second breaker contact closing operation CM112, and the energized contact closing operation CM101 may be started simultaneously by adjusting the closing speed of each of the energized contact 101, the first breaker contact 111, and the second breaker contact 112. Furthermore, for example, in the vacuum circuit breaker 211 that constitutes the first breaker contact 111, the first breaker contact closing operation CM111, the second breaker contact closing operation CM112, and the energized contact closing operation CM101 may be started simultaneously by adjusting the length of the gap between the movable electrode 111A and the fixed electrode 111B.

[0198] <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.

[0199] 3: opposing unit, 4: driving unit, 100: circuit breaker, 101: current-carrying contact, 111: first breaking contact, 111A: movable electrode, 111B: fixed electrode, 112: second breaking contact, 200: grounding tank, 202: insulating gas container, 211: vacuum circuit breaker, 212: vacuum container, 212a: porcelain tube, 212b: flange, 213: vacuum circuit breaker fixed current-carrying shaft, 214: vacuum circuit breaker movable current-carrying shaft, 215: bellows, 216: insulating rod, 217: operating mechanism (vacuum circuit breaker operating mechanism ), 218: Arc shield, 251: Gas circuit breaker, 253: Gas circuit breaker fixed current-carrying shaft, 256: Insulating rod, 257: Operation mechanism (gas circuit breaker operation mechanism), 257b: Operation mechanism, 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: Gas circuit breaker movable current-carrying shaft, 402: Puffer cylinder, 4 03: puffer piston, 405: driving side contact portion, 406: cylinder support, 407: piston support, 411: movable current-carrying shaft solid portion, 412: movable current-carrying shaft hollow portion, 421: cylinder cylindrical portion, 422: cylinder bottom plate portion, 451: driving side arc contact, 451a: end portion, 455: driving side current-carrying contact, 455a: end portion, 461: cylinder support cylindrical portion, 462: cylinder support ring portion, 471: piston support cylindrical portion, 472: piston support ring part, 500: insulating nozzle, 510: large diameter nozzle part, 520: small diameter nozzle part, 530: inclined nozzle part, 530a: end part, 800: control part, DS: drive side, EC: electrical circuit, EC1: interrupting electrical circuit, EC2: energizing electrical circuit, H412: first ventilation hole, H422a: rod through hole, H422b: exhaust hole, H461: second ventilation hole, H471: third ventilation hole, L216: operation link, OS: opposite side, PR: puffer chamber, S500: nozzle internal space, SL214: sliding part, SP: support part

Claims

1. A circuit breaker having a current-carrying contact, a first breaking contact connected in parallel with the current-carrying contact, and a second breaking contact connected in parallel with the current-carrying contact and in series to the first breaking contact, wherein the first breaking contact is constituted by a vacuum circuit breaker that switches between a closed state and an open state inside a vacuum container, and the second breaking contact and the current-carrying contact are constituted by gas circuit breakers that switch between a closed state and an open state inside an insulating gas container filled with insulating gas, and when performing an electric circuit closing operation to change an electric circuit from a cut-off state to an electric circuit, the circuit breaker executes a first breaking contact closing operation to change the first breaking contact from an open state to a closed state, a second breaking contact closing operation to change the second breaking contact from an open state to a closed state, and a current-carrying contact closing operation to change the current-carrying contact from an open state to a closed state, wherein the time when the second breaking contact changes from an open state to a closed state in the second breaking contact closing operation is before the time when the first breaking contact changes from an open state to a closed state in the first breaking contact closing operation, The circuit breaker is configured such that the point in time at which the current-carrying contact changes from an open state to a closed state in the current-carrying contact closing operation is later than the point in time at which the first breaking contact changes from an open state to a closed state in the first breaking contact closing operation, and when the first breaking contact changes to a closed state due to the occurrence of an arc discharge in the first breaking contact closing operation after the second breaking contact has changed to a closed state in the second breaking contact closing operation, a current flows through the first breaking contact and the second breaking contact, and when the current-carrying contact changes to a closed state in the current-carrying contact closing operation, a larger current flows through the current-carrying contact than through the first breaking contact and the second breaking contact.

2. A vacuum circuit breaker operating mechanism for operating the vacuum circuit breaker, a gas circuit breaker operating mechanism for operating the gas circuit breaker, and a control unit for controlling the vacuum circuit breaker operating mechanism and the gas circuit breaker operating mechanism, wherein the vacuum circuit breaker includes a movable electrode mounted on a vacuum circuit breaker movable current-carrying shaft, and a fixed electrode mounted on a vacuum circuit breaker fixed current-carrying shaft aligned coaxially with the vacuum circuit breaker movable current-carrying shaft, and wherein the first breaking contact is closed when the movable electrode and the fixed electrode are connected, and the first breaking contact is opened when the movable electrode and the fixed electrode are insulated, 2. The circuit breaking device according to claim 1, wherein, when a value of a current flowing between the movable electrode and the fixed electrode exceeds a predetermined threshold value after an arc discharge occurs between the movable electrode and the fixed electrode during the first breaking contact closing operation and the movable electrode and the fixed electrode are electrically connected, but before the movable electrode and the fixed electrode come into contact with each other, the control unit stops the first breaking contact closing operation, maintaining a state in which an arc discharge has occurred between the movable electrode and the fixed electrode, and stops the current-carrying contact closing operation, maintaining a state in which no current flows through the current-carrying contact.

3. The circuit breaker according to claim 1, further comprising an operating mechanism for operating both the vacuum circuit breaker and the gas circuit breaker so as to simultaneously start the first circuit breaker contact closing operation, the second circuit breaker contact closing operation, and the current carrying contact closing operation.

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