Gas insulated switchgear

Abstract

Provided is a gas insulated switchgear (1) that is capable of reducing the influence of a by-product (90) and easily realizing miniaturization.　A pressure accumulation unit (30), an operation mechanism (40), and a gas nozzle (50) are provided, and a by-product (90), which is generated inside a tank (10) by execution of a cut-off operation of shifting to a cut-off state from an inputting state, adheres to the inside of the tank (10). The pressure accumulation unit (30) is configured to execute a pressure accumulation operation of increasing, in a pressure accumulation chamber into which an insulation gas is introduced from the inside of the tank (10), the pressure of the insulation gas. The operation mechanism (40) is configured to operate a contact part (20) and operate the pressure accumulation unit (30). The gas nozzle (50) is configured to execute an injection operation of injecting, from the pressure accumulation chamber to the inside of the tank (10), the insulation gas having increased pressure by the execution of the pressure accumulation operation, to thereby remove the by-product (90) adhering to the inside of the tank (10).

Description

Gas-insulated switchgear

[0001] An embodiment of the present invention relates to a gas-insulated switchgear.

[0002] Gas insulated switchgear (GIS) is installed in substations and power plants. The gas insulated switchgear has an insulating gas sealed inside a tank, and the tank contains an energizing bus, a circuit breaker (CB), a disconnector (DS), and the like.

[0003] When a disconnector or circuit breaker interrupts a current flowing through a busbar, it separates a pair of electrodes inside the tank, resulting in the interruption of the current. At this time, an arc discharge occurs between the pair of electrodes, generating by-products. These by-products include, for example, decomposition products of insulating gas and metallic materials scattered by melting of the electrodes, which adhere to and accumulate inside the tank. As a result, the insulation performance of the gas-insulated switchgear may be degraded.

[0004] For this reason, gas-insulated switchgear must be designed taking into account the degradation of insulation performance due to by-products, and therefore it is not easy to achieve miniaturization of the gas-insulated switchgear.

[0005] Various techniques have been proposed to suppress the occurrence of problems caused by by-products.

[0006] JP 2016-62679 JP 2015-226436

[0007] However, in the past, it was not easy to effectively prevent the occurrence of problems caused by by-products, and it was therefore difficult to fully achieve the miniaturization of gas-insulated switchgear.

[0008] Therefore, an object of the present invention is to provide a gas-insulated switchgear that can mitigate the effects of by-products and can be easily downsized.

[0009] A gas-insulated switchgear according to an embodiment includes a tank and a contact unit. The tank is filled with insulating gas. The contact unit accommodates a fixed electrode and a movable electrode within the tank, and is configured to enter a closed state when the movable electrode comes into contact with the fixed electrode and enter a closed state when the movable electrode separates from the fixed electrode. The gas-insulated switchgear according to an embodiment includes a pressure accumulator, an operation mechanism, and a gas nozzle. By-products generated within the tank during a breaking operation that switches from a closed state to a closed state adhere to the interior of the tank. The pressure accumulator is configured to perform a pressure accumulating operation in which insulating gas is introduced from within the tank into a pressure accumulator chamber and the pressure of the insulating gas is increased in the pressure accumulator chamber. The operation mechanism is configured to operate the contact unit and the pressure accumulator. The gas nozzle is configured to perform an injection operation in which insulating gas, the pressure of which has increased during the pressure accumulating operation, is injected from the pressure accumulator chamber into the interior of the tank, thereby removing by-products that have adhered to the interior of the tank.

[0010] FIG. 1A is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to the first embodiment. FIG. 1B is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to the first embodiment. FIG. 2 is a diagram schematically showing the configuration of the pressure accumulator 30 in the gas-insulated switchgear 1 according to the first embodiment. FIG. 3 is a flowchart showing the operation of the gas-insulated switchgear 1 according to the first embodiment. FIG. 4A is a diagram showing a state when a breaking operation (ST10) is performed in the gas-insulated switchgear 1 according to the first embodiment. FIG. 4B is a diagram showing a state when a pressure accumulating operation (ST20) is performed in the gas-insulated switchgear 1 according to the first embodiment. FIG. 4C is a diagram showing a state when an injection operation (ST30) is performed in the gas-insulated switchgear 1 according to the first embodiment. FIG. 4D is a diagram showing a state after the injection operation (ST30) has been performed in the gas-insulated switchgear 1 according to the first embodiment. FIG. 5 is a flowchart showing the operation of the gas-insulated switchgear 1 according to a modified example of the first embodiment. FIG. 6 is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to a second embodiment. Fig. 7 is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to a third embodiment. Fig. 8 is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to a fourth embodiment. Fig. 9A is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to a fifth embodiment. Fig. 9B is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to the fifth embodiment. Fig. 10 is a diagram schematically showing the configuration of the gas-insulated switchgear 1 according to a sixth embodiment.

[0011] First Embodiment [A] Configuration of Gas-Insulated Switchgear 1 FIGS. 1A and 1B are diagrams schematically showing the configuration of a gas-insulated switchgear 1 according to a first embodiment.

[0012] 1A, the longitudinal direction is the vertical direction z, the horizontal direction is the first horizontal direction x, and the direction perpendicular to the paper surface is the second horizontal direction y perpendicular to the vertical direction z and the first horizontal direction x. FIG. 1A shows a partial cross section of a plane (xz plane) along the vertical direction z and the first horizontal direction x.

[0013] 1B, the longitudinal direction is the vertical direction z, the horizontal direction is the second horizontal direction y, and the direction perpendicular to the paper surface is the first horizontal direction x. Fig. 1B is a partial cross section of a plane (yz plane) along the vertical direction z and the second horizontal direction y, and shows the X1-X1 portion in Fig. 1A.

[0014] 1A and 1B, the gas-insulated switchgear 1 includes a tank 10, a contact unit 20, a pressure accumulator 30, an operation mechanism 40, a gas nozzle 50, and a control unit 80. Each of the components of the gas-insulated switchgear 1 will be described in turn.

[0015] 1A and 1B, the tank 10 is, for example, a cylindrical tubular body, and is installed so that its axial direction (tube axis direction) is aligned with, for example, the first horizontal direction x. The tank 10 is made of a metal material and is electrically connected to a reference potential point (such as the ground).

[0016] The tank 10 is a pressure vessel whose internal space is filled with an insulating gas having a pressure higher than that of the outside. The insulating gas is, for example, SF ６ It's gas.

[0017] The internal space of the tank 10 is partitioned by, for example, spacers 11a and 11b. The spacers 11a and 11b are formed using an insulating material. In the internal space of the tank 10, the spacer 11a supports a conductor EC1a (a current-carrying bus bar), and the spacer 11b supports a conductor EC1b (a current-carrying bus bar). The conductors EC1a and EC1b are, for example, rod-shaped bodies and are installed coaxially with the tube axis of the tank 10 so as to extend along the first horizontal direction x.

[0018] [A-2] Contact Unit 20 As shown in Figures 1A and 1B, the contact unit 20 is housed in the internal space of the tank 10. The contact unit 20 has a shield electrode 21A (fixed electrode), a shield electrode 21B, and a current-carrying electrode 22 (movable electrode), and constitutes a disconnector.

[0019] [A-2-1] Shield Electrode 21A In the contact portion 20, the shield electrode 21A is, for example, disk-shaped and is installed at the end of the conductor EC1a that is located on the conductor EC1b side. The shield electrode 21A is electrically connected to the conductor EC1a. A recess T21 is formed on the surface of the shield electrode 21A that is located on the conductor EC1b side. The shield electrode 21A is supported by a support member (not shown) in the internal space of the tank 10. Alternatively, the shield electrode 21A may be supported by the conductor EC1a in the internal space of the tank 10.

[0020] [A-2-2] Shield Electrode 21B In the contact portion 20, the shield electrode 21B is, for example, disk-shaped and is arranged to be aligned with the shield electrode 21A in the first horizontal direction x (axial direction of the tank 10). The shield electrode 21B is installed at the end of the conductor EC1b that is located on the conductor EC1a side and is electrically connected to the conductor EC1b. The shield electrode 21B is supported by a support member (not shown) in the internal space of the tank 10. Alternatively, the shield electrode 21B may be supported by the conductor EC1b in the internal space of the tank 10. A through hole H22 is formed in the shield electrode 21B. The through hole H22 is coaxial with the tube axis of the tank 10 and is arranged along the first horizontal direction x.

[0021] [A-2-2] Current-carrying electrode 22 In the contact portion 20, the current-carrying electrode 22 is, for example, a rod-shaped body and is arranged alongside the shield electrode 21A in the axial direction (first horizontal direction x) of the tank 10. The current-carrying electrode 22 is housed inside a through-hole H22 formed in the shield electrode 21B. The current-carrying electrode 22 moves within the through-hole H22 along the first horizontal direction x.

[0022] 1A, when the current-carrying electrode 22 contacts the shield electrode 21A, the conductors EC1a and EC1b are electrically connected to each other, and the contact portion 20 is in a closed state (current-carrying state, closed-contact state). Specifically, when the end of the current-carrying electrode 22 is received in the recess T21 formed in the shield electrode 21A, the shield electrode 21A and the current-carrying electrode 22 come into contact with each other, and the contact portion 20 is in a closed state.

[0023] Although not shown in FIG. 1A, when the current-carrying electrode 22 separates from the shield electrode 21A, the contact portion 20 becomes electrically disconnected between the conductors EC1a and EC1b, and enters a disconnected state (open state).

[0024] Details will be described later, but when the contact portion 20 performs a disconnecting operation to change from an on state to an off state, by-products are generated inside the tank 10, and these generated by-products adhere to the inside of the tank 10.

[0025] The shield electrodes 21A and 21B are provided in the contact portion 20 to maintain a favorable electric field distribution around the contact portion 20 when the disconnection state is established. In addition, the shield electrodes 21A and 21B may be configured to prevent the current-carrying electrode 22 from being worn down due to an arc discharge that occurs when the current-carrying electrode 22 is closed during the closing operation from the disconnection state to the closing state.

[0026] [A-3] Pressure Accumulator 30 As shown in FIG. 1A, the pressure accumulator 30 is provided outside the tank 10 and is configured to perform a pressure accumulation operation to increase the pressure of the insulating gas.

[0027] FIG. 2 is a diagram schematically showing the configuration of the pressure accumulator 30 in the gas-insulated switchgear 1 according to the first embodiment.

[0028] 2, the pressure accumulator 30 has, for example, a cylinder 31 and a piston 32, with the piston 32 housed inside the cylinder 31. In the pressure accumulator 30, the cylinder 31 includes a pressure accumulator chamber S30. The pressure accumulator chamber S30 communicates with the gas nozzle 50 via a gas pipe P60, and a control valve V60 is installed in the gas pipe P60.

[0029] As will be described in detail later, in the pressure accumulator 30, insulating gas is introduced from the inside of the tank 10 into the pressure accumulator chamber S30 via the gas nozzle 50 and the control valve V60. Then, in the pressure accumulator 30, a pressure accumulating operation is performed using the piston 32 to increase the pressure of the insulating gas in the pressure accumulator chamber S30.

[0030] [A-4] Operation Mechanism 40 As shown in FIG. 1A , the operation mechanism 40 includes a contact portion operating rod 41 and is configured to operate the contact portion 20 using the contact portion operating rod 41. For example, the contact portion operating rod 41 that constitutes the operation mechanism 40 is provided with a pinion gear (not shown), and the current-carrying electrode 22 that constitutes the contact portion 20 is provided with a rack gear (not shown). When the pinion gear (not shown) of the contact portion operating rod 41 rotates around a rotation axis that extends along the radial direction, the rack gear of the current-carrying electrode 22 moves along the first horizontal direction x. The contact portion operating rod 41 is operated, for example, using the biasing force of a spring. Alternatively, the contact portion operating rod 41 may be configured to be operated by a motor.

[0031] 1A, the operation mechanism 40 includes a pressure accumulator operating rod 43, and is configured to operate the pressure accumulator 30 using the pressure accumulator operating rod 43. For example, as shown in FIG. 2, the pressure accumulator operating rod 43 constituting the operation mechanism 40 is connected to the piston 32 constituting the pressure accumulator 30, and the pressure accumulator operating rod 43 drives the piston 32, thereby reducing the volume of the pressure accumulator chamber S30 and performing the pressure accumulation operation. The pressure accumulator operating rod 43 is operated using, for example, a hydraulic mechanism. Alternatively, the pressure accumulator operating rod 43 may be configured to be operated using an electromagnetic repulsion mechanism, or may be configured to be operated using a spring, a motor, and a link mechanism.

[0032] In addition, in the operation mechanism 40, the device for operating the contact unit 20 (first operation unit) and the device for operating the pressure accumulator unit 30 (second operation unit) may be housed in different housings so that they are physically separated from each other. Alternatively, in the operation mechanism 40, the device for operating the contact unit 20 (first operation unit) and the device for operating the pressure accumulator unit 30 (second operation unit) may be housed together in a single housing so that they are physically close to each other.

[0033] 1A and 1B, the gas nozzle 50 is installed in the tank 10. As described above, the gas nozzle 50 communicates with the pressure accumulator chamber S30 via the gas pipe P60 (see FIG. 2).

[0034] As will be described in detail later, the gas nozzle 50 performs an injection operation of injecting the insulating gas, the pressure of which has increased as a result of the pressure accumulation operation being performed in the pressure accumulator 30, from the pressure accumulation chamber S30 into the inside of the tank 10.

[0035] [A-6] Control Unit 80 The control unit 80 includes a computing unit (not shown) and a memory device (not shown), and is configured so that the computing unit performs arithmetic processing using a program stored in the memory device, thereby controlling the operation of each unit constituting the gas-insulated switchgear 1. Here, the control unit 80 controls the operation of the control valve V60 and the operation of the operating mechanism 40 based on various commands.

[0036] [B] Operation of Gas-Insulated Switchgear 1 FIG. 3 is a flow chart showing the operation of the gas-insulated switchgear 1 according to the first embodiment.

[0037] In the gas-insulated switchgear 1 of this embodiment, a breaking operation (ST10), a pressure accumulation operation (ST20), and an injection operation (ST30) are sequentially performed as shown in Fig. 3. Each operation will be described in turn.

[0038] [B-1] Shut-off Operation (ST10) The shut-off operation (ST10) is performed by the operation mechanism 40 operating the contact unit 20 using the contact unit operating rod 41 based on a command output from the control unit 80 (see FIG. 1A). The shut-off operation (ST10) is performed, for example, when an accident occurs.

[0039] FIG. 4A is a diagram showing a state when a breaking operation (ST10) is performed in the gas-insulated switchgear 1 according to the first embodiment.

[0040] 4A, by performing the breaking operation (ST10), the conducting electrode 22 separates from the shield electrode 21A in the contact unit 20. This causes the contact unit 20 to change from the closed state to the broken state.

[0041] When the interruption operation (ST10) is performed, an arc discharge (not shown) occurs between the shield electrode 21A and the current-carrying electrode 22 at the contact unit 20. The arc discharge causes the insulating gas to decompose inside the tank 10, generating decomposition products as by-products 90. Furthermore, at the contact unit 20, the arc discharge melts the shield electrode 21A, the current-carrying electrode 22, and the like, generating the melted metal material as by-products 90. The by-products 90 then adhere to, for example, the contact unit 20 and accumulate inside the tank 10. For example, at the contact unit 20, the by-products 90 adhere to the upper surface portions of the shield electrodes 21A and 21B.

[0042] [B-2] Pressure accumulation operation (ST20) The pressure accumulation operation (ST20) is performed by the operating mechanism 40 operating the pressure accumulation unit 30 using the pressure accumulation unit operating rod 43 based on a command output from the control unit 80 (see FIG. 1A).

[0043] FIG. 4B is a diagram showing a state when the pressure accumulation operation (ST20) is performed in the gas-insulated switchgear 1 according to the first embodiment.

[0044] As shown in Fig. 4B, before the pressure accumulation operation (ST20) is performed, the control unit 80 controls the operation of the control valve V60 so that the control valve V60 changes from the open state (see Fig. 4A) to the closed state. As a result, the insulating gas introduced into the pressure accumulation chamber S30 from inside the tank 10 is sealed in the pressure accumulation chamber S30. Thereafter, the pressure accumulation operation (ST20) is performed, and the pressure of the insulating gas in the pressure accumulation chamber S30 increases (see Fig. 2).

[0045] [B-3] Injection Operation (ST30) The injection operation (ST30) is performed by the control unit 80 controlling the operation of the control valve V60 based on a command output from the control unit 80 (see FIG. 1A).

[0046] FIG. 4C is a diagram showing a state when the injection operation (ST30) is performed in the gas-insulated switchgear 1 according to the first embodiment.

[0047] 4C, when the injection operation (ST30) is performed, the control unit 80 controls the operation of the control valve V60 so that the control valve V60 changes from a closed state (see FIG. 4B) to an open state. As a result, the insulating gas whose pressure has increased in the accumulator chamber S30 due to the execution of the pressure accumulation operation (ST20) is injected from the gas nozzle 50 into the tank 10.

[0048] Here, the gas nozzle 50 sprays insulating gas toward the by-products 90 adhering to the upper surface portions of the shield electrode 21A and the shield electrode 21B.

[0049] FIG. 4D is a diagram showing a state after the injection operation (ST30) has been performed in the gas-insulated switchgear 1 according to the first embodiment.

[0050] By-products 90 (see FIG. 4C ) adhering to the upper surface portions of shield electrode 21A and shield electrode 21B are removed by performing the ejection operation (ST30) and fall into the interior of tank 10 as shown in FIG. 4D . Here, by-products 90 move to a portion of the bottom surface of tank 10 where the electric field is low. This restores the insulating performance.

[0051] [C] Summary As described above, in the gas-insulated switchgear 1 of the present embodiment, by-products 90 are generated inside the tank 10 by performing the interruption operation (ST10), and the by-products 90 adhere to the shield electrodes 21A and 21B. At this time, in the present embodiment, the accumulator 30 performs a pressure accumulation operation (ST20). In the pressure accumulation operation (ST20), the pressure of the insulating gas increases in the accumulator chamber S30. Then, the gas nozzle 50 performs a spraying operation (ST30). In the spraying operation (ST30), the insulating gas whose pressure has increased due to the execution of the pressure accumulation operation (ST20) is sprayed from the accumulator chamber S30. As a result, in the present embodiment, the by-products 90 adhering to the shield electrodes 21A and 21B inside the tank 10 are removed (see FIGS. 4A to 4D ).

[0052] Therefore, in the gas-insulated switchgear 1 of this embodiment, it is possible to suppress a deterioration in insulation performance due to the by-products 90. As a result, in this embodiment, it is not necessary to increase the size of the gas-insulated switchgear 1 in consideration of a deterioration in insulation performance due to the by-products 90, and therefore it is possible to easily achieve a reduction in the size of the gas-insulated switchgear 1.

[0053] In this embodiment, as described above, the control unit 80 controls the operation of the control valve V60 and the operation of the operating mechanism 40 so that the pressure accumulation operation (ST20) and the injection operation (ST30) are performed sequentially after the shutoff operation (ST10) (see FIG. 3). In this embodiment, the pressure accumulation operation (ST20) and the injection operation (ST30) are performed sequentially, so that it is possible to prevent the insulating gas whose pressure has increased in the pressure accumulation operation (ST20) from leaking from the pressure accumulation chamber S30 before the injection operation (ST30) is performed. Therefore, in this embodiment, it is possible to accurately perform the injection operation (ST30).

[0054] [D] Modifications [D-1] Modifications In the above embodiment, a case has been described in which the shut-off operation (ST10) is performed, followed by the pressure accumulation operation (ST20) and the injection operation (ST30) in sequence (see FIG. 3), but this is not limited to this.

[0055] FIG. 5 is a flowchart showing the operation of the gas-insulated switchgear 1 according to the modified example of the first embodiment.

[0056] As shown in FIG. 5, in this modified example, the control unit 80 may control the operation of the control valve V60 and the operation of the operating mechanism 40 so that the pressure accumulation operation (ST20) is performed before the shutoff operation (ST10) is performed, and the injection operation (ST30) is performed after the shutoff operation (ST10) is performed.

[0057] In this modification, the breaking operation (ST10) is performed in a state in which the pressure of the insulating gas in the accumulator chamber S30 has increased due to the execution of the pressure accumulation operation (ST20). Therefore, in this modification, the time between the execution of the breaking operation (ST10) and the execution of the injection operation (ST30) can be shortened, and the by-products 90 can be efficiently removed from the gas-insulated switchgear 1.

[0058] [D-2] Other Modifications In the above embodiment, the gas nozzle 50 is installed above the shield electrode 21A and the shield electrode 21B to remove by-products 90 adhering to the upper surface portions of the shield electrode 21A and the shield electrode 21B, but this is not limiting. The gas nozzle 50 may be installed in other portions to remove by-products 90 adhering to portions other than the shield electrode 21A and the shield electrode 21B. For example, the gas nozzle 50 may be installed to remove by-products 90 adhering to the spacers 11a and 11b. In this case, it is preferable that the gas nozzle 50 be configured to inject the insulating gas into locations where the electric field is relatively strong and which may become the starting point of dielectric breakdown or where by-products are likely to accumulate.

[0059] 1A of the tank 10. The gas pipe P60 is used to draw a vacuum to remove atmospheric air during manufacturing and installation, and may also be used to fill the tank with new insulating gas.

[0060] The control valve V60 may be configured so that its opening and closing operations are performed by the operation mechanism 40. The control unit 80 may be installed outside the tank 10 (in a control room or the like), or may be housed inside a housing (not shown) that constitutes the operation mechanism 40.

[0061] In the pressure accumulator 30, the size of the pressure accumulator chamber S30 is preferably designed taking into consideration the required amount of insulating gas to be sprayed from the gas nozzle 50. A plurality of pressure accumulators 30 may be provided in each of a plurality of compartments in the tank 10, and in this case, the sizes of the pressure accumulator chambers S30 in the plurality of pressure accumulators 30 may differ from one another.

[0062] In the injection operation (ST30), the insulating gas may be injected once or multiple times. In the above embodiment, the injection operation (ST30) is performed each time the interruption operation (ST10) is performed once. However, the injection operation (ST30) may be controlled to be performed each time the interruption operation (ST10) is performed multiple times. The injection operation (ST30) may be configured to be performed by the control unit 80 based on data detected in the interruption operation (ST10). For example, the timing at which the injection operation (ST30) is performed and the number of times the injection operation (ST30) is performed may be controlled according to the transition of the energy or current value of the arc discharge.

[0063] The insulating gas is SF ６ The insulating gas may be other than SF ６ It may also be an alternative gas with a lower greenhouse effect than SF gas. ６ Alternative gases with a smaller greenhouse effect than gases include, for example, nitrogen, oxygen, carbon dioxide, argon, helium, dry air, as well as other artificial gases (e.g., C ４ F ７ N(F-nitrile), C ５ F １０ Generally, naturally occurring gases such as nitrogen, oxygen, carbon dioxide, dry air, and mixtures thereof are used as the SF ６ The breakdown field is smaller than that of gases, so removing the by-products is useful for miniaturizing devices.

[0064] In this embodiment, the form of the disconnector constituting the contact unit 20 is merely an example and can be changed to various forms. For example, although the case where the disconnector is a single-phase type has been described, it may also be a three-phase integrated type. Furthermore, a grounding switch may also be provided, and the disconnector and the grounding switch may be provided in the same gas compartment or in different gas compartments.

[0065] Second Embodiment [A] Configuration of Gas-Insulated Switchgear 1 FIG. 6 is a diagram schematically showing the configuration of a gas-insulated switchgear 1 according to a second embodiment.

[0066] 6, similarly to FIG. 1A, a partial cross section of a plane (xz plane) along the vertical direction z and the first horizontal direction x is shown.

[0067] As shown in Fig. 6, in this embodiment, unlike the first embodiment (see Fig. 1A), there is a plurality of gas nozzles 50 instead of a single one. Except for this point and related points, this embodiment is similar to the above-described embodiment. Therefore, explanations of overlapping points will be omitted as appropriate.

[0068] In the gas-insulated switchgear 1 of this embodiment, for example, two gas nozzles 50 are provided, and the two gas nozzles 50 are arranged side by side in the axial direction (first horizontal direction x) of the tank 10. Specifically, the gas nozzle 50A is provided above the shield electrode 21A that constitutes the contact unit 20, and the gas nozzle 50B is provided above the shield electrode 21B that constitutes the contact unit 20.

[0069] In this embodiment, when the injection operation (ST30) is performed, the control valve V60 is changed from a closed state to an open state. As a result, the insulating gas whose pressure has increased in the pressure accumulator chamber S30 due to the execution of the pressure accumulator operation (ST20) is simultaneously injected into the tank 10 from the gas nozzle 50A and the gas nozzle 50B. As a result, by-products (not shown) adhering above the shield electrode 21A and above the shield electrode 21B in the contact portion 20 are removed over a wide area.

[0070] [B] Summary As described above, in this embodiment, multiple gas nozzles 50 are installed so as to be aligned in the axial direction of the tank 10 (first horizontal direction x), so that by-products can be removed more efficiently than in the first embodiment.

[0071] Therefore, in this embodiment, it is possible to more effectively prevent the deterioration of insulation performance due to by-products, and it is possible to more easily achieve miniaturization of the gas-insulated switchgear 1, etc.

[0072] Third Embodiment [A] Configuration of Gas-Insulated Switchgear 1 FIG. 7 is a diagram schematically showing the configuration of a gas-insulated switchgear 1 according to a third embodiment.

[0073] 7, similar to FIG. 1B, a partial cross section of a plane (yz plane) along the vertical direction z and the second horizontal direction y is shown.

[0074] 7, unlike the first embodiment (see FIG. 1A), this embodiment has a plurality of gas nozzles 50 instead of a single one. Except for this and related points, this embodiment is similar to the above-described embodiment. Therefore, explanations of overlapping points will be omitted as appropriate.

[0075] In the gas-insulated switchgear 1 of this embodiment, for example, three gas nozzles 50 are provided, and the three gas nozzles 50 are arranged in a line in the circumferential direction of the tank 10. Specifically, above the contact portion 20, gas nozzle 50A, gas nozzle 50B, and gas nozzle 50C are arranged at equal intervals.

[0076] In this embodiment, when the injection operation (ST30) is performed, the control valve V60 is changed from a closed state to an open state. As a result, the insulating gas whose pressure has increased in the accumulator chamber S30 due to the execution of the pressure accumulation operation (ST20) is simultaneously injected into the tank 10 from each of the three gas nozzles 50. That is, the insulating gas is injected from gas nozzle 50A along the vertical direction z. In addition, the insulating gas is injected from gas nozzle 50B and gas nozzle 50C along directions inclined with respect to the vertical direction z. As a result, by-products (not shown) adhering above the contact portion 20 are removed over a wide area.

[0077] [B] Summary As described above, in this embodiment, multiple gas nozzles 50 are arranged in a circumferential direction of the tank 10, making it possible to remove by-products more efficiently than in the first embodiment.

[0078] Therefore, in this embodiment, it is possible to more effectively prevent the deterioration of insulation performance due to by-products, and it is possible to more easily achieve miniaturization of the gas-insulated switchgear 1, etc.

[0079] Fourth Embodiment [A] Configuration of Gas-Insulated Switchgear 1 FIG. 8 is a diagram schematically showing the configuration of a gas-insulated switchgear 1 according to a fourth embodiment.

[0080] 8, similarly to FIG. 7, a partial cross section of a plane (yz plane) along the vertical direction z and the second horizontal direction y is shown.

[0081] As shown in Fig. 8, in this embodiment, unlike the third embodiment (see Fig. 7), there is a plurality of control valves V60 instead of a single one. Except for this point and related points, this embodiment is similar to the above-described embodiment. Therefore, explanations of overlapping points will be omitted as appropriate.

[0082] In the gas-insulated switchgear 1 of this embodiment, the number of control valves V60 is, for example, three, similar to the gas nozzles 50. The three control valves V60 are provided for the three gas nozzles 50, respectively. Specifically, the control valve V60A is provided corresponding to the gas nozzle 50A, the control valve V60B is provided corresponding to the gas nozzle 50B, and the control valve V60C is provided corresponding to the gas nozzle 50C.

[0083] In this embodiment, when the injection operation (ST30) is performed, the three control valves V60 are changed from a closed state to an open state, whereby the insulating gas whose pressure has increased in the accumulator chamber S30 due to the execution of the pressure accumulation operation (ST20) is injected into the tank 10 from each of the three gas nozzles 50.

[0084] In the execution of the injection operation (ST30), the three control valves V60 change from the closed state to the open state at different times.

[0085] Specifically, first, the control valve V60A is controlled so that insulating gas is injected from gas nozzle 50A, and a pressure-accumulating operation (ST20) and an injection operation (ST30) are performed. Next, the control valve V60B is controlled so that insulating gas is injected from gas nozzle 50B, and a pressure-accumulating operation (ST20) and an injection operation (ST30) are performed. Next, the control valve V60C is controlled so that insulating gas is injected from gas nozzle 50C, and a pressure-accumulating operation (ST20) and an injection operation (ST30) are performed. Note that the injection order is not particularly important; for example, the control valve V60B may be controlled so that insulating gas is injected from gas nozzle 50B first.

[0086] As a result, by-products (not shown) adhering above the contact portion 20 are removed over a wide area.

[0087] [B] Summary As described above, in this embodiment, insulating gas is sprayed from each of the multiple gas nozzles 50 using each of the multiple control valves V60. As a result, even if by-products (not shown) are scattered by one spraying operation (ST30) and adhere again above the contact portion 20, the by-products (not shown) that have adhered again above the contact portion 20 can be removed by the next spraying operation (ST30). Therefore, in this embodiment, by-products can be removed more efficiently than in the third embodiment.

[0088] Therefore, in this embodiment, it is possible to more effectively prevent the deterioration of insulation performance due to by-products, and it is possible to more easily achieve miniaturization of the gas-insulated switchgear 1, etc.

[0089] Fifth Embodiment [A] Configuration of Gas-Insulated Switchgear 1 FIGS. 9A and 9B are diagrams schematically showing the configuration of a gas-insulated switchgear 1 according to a fifth embodiment.

[0090] 9A shows a partial cross section of a plane (xz plane) along the vertical direction z and the first horizontal direction x, similar to FIG. 4D.

[0091] FIG. 9B is a partial cross section taken along a plane (yz plane) along the vertical direction z and the second horizontal direction y, and shows the X2-X2 portion in FIG. 9A.

[0092] 9A and 9B, unlike the first embodiment (see FIG. 4D), this embodiment is provided with a trap 15. Except for this and related points, this embodiment is similar to the above-described embodiment. Therefore, explanations of overlapping points will be omitted as appropriate.

[0093] In this embodiment, the trap 15 is provided in a lower portion of the tank 10 in the vertical direction z, as shown in FIGS. 9A and 9B.

[0094] Here, the trap 15 includes, for example, a tubular portion 151 and a bottom plate portion 153. The tubular portion 151 has, for example, a cylindrical shape, and the tube axis of the tubular portion 151 is aligned along the vertical direction z. The bottom plate portion 153 has, for example, a disk shape, and is provided at a lower portion of the tubular portion 151 in the vertical direction z.

[0095] The trap 15 is installed to collect the by-products 90. Specifically, when the injection operation (ST30) is performed, the by-products 90 that fall inside the tank 10 are collected in the trap 15.

[0096] [B] Summary As described above, in this embodiment, the by-products 90 are collected in the trap 15. The by-products 90 collected in the trap 15 remain in the trap 15 and are unlikely to scatter again.

[0097] Therefore, in this embodiment, it is possible to more effectively prevent the deterioration of insulation performance due to the by-products 90, and it is possible to more easily achieve a reduction in size of the gas-insulated switchgear 1, etc.

[0098] [C] Modifications The bottom plate portion 153 may be configured to be detachable from the tubular portion 151 so as to function as a lid. In this case, inspection work and the like can be performed by opening the bottom plate portion 153, which serves as the lid.

[0099] The trap 15 may also be provided with an adsorbent capable of adsorbing decomposition gases generated by decomposition of the insulating gas during the interruption operation (ST10).

[0100] Alternatively, the trap 15 may be configured to suppress the local generation of an electric field. The depth and size of the trap 15 may be designed in advance to be equal to or less than the levitation electric field of the by-products 90, which is determined by examining the levitation electric field.

[0101] Sixth Embodiment [A] Configuration of Gas-Insulated Switchgear 1 FIG. 10 is a diagram schematically showing the configuration of a gas-insulated switchgear 1 according to a sixth embodiment.

[0102] 1A, FIG. 10 shows a partial cross section of a plane (xz plane) along the vertical direction z and the first horizontal direction x.

[0103] In the first embodiment (see FIG. 1A ) described above, the contact unit 20 constitutes a disconnector. In contrast, in this embodiment, as shown in FIG. 10 , the contact unit 20 constitutes a puffer-type circuit breaker, not a disconnector. Except for this point and related points, this embodiment is the same as the above embodiment. Therefore, descriptions of overlapping points will be omitted as appropriate.

[0104] In this embodiment, the contact portion 20 has a fixed contactor 210 (fixed electrode) and a movable contactor 220 (movable electrode), as shown in FIG.

[0105] [A-1] Fixed Contact 210 In the contact portion 20, the fixed contact 210 includes a fixed arc contact 211 and a fixed current-carrying contact 215, and is electrically connected to a conductor EC1a extending in the vertical direction z.

[0106] [A-1-1] Fixed Arc Contact 211 Of the fixed contacts 210, the fixed arc contact 211 is, for example, a cylindrical rod-like body that extends in the axial direction and is installed coaxially with the tank 10, for example.

[0107] [A-1-2] Fixed current-carrying contactor 215 Of the fixed contactors 210, the fixed current-carrying contactor 215 is, for example, a cylindrical tubular body, and is, for example, installed coaxially with the fixed arc contactor 211, and houses the fixed arc contactor 211 inside.

[0108] A cooling cylinder 301 is installed via a support portion 302 at the other end of the fixed conductive contact 215 opposite to the one end located on the movable contact 220 side.

[0109] [A-1-3] Cooling cylinder 301 The cooling cylinder 301 is, for example, a cylindrical tubular body made of a metal material and is electrically connected to the conductor EC1a. The cooling cylinder 301 is, for example, supported by the conductor EC1a.

[0110] [A-1-4] Support portion 302 The support portion 302 is, for example, an annular ring-shaped body and is configured to have a protrusion that protrudes inward from the annular ring-shaped body. The fixed arc contact 211 is installed on the protrusion of the support portion 302. The support portion 302 includes a portion formed using an insulating material to electrically insulate the fixed arc contact 211 from the fixed current-carrying contact 215, and also includes a portion formed using a conductive material to electrically connect the fixed arc contact 211 and the conductor EC1a.

[0111] [A-2] Movable Contactor 220 In the contact portion 20, the movable contactor 220 includes a movable arcing contactor 221 and a movable current-carrying contactor 225, and is electrically connected to a conductor EC1b extending in the vertical direction z. The movable contactor 220 is configured to slide in the axial direction by an operating mechanism 40.

[0112] [A-2-1] Movable Arcing Contact 221 Of the movable contacts 220, the movable arcing contact 221 is, for example, a cylindrical tubular body, and is installed coaxially with the fixed arcing contact 211.

[0113] The movable arc contactor 221 is fixed to the movable current-carrying shaft 401 and is electrically connected to the movable current-carrying shaft 401. The movable arc contactor 221 is also connected to the contact portion operating rod 41 via the movable current-carrying shaft 401, and is configured to slide in the axial direction by the operating mechanism 40.

[0114] [A-2-2] Movable current-carrying contactor 225 Of the movable contactor 220, the movable current-carrying contactor 225 is, for example, an annular ring-shaped body, and is installed coaxially with the fixed arc contactor 211. The movable current-carrying contactor 225 includes a portion that houses the movable arc contactor 221 therein.

[0115] The movable current-carrying contact 225 is fixed to the puffer cylinder 402 so as to surround the movable arc contact 221, and is electrically connected to the puffer cylinder 402. The movable current-carrying contact 225, together with the movable arc contact 221, is configured to slide in the axial direction by the operating mechanism 40.

[0116] [A-2-3] Movable Conductor Shaft 401 The movable conductive shaft 401 is, for example, a rod-shaped body including a cylindrical portion, and is disposed coaxially with the fixed arc contact 211 .

[0117] [A-2-4] Puffer Cylinder 402 The puffer cylinder 402 is fixed to the movable current-carrying shaft 401, and is configured to slide in the axial direction together with the movable current-carrying shaft 401 by the operation mechanism 40. The puffer cylinder 402 includes, for example, a cylindrical tubular portion, and is installed coaxially with the fixed arcing contact 211. One end of the cylindrical tubular portion of the puffer cylinder 402 is closed with a disk-shaped bottom plate, and the movable current-carrying shaft 401 passes through the center of the bottom plate.

[0118] [A-2-5] Puffer Piston 403 The puffer piston 403 is, for example, an annular ring-shaped body, and is installed coaxially with the fixed arcing contact 211. The puffer piston 403 is slidably housed inside the puffer cylinder 402. In addition, the movable current-carrying shaft 401 slidably passes through the puffer piston 403.

[0119] The puffer piston 403 defines the interior of the puffer cylinder 402 in the axial direction. Within the puffer cylinder 402, the space located closer to the movable contact 220 than the puffer piston 403 is a puffer chamber PR. The volume of the puffer chamber PR changes as the puffer cylinder 402 moves axially together with the 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. The insulating gas whose pressure has increased in the puffer chamber PR is released from the puffer chamber PR via an exhaust hole (not shown) formed in the puffer cylinder 402.

[0120] [A-2-5] Cylinder support 406 The cylinder support 406 includes, for example, a cylindrical tubular portion and is installed coaxially with the fixed arc contact 211. One end of the cylindrical tubular portion of the cylinder support 406 is closed with a disk-shaped bottom plate, and the puffer cylinder 402 is provided so as to slide axially in the center of the bottom plate. The cylinder support 406 is fixed to the tank 10 and is electrically connected to the puffer cylinder 402 and the conductor EC1b.

[0121] [A-2-6] Piston support 407 The piston support 407 includes, for example, a cylindrical tubular portion, and is installed coaxially with the fixed arcing contact 211. The piston support 407 is fixed to the cylinder support 406 inside the cylinder support 406, and supports the puffer piston 403 at its end. The movable current-carrying shaft 401 passes through the inside of the piston support 407.

[0122] [A-2-7] Nozzle 500 The puffer cylinder 402 is further provided with a nozzle 500. The nozzle 500 is a cylindrical tubular body, and is installed inside the tank 10 coaxially with the fixed arc contact 211. The nozzle 500 is made of an insulating material.

[0123] The nozzle 500 accommodates the fixed arcing contact 211 and the movable arcing contact 221. The nozzle 500 is configured so that when an arc discharge occurs between the fixed arcing contact 211 and the movable arcing contact 221 during the breaking operation (ST10), insulating gas is introduced into the nozzle 500 from the puffer chamber PR and the insulating gas is sprayed outward.

[0124] [B] Operation of Gas-Insulated Switchgear 1 The operation of the gas-insulated switchgear 1 of this embodiment will be described.

[0125] In this embodiment, as in the first embodiment, for example, a cutoff operation (ST10), a pressure accumulation operation (ST20), and an injection operation (ST30) are executed in sequence (see FIG. 3).

[0126] [B-1] Breaking operation (ST10) In the breaking operation (ST10) of this embodiment, the fixed contact 210 and the movable contact 220 are in contact with each other in an on state (see Figure 10), and are changed to a breaking state (not shown) in which the fixed contact 210 and the movable contact 220 are separated from each other.

[0127] Specifically, when the contact portion 20 is in the closed state, the movable current contactor 225 and the fixed current contactor 215 are in contact with each other, and the movable arc contactor 221 and the fixed arc contactor 211 are in contact with each other (see Figure 10).

[0128] During the breaking process when the contact unit 20 transitions from the closed state to the broken state, the contact unit operating rod 41 is operated by the operating mechanism 40. Although not shown in the figure, this causes the movable current-carrying shaft 401, the puffer cylinder 402, the movable contactor 220, and the nozzle 500 to move axially toward the operating mechanism 40.

[0129] In the breaking process, first, the movable current-carrying contact 225 and the fixed current-carrying contact 215 of the movable contactor 220 change from a contact state to a separated state. Next, the movable arcing contactor 221 and the fixed arcing contactor 211 change from a contact state to a separated state. As a result, an arc discharge occurs between the fixed arcing contactor 211 and the movable arcing contactor 221 inside the nozzle 500.

[0130] At this time, the volume of the puffer chamber PR decreases as the puffer cylinder 402 slides relative to the puffer piston 403 in accordance with the movement of the movable current-carrying shaft 401. As a result, the pressure of the insulating gas introduced from the nozzle 500 increases in the puffer chamber PR. Then, the high-pressure insulating gas is released from the puffer chamber PR into the nozzle 500. The insulating gas released from the puffer chamber PR flows between the nozzle 500 and the movable arcing contact 221 and is sprayed onto the arc discharge, thereby extinguishing the arc discharge.

[0131] Then, as the movable current-carrying shaft 401 moves further, the fixed current-carrying contact 215 and the movable current-carrying contact 225 become the most distant from each other, and the fixed arcing contact 211 and the movable arcing contact 221 become the most distant from each other, thereby bringing the contact unit 20 into an open state.

[0132] In this embodiment, as in the first embodiment, by performing the shutoff operation (ST10), by-products are generated inside the tank 10, and the generated by-products adhere to the inside of the tank 10.

[0133] [B-2] Pressure Accumulation Operation (ST20), Injection Operation (ST30) After the cutoff operation (ST10) is performed, the pressure accumulation operation (ST20) and the injection operation (ST30) are performed in the same manner as in the first embodiment.

[0134] 10 , in this embodiment, the gas nozzle 50 is provided below the contact portion 20 in the vertical direction z. Therefore, by performing the spraying operation (ST30), by-products (not shown) adhering below the contact portion 20 inside the tank 10 are removed.

[0135] [C] Summary As described above, in the gas-insulated switchgear 1 of this embodiment, as in the first embodiment, by-products (not shown) adhering to the inside of the tank 10 are removed by performing the injection operation (ST30). This makes it possible to prevent degradation of insulation performance due to the by-products. As a result, in this embodiment, it is not necessary to increase the size of the gas-insulated switchgear 1 in consideration of degradation of insulation performance due to the by-products, and therefore it is possible to easily achieve miniaturization of the gas-insulated switchgear 1.

[0136] [D] Modifications This embodiment can appropriately adopt the configurations described in the other embodiments above. For example, the pressure accumulation operation (ST20) may be performed before the shutoff operation (ST10), and the injection operation (ST30) may be performed after the shutoff operation (ST10) (see FIG. 5). Also, multiple gas nozzles 50 and control valves V60 may be provided (see FIGS. 6, 7, and 8). Furthermore, a trap 15 may be provided (see FIGS. 9A and 9B).

[0137] In the present embodiment, the form of the circuit breaker constituting the contact unit 20 is merely an example and can be changed to various forms. For example, in the above embodiment, the circuit breaker is of a horizontal type, but it may naturally be of a vertical type. Also, the circuit breaker is of a single-phase type, but it may be of a three-phase integrated type.

[0138] <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.

[0139] 1: gas insulated switchgear, 10: tank, 11a: spacer, 11b: spacer, 15: trap, 20: contact portion, 21A: shield electrode (fixed electrode), 21B: shield electrode, 22: current-carrying electrode (movable electrode), 30: pressure accumulator, 31: cylinder, 32: piston, 40: operation mechanism, 41: contact portion operating rod, 43: pressure accumulator operating rod, 50: gas nozzle, 50A: gas nozzle, 50B: gas nozzle, 50C: gas nozzle, 80: control portion, 90: by-product, 151: tubular portion, 153: bottom plate portion, 210: fixed contactor (fixed electrode), 211: fixed arc contactor , 215: fixed current-carrying contact, 220: moving contact (movable electrode), 221: moving arc contact, 225: moving current-carrying contact, 301: cooling cylinder, 302: support portion, 401: moving current-carrying shaft, 402: puffer cylinder, 403: puffer piston, 406: cylinder support, 407: piston support, 500: nozzle, H22: through hole, P60: gas pipe, PR: puffer chamber, S30: pressure accumulator chamber, ST10: shut-off operation, ST20: pressure accumulator operation, ST30: injection operation, T21: recess, V60: control valve, V60A: control valve, V60B: control valve, V60C: control valve

Claims

1. A gas-insulated switchgear comprising: a tank filled with an insulating gas therein; a contact portion in which a fixed electrode and a movable electrode are accommodated inside the tank, and which is configured such that when the movable electrode contacts the fixed electrode, it is in a closed state, and when the movable electrode separates from the fixed electrode, it is in an open state; and a by-product generated inside the tank adheres inside the tank when performing a breaking operation from the closed state to the open state. A pressure accumulating portion configured to introduce the insulating gas from inside the tank into a pressure accumulating chamber and perform a pressure accumulating operation to increase the pressure of the insulating gas in the pressure accumulating chamber; an operating mechanism configured to operate the pressure accumulating portion in addition to operating the contact portion; and a gas nozzle configured to remove the by-product adhering inside the tank by performing an injection operation of injecting the insulating gas whose pressure has increased by performing the pressure accumulating operation from the pressure accumulating chamber into the tank.

2. A gas-insulated switchgear according to claim 1, further comprising: a control valve provided in a gas pipe interposed between the gas nozzle and the pressure accumulating portion; and a control portion configured to control the operation of the control valve and the operation of the operating mechanism, wherein the control portion controls the operation of the operating mechanism to perform the pressure accumulating operation in a state where the operation of the control valve is controlled such that the control valve changes from an open state to a closed state, and then controls the operation of the control valve such that the control valve changes from the closed state to the open state, thereby performing the injection operation.

3. The gas-insulated switchgear according to claim 2, wherein the control portion controls the operation of the control valve and the operation of the operating mechanism to sequentially perform the pressure accumulating operation and the injection operation after performing the breaking operation.

4. The gas-insulated switchgear according to claim 2, wherein the control portion controls the operation of the control valve and the operation of the operating mechanism to perform the pressure accumulating operation before performing the breaking operation and perform the injection operation after performing the breaking operation.

5. The tank is a tubular body, the contact portion is provided such that the fixed electrode and the movable electrode are arranged in the axial direction of the tank, the gas nozzles are plural, and the plural gas nozzles are installed so as to be arranged in the axial direction. The gas-insulated switchgear according to claim 1.

6. The tank is a tubular body, the contact portion is provided such that the fixed electrode and the movable electrode are arranged in the axial direction of the tank, the gas nozzles are plural, and the plural gas nozzles are installed so as to be arranged in the circumferential direction of the tank. The gas-insulated switchgear according to claim 1.

7. It has control valves provided in the gas piping intervening between the gas nozzles and the accumulator portion, the control valves are plural, and each of the plural control valves is installed in each of the plural gas nozzles. The gas-insulated switchgear according to claim 6.

8. The tank includes a trap for collecting the by-product in a lower portion in the vertical direction. The gas-insulated switchgear according to claim 1.

9. The contact portion constitutes a circuit breaker. The gas-insulated switchgear according to claim 1.

10. The contact portion constitutes a disconnector. The gas-insulated switchgear according to claim 1.

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