Cutoff device

Abstract

Provided is a cutoff device comprising sufficient withstand voltage performance and energization performance even when a vacuum circuit breaker is used. In a cutoff device according to an embodiment, a first cutoff contact is connected in parallel with an energization contact. A second cutoff contact is connected in parallel with the energization contact and is connected in series to the first cutoff contact. The resistance of the energization contact is less than the resistance of the first cutoff contact and the resistance of the second cutoff contact. In an energized state, the energization contact, the first cutoff contact, and the second cutoff contact are in a closed state, and a greater current flows through the energization contact than through the first cutoff contact and the second cutoff contact. In a cutoff state, after the energization contact is switched from the closed state to an open state, the first cutoff contact and the second cutoff contact are switched from the closed state to the open state. At least one of the first cutoff contact and the second cutoff contact is configured from a vacuum circuit breaker that switches between the closed state and the open state inside a vacuum container.

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 has, for example, a pair of contacts housed inside a vacuum vessel that is in a vacuum state. In a vacuum circuit breaker, the pair of contacts are in contact with each other in a vacuum atmosphere when in a conducting state, and the pair of contacts are in a separated state when in a cut-off state.

[0004] A gas circuit breaker has, for example, a pair of contacts housed inside a grounded container filled with insulating gas. In a conducting state, the pair of contacts are in contact with each other in an atmosphere filled with insulating gas, and in a cut-off state, the pair of contacts are in a separated state in an atmosphere filled with insulating gas. The gas circuit breaker is configured to spray, for example, insulating gas onto an arc discharge that occurs during a breaking operation to switch from a conducting state to a cut-off state, 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 on circuits that are subject to higher voltages (such as power transmission class circuits) than circuits that are interrupted by vacuum circuit breakers.

[0006] Patent No. 6044645

[0007] SF is the main insulating gas used in gas circuit breakers. ６ Gas has a high greenhouse effect potential. ６ Although techniques using insulating gases other than gas have been proposed, it is not easy to obtain sufficient performance.

[0008] Furthermore, when a vacuum circuit breaker is applied to an electric circuit (a power transmission class electric circuit) to which a higher voltage is applied, it is necessary to further improve the withstand voltage performance and current-carrying performance of the vacuum circuit breaker. However, to improve the withstand voltage performance of the vacuum circuit breaker, it is necessary to increase the distance between the movable electrode and the fixed electrode that constitute a pair of contacts. Furthermore, to improve the current-carrying performance of the vacuum circuit breaker, it is necessary to increase the thickness of the movable current-carrying shaft on which the movable electrode is provided. As a result, it is difficult for the vacuum circuit breaker to switch from a closed state to an open state more quickly during an interruption operation.

[0009] Due to the above circumstances, SF ６ When a vacuum circuit breaker is used instead of a gas circuit breaker using an insulating gas such as gas, it is not easy to improve the withstand voltage performance and current carrying performance.

[0010] Therefore, an object of the present invention is to provide a circuit breaker that has sufficient voltage resistance and current carrying performance even when a vacuum circuit breaker is used.

[0011] The circuit breaker of one embodiment is a device for switching an electric circuit from a conducting state to a cut-off state, and includes a conducting contact, a first cut-off contact, and a second cut-off contact. The first cut-off contact is connected in parallel with the conducting contact. The second cut-off contact is connected in parallel with the conducting contact and in series with the first cut-off contact. The resistance of the conducting contact is smaller than the resistance of the first cut-off contact and the resistance of the second cut-off contact. In the conducting state, the conducting contact, the first cut-off contact, and the second cut-off contact are in a closed state, and a larger current flows through the conducting contact than through the first cut-off contact and the second cut-off contact. In the cut-off state, the first cut-off contact and the second cut-off contact are configured to switch from a closed state to an open state after the conducting contact switches from a closed state to an open state. At least one of the first cut-off contact and the second cut-off contact is configured as a vacuum circuit breaker that switches between a closed state and an open state inside a vacuum vessel.

[0012] FIG. 1 is a circuit diagram of a circuit breaker 100 according to the first embodiment. FIG. 2 is a cross-sectional view schematically showing the configuration of the circuit breaker 100 according to the first embodiment. FIG. 3A is a circuit diagram showing the operation of the circuit breaker 100 according to the first embodiment. FIG. 3B is a circuit diagram showing the operation of the circuit breaker 100 according to the first embodiment. FIG. 4 is a cross-sectional view schematically showing the configuration of a circuit breaker 100 according to a second embodiment. FIG. 5 is a cross-sectional view showing a detailed configuration of a gas circuit breaker 251 in the circuit breaker 100 according to the second embodiment. FIG. 6A is a view showing the operation of the gas circuit breaker 251 in the circuit breaker 100 according to the second embodiment. FIG. 6B is a view showing the operation of the gas circuit breaker 251 in the circuit breaker 100 according to the second embodiment. FIG. 6C is a view showing the operation of the gas circuit breaker 251 in the circuit breaker 100 according to the second embodiment. FIG. 7 is a cross-sectional view schematically showing the configuration of a vacuum circuit breaker 211 in the circuit breaker 100 according to a third embodiment. Fig. 8 is a cross-sectional view schematically showing the configuration of a vacuum circuit breaker 211 in the circuit breaker 100 according to a modification of the third embodiment. Fig. 9 is a cross-sectional view schematically showing the configuration of the circuit breaker 100 according to a fourth embodiment. Fig. 10 is a cross-sectional view schematically showing the configuration of the circuit breaker 100 according to a fifth embodiment. Fig. 11 is a cross-sectional view schematically showing the configuration of the circuit breaker 100 according to a sixth embodiment. Fig. 12 is a cross-sectional view schematically showing the configuration of the circuit breaker 100 according to a modification of the sixth embodiment.

[0013] First Embodiment [A] Circuit of Breaker Device 100 FIG. 1 is a circuit diagram of a breaker device 100 according to a first embodiment.

[0014] 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.

[0015] The following describes each component of the circuit breaker 100. Note that Fig. 1 shows a state in which the circuit breaker 100 has switched the electrical circuit EC to an interrupted state.

[0016] [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.

[0017] [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.

[0018] [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.

[0019] [B] Configuration of the Breaker Device 100 FIG. 2 is a cross-sectional view that schematically shows the configuration of the breaker device 100 according to the first embodiment.

[0020] 2, the circuit breaker 100 of this embodiment accommodates a gas circuit breaker 201, a vacuum circuit breaker 211 (first vacuum circuit breaker), and a vacuum circuit breaker 221 (second vacuum circuit breaker) inside a grounded tank 200. Each part constituting the circuit breaker 100 will be described in order.

[0021] [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).

[0022] [B-2] Gas Circuit Breaker 201 The gas circuit breaker 201 accommodates a gas circuit breaker movable electrode 101A and a gas circuit breaker fixed electrode 101B as current-carrying contacts 101 inside an insulating gas container 202. The gas circuit breaker 201 is configured so that the current-carrying contacts 101 can be switched between a closed state and an open state inside the insulating gas container 202.

[0023] Here, the insulating gas container 202 is made of an insulating material and is filled with an insulating gas. 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.

[0024] The gas circuit breaker movable electrode 101A and the gas circuit breaker fixed electrode 101B are made of a metal material and are installed inside the insulating gas container 202 so that their ends face each other. The gas circuit breaker movable electrode 101A is slidably supported by a sliding portion SL101A. The gas circuit breaker fixed electrode 101B is connected to an electric wire EC1a, and the gas circuit breaker movable electrode 101A is connected to an electric wire EC1b via the sliding portion SL101A. The electric wires EC1a and EC1b constitute a current-carrying electric circuit EC1 (see FIG. 1 ).

[0025] The gas circuit breaker movable electrode 101A is connected to an operation mechanism 207 via an insulating rod 206. The gas circuit breaker 201 is placed in a closed state when the gas circuit breaker movable electrode 101A and the gas circuit breaker fixed electrode 101B are brought into contact with each other through the operation of the operation mechanism 207. At the same time, the gas circuit breaker 201 is placed in an open state when the gas circuit breaker movable electrode 101A and the gas circuit breaker fixed electrode 101B are brought into a separated state through the operation of the operation mechanism 207.

[0026] [B-3] Vacuum Circuit Breaker 211 The vacuum circuit breaker 211 is a vacuum valve, and accommodates a movable electrode 111A (first movable electrode) and a fixed electrode 111B (first fixed electrode) as a 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.

[0027] 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.

[0028] The movable electrode 111A and the fixed electrode 111B are made of a metal material and are installed inside the vacuum vessel 212 so that their ends face each other. Here, the movable electrode 111A is installed at an end of the vacuum circuit breaker movable current-carrying shaft 214 (first vacuum circuit breaker movable current-carrying shaft). The fixed electrode 111B is installed at an end of the vacuum circuit breaker fixed current-carrying shaft 213 (first vacuum circuit breaker fixed current-carrying shaft). 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.

[0029] The vacuum circuit breaker movable current-carrying shaft 214 is connected to an operating mechanism 217 via an insulating rod 216. When the operating mechanism 217 is operated, the vacuum circuit breaker 211 is placed in a closed state by bringing the movable electrode 111A and the fixed electrode 111B into contact with each other, and is placed in an open state by bringing the movable electrode 111A and the fixed electrode 111B into a separated state.

[0030] 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 gas circuit breaker fixed electrode 101B via an electric wire EC2a. The electric wire EC2a constitutes the interrupting electric circuit EC2 (see FIG. 1).

[0031] The vacuum vessel 212 further contains a bellows 215 and an arc shield 218 .

[0032] 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.

[0033] The arc shield 218 is disposed so as to surround the movable electrode 111A and the fixed electrode 111B in the circumferential direction.

[0034] [B-4] Vacuum Circuit Breaker 221 Like the vacuum circuit breaker 211, the vacuum circuit breaker 221 is a vacuum valve, and accommodates a movable electrode 121A (second movable electrode) and a fixed electrode 121B (second fixed electrode) as a second interrupter contact 112 inside a vacuum container 222. The vacuum circuit breaker 221 is configured so that the second interrupter contact 112 switches between a closed state and an open state inside the vacuum container 222.

[0035] Here, the vacuum vessel 222 includes a porcelain tube 222 a and a pair of flanges 222 b, and for example, the pair of flanges 222 b are installed at both ends of the cylindrical porcelain tube 222 a. The inside of the vacuum vessel 222 is in a vacuum state, and the pressure inside the vacuum vessel 222 is lower than the pressure inside the grounded tank 200.

[0036] The movable electrode 121A and the fixed electrode 121B are made of a metal material and are installed inside the vacuum vessel 222 so that their ends face each other. Here, the movable electrode 121A is installed at an end of the vacuum circuit breaker movable current-carrying shaft 224 (second vacuum circuit breaker movable current-carrying shaft). And the fixed electrode 121B is installed at an end of the vacuum circuit breaker fixed current-carrying shaft 223 (second vacuum circuit breaker fixed current-carrying shaft). The vacuum circuit breaker fixed current-carrying shaft 223 is installed so as to be aligned coaxially with the vacuum circuit breaker movable current-carrying shaft 224. Here, the vacuum circuit breaker fixed current-carrying shaft 223 is configured integrally with the vacuum circuit breaker fixed current-carrying shaft 213 and is supported by a support part SP.

[0037] Furthermore, the vacuum circuit breaker movable current-carrying shaft 224 is connected to an operating mechanism 227 via an insulating rod 226. When the operating mechanism 227 is operated, the vacuum circuit breaker 221 is brought into a closed state by bringing the movable electrode 121A and the fixed electrode 121B into contact with each other, and is brought into an open state by bringing the movable electrode 121A and the fixed electrode 121B into a separated state.

[0038] The vacuum circuit breaker movable current-carrying shaft 224 is slidably supported by a sliding portion SL224. The sliding portion SL224 is made of a metal material and is electrically connected to the gas circuit breaker movable electrode 101A via an electric wire EC2b. The electric wire EC2b constitutes the circuit breaking electric circuit EC2 (see FIG. 1).

[0039] The vacuum vessel 222 further contains a bellows 225 and an arc shield 228 .

[0040] The bellows 225 is cylindrical, and the vacuum circuit breaker movable current-carrying shaft 224 passes through it. The internal space of the bellows 225 communicates with the internal space of the grounded tank 200. The bellows 225 is configured to expand and contract in the direction of movement when the movable electrode 121A moves in accordance with the sliding of the vacuum circuit breaker movable current-carrying shaft 224.

[0041] The arc shield 228 is disposed so as to surround the movable electrode 121A and the fixed electrode 121B in the circumferential direction.

[0042] [C] Operation of the Breaker Device 100 FIGS. 3A and 3B are circuit diagrams showing the operation of the breaker device 100 according to the first embodiment.

[0043] In the interruption operation of this embodiment, the current flow in the electric circuit EC is interrupted by going from the energized state (closed state, closed state) shown in Fig. 3A through the interruption process (opening process) shown in Fig. 3B to the interruption state (completely open state) shown in Fig. 1. The interruption operation is performed, for example, by operating the operation mechanisms 207, 217, and 227 based on a control command output from a control device (not shown).

[0044] [C-1] Conducted State First, in the conducted state, as shown in FIG. 3A, the conducting contact 101, the first breaking contact 111, and the second breaking contact 112 are in a closed state.

[0045] Specifically, in a conducting state, in the gas circuit breaker 201, a gas circuit breaker movable electrode 101A and a gas circuit breaker fixed electrode 101B, which are housed as the conducting contact 101 inside the insulating gas container 202, are in a closed state. In the vacuum circuit breaker 211, a movable electrode 111A and a fixed electrode 111B, which are housed as the first breaking contact 111 inside the vacuum container 212, are in a closed state. Furthermore, in the vacuum circuit breaker 221, a movable electrode 121A and a fixed electrode 121B, which are housed as the second breaking contact 112 inside the vacuum container 222, are in a closed state (see FIG. 2).

[0046] As described above, the current-carrying contact 101 is configured to have a smaller resistance than the first breaking contact 111 and the second breaking contact 112. Therefore, in a conducting state, a larger current flows in the current-carrying electric circuit EC1 in which the current-carrying 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.

[0047] [C-2] Breaking Process Next, in the breaking process when the current-carrying state is changed over to the breaking state, the current-carrying contact 101 is switched from the closed state to the open state as shown in FIG. 3B.

[0048] Specifically, during the breaking process, in the gas circuit breaker 201, the gas circuit breaker movable electrode 101A and the gas circuit breaker fixed electrode 101B, which are housed inside the insulating gas container 202 as conductive contacts 101, are switched to an open state (see Figure 2).

[0049] As a result, the fault current flowing through the current-carrying circuit EC1 on which the current-carrying contact 101 is installed is diverted to flow through the interrupting circuit EC2 on which the first interrupting contact 111 and the second interrupting contact 112 are installed.

[0050] [C-3] Breaking State Next, in the breaking state, the first breaking contact 111 and the second breaking contact 112 are switched from the closed state to the open state as shown in Fig. 1. The first breaking contact 111 and the second breaking contact 112 are switched from the closed state to the open state, for example, simultaneously.

[0051] Specifically, in the vacuum circuit breaker 211, the movable electrode 111A and the fixed electrode 111B housed inside the vacuum container 212 as the first breaking contact 111 are switched to an open state. Furthermore, in the vacuum circuit breaker 221, the movable electrode 121A and the fixed electrode 121B housed inside the vacuum container 222 as the second breaking contact 112 are switched to an open state (see FIG. 2).

[0052] As a result, the flow of the fault current is interrupted in both the current-carrying electric circuit EC1 and the interrupting electric circuit EC2, and the interrupting operation is completed.

[0053] [D] Summary As described above, the circuit breaker 100 of this embodiment is a device that switches the electrical circuit EC from a conducting state (see FIG. 3A) to a breaking state (see FIG. 1), and includes the energizing contact 101, the first breaking contact 111, and the second breaking contact 112. The first breaking contact 111 is connected in parallel with the energizing contact 101. The second breaking contact 112 is connected in parallel with the energizing contact 101 and in series with the first breaking contact 111.

[0054] In this embodiment, the resistance of the energizing contact 101 is smaller than the resistance of the first interrupting contact 111 and the resistance of the second interrupting contact 112. Therefore, in the energized state (see FIG. 3A ), the energizing contact 101, the first interrupting contact 111, and the second interrupting contact 112 are closed, and a larger current flows through the energizing contact 101 than through the first interrupting contact 111 and the second interrupting contact 112. Then, in the interrupting process (see FIG. 3B ) when transitioning from the energized state to the interrupting state, the energizing contact 101 switches from a closed state to an open state. Thereafter, in the interrupting state (see FIG. 2 ), the first interrupting contact 111 and the second interrupting contact 112 switch from a closed state to an open state.

[0055] In the circuit breaker 100 of this embodiment, the current-carrying contact 101 is constituted by a gas circuit breaker 201 that switches between a closed state and an open state inside an insulating gas container 202 filled with insulating gas. The first circuit breaker 111 is constituted by a vacuum circuit breaker 211 that switches between a closed state and an open state inside a vacuum container 212. The second circuit breaker 112 is constituted by a vacuum circuit breaker 221 that switches between a closed state and an open state inside a vacuum container 222 (see FIG. 2 ).

[0056] As described above, in this embodiment, the function of establishing a conducting state (see FIG. 3A ) is mainly realized by the conducting contact 101 configured in the gas circuit breaker 201. In contrast, in this embodiment, the function of finally transitioning from the conducting state to the interrupting state through the interrupting process (see FIG. 3B ) is realized by the first interrupting contact 111 configured in the vacuum circuit breaker 211 and the second interrupting contact 112 configured in the vacuum circuit breaker 221.

[0057] In the circuit breaker 100 of this embodiment, the current-carrying contact 101 is configured as a gas circuit breaker 201, so sufficient current-carrying performance can be obtained in the current-carrying state (see FIG. 3A ). Therefore, the vacuum circuit breaker 211 that configures the first interrupting contact 111 and the vacuum circuit breaker 221 that configures the second interrupting contact 112 do not need to have improved current-carrying performance, so they can be made lighter and can be switched from a closed state to an open state more quickly. Furthermore, because multiple vacuum circuit breakers (vacuum circuit breakers 211, vacuum circuit breakers 221) are connected in series, sufficient voltage-resistance performance can be obtained.

[0058] In addition, in the circuit breaker 100 of this embodiment, the first and second breaking contacts 111 and 112, which are configured as vacuum circuit breakers (vacuum circuit breaker 211, vacuum circuit breaker 221), are used to finally achieve a breaking state. For this reason, the gas circuit breaker 201 configuring the energizing contact 101 is made of SF, which has high performance in insulation performance, arc extinguishing performance, etc. ６ In addition to being able to reduce gas consumption, ６ A gas having a lower greenhouse effect coefficient than gas can be used as the insulating gas. Furthermore, depending on the required current-carrying performance, the gas circuit breaker 201 can be replaced with an air circuit breaker or the like.

[0059] Therefore, in the circuit breaker 100 of this embodiment, an insulating gas with a high greenhouse effect coefficient (SF ６ In addition, the circuit breaker 100 of the present embodiment has sufficient voltage resistance and current-carrying performance even when a vacuum circuit breaker (vacuum circuit breaker 211, vacuum circuit breaker 221) is used, and therefore can be applied to electric circuits to which higher voltages are applied (electric circuits of the power transmission class).

[0060] Second Embodiment [A] Configuration of the shutoff device 100 Fig. 4 is a cross-sectional view schematically showing the configuration of the shutoff device 100 according to the second embodiment. Fig. 4 shows the shutoff device 100 in a shutoff state.

[0061] As shown in Fig. 4, the circuit breaker 100 of this embodiment differs from the first embodiment (see Fig. 2) in that, in addition to the vacuum circuit breaker 211, a gas circuit breaker 251 is accommodated inside the grounded tank 200 instead of the gas circuit breaker 201 and the vacuum circuit breaker 221. Except for this point and related matters, the circuit breaker 100 of this embodiment is the same as the first embodiment (see Fig. 2). Therefore, explanations of overlapping matters will be omitted as appropriate.

[0062] As shown in Fig. 4, in the circuit breaker 100 of this embodiment, the first breaking contact 111 is configured by a vacuum circuit breaker 211. However, in this embodiment, the energizing contact 101 and the second breaking contact 112 are configured by a gas circuit breaker 251 that switches between a closed state and an open state inside the grounded tank 200. The inside of the grounded tank 200 contains, for example, SF ６ A gas with a lower greenhouse effect potential than gas is used as the insulating gas.

[0063] As shown in Fig. 4, 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.

[0064] 5 is a cross-sectional view showing the detailed configuration of the gas circuit breaker 251 in the circuit breaker 100 according to the second embodiment. The detailed configuration of the gas circuit breaker 251 will be described below with reference to FIG. 5 in addition to FIG.

[0065] The gas circuit breaker 251 is of a puffer type, and includes an opposing unit 3 and a driving unit 4 as shown in FIG.

[0066] [A-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.

[0067] [A-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. 4).

[0068] [A-1-2] Support Portion 302 The support portion 302 includes a support ring portion 321 and a support protrusion portion 322 .

[0069] 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.

[0070] The support protrusion 322 is, for example, a rod-shaped body and is provided on the inner circumferential 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 that the gas circuit breaker fixed current-carrying shaft 253 and the opposing arc contact 331 are electrically connected (see FIG. 4 ).

[0071] [A-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 .

[0072] [A-1-3-1] Opposing Arc Contact 331 The opposing arc contact 331 is, for example, a cylindrical rod-shaped body extending in the axial direction. The opposing arc contact 331 is installed coaxially with the cooling cylinder 301, etc., on the surface of the support protrusion 322 located on the driving side DS. An end 331a of the opposing arc contact 331 located on the driving side DS has a curved surface.

[0073] [A-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.

[0074] 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.

[0075] [A-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.

[0076] [A-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 the operating mechanism 257 via an insulating rod 256, and is configured to be moved in the axial direction by the operating mechanism 257.

[0077] 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 .

[0078] The movable current-carrying shaft solid portion 411 is, for example, cylindrical.

[0079] 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.

[0080] [A-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 .

[0081] Here, the puffer cylinder 402 includes a cylinder cylindrical portion 421 and a cylinder bottom plate portion 422 .

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] [A-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.

[0087] 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.

[0088] 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 relative to 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, as will be described in detail later, 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.

[0089] [A-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.

[0090] Here, the drive-side contact portion 405 includes a drive-side arc contact 451 and a drive-side current-carrying contact 455 .

[0091] [A-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.

[0092] 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.

[0093] 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 .

[0094] Details will be described later, but the driving side arc contactor 451 is configured so that the opposing side arc contactor 331 is inserted inside it when it is in a conducting state, and an arc discharge occurs between it and the opposing side arc contactor 331 during the breaking process.

[0095] [A-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.

[0096] 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.

[0097] An end 455a of the driving-side conductive contact 455 located on the opposing side OS has, for example, a curved surface.

[0098] Although details will be described later, the driving-side conductive contact 455 is configured to be inserted into the opposing-side conductive contact 335 in a conducting state.

[0099] [A-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.

[0100] Here, the cylinder support 406 includes a cylinder support cylindrical portion 461 and a cylinder support annular portion 462 .

[0101] 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.

[0102] 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.

[0103] 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.

[0104] [A-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.

[0105] Here, the piston support 407 includes a piston support cylindrical portion 471 and a piston support annular portion 472 .

[0106] 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.

[0107] 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.

[0108] 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.

[0109] [A-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.

[0110] The insulating nozzle 500 is fixed to the puffer cylinder 402 and configured to move together with the puffer cylinder 402 and the driving side contact portion 405 etc. during the interruption process from the energized state to the open state.

[0111] 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.

[0112] The insulating nozzle 500 has a large diameter nozzle portion 510 , a small diameter nozzle portion 520 , and an inclined nozzle portion 530 .

[0113] 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.

[0114] 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.

[0115] 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.

[0116] [B] Operation of Circuit Breaker 100 FIGS. 6A, 6B, and 6C are diagrams showing the operation of the gas circuit breaker 251 in the circuit breaker 100 according to the second embodiment.

[0117] In the interruption operation of this embodiment, the current flow in the electric circuit EC is interrupted by going from the energized state (closed state, closed state) shown in Fig. 6A through the interruption process (opening process) shown in Fig. 6B and Fig. 6C in sequence to the interruption state (completely open state) shown in Fig. 5. The interruption operation is performed, for example, by operating the operation mechanisms 217 and 257 based on a control command output from a control device (not shown).

[0118] The interruption operation of this embodiment will be described below with reference to FIGS. 4, 6A, 6B, 6C, and 5 in addition to FIGS. 3A, 3B, and 1 used in the first embodiment.

[0119] [B-1] Conducted State First, in the conducted state, as shown in FIG. 3A, the conducting contact 101, the first breaking contact 111, and the second breaking contact 112 are in a closed state.

[0120] Specifically, in the energized state, the driving-side energized contact 455 and the opposing-side energized contact 335 constituting the energized contact 101 of the gas circuit breaker 251 are in contact with each other, thereby achieving a closed state. Furthermore, the driving-side arcing contact 451 and the opposing-side arcing contact 331 constituting the second breaking contact 112 are in contact with each other, thereby achieving a closed state (see FIG. 6A). Although not shown, the movable electrode 111A and the fixed electrode 111B constituting the first breaking contact 111 of the vacuum circuit breaker 211 are also in a closed state (see FIG. 4).

[0121] In this embodiment, as in the first embodiment, the current-carrying contact 101 is configured to have a smaller resistance than the first breaking contact 111 and the second breaking contact 112. Therefore, in a conducting state, a larger current flows in the current-carrying electric circuit EC1 in which the current-carrying contact 101 is provided than in the breaking electric circuit EC2 in which the first breaking contact 111 and the second breaking contact 112 are provided (see FIG. 3A).

[0122] [B-2] Breaking Process Next, in the breaking process when the current-carrying state is changed over to the breaking state, the current-carrying contact 101 is switched from the closed state to the open state as shown in FIG. 3B.

[0123] Here, in the gas circuit breaker 251, the driving side conductive contact 455 and the opposing side conductive contact 335 that constitute the conductive contact 101 are separated from each other, thereby switching to an open state (see FIG. 6B).

[0124] Specifically, in the drive side unit 4 constituting the gas circuit breaker 251, the gas circuit breaker movable current-carrying shaft 401 moves axially toward the drive side DS. As the gas circuit breaker movable current-carrying shaft 401 moves, the puffer cylinder 402, drive side contact portion 405, and insulating nozzle 500 in the drive side unit 4 move axially toward the drive side DS. As a result, the opposing side current-carrying contact 335 and the drive side current-carrying contact 455 change from a contact state to a separated state, while the opposing side arcing contact 331 and the drive side arcing contact 451 remain in contact with each other.

[0125] As a result, as in the first embodiment, the fault current flowing through the current-carrying circuit EC1 on which the current-carrying contact 101 is installed is diverted to flow through the interrupting circuit EC2 on which the first interrupting contact 111 and the second interrupting contact 112 are installed.

[0126] [B-3] Breaking State Next, in the breaking state, the first breaking contact 111 and the second breaking contact 112 are switched from the closed state to the open state as shown in Fig. 1. The first breaking contact 111 and the second breaking contact 112 are switched from the closed state to the open state, for example, simultaneously.

[0127] Here, in the vacuum circuit breaker 211, the movable electrode 111A and the fixed electrode 111B that constitute the first breaking contact 111 are switched to an open state (see FIG. 4).

[0128] In addition, 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 are separated from each other, thereby switching to an open state (see Figures 6C and 5).

[0129] Specifically, as shown in FIG. 6C, in the gas circuit breaker 251, as the gas circuit breaker movable current-carrying shaft 401 moves further toward the driving side DS, the opposing side arc contactor 331 moves from the inside to the outside of the driving side arc contactor 451, and the opposing side arc contactor 331 and the driving side arc contactor 451 change from a contact state to a separated state.

[0130] At this time, an arc discharge AR occurs between the opposing-side arcing contact 331 and the driving-side arcing contact 451 inside the insulating nozzle 500. Inside the insulating nozzle 500, the arc discharge AR heats and expands the insulating gas, causing the insulating gas to flow from inside the insulating nozzle 500 into the puffer chamber PR. In addition, the volume of the puffer chamber PR decreases as the puffer cylinder 402 slides against the puffer piston 403 as the gas circuit breaker movable current-carrying shaft 401 moves. This causes the pressure of the insulating gas to increase in the puffer chamber PR.

[0131] Then, as the distance between the opposing-side arcing contact 331 and the driving-side arcing contact 451 becomes further longer, the arc discharge AR decreases. When the arc discharge AR decreases and the pressure of the insulating gas in the puffer chamber PR becomes further higher, the inflow of insulating gas from the inside of the insulating nozzle 500 into the puffer chamber PR stops. Then, high-pressure insulating gas is released from the puffer chamber PR into the insulating nozzle 500. The insulating gas released from the puffer chamber PR flows between the insulating nozzle 500 and the driving-side arcing contact 451 and is sprayed onto the arc discharge AR. As a result, the arc discharge AR is extinguished at the current zero point.

[0132] Then, as shown in Figure 5, as the gas circuit breaker movable current-carrying shaft 401 moves further axially toward the driving side DS, the opposing side current-carrying contact 335 and the driving side current-carrying contact 455 become the farthest apart, and the opposing side arc contact 331 and the driving side arc contact 451 become the farthest apart.

[0133] At this time, the volume of the puffer chamber PR further decreases as the gas circuit breaker movable current-carrying shaft 401 moves, and more insulating gas is released from the inside of the puffer chamber PR into the inside of the insulating nozzle 500. Here, the insulating gas flows from the inside of the insulating nozzle 500 sequentially through the inside of the opposing-side conductive contact 335 and the inside of the cooling cylinder 301, and then is released from the inside of the cooling cylinder 301 to the outside. In addition, the insulating gas flows from the inside of the insulating nozzle 500 sequentially through the inside of the driving-side arcing contact 451, the inside of the movable current-carrying shaft hollow portion 412, and the inside of the piston support cylindrical portion 471, and then is released from the inside of the piston support cylindrical portion 471 to the outside. The insulating gas released from the piston support cylindrical portion 471 to the outside is released from the inside of the cylinder support 406 to the outside.

[0134] In this manner, in this embodiment, as in the first embodiment, the first breaking contact 111 and the second breaking contact 112 are switched from a closed state to an open state, thereby cutting off the flow of current in each of the current-carrying electrical circuit EC1 and the breaking electrical circuit EC2, and completing the breaking operation.

[0135] [C] Summary As described above, in the circuit breaker 100 of this embodiment, the first breaking contact 111 is configured by the vacuum circuit breaker 211, as in the first embodiment. In contrast, unlike the first embodiment, the energized contact 101 and the second breaking contact 112 are configured by the gas circuit breaker 251 that switches between a closed state and an open state inside the grounded tank 200 filled with insulating gas.

[0136] In this embodiment, the function of establishing a conducting state (see FIG. 3A) is mainly realized by the conducting contact 101 configured in the gas circuit breaker 251. In contrast, in this embodiment, the function of finally transitioning from the conducting state to the interrupting state through the interrupting process (see FIG. 3B) is realized by the first interrupting contact 111 configured in the vacuum circuit breaker 211 and the second interrupting contact 112 configured in the gas circuit breaker 251.

[0137] In the circuit breaker 100 of this embodiment, as in the first embodiment, the current-carrying contact 101 is configured as a gas circuit breaker 251, so that sufficient current-carrying performance can be obtained in the current-carrying state (see FIG. 3A ). 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 that it is possible to switch from a closed state to an open state more quickly and obtain sufficient voltage-resistance performance.

[0138] In addition, in the circuit breaker 100 of this embodiment, the first breaking contact 111 configured as the vacuum circuit breaker 211 is used to finally achieve the breaking state. For this reason, the gas circuit breaker 251 configuring the energizing contact 101 and the second breaking contact 112 is made of SF, which has high performance such as insulation performance and arc extinguishing performance. ６ In addition to being able to reduce gas consumption, ６ A gas having a lower greenhouse effect coefficient than gas can be used as the insulating gas. Furthermore, depending on the required current-carrying performance, the gas circuit breaker 251 can be replaced with an air circuit breaker or the like.

[0139] Therefore, in the circuit breaker 100 of this embodiment, an insulating gas with a high greenhouse effect coefficient (SF ６ In addition, the circuit breaker 100 of the present embodiment has sufficient voltage resistance and current carrying performance even when the vacuum circuit breaker 211 is used, and therefore can be applied to electric circuits to which higher voltages are applied (electric circuits of the power transmission class).

[0140] In addition, immediately after the current zero point during the interruption operation, the vacuum circuit breaker 211 has better withstand voltage performance than the gas circuit breaker 251. After several milliseconds have passed since the current zero point, the gas circuit breaker 251 has better withstand voltage performance than the vacuum circuit breaker 211. Therefore, in this embodiment, when performing the interruption operation, first, the vacuum circuit breaker 211 provides better withstand voltage performance, and then the gas circuit breaker 251 provides better withstand voltage performance.

[0141] Third Embodiment [A] Configuration of Vacuum Circuit Breaker 211 FIG. 7 is a cross-sectional view schematically showing the configuration of a vacuum circuit breaker 211 in a circuit breaker 100 according to a third embodiment.

[0142] As shown in Fig. 7, the vacuum circuit breaker 211 of this embodiment differs from the first embodiment (see Fig. 2) in that it includes a vacuum circuit breaker housing vessel 700. Except for this point and related matters, the circuit breaker 100 of this embodiment is the same as the first embodiment (see Fig. 2). Therefore, explanations of overlapping matters will be omitted where appropriate.

[0143] 7 , the vacuum circuit breaker housing vessel 700 houses the vacuum circuit breaker 211 inside the grounded tank 200. The vacuum circuit breaker housing vessel 700 is made of an insulating material and is installed so as to cover the entire vacuum circuit breaker 211.

[0144] Here, the vacuum circuit breaker fixed current-carrying shaft 213 and the vacuum circuit breaker movable current-carrying shaft 214 pass through the vacuum circuit breaker housing vessel 700. Sealing materials 219a are interposed between the vacuum circuit breaker housing vessel 700 and the vacuum circuit breaker fixed current-carrying shaft 213, and between the vacuum circuit breaker housing vessel 700 and the vacuum circuit breaker movable current-carrying shaft 214, and the inside of the vacuum circuit breaker housing vessel 700 is sealed.

[0145] The pressure inside the vacuum circuit breaker housing vessel 700 is lower than the pressure inside the grounded tank 200 and higher than the pressure inside the vacuum vessel 212. The internal space of the vacuum circuit breaker housing vessel 700 and the internal space of the bellows 215 that constitutes the vacuum circuit breaker 211 are in communication with each other.

[0146] [B] Summary As described above, in this embodiment, the vacuum circuit breaker housing vessel 700 houses the vacuum circuit breaker 211 inside the grounded tank 200. As described above, the pressure inside the vacuum circuit breaker housing vessel 700 is lower than the pressure inside the grounded tank 200 and higher than the pressure inside the vacuum vessel 212. Therefore, in this embodiment, even when the movable electrode 111A moves at high speed as the vacuum circuit breaker movable current-carrying shaft 214 slides, causing the bellows 215 to expand and contract at high speed, damage to the bellows 215 can be effectively prevented.

[0147] [C] Modification FIG. 8 is a cross-sectional view that schematically shows the configuration of a vacuum circuit breaker 211 in the circuit breaker 100 according to a modification of the third embodiment.

[0148] In this modification, the vacuum circuit breaker housing vessel 700 is installed so as to cover a part of the vacuum circuit breaker 211, as shown in FIG.

[0149] Here, the vacuum interrupter housing vessel 700 includes a portion through which the vacuum interrupter fixed current-carrying shaft 213 passes and a portion through which one of the pair of flanges 212b, the flange 212b on which the bellows 215 is installed, passes. Sealing materials 219a are interposed between the vacuum interrupter housing vessel 700 and the vacuum interrupter fixed current-carrying shaft 213, and between the vacuum interrupter housing vessel 700 and the flange 212b, and the interior of the vacuum interrupter housing vessel 700 is sealed. In this modification, the vacuum interrupter housing vessel 700 may be made of a metal material.

[0150] The pressure inside the vacuum circuit breaker housing vessel 700 is lower than the pressure inside the grounded tank 200 and higher than the pressure inside the vacuum vessel 212. The internal space of the vacuum circuit breaker housing vessel 700 and the internal space of the bellows 215 that constitutes the vacuum circuit breaker 211 are in communication with each other. Therefore, in this modified example, the same effects as those of the above embodiment can be obtained.

[0151] In the above embodiment, the vacuum circuit breaker housing vessel 700 houses the vacuum circuit breaker 211 in the first embodiment (see FIG. 2 ), but the present invention is not limited to this. In the first embodiment (see FIG. 2 ), the vacuum circuit breaker housing vessel 700 may be configured to house the vacuum circuit breaker 221. Also, in the second embodiment (see FIG. 4 ), the vacuum circuit breaker housing vessel 700 may be configured to house the vacuum circuit breaker 211.

[0152] <Fourth embodiment> [A] Configuration of the interrupter 100 Fig. 9 is a cross-sectional view schematically showing the configuration of the interrupter 100 according to the fourth embodiment. Fig. 9 shows the interrupter 100 in a disconnecting state.

[0153] As shown in Fig. 9, the interrupting device 100 of this embodiment includes a shield 800, unlike the second embodiment (see Fig. 4). Except for this point and related matters, the interrupting device 100 of this embodiment is similar to the second embodiment (see Fig. 4). Therefore, explanations of overlapping matters will be omitted as appropriate.

[0154] As shown in FIG. 9 , the shield 800 is installed inside the grounded tank 200 so as to be interposed between the vacuum circuit breaker 211 and the gas circuit breaker 251 .

[0155] Specifically, the shield 800 is located between the vacuum circuit breaker 211 and the gas circuit breaker 251, closer to the gas circuit breaker 251 than the support part SP made of an insulating material. The shield 800 is, for example, ring-shaped, and is installed so that the vacuum circuit breaker fixed current-carrying shaft 213 passes through the center. The outer diameter of the shield 800 is larger than the outer diameter of the porcelain tube 212a that constitutes the vacuum vessel 212 of the vacuum circuit breaker 211.

[0156] The shield 800 is made of a metal material and is installed so as to maintain an insulating state between the shield 800 and the gas circuit breaker 251. In order to prevent dielectric breakdown between the shield 800 and the conductive material provided around the shield 800, the end of the shield 800 is configured to have a curved shape.

[0157] [B] Summary As described in the second embodiment, in the gas circuit breaker 251, an arc discharge AR occurs between the opposing-side arcing contact 331 and the driving-side arcing contact 451 during the interruption process when the gas circuit breaker 251 transitions from a conducting state to an interrupted state (see FIG. 6C ). The arc discharge AR is extinguished by spraying insulating gas. Therefore, if metal vapor generated by the arc discharge AR travels from an open portion of the gas circuit breaker 251 (for example, the inside of the cooling cylinder 301, etc.; see FIG. 6C ) toward the vacuum circuit breaker 211 and adheres to the insulators that make up the vacuum circuit breaker 211, etc., there is a possibility that the insulation performance will be reduced.

[0158] However, in this embodiment, the shield 800 prevents the metal vapor generated by the arc discharge AR from progressing toward the vacuum circuit breaker 211. Therefore, the circuit breaker 100 of this embodiment can effectively suppress the deterioration of insulation performance.

[0159] In the above embodiment, the case where the shield 800 is provided in the second embodiment (see FIG. 4) has been described, but this is not limiting. The shield 800 may also be provided in the third embodiment (see FIG. 7) in the same manner.

[0160] Fifth Embodiment [A] Configuration of the shutoff device 100 Fig. 10 is a cross-sectional view schematically showing the configuration of the shutoff device 100 according to the fifth embodiment. Fig. 10 shows the shutoff device 100 in a shutoff state.

[0161] As shown in Fig. 10 , the circuit breaker 100 of this embodiment differs from the fourth embodiment (see Fig. 9 ) in that the shield 800 is not installed and in the relative positioning of the vacuum circuit breaker 211 and the gas circuit breaker 251. Except for this point and related matters, the circuit breaker 100 of this embodiment is the same as the fourth embodiment. Therefore, explanations of overlapping matters will be omitted as appropriate.

[0162] In this embodiment, as shown in FIG. 10 , the vacuum circuit breaker movable current-carrying shaft 214 and the vacuum circuit breaker fixed current-carrying shaft 213 that constitute the vacuum circuit breaker 211 are not aligned coaxially with the gas circuit breaker movable current-carrying shaft 401 and the gas circuit breaker fixed current-carrying shaft 253 that constitute the gas circuit breaker 251, but are aligned along different axes.

[0163] [B] Summary As explained in the fourth embodiment, during the interruption process, metal vapor generated by the arc discharge AR travels from the open part of the gas circuit breaker 251 (for example, the inside of the cooling cylinder 301, etc.; see Figure 6C) toward the vacuum circuit breaker 211, and if it adheres to the insulators that make up the vacuum circuit breaker 211, etc., there is a possibility that the insulating performance will be reduced.

[0164] However, in this embodiment, the vacuum circuit breaker 211 is not located in the direction in which the metal vapor generated by the arc discharge AR travels, and therefore no insulators are present in the direction in which the metal vapor travels. Therefore, the circuit breaker 100 of this embodiment can effectively suppress the deterioration of the insulation performance.

[0165] Sixth Embodiment [A] Configuration of the shutoff device 100 Fig. 11 is a cross-sectional view schematically showing the configuration of the shutoff device 100 according to the sixth embodiment. Fig. 11 shows the shutoff device 100 in a shutoff state.

[0166] As shown in Fig. 11 , the circuit breaking device 100 of this embodiment differs from that of the fifth embodiment (see Fig. 10 ) in the configuration of the ground tank 200. Except for this point and related matters, the circuit breaking device 100 of this embodiment is the same as that of the fifth embodiment. Therefore, explanations of overlapping matters will be omitted as appropriate.

[0167] 11 , the grounded tank 200 includes a first grounded tank portion 200A, a second grounded tank portion 200B, and a communication passage 203. The interiors of the first grounded tank portion 200A and the second grounded tank portion 200B are in communication with each other via the communication passage 203, and the pressures inside the first grounded tank portion 200A and the second grounded tank portion 200B are the same. The first grounded tank portion 200A accommodates a vacuum circuit breaker 211 therein. The second grounded tank portion 200B accommodates a gas circuit breaker 251 therein.

[0168] In addition, in this embodiment, as shown in FIG. 11 , the vacuum circuit breaker movable conductive shaft 214 and the vacuum circuit breaker fixed conductive shaft 213 that constitute the vacuum circuit breaker 211 are not aligned coaxially with the gas circuit breaker movable conductive shaft 401 and the gas circuit breaker fixed conductive shaft 253 that constitute the gas circuit breaker 251, but are aligned along different axes.

[0169] [B] Summary As explained in the fifth embodiment, during the interruption process, metal vapor generated by the arc discharge AR travels from the open part of the gas circuit breaker 251 (for example, the inside of the cooling cylinder 301, etc.; see Figure 6C) toward the vacuum circuit breaker 211, and if it adheres to the insulators that make up the vacuum circuit breaker 211, etc., there is a possibility that the insulating performance will be reduced.

[0170] However, in this embodiment, the vacuum circuit breaker 211 is not located in the direction in which the metal vapor generated by the arc discharge AR travels, and therefore no insulators are present in the direction in which the metal vapor travels. Therefore, the circuit breaker 100 of this embodiment can effectively suppress the deterioration of the insulation performance.

[0171] [C] Modification Fig. 12 is a cross-sectional view that schematically shows the configuration of the interrupter 100 according to a modification of the sixth embodiment. Fig. 12 shows the interrupter 100 in the interrupting state.

[0172] 12 , in the circuit breaker 100 of this modification, the vacuum circuit breaker movable current-carrying shaft 214 and the vacuum circuit breaker fixed current-carrying shaft 213 that constitute the vacuum circuit breaker 211 are aligned coaxially with the gas circuit breaker movable current-carrying shaft 401 and the gas circuit breaker fixed current-carrying shaft 253 that constitute the gas circuit breaker 251. However, in this modification, as in the above embodiment, the vacuum circuit breaker 211 is housed inside the first grounded tank section 200A, and the gas circuit breaker 251 is housed inside the second grounded tank section 200B. Therefore, in this modification, as in the above embodiment, it is possible to easily prevent metal vapor generated by the arc discharge AR from adhering to the insulators that constitute the vacuum circuit breaker 211, etc.

[0173] In this modified example, the vacuum circuit breaker fixed current-carrying shaft 213 and the gas circuit breaker fixed current-carrying shaft 253 are electrically connected using a conductor in an insulator G201 installed outside the first grounded tank section 200A and a conductor in an insulator G202 installed outside the second grounded tank section 200B.

[0174] In this modification, in consideration of the progress of metal vapor generated by the arc discharge AR, it is preferable that the end of the communication path 203 (gas piping) located on the second grounded tank unit 200B side does not face the open part of the gas circuit breaker 251. Similarly, it is preferable that the inner surface of the insulator G202 installed outside the second grounded tank unit 200B does not face the open part of the gas circuit breaker 251.

[0175] <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.

[0176] 3: opposing side unit, 4: driving side unit, 100: circuit breaker, 101: current-carrying contact, 101A: gas circuit breaker movable electrode, 101B: gas circuit breaker fixed electrode, 111: first circuit breaker contact, 111A: movable electrode, 111B: fixed electrode, 112: second circuit breaker contact, 121A: movable electrode, 121B: fixed electrode, 200: ground tank, 200A: first ground tank part, 200B: second ground tank part, 201: gas circuit breaker, 202: insulating gas container, 203: communicating path, 206: insulating rod, 207: operating mechanism, 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, 218: Arc shield, 219a: Sealing material, 221: Vacuum circuit breaker, 222: Vacuum vessel, 222a: Insulating tube, 222b: Flange, 223: Vacuum circuit breaker fixed current-carrying shaft, 224: Vacuum circuit breaker movable current-carrying shaft, 225: Bellows, 226: Insulating rod, 227: Operating mechanism, 228: Arc shield, 251: Gas circuit breaker, 253: Gas circuit breaker fixed current-carrying shaft, 256: Insulating rod, 257: Operating 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, 403: 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, 461: cylinder support cylindrical portion, 462: cylinder support annular portion, 471: piston support cylindrical portion, 472: piston support annular portion, 500: insulating nozzle, 510: nozzle large diameter portion, 520: nozzle small diameter portion, 530: nozzle inclined portion, 530a: end, 700: vacuum circuit breaker housing, 800: shield, AR: arc discharge, DS: drive side, EC: electric circuit, EC1: current-carrying electric circuit, EC1a: electric wire, EC1b: electric wire, EC2: interrupting electric circuit, EC2a: electric wire, EC2b: electric wire, G201: insulator, G202: insulator, H412: first ventilation hole,H422a: rod through hole, H422b: exhaust hole, H461: second ventilation hole, H471: third ventilation hole, OS: opposite side, PR: puffer chamber, S500: nozzle internal space, SL101A: sliding part, SL214: sliding part, SL224: sliding part, SP: support part,

Claims

1. A circuit breaker for switching an electric circuit from a conducting state to a cut-off state, comprising: an energized contact; a first cut-off contact connected in parallel with the energized contact; and a second cut-off contact connected in parallel with the energized contact and in series with the first cut-off contact, wherein the resistance of the energized contact is smaller than the resistance of the first cut-off contact and the resistance of the second cut-off contact, wherein in the conducting state, the energized contact, the first cut-off contact, and the second cut-off contact are in a closed state and a larger current flows in the energized contact than in the first cut-off contact and the second cut-off contact, wherein in the cut-off state, the first cut-off contact and the second cut-off contact are configured to switch from a closed state to an open state after the energized contact switches from a closed state to an open state, and wherein at least one of the first cut-off contact and the second cut-off contact is constituted by a vacuum circuit breaker that switches between a closed state and an open state inside a vacuum container.

2. A ground tank, the ground tank housing, as the vacuum circuit breakers, a first vacuum circuit breaker constituting the first interrupting contact and a second vacuum circuit breaker constituting the second interrupting contact, the first vacuum circuit breaker including, as the first interrupting contact, a first movable electrode provided on a first vacuum circuit breaker moving current shaft and a first fixed electrode provided on a first vacuum circuit breaker fixed current shaft aligned coaxially with the first vacuum circuit breaker moving current shaft, and configured to be in a closed state when the first movable electrode and the first fixed electrode are in a contact state and to be in an open state when the first movable electrode and the first fixed electrode are separated from each other, the second vacuum circuit breaker including: a second movable electrode provided on a second vacuum circuit breaker moving current shaft and a second fixed electrode provided on a second vacuum circuit breaker fixed current shaft aligned coaxially with the second vacuum circuit breaker moving current shaft, as the second breaking contact, and configured to be in a closed state when the second movable electrode and the second fixed electrode are in a contact state, and to be in an open state when the second movable electrode and the second fixed electrode are in a separated state.

3. The circuit breaker according to claim 2, wherein the current-carrying contact is constituted by a gas circuit breaker that switches between a closed state and an open state in an atmosphere filled with insulating gas, and the grounding tank accommodates the gas circuit breaker therein.

4. The circuit breaker according to claim 1, wherein the first circuit breaker contact is constituted by the vacuum circuit breaker, the vacuum circuit breaker is housed in a grounded tank filled with insulating gas, and the conductive contact and the second circuit breaker contact are constituted by gas circuit breakers which switch between a closed state and an open state inside the grounded tank.

5. The vacuum circuit breaker includes a movable electrode mounted on a vacuum circuit breaker movable current shaft, and a fixed electrode mounted on a vacuum circuit breaker fixed current shaft aligned coaxially with the vacuum circuit breaker movable current shaft; the gas circuit breaker includes a gas circuit breaker movable current shaft on which a driving side arc contact and a driving side current contact are mounted, and a gas circuit breaker fixed current shaft aligned coaxially with the gas circuit breaker movable current shaft and on which an opposing side arc contact and an opposing side current contact are mounted; the current-carrying contacts are configured to be in a closed state when the driving side current contact and the opposing side current contact are in a contact state, and in an open state when the driving side current contact and the opposing side current contact are in a separated state; the first breaking contact is configured to be in a closed state when the movable electrode and the fixed electrode are in a contact state, and in an open state when the movable electrode and the fixed electrode are in a separated state; the second breaking contact is The circuit breaker according to claim 4, wherein the circuit breaker is configured to be in a closed state when the driving side arc contact and the opposing side arc contact are in a contact state, and to be in an open state when the driving side arc contact and the opposing side arc contact are in a separated state.

6. The circuit breaker according to claim 4, further comprising a vacuum circuit breaker housing vessel that houses the vacuum circuit breaker inside the grounded tank, the pressure inside the vacuum circuit breaker housing vessel being lower than the pressure inside the grounded tank and higher than the pressure inside the vacuum vessel.

7. The circuit breaker according to claim 4, further comprising a shield disposed inside said earth tank so as to be interposed between said vacuum circuit breaker and said gas circuit breaker.

8. The circuit breaker according to claim 5, wherein the vacuum circuit breaker movable current-carrying shaft and the vacuum circuit breaker fixed current-carrying shaft are aligned along an axis different from that of the gas circuit breaker movable current-carrying shaft and the gas circuit breaker fixed current-carrying shaft.

9. The circuit breaker according to claim 4, wherein the grounded tank has a first grounded tank portion that houses the vacuum circuit breaker therein, and a second grounded tank portion that houses the gas circuit breaker therein, and the interiors of the first grounded tank portion and the second grounded tank portion are connected via a communication passage.

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