Gas insulated switchgear

Abstract

The gas-insulated switchgear (50) includes a fixed-side electrode portion (52) having a fixed-side contactor (5b) installed inside a grounded tank (1) filled with insulating gas, a puffer cylinder (92), a puffer piston (91) installed inside the puffer cylinder (92), a conductor rod (14) fixed to the puffer piston (91), and a movable-side contactor (5a) fixed to the conductor rod (14). The movable-side electrode portion (51) is movably installed inside the grounded tank (1) and blows insulating gas inside the puffer chamber (32) toward the fixed-side contactor (5b) in an interrupting operation. The movable-side electrode portion (51) is also provided with a cylindrical fixed-side frame (16) supporting the fixed-side electrode portion (52), a fixed-side insulating support member (10) supporting the fixed-side frame (16), and an inner lid (39) attached to the fixed-side frame (16) and closing an opening at an end of the fixed-side frame (16) that leads to the fixed-side insulating support member (10).

Description

[Technical field]

[0001] The present disclosure relates to a gas-insulated switchgear that interrupts a current in a grounded tank filled with an insulating gas. [Background technology]

[0002] Conventionally, when interrupting high voltage current, a puffer-type gas-insulated switchgear is used, which interrupts the current in a cylindrical grounded tank filled with insulating gas. The puffer-type gas-insulated switchgear blows a gas flow onto the arc generated between the fixed contact and the moving contact when interrupting the current, thereby cooling and extinguishing the arc. In the puffer-type gas-insulated switchgear, a puffer cylinder is provided around the moving contact, and a puffer piston linked to the moving contact pushes the insulating gas in the puffer cylinder out of the puffer cylinder from a nozzle connected to the puffer cylinder during an interruption operation. The insulating gas pushed out of the puffer cylinder from the nozzle becomes a gas flow and is blown onto the arc generated between the fixed contact and the moving contact.

[0003] Inside the ground tank, the fixed contact is supported by a cylindrical frame. The frame is fixed to a cylindrical insulating support member and supported inside the ground tank so that the fixed contact is located on the central axis.

[0004] When the current is interrupted, the gas flow that is blown onto the arc becomes hot by absorbing the heat from the arc. After passing through the fixed contact, the gas flow, now at a high temperature, enters the inside of the frame and is blown onto the insulating support member. Because the insulating support member is made of plastic that contains carbon, when the hot gas flow is blown onto it, the part onto which the gas flow is blown becomes carbonized, resulting in a decrease in insulating performance.

[0005] Patent Document 1 discloses a gas-insulated switchgear having a structure in which the insulating support member is a solid cone shape and the frame is supported above the central axis of the grounding tank. In the gas-insulated switchgear disclosed in Patent Document 1, the insulating support member is not present in front of the nozzle that sprays the gas flow, so the gas flow is not sprayed onto the insulating support member. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-118476 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the gas-insulated switchgear disclosed in Patent Document 1, the gas flow that has absorbed the heat of the arc and has become hot passes under the insulating support member, so the hot gas flow comes into contact with the insulating support member. Therefore, although carbonization of the insulating support member can be suppressed compared to when the hot gas flow is blown onto the insulating support member, there is a problem that it cannot be prevented.

[0008] The present disclosure has been made in consideration of the above, and aims to provide a gas-insulated switchgear in which a high-temperature gas flow is prevented from coming into contact with an insulating support member to which a frame supporting a fixed contact is fixed. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the gas-insulated switchgear according to the present disclosure includes a grounded tank whose end is closed by a removable lid and filled with insulating gas, a fixed electrode unit having a fixed contactor installed inside the grounded tank, and a movable electrode unit having a puffer cylinder, a puffer piston installed in the puffer cylinder, a conductor rod fixed to the puffer piston, and a movable contactor fixed to the conductor rod, which is movably installed inside the grounded tank and blows insulating gas in a puffer chamber, which is a space formed between the puffer cylinder and the puffer piston, toward the fixed contactor in a breaking operation in which the movable contactor transitions from a closed state in which the movable contactor is in contact with the fixed contactor to an open state in which the movable contactor is separated from the fixed contactor. The gas-insulated switchgear includes a cylindrical fixed frame that supports the fixed electrode unit, a fixed insulating support member that supports the fixed frame, and an inner lid that is attached to the fixed frame and closes an opening at an end of the fixed frame that leads to the fixed insulating support member. Effect of the Invention

[0010] According to the present disclosure, it is possible to obtain an advantageous effect of a gas-insulated switchgear in which a high-temperature gas flow is prevented from coming into contact with an insulating support member to which a frame supporting a fixed contact is fixed. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a gas-insulated switchgear according to a first embodiment in a closed state; [Diagram 2] 1 is a cross-sectional view of a gas-insulated switchgear according to a first embodiment in an open state; [Diagram 3] FIG. 1 is an enlarged view of a fixed portion between a fixed-side frame and an inner cover of a gas-insulated switchgear according to a first embodiment; [Figure 4] FIG. 1 is a diagram showing an example of a gas flow blown out from a nozzle in a gas-insulated switchgear according to the first embodiment; [Diagram 5] FIG. 1 is a diagram showing an example of a gas flow blown out from a nozzle in a gas-insulated switchgear according to a modification of the first embodiment. [Figure 6]FIG. 1 is a diagram showing a state in which a fixed-side cover of a gas-insulated switchgear according to the first embodiment has been removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas-insulated switchgear according to an embodiment will be described in detail below with reference to the drawings.

[0013] Embodiment 1 FIG. 1 is a cross-sectional view of the gas-insulated switchgear according to the first embodiment in a closed state. FIG. 2 is a cross-sectional view of the gas-insulated switchgear according to the first embodiment in an open state. The gas-insulated switchgear 50 according to the first embodiment includes a cylindrical ground tank 1, a switching unit 4 having a movable electrode portion 51 and a fixed electrode portion 52, and a movable outer conductor 34 and a fixed outer conductor 36 disposed in a pair of bushings 22 extending above the ground tank 1. In the gas-insulated switchgear 50 according to the first embodiment, the ground tank 1 and the bushings 22 are integrally formed to form a sealed container in which insulating gas is sealed. The ground tank 1 is, for example, cylindrical, but the cross-sectional shape of the ground tank 1 is not limited to a perfect circle.

[0014] A lid 3a is removably attached to the end of the movable side of the grounded tank 1, and a lid 3b is removably attached to the end of the fixed side of the grounded tank 1. The lid 3a is disk-shaped with a hole formed in the center. The lid 3b is disk-shaped without a hole. In the arrangement direction of the movable side electrode part 51 and the fixed side electrode part 52, the direction from the fixed side electrode part 52 to the movable side electrode part 51 is called the "movable side", and the direction from the movable side electrode part 51 to the fixed side electrode part 52 is called the "fixed side". In Figs. 1 and 2, the movable side electrode part 51 and the fixed side electrode part 52 are aligned in the left-right direction of the paper, so the left side of the paper is the movable side and the right side is the fixed side.

[0015] The gas-insulated switchgear 50 has a cylindrical movable-side frame 8 connected to the lower end of the movable-side outer conductor 34, and a cylindrical fixed-side frame 16 connected to the lower end of the fixed-side outer conductor 36. The movable-side frame 8 and the fixed-side frame 16 are formed of a conductive material. The movable-side frame 8 and the fixed-side frame 16 are, for example, cylindrical, but the cross-sectional shapes of the movable-side frame 8 and the fixed-side frame 16 are not limited to being perfect circles.

[0016] The movable side frame 8 is supported inside the grounded tank 1 by a cylindrical movable side insulating support member 17. Furthermore, the fixed side frame 16 is supported inside the grounded tank 1 by a cylindrical fixed side insulating support member 10. The movable side insulating support member 17 and the fixed side insulating support member 10 are, for example, cylindrical, but the cross-sectional shapes of the movable side insulating support member 17 and the fixed side insulating support member 10 are not limited to being perfect circles. Furthermore, the movable side insulating support member 17 and the fixed side insulating support member 10 do not have to be cylindrical, and may be, for example, rod-shaped, as long as they can support the movable side frame 8 and the fixed side frame 16 inside the grounded tank 1.

[0017] The movable electrode section 51 includes a cylindrical puffer cylinder 92, a puffer piston 91 installed in the puffer cylinder 92, a conductor rod 14 having a smaller diameter than the puffer cylinder 92 and fixed to the puffer piston 91, a movable contact 5a fixed to the conductor rod 14, a cylindrical movable shield 35 surrounding the movable contact 5a from the outer circumferential direction of the grounded tank 1, and a nozzle 11 arranged around the movable contact 5a. The conductor rod 14 is connected to an insulating rod 12 connected to a shaft 6 of an operating device (not shown) installed outside the grounded tank 1 to operate the movable contact 5a. The puffer cylinder 92 is fixed to the conductor rod 14. The movable shield 35 is installed at the end of the puffer cylinder 92. The puffer piston 91 is fixed to the movable frame 8. The puffer piston 91 surrounds the conductor rod 14 from the outer circumferential direction of the grounded tank 1 to close the gap between the conductor rod 14 and the puffer cylinder 92.

[0018] A contact 33 is formed inside the cylinder of the movable-side frame 8. A hole is formed in the contact 33, and the inner peripheral surface of the hole is in contact with the conductor rod 14. The conductor rod 14 passes through the hole formed in the contact 33 and is connected to the insulating rod 12. Therefore, the movable-side outer conductor 34 is electrically connected to the conductor rod 14 via the movable-side frame 8.

[0019] The fixed electrode portion 52 has a fixed contact 5b and a cylindrical fixed shield 15 that surrounds the fixed contact 5b from the outer circumferential direction of the grounded tank 1. The fixed contact 5b and the fixed shield 15 are supported by a fixed frame 16.

[0020] The movable electrode portion 51 is installed inside the grounded tank 1 so as to be movable in the axial direction of the grounded tank 1. In the first embodiment, a state in which the movable contact 5a and the fixed contact 5b are in contact with each other is called a "closed state", and a state in which the movable contact 5a is separated from the fixed contact 5b is called an "open state". An operation of transitioning from the closed state to the open state is called an "interrupting operation", and an operation of transitioning from the open state to the closed state is called an "closing operation". The gas-insulated switchgear 50 switches between an open state and a closed state by the movable electrode portion 51 moving so that the movable contact 5a comes into contact with the fixed contact 5b, or the movable contact 5a, which was in contact with the fixed contact 5b, separates from the fixed contact 5b.

[0021] In a closed state in which the movable contact 5a and the fixed contact 5b are in contact with each other, the movable shield 35 contacts the fixed shield 15.

[0022] The space surrounded by the puffer cylinder 92 and the puffer piston 91 is the puffer chamber 32 connected to the nozzle 11. During an interruption operation in which a closed state is changed to an open state, the protrusion amount of the puffer cylinder 92 from the movable frame 8 is reduced, so that the volume of the puffer chamber 32 is reduced and insulating gas is sprayed from the nozzle 11. That is, during an interruption operation in which a closed state in which the movable contact 5a is in contact with the fixed contact 5b is changed to an open state in which the movable contact 5a is separated from the fixed contact 5b, the movable electrode portion 51 blows insulating gas from the inside of the puffer chamber 32, which is the space formed between the puffer cylinder 92 and the puffer piston 91, toward the fixed contact 5b. An arc formed between the movable contact 5a and the fixed contact 5b during an open operation is cooled and extinguished by the blowing of insulating gas from the nozzle 11.

[0023] An inner lid 39 is installed on the fixed side frame 16. The inner lid 39 has a shape that closes the end of the fixed side frame 16, and has the same shape as the cross-sectional shape of the fixed side frame 16, for example. As an example, when the cross-sectional shape of the fixed side frame 16 is a perfect circle, the inner lid 39 is disk-shaped. FIG. 3 is an enlarged view of a fixed portion between the fixed side frame and the inner lid of the gas-insulated switchgear according to the first embodiment. The fixed side frame 16 is provided with a fixing rib 16a. The fixing rib 16a is formed so as to be connected to the inner peripheral surface of the fixed side frame 16 over the entire circumference without any gaps. The fixed side frame 16 does not have any holes formed on the side surface. The inner lid 39 is attached to the fixed side frame 16 and closes the opening of the end of the fixed side frame 16 that leads to the fixed side insulating support member 10. The inner lid 39 abuts against the fixing rib 16a from the fixed side and is fixed to the fixing rib 16a by a fixing member 38 such as a bolt. The maximum width of the inner lid 39 is smaller than the inner diameter of the fixed-side insulating support member 10 and larger than the inner diameter of the fixing rib 16a of the fixed-side frame 16. When the inner lid 39 is disk-shaped, the diameter of the inner lid 39 is the maximum width of the inner lid 39. When the inner lid 39 is elliptical-plate-shaped, the major axis of the inner lid 39 is the maximum width of the inner lid 39.

[0024] FIG. 4 is a diagram showing an example of a gas flow blown out from a nozzle in the gas-insulated switchgear according to the first embodiment. In FIG. 4, the solid arrow indicates the gas flow blown out from the nozzle 11, and the dashed arrow indicates the flow of insulating gas pushed out from the fixed frame 16. Since no hole is formed in the side surface of the fixed frame 16, the gas flow that flows into the inside of the fixed frame 16 from the end of the movable side turns back after hitting the inner lid 39, and the insulating gas that was originally in the fixed frame 16 is pushed out by the gas flow and flows out of the fixed frame 16. In the breaking operation and the closing operation, metal powder is generated by sliding between the movable contact 5a and the fixed contact 5b. Therefore, the gas flow blown out from the nozzle 11 and passing through the fixed contact 5b during the breaking operation contains metal powder. In the gas-insulated switchgear 50 according to the first embodiment, the insulating gas in the fixed-side frame 16 is pushed out and flows out of the fixed-side frame 16 by the gas flow that hits the inner lid 39 and turns back toward the end of the movable side, so that the metal powder tends to remain in the fixed-side frame 16. Therefore, in the gas-insulated switchgear 50 according to the first embodiment, it is possible to prevent the metal powder scattered in the ground tank 1 from adhering to the movable-side insulating support member 17 and the fixed-side insulating support member 10 and causing a deterioration in insulation performance.

[0025] 5 is a diagram showing an example of a gas flow blown out from a nozzle in a gas-insulated switchgear according to a modification of the first embodiment. In a gas-insulated switchgear 50 according to the modification, a hole 16b is provided in a side surface of the fixed-side frame 16. The gas flow that has flowed into the inside of the fixed-side frame 16 from the end of the movable side flows out of the fixed-side frame 16 from the hole 16b. Therefore, the gas flow can pass through the inside of the fixed-side frame 16 smoothly, so that the gas flow is less likely to decelerate, and the arc can be quickly cooled and extinguished.

[0026] 6 is a diagram showing a state in which the fixed-side cover of the gas-insulated switchgear according to the first embodiment is removed. By removing the cover 3b, the fixed member 38 and the inner cover 39 can be removed through the inside of the fixed-side insulating support member 10. Since the maximum width of the inner cover 39 is smaller than the inside diameter of the fixed-side insulating support member 10, the inner cover 39 removed from the fixed-side frame 16 can be taken out to the outside of the ground tank 1 through the inside of the fixed-side insulating support member 10. By taking the inner cover 39 out of the ground tank 1, the maintenance and replacement of the fixed-side contactor 5b can be performed through the inside of the fixed-side insulating support member 10 and the fixed-side frame 16. Therefore, the gas-insulated switchgear 50 according to the first embodiment allows the maintenance and replacement of the fixed-side contactor 5b without providing an opening for maintenance on the side of the ground tank 1.

[0027] Although the structure in which the inner lid 39 is fixed to the fixed-side frame 16 using the fixing member 38 has been exemplified here, the inner lid 39 may be fixed to the fixed-side frame 16 without using the fixing member 38. For example, the inner lid 39 may be fixed by adhesion to the fixing rib 16a, and when performing maintenance or replacement of the fixed-side contactor 5b, the adhesive may be removed using a solvent or the like before the inner lid 39 is removed from the fixed-side frame 16. Also, a female thread may be formed at the fixed-side end of the inner peripheral surface of the fixed-side frame 16, and a male thread may be formed on the outer peripheral surface of the inner lid 39, and the female thread of the fixed-side frame 16 and the male thread of the inner lid 39 may be engaged to fix the inner lid 39 to the fixed-side frame 16.

[0028] In the gas-insulated switchgear 50 according to the first embodiment, the fixed-side frame 16 and the fixed-side insulating support member 10 are separated by the inner lid 39 attached to the fixed-side frame 16, so that the gas flow that is blown out through the nozzle 11 during an interruption operation and passes through the fixed-side contactor 5b and enters the fixed-side frame 16 does not come into contact with the fixed-side insulating support member 10. Therefore, the gas-insulated switchgear 50 according to the first embodiment can prevent the fixed-side insulating support member 10 from being carbonized.

[0029] Furthermore, in the gas-insulated switchgear 50 of embodiment 1, the fixed member 38 and the inner lid 39 can be taken out of the grounded tank 1 through the inside of the fixed-side insulating support member 10 by removing the fixed-side lid 3b, thereby enabling maintenance and replacement of the fixed-side contactor 5b to be performed, and therefore there is no need to provide an opening for maintenance on the side of the grounded tank 1.

[0030] The configurations shown in the above embodiments are merely examples of the contents, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0031] 1 ground tank, 3a, 3b lids, 4 opening / closing portion, 5a movable contact, 5b fixed contact, 6 shaft, 8 movable frame, 10 fixed insulating support member, 11 nozzle, 12 insulating rod, 14 conductor rod, 15 fixed shield, 16 fixed frame, 16a fixing rib, 16b hole, 17 movable insulating support member, 22 bushing, 32 puffer chamber, 33 contact, 34 movable outer conductor, 35 movable shield, 36 fixed outer conductor, 38 fixed member, 39 inner lid, 50 gas insulated switchgear, 51 movable electrode portion, 52 fixed electrode portion, 91 puffer piston, 92 puffer cylinder.

Claims

1. a grounded tank having an end closed by a removable lid and filled with insulating gas; a fixed electrode portion having a fixed contactor disposed inside the grounded tank; a movable electrode section which has a puffer cylinder, a puffer piston installed in the puffer cylinder, a conductor rod fixed to the puffer piston, and a movable contactor fixed to the conductor rod, and which is movably installed inside the grounded tank, and which, in a breaking operation in which a closed state in which the movable contactor is in contact with the fixed contactor transitions to an open state in which the movable contactor is separated from the fixed contactor, blows insulating gas inside a puffer chamber, which is a space formed between the puffer cylinder and the puffer piston, toward the fixed contactor through a nozzle connected to the puffer chamber; a cylindrical fixed-side frame that is installed inside the ground tank and supports the fixed-side electrode portion; a fixed-side insulating support member installed inside the ground tank and supporting the fixed-side frame; and an inner lid attached to the fixed-side frame, closing an opening at an end of the fixed-side frame that leads to the fixed-side insulating support member, and blocking the insulating gas sprayed from the nozzle inside the grounding tank during contact-opening operation.

2. The fixed-side insulating support member is cylindrical, The inner lid is detachably attached to the fixed frame, 2. The gas-insulated switchgear according to claim 1, wherein a maximum width of the inner cover is smaller than an inner diameter of the fixed-side insulating support member.

3. 3. The gas-insulated switchgear according to claim 1, wherein no holes are formed in the side surface of the fixed frame.