Insulation structure of vacuum valve and switchgear

Abstract

To provide a technology for realizing miniaturization of switchgear that employs an insulating structure in which a vacuum valve is covered with multiple different types of insulating media.SOLUTION: Switchgear includes: a first container 11 accommodating a vacuum valve P; a first insulating medium 11t filled in the first container and having fluidity; a second container 12 accommodating the first container; a second insulating medium 12t filled in the second container; and pressure adjustment means Mp provided by penetrating the first container into the second container. Therein the pressure adjustment means includes: a path portion 13 formed by penetrating the first container into the second container; a displacement portion 13p configured to be displaceable following pressure changes in the first insulating medium; and a third insulating medium 13t supporting displaceably the displacement portion.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to an insulation structure of a vacuum valve and a switchgear.

Background Art

[0002] As a switching device for power reception and distribution provided in buildings and large facilities, for example, a switchgear equipped with a switch such as a circuit breaker or a disconnector is known. A vacuum valve is applied to the switchgear as a component of the switch. The vacuum valve has a pair of electrodes detachably accommodated therein, and its exterior is covered with a predetermined insulation structure. As a result, the interior of the vacuum valve is maintained in a certain vacuum state. In this state, by separating and connecting the pair of electrodes, the interruption of fault current and the opening and closing of load current are performed, and power is stably supplied from the switchgear.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in order to miniaturize the switch gear, as the above-described insulation structure, a structure in which a vacuum valve is covered with two different types of insulating media may be applied. In this case, the insulation structure includes a first container that houses the vacuum valve and a second container that houses the first container, and each container is filled with two types of insulating media (a first insulating media and a second insulating media) having different insulation performances (for example, a predetermined breakdown voltage) one by one. The breakdown voltage represents the voltage when the voltage applied to the insulating media exceeds a certain limit, the insulating media is electrically broken down, loses its insulation property, and starts to conduct current.

[0005] Here, the insulation performance of the second insulating media filled in the second container is set higher than the insulation performance of the first insulating media filled in the first container. For example, both insulating media are dry air, and the air pressure of the second insulating media is set higher than the air pressure of the first insulating media. Thereby, the insulation performance of the second insulating media is set higher than the insulation performance of the first insulating media. As a result, it becomes possible to shorten the insulation distance required for the insulation of the vacuum valve, and miniaturization of the switch gear is realized.

[0006] In addition, in such an insulation structure, a pipe that extends through the second container from the first container may be applied to measure and adjust the pressure of the first insulating media filled in the first container. In this case, the inside of the pipe is in a state filled with the first insulating media filled in the first container.

[0007] According to this state, depending on the length of the pipe filled with the first insulating media, in other words, depending on the occupied area (range) of the first insulating media filled inside the pipe, the insulation distance required for the insulation of the vacuum valve is ensured.

[0008] However, in order to ensure the insulation distance required for the insulation of the vacuum valve, it is necessary to expand the occupied area (range) of the first insulating media, and in order to meet this requirement, the pipe for filling the first insulating media also has to be expanded. As a result, it cannot be denied that the miniaturization of the switch gear is strongly restricted by the amount of expansion of the pipe.

[0009] An object of the present invention is to provide a technique for realizing miniaturization of a switchgear to which an insulation structure covering a vacuum valve with a plurality of different types of insulating media is applied.

Means for Solving the Problems

[0010] According to an embodiment, it includes a first container that houses a vacuum valve, a first insulating medium that is filled in the first container and has fluidity, a second container that houses the first container, a second insulating medium that is filled in the second container, and a pressure adjustment means provided so as to penetrate the second container from the first container. The pressure adjustment means has a path portion configured to penetrate the second container from the first container, a displacement portion configured to be displaceable following a pressure change of the first insulating medium, and a third insulating medium that supports the displacement portion so as to be displaceable.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0012] "First Embodiment" FIG. 1 is an internal structure diagram of an insulation structure Ts of a vacuum valve P and a switchgear Sg according to the present embodiment. FIG. 1 shows a switchgear Sg having an insulation structure Ts that covers a vacuum valve P with a plurality of different types of insulating media 11t and 12t. In FIG. 1, as an example of the insulation structure Ts, the vacuum valve P is covered with two different types of insulating media 11t and 12t.

[0013] As shown in Fig. 1, the vacuum valve P is configured by housing a pair of electrodes (fixed electrode E1 and movable electrode E2) and an airtight maintenance mechanism 2 (for example, a thin metal bellows having elasticity) inside an insulating container 1 (also referred to as a vacuum container). The fixed electrode E1 includes a fixed contact 3 and a fixed current-carrying shaft 4. The movable electrode E2 includes a movable contact 5 and a movable current-carrying shaft 6.

[0014] The fixed contact 3 is connected to one end of the fixed current-carrying shaft 4, and the other end of the fixed current-carrying shaft 4 is fixedly connected to the vacuum valve P in a non-movable manner. The movable contact 5 is connected to one end of the movable current-carrying shaft 6, and the other end of the movable current-carrying shaft 6 is connected to an operating mechanism 8 via an operating rod 7. The airtight maintenance mechanism 2 is arranged to cover the other end side of the movable current-carrying shaft 6 in an airtight (liquid-tight) manner without any gaps.

[0015] Here, by operating the operating rod 7 with the operating mechanism 8, and thereby moving the movable current-carrying shaft 6, the movable contact 5 can be separated from and contacted with the fixed contact 3. As a result, the vacuum valve P can be opened and closed (that is, the electrodes E1 and E2 can be separated and contacted). At this time, the inside of the vacuum valve P is maintained in a certain vacuum state by the airtight maintenance mechanism 2, and the atmosphere (air) does not penetrate.

[0016] The above-described vacuum valve P is applied to the switch gear Sg. In Fig. 1, as an application example, the switch gear Sg is equipped with a high-voltage conductor 9 that electrically connects the vacuum valve P to an external power system (not shown) together with the operating mechanism 8 (operating rod 7).

[0017] One high-voltage conductor 9 is provided on each of the fixed current-carrying shaft 4 and the movable current-carrying shaft 6. The base end of the high-voltage conductor 9 is connected to the fixed current-carrying shaft 4 and the movable current-carrying shaft 6, and the tip end thereof is electrically connected to the external power system via a bushing 10. Further, the operating rod 7 and the high-voltage conductor 9 extend through an insulating structure Ts of the vacuum valve P to be described later.

[0018] The insulation structure Ts is arranged to cover the above-described vacuum valve P (specifically, the insulating container 1). In FIG. 1, as an example of the arrangement configuration, the insulation structure Ts includes a first container 11 that houses the vacuum valve P and a second container 12 that houses the first container 11, and both containers 11 and 12 are made of a material having insulation properties.

[0019] The first and second containers 11 and 12 are each filled with one type of two types of insulating media (first insulating media 11t, second insulating media 12t) having different insulation performances (for example, a predetermined breakdown voltage).

[0020] Note that the insulation performance is a parameter representing the degree (extent) of the difficulty of the flow of electricity of the first and second insulating media 11t and 12t, and the third insulating media 13t described later. For example, when the voltage applied to the insulating media exceeds a certain limit, the insulating media is electrically broken down and loses its insulation property and current flows, it can be defined as the voltage level (that is, the breakdown voltage). From another perspective, the insulation performance can be defined as the resistance value of the insulating media and the insulation resistance representing the insulation property. Therefore, the higher (larger) the insulation performance (insulation resistance), the more difficult it is for electricity to flow (that is, the more difficult it is to leak electricity).

[0021] In this case, the first insulating media 11t is filled in the first container 11 at a preset initial pressure so that the internal vacuum state of the vacuum valve P is maintained constant. On the other hand, the second insulating media 12t has a higher insulation performance (breakdown voltage) than the first insulating media 11t and is filled in the second container 12. In this state, as long as the pressure of the first insulating media 11t filled in the first container 11 is maintained at the initial pressure, the inside of the vacuum valve P is maintained in a constant vacuum state.

[0022] Furthermore, the insulation structure Ts includes a pressure adjustment means Mp capable of measuring and adjusting the pressure of the first insulating medium 11t inside the first container 11. In FIG. 1, as an example of pressure adjustment, when the pressure adjustment means Mp measures that the pressure of the first insulating medium 11t in the first container 11 has changed in increase or decrease with respect to the initial pressure, the pressure of the first insulating medium 11t is adjusted to be the initial pressure.

[0023] On the other hand, in a state where the first insulating medium 11t is maintained at the initial pressure, a displacement portion 13p described later is supported at a fixed position without displacement on the one end 13a side of the path portion 13. At this time, the pressure of the third insulating medium 13t provided (i.e., filled) along the path portion 13 is maintained at the same pressure as the initial pressure. During this period, the pressure adjustment means Mp does not perform pressure adjustment, and the pressure of the first insulating medium 11t is measured.

[0024] The pressure adjustment means Mp is provided so as to penetrate from the first container 11 (first insulating medium 11t) to the second container 12 (second insulating medium 12t), and includes a path portion 13, a displacement portion 13p, and a third insulating medium 13t. The entire pressure adjustment means Mp is configured to have insulation properties. In this configuration, the third insulating medium 13t is filled inside the path portion 13 so as to support the displacement portion 13p in a displaceable manner.

[0025] The path portion 13 is configured to penetrate from the first container 11 (first insulating medium 11t) to the second container 12 (second insulating medium 12t). In FIG. 1, as an example of the path portion 13, a single pipe (path portion) 13 having a hollow cylindrical shape (i.e., a hollow circular cylindrical shape) is applied. The pipe (path portion) 13 is made of a material having insulation properties and extends through the first container 11 to the second container 12. One end 13a of the pipe (path portion) 13 protrudes and opens inside the first container 11, and a pressure adjustment portion 15 having a pressure gauge 14 is provided at the other end 13b of the pipe (path portion) 13.

[0026] A pressure control device (not shown) is connected to the pressure adjustment unit 15. The pressure control device is configured to be able to measure and adjust the pressure of the first insulating medium 11t inside the first container 11 based on the monitoring result while constantly monitoring the pressure gauge 14.

[0027] In this configuration, the pressure measured by the pressure gauge 14 is the pressure of the third insulating medium 13t. However, the third insulating medium 13t is maintained in a state of being adjacent to the first insulating medium 11t without a gap via a movable plug (displacement part) 13p described later.

[0028] The displacement part 13p is provided so as to block the pipe (path part) 13. In FIG. 1, as an example of the displacement part 13p, a single movable plug 13p having a cylindrical shape is applied. The movable plug (displacement part) 13p is made of an insulating material and is inserted into the inside of the pipe (path part) 13 so as to be displaceable (movable) at one end 13a side of the pipe (path part) 13 opened inside the first container 11.

[0029] The outer diameter of the movable plug (displacement part) 13p may be set to match the inner diameter of the pipe (path part) 13, or may be set to be slightly smaller than the inner diameter of the pipe (path part) 13. When the outer diameter of the movable plug (displacement part) 13p is set to match the inner diameter of the pipe (path part) 13, it is preferable to configure the contact surfaces of both to be smooth without unevenness so that the movable plug (displacement part) 13p can displace (move) smoothly along the pipe (path part) 13. On the other hand, when the outer diameter of the movable plug (displacement part) 13p is set to be slightly smaller than the inner diameter of the pipe (path part) 13, it is preferable to set the gap between both so that gas or liquid does not flow through.

[0030] Thereby, the movable plug (displacement part) 13p is configured to be displaceable (movable) following the pressure change of the first insulating medium 11t without leaking the first insulating medium 11t from the first container 11 at one end 13a side of the pipe (path part) 13 opened inside the first container 11.

[0031] The third insulating medium 13t is provided along the pipe (path portion) 13. In the example of FIG. 1, the third insulating medium 13t is filled along the inner side from one end 13a to the other end 13b of the pipe (path portion) 13. At this time, the third insulating medium 13t spreads without a gap from the movable plug (displacement portion) 13p to the pressure adjustment portion 15 and is accommodated inside the pipe (path portion) 13. Thereby, the third insulating medium 13t is adjacent to the movable plug (displacement portion) 13p without a gap, and as a result, the movable plug (displacement portion) 13p is supported by the third insulating medium 13t so as to be displaceable (movable).

[0032] Therefore, the pressure change of the first insulating medium 11t acts directly (in other words, in real time) on the third insulating medium 13t via the movable plug (displacement portion) 13p. As a result, even if the pressure measured by the pressure gauge 14 is the pressure of the third insulating medium 13t, the pressure change of the first insulating medium 11t at the current time is directly reflected in the pressure gauge 14. As a result, the pressure of the first insulating medium 11t can be measured in real time by the pressure gauge 14.

[0033] For example, when the pressure value of the pressure gauge 14 increases or decreases, it is measured by the pressure control device that the pressure of the first insulating medium 11t inside the first container 11 has increased or decreased with respect to the initial pressure. At this time, the pressure change of the first insulating medium 11t acts directly on the third insulating medium 13t via the movable plug (displacement portion) 13p. Then, the pressure of the third insulating medium 13t also becomes the same value as the pressure of the first insulating medium 11t that has increased or decreased at the current time, and that is reflected in the pressure gauge 14 in real time.

[0034] The pressure control device calculates the difference value between the current pressure value of the pressure gauge 14 and the initial pressure of the first insulating medium 11t, and adjusts (i.e., pressurizes or depressurizes) the pressure of the third insulating medium 13t so that this difference value disappears (in other words, so that the pressure value of the pressure gauge 14 becomes the initial pressure). At this time, the pressure adjustment of the third insulating medium 13t acts directly on the first insulating medium 11t via the movable plug (displacement part) 13p. As a result, the pressure of the first insulating medium 11t inside the first container 11 is adjusted in real time and returned to the initial pressure. As a result, the inside of the vacuum valve P is maintained in a constant vacuum state.

[0035] By the way, further miniaturization of the switch gear Sg is required. In response to this, in the insulating structure Ts that covers the vacuum valve P with a plurality of different types of insulating media 11t and 12t, the third insulating medium 13t has a higher insulating performance (i.e., a predetermined breakdown voltage) than the first insulating medium 11t.

[0036] Furthermore, as described above, the second insulating medium 12t has a higher insulating performance (i.e., breakdown voltage) than the first insulating medium 11t. In this case, the third insulating medium 13t may be configured to have the same breakdown voltage as the second insulating medium 12t, or a breakdown voltage higher than that of the second insulating medium 12t, or a breakdown voltage lower than that of the second insulating medium 12t.

[0037] Here, an example of a material that can constitute the first to third insulating media 11t, 12t, and 13t to achieve the above-described insulating performance (breakdown voltage) is listed. The first insulating medium 11t can be composed of a material having fluidity. Materials having fluidity include gases and liquids, excluding solids. As an example of a gas, dry air, nitrogen, carbon dioxide gas, sulfur hexafluoride, etc. can be applied. Also, as an example of a liquid, water, vegetable oil, mineral oil, synthetic insulating oil, etc. can be applied.

[0038] The second insulating medium 12t can be composed of materials having not only fluidity but also non-fluidity. Materials having fluidity and non-fluidity include gases, liquids, and solids. As an example of a gas and a liquid, the same materials as those of the above-described first insulating medium 11t can be applied. As an example of a solid, inorganic materials such as mica and ceramics (porcelain), glass, organic materials such as polyester and polyamide, resin materials such as epoxy resin and silicone resin, and rubber materials such as natural rubber and silicone rubber can be applied.

[0039] The third insulating medium 13t can be composed of materials having not only fluidity but also non-fluidity. Materials having fluidity and non-fluidity include gases, liquids, and solids. As an example of a gas, a liquid, and a solid, the same materials as those of the above-described first and second insulating media 11t, 12t can be applied.

[0040] In the example of FIG. 1, the third insulating medium 13t needs to be filled inside the path portion 13 so as to displaceably support the movable plug (displacement portion) 13p. For this reason, as the material of the third insulating medium 13t, those composed of a gas and a liquid are preferable.

[0041] Furthermore, when the pressure change of the first insulating medium 11t acts on the third insulating medium 13t via the movable plug (displacement portion) 13p, it is necessary to reflect the pressure acting on the third insulating medium 13t on the pressure gauge 14 in real time. For this reason, the third insulating medium 13t is preferably composed of a material having fluidity and non-compressibility.

[0042] As described above, according to the present embodiment, the vacuum valve P is covered with two different types of insulating media 11t and 12t, and the insulation performance (dielectric breakdown voltage) of the outer second insulating medium 12t is set higher than the insulation performance (dielectric breakdown voltage) of the inner first insulating medium 11t. As a result, it becomes possible to shorten the insulation distance required for the insulation of the vacuum valve P, and as a result, miniaturization of the switch gear Sg is realized.

[0043] In addition, according to the present embodiment, a third insulating medium 13t is provided along a pipe (path portion) 13 penetrating through the second insulating medium 12t from the first insulating medium 11t, and the third insulating medium 13t is configured to have an insulating performance (dielectric breakdown voltage) higher than that of the first insulating medium 11t. According to this configuration, the pipe (path portion) 13 is provided with the third insulating medium 13t having a high insulating performance (dielectric breakdown voltage) instead of the first insulating medium 11t having a low insulating performance (dielectric breakdown voltage). In this case, the potential difference between the high-voltage conductor 9 and the vacuum valve P and between the second container 12 and the switch gear Sg is insulated by the third insulating medium 13t having a high insulating performance (dielectric breakdown voltage). As a result, the length of the pipe (path portion) 13 provided with the third insulating medium 13t can be shortened, and accordingly, the insulating distance required for insulating the vacuum valve P can be further shortened by the amount of shortening of the length of the pipe (path portion) 13. As a result, further miniaturization of the switch gear Sg can be achieved.

[0044] According to the present embodiment, the third insulating medium 13t provided along the pipe (path portion) 13 is made of a material having fluidity and non-compressibility. Thereby, in a state where the pressure of the first insulating medium 11t changes from the initial pressure, the movable plug (displacement portion) 13p can be displaced along the pipe (path portion) 13 according to the pressure acting on the movable plug (displacement portion) 13p. At this time, the movable plug (displacement portion) 13p acts directly (in real time) on the third insulating medium 13t. As a result, the pressure change of the first insulating medium 11t at the current time is directly reflected in the pressure gauge 14. As a result, the pressure of the first insulating medium 11t can be measured in real time by the pressure gauge 14.

[0045] In addition, according to the present embodiment, a difference value between the current pressure value of the pressure gauge 14 and the initial pressure of the first insulating medium 11t is calculated, and the pressure of the third insulating medium 13t is adjusted (i.e., pressurized or depressurized) so that the difference value disappears (in other words, the pressure value of the pressure gauge 14 becomes the initial pressure). At this time, the pressure adjustment of the third insulating medium 13t acts directly on the first insulating medium 11t via the movable plug (displacement portion) 13p. Thereby, the pressure of the first insulating medium 11t inside the first container 11 can be adjusted in real time and returned to the initial pressure. As a result, the inside of the vacuum valve P can be maintained in a constant vacuum state.

[0046] "Second Embodiment" FIG. 2 is an internal structure diagram of the insulation structure Ts of the vacuum valve P and the switch gear Sg according to the present embodiment. In the example of FIG. 2, the path portion 13 is configured as a single pipe having a hollow cylindrical shape penetrating from the first container 11 (first insulating medium 11t) to the second container 12 (second insulating medium 12t). One end 13a of the hollow cylindrical pipe (path portion) 13 protrudes into the first container 11 and is opened.

[0047] As shown in FIG. 2, the displacement portion 13p is provided so as to close the pipe (path portion) 13. In FIG. 2, as an example of the displacement portion 13p, a single elastic container 13p having a spherical shape is applied. The elastic container (displacement portion) 13p is configured such that its entire body can be elastically deformed. In other words, the elastic container (displacement portion) 13p has a spherical shape, and the spherical elastic container (displacement portion) 13p is configured to expand and contract as a whole. The elastic container (displacement portion) 13p is made of an insulating material and is arranged so as to hermetically (liquid-tightly) cover the protruding tip (i.e., the opening of one end 13a) protruding into the first container 11 without any gap.

[0048] Thereby, the elastic container (displacement portion) 13p is configured to be displaceable (expand and contract) following the pressure change of the first insulating medium 11t without leaking the first insulating medium 11t from the first container 11 on the one end 13a side of the pipe (path portion) 13 opened inside the first container 11.

[0049] The third insulating medium 13t is provided along the pipe (path portion) 13. In the example of FIG. 2, the third insulating medium 13t is filled from one end 13a to the other end 13b inside the pipe (path portion) 13. At this time, the third insulating medium 13t spreads without a gap from the elastic container (displacement portion) 13p to the pressure adjustment portion 15 and is accommodated inside the pipe (path portion) 13. Thereby, the third insulating medium 13t is adjacent to the elastic container (displacement portion) 13p without a gap, and as a result, the elastic container (displacement portion) 13p is supported by the third insulating medium 13t so as to be displaceable.

[0050] Similar to the first embodiment described above, the third insulating medium 13t of the present embodiment also has higher insulation performance (i.e., a predetermined dielectric breakdown voltage) than the first insulating medium 11t. Since the other configurations and effects are the same as those of the first embodiment described above, the description thereof is omitted.

[0051] "Third Embodiment" FIG. 3 is an internal structure diagram of the insulation structure Ts of the vacuum valve P and the switch gear Sg according to the present embodiment. In the example of FIG. 2, the path portion 13 is configured as a single pipe having a hollow cylindrical shape that penetrates the first container 11 (first insulating medium 11t) and the second container 12 (second insulating medium 12t). One end 13a of the hollow cylindrical pipe (path portion) 13 protrudes into the first container 11 and is opened.

[0052] As shown in FIG. 3, the displacement portion 13p is provided so as to block the pipe (path portion) 13. In FIG. 3, as an example of the displacement portion 13p, a single partition wall 13p that partitions the inside of the first container 11 is applied. The partition wall (displacement portion) 13p is made of an insulating material and is inserted along the inside of the first container 11 so as to be displaceable (movable).

[0053] The shape and size of the partition wall (displacement part) 13p are preferably set so that the first insulating medium 11t filled inside the first container 11 does not leak past the partition wall (displacement part) 13p (in other words, does not leak through the space between the first container 11 and the partition wall (displacement part) 13p).

[0054] As a result, the partition wall (displacement part) 13p is configured to be displaceable (movable) following the pressure change of the first insulating medium 11t without leaking the first insulating medium 11t inside the first container 11.

[0055] Furthermore, a medium storage tank 16 is provided adjacent to the outside of the second container 12 in the pipe (path part) 13. The medium storage tank 16 is configured to be able to secure in advance an amount of the third insulating medium 13t required when displacing (moving) the partition wall (displacement part) 13p along the inside of the first container 11. As a result, the partition wall (displacement part) 13p can be largely displaced (moved) without increasing the pressure adjustment (pressure increase adjustment or pressure decrease adjustment) of the third insulating medium 13t (in other words, with only a small pressure adjustment).

[0056] The third insulating medium 13t is provided along the pipe (path part) 13. In the example of FIG. 3, the third insulating medium 13t is filled from the other end 13b inside the pipe (path part) 13 through the medium storage tank 16 and along the inside of the first container 11 beyond one end 13a inside the pipe (path part) 13. At this time, the third insulating medium 13t spreads without a gap from the partition wall (displacement part) 13p to the pressure adjustment part 15 and is accommodated inside the pipe (path part) 13. As a result, the third insulating medium 13t is adjacent to the partition wall (displacement part) 13p without a gap, and as a result, the partition wall (displacement part) 13p is supported to be displaceable (movable) by the third insulating medium 13t.

[0057] The third insulating medium 13t of this embodiment also has a higher insulation performance (i.e., a predetermined breakdown voltage) than the first insulating medium 11t, similar to the above-described first embodiment. Since the other configurations and effects are the same as those of the above-described first embodiment, the description thereof is omitted.

[0058] "Fourth Embodiment" FIG. 4 is an internal structure diagram of the insulation structure Ts of the vacuum valve P and the switch gear Sg according to this embodiment. In the example of FIG. 4, the path portion 13 is configured as a single pipe having a hollow cylindrical shape that penetrates the second container 12 (the second insulating medium 12t) from the first container 11 (the first insulating medium 11t). One end 13a of the hollow cylindrical pipe (path portion) 13 protrudes into the first container 11 and is opened.

[0059] As shown in FIG. 4, the displacement portion 13p is provided so as to block the pipe (path portion) 13. In FIG. 4, as an example of the displacement portion 13p, a single movable plug 13p having a cylindrical shape is applied. The movable plug (displacement portion) 13p is made of an insulating material and is inserted into the pipe (path portion) 13 so as to be displaceable (movable) inside the pipe (path portion) 13 on the one end 13a side of the pipe (path portion) 13 opened inside the first container 11.

[0060] The shape and size of the movable plug (displacement portion) 13p are preferably set so that the first insulating medium 11t filled inside the first container 11 does not leak past the movable plug (displacement portion) 13p (in other words, does not leak through the space between the pipe (path portion) 13 and the movable plug (displacement portion) 13p).

[0061] Thereby, the movable plug (displacement portion) 13p is configured to be displaceable (movable) following the pressure change of the first insulating medium 11t without leaking the first insulating medium 11t from the first container 11 on the one end 13a side of the pipe (path portion) 13 opened inside the first container 11.

[0062] The third insulating medium 13t is provided along the pipe (path portion) 13. In the example of FIG. 4, the third insulating medium 13t is filled from one end 13a to the other end 13b inside the pipe (path portion) 13. At this time, the third insulating medium 13t spreads without a gap from the movable plug (displacement portion) 13p to the pressure adjustment portion 15 and is accommodated inside the pipe (path portion) 13. As a result, the third insulating medium 13t is adjacent to the movable plug (displacement portion) 13p without a gap, and as a result, the movable plug (displacement portion) 13p is supported by the third insulating medium 13t so as to be displaceable (movable).

[0063] Similar to the first insulating medium 11t in the above-described first embodiment, the third insulating medium 13t in the present embodiment also has a higher insulating performance (i.e., a predetermined breakdown voltage).

[0064] Furthermore, in the present embodiment, inside the first container 11, the vacuum valve P is covered with a solid fourth insulating medium 17 except for its movable side end face. In this case, the movable side end face of the vacuum valve P is covered with the first insulating medium 11t filled in the first container 11.

[0065] The solid fourth insulating medium 17 has a higher insulating performance (i.e., a predetermined breakdown voltage) than the first insulating medium 11t. As the material constituting the fourth insulating medium 17, similar to the first embodiment described above, for example, inorganic materials such as mica and ceramics, organic materials such as polyester and polyamide, resin materials such as epoxy resin and silicone resin, and rubber materials such as natural rubber and silicone rubber can be applied.

[0066] As described above, according to the present embodiment, by covering the portion other than the movable side end face of the vacuum valve P with the solid fourth insulating medium 17, the size of the first container 11 can be reduced, and thus the size of the second container 12 that houses the first container 11 can also be reduced. As a result, it is possible to make the insulating structure Ts more compact, and as a result, further miniaturization of the switch gear Sg can be achieved. Note that since the other configurations and effects are the same as those in the first embodiment described above, the description thereof is omitted.

[0067] "Fifth Embodiment" FIG. 5 is a diagram showing the insulation structure Ts of the vacuum valve P and the internal structure of the switch gear Sg according to the present embodiment. In the example of FIG. 5, the path portion 13 has a hollow cylindrical shape penetrating from the first container 11 (first insulating medium 11t) to the second container 12 (second insulating medium 12t), and is configured to be distributed to one end 13a side and the other end 13b side thereof. Specifically, the path portion 13 is configured such that one end 13a side thereof protrudes into the first container 11 and the other end 13b side protrudes outside the second container 12.

[0068] As shown in FIG. 5, the displacement portions 13p are provided so as to block the distributed path portions 13 respectively. In FIG. 5, as an example of the displacement portion 13p, a single movable plug 13p having a cylindrical shape is applied. The movable plug (displacement portion) 13p is made of an insulating material and is displaceably (movable) inserted into the pipes (path portions) 13 distributed to the inside of the first container 11 and the outside of the second container 12 respectively.

[0069] Inside the one end 13a side of the pipe (path portion) 13 protruding into the first container 11, the shape and size of the movable plug (displacement portion) 13p are set so that the first insulating medium 11t filled inside the first container 11 does not leak beyond the movable plug (displacement portion) 13p (in other words, does not leak through the space between the pipe (path portion) 13 and the movable plug (displacement portion) 13p).

[0070] Thereby, on the one end 13a side of the pipe (path portion) 13 protruding into the first container 11, the movable plug (displacement portion) 13p is configured to be displaceable (movable) following the pressure change of the first insulating medium 11t without leaking the first insulating medium 11t from the first container 11.

[0071] On one hand, inside the other end 13b side of the pipe (path portion) 13 protruding outside the second container 12, the shape and size of the movable plug (displacement portion) 13p are set so that the second insulating medium 12t filled inside the second container 12 does not leak beyond the movable plug (displacement portion) 13p (in other words, does not leak through the space between the pipe (path portion) 13 and the movable plug (displacement portion) 13p).

[0072] Furthermore, inside the other end 13b side of the pipe (path portion) 13 protruding outside the second container 12, a support medium 18 for supporting the movable plug (displacement portion) 13p in a certain state (position) is filled. As the material constituting the support medium 18, a material whose pressure can be adjusted (i.e., pressurized or depressurized) by the pressure control device described in the above first embodiment can be applied, for example, an insulating gas or liquid.

[0073] Thereby, on the other end 13b side of the pipe (path portion) 13 protruding outside the second container 12, the movable plug (displacement portion) 13p is configured to be displaceable (movable) following the pressure change of the support medium 18 without leaking the second insulating medium 12t from the second container 12.

[0074] In this embodiment, the third insulating medium 13t is composed of a non-compressible rod-shaped solid. This solid third insulating medium 13t is provided between the movable plug (displacement portion) 13p inserted inside the first container 11 and the movable plug (displacement portion) 13p inserted outside the second container 12 so as to be adjacent to both movable plugs (displacement portions) 13p without a gap.

[0075] Similar to the first embodiment described above, the third insulating medium 13t of this embodiment also has higher insulating performance (i.e., a predetermined breakdown voltage) than the first insulating medium 11t. As the material constituting the third insulating medium 13t, similar to the first embodiment described above, for example, inorganic materials such as mica and ceramics and glass, organic materials such as polyester and polyamide, resin materials such as epoxy resin and silicone resin, and rubber materials such as natural rubber and silicone rubber can be applied.

[0076] As described above, according to the present embodiment, the solid third insulating medium 13t can be displaced (moved) along the path portion 13 while being sandwiched between the movable plugs (displacement portions) 13p on both sides, and at this time, it is always exposed to the second insulating medium 12t. In this state, the surface insulation of the third insulating medium 13t in the second insulating medium 12t is higher than that of the first insulating medium 11t. As a result, it is possible to set the overall length of the third insulating medium 13t shorter, and as a result, further miniaturization of the switch gear Sg can be achieved. Note that since the other configurations and effects are the same as those of the first embodiment described above, the description thereof is omitted.

[0077] "Sixth Embodiment" FIG. 6 is an internal structure diagram of the insulation structure Ts of the vacuum valve P and the switch gear Sg according to the present embodiment. This embodiment is an improvement of the first embodiment described above, and hereinafter, the description will be limited to the improved portions.

[0078] As shown in FIG. 6, the second insulating medium 12t filled in the second container 12 is composed of a liquid. As the liquid, for example, water, vegetable oil, mineral oil, synthetic insulating oil, etc. can be applied in the same manner as in the first embodiment described above.

[0079] In this case, it is preferable to dispose a conservator 19 in the second container 12. By disposing the conservator 19, it is possible to absorb the pressure change of the liquid second insulating medium 12t that repeats expansion and contraction due to a pressure change in the second container 12, for example, a temperature change. Thereby, early deterioration of the second container 12 can be prevented.

[0080] In addition, the first container 11 is provided with a liquid reservoir portion 20 that can store the leaked second insulating medium 12t when the second insulating medium 12t leaks from the second container 12 to the first container 11. The liquid reservoir portion 20 is formed in the space region on the lower side of the first container 11 when viewed in the direction of gravity.

[0081] By providing the liquid reservoir portion 20, it is possible to prevent deterioration of electrical components such as the vacuum valve P and the high-voltage conductor 9, for example, due to the leaked second insulating medium 12t. In this case, the liquid reservoir portion 20 may be configured to extend over the entire space region on the lower side of the first container 11, or may be configured only for the space region having a possibility of leakage.

[0082] As described above, according to the present embodiment, when the second insulating medium 12t leaks from the second container 12 to the first container 11, the pressure of the first insulating medium 11t in the first container 11 changes (for example, the pressure increases) according to the leakage amount. At this time, the pressure change of the first insulating medium 11t acts directly (in other words, in real time) on the third insulating medium 13t via the movable plug (displacement portion) 13p. As a result, the pressure change of the first insulating medium 11t at the current time is directly reflected in the pressure gauge 14. As a result, by measuring the pressure of the first insulating medium 11t with the pressure gauge 14, it is detected in real time that the second insulating medium 12t has leaked from the second container 12 to the first container 11. Note that since other configurations and effects are the same as those of the first embodiment described above, the description thereof is omitted.

[0083] "Other Modifications" In the first to sixth embodiments described above, variations in covering the vacuum valve P with two different types of insulating media (the first insulating medium 11t and the second insulating medium 12t) have been described. Needless to say, variations in covering the vacuum valve P with two or more different types of insulating media are also included in the technical scope of the present invention. For example, a third container (not shown) that houses the first container 11 (vacuum valve P) and the second container 12 is provided, and a new insulating medium is filled inside the third container. In this case, the new insulating medium may have a higher insulating performance (that is, breakdown voltage) than the first and second insulating media 11t and 12t. Note that since other configurations and effects are the same as those of the first embodiment described above, the description thereof is omitted.

[0084] The above describes several embodiments and modifications of the present invention. These embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. These embodiments and modifications can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications are included in the scope and gist of the invention and are also included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0085] E1, E2... electrodes, Mp... pressure adjusting means, P... vacuum valve, Ts... insulation structure, Sg... switch gear, 1... insulating container, 2... airtight maintenance mechanism, 3... fixed contact, 4... fixed energizing shaft, 5... movable contact, 6... movable energizing shaft, 7... operating rod, 8... operating mechanism, 9... high voltage conductor, 10... bushing, 11... first container, 11t... first insulating medium, 12... second container, 12t... second insulating medium, 13... path portion, 13a... one end, 13b... the other end, 13p... displacement portion, 13t... third insulating medium, 14... pressure gauge, 15... pressure adjusting portion, 16... medium storage tank, 17... fourth insulating medium, 18... support medium, 19... conservator, 20... liquid reservoir portion.

Claims

1. An insulating structure that covers a vacuum valve with a plurality of different types of insulating media, a first container that houses the vacuum valve, a first insulating medium that is filled in the first container and has fluidity, a second container that houses the first container, a second insulating medium that is filled in the second container, and a pressure adjustment means provided so as to penetrate the second container from the first container, and comprises: The pressure adjustment means is a path portion configured to penetrate the second container from the first container, a displacement portion configured to be displaceable following a pressure change of the first insulating medium, and a third insulating medium that supports the displacement portion so as to be displaceable. An insulating structure of a vacuum valve.

2. The third insulating medium is while supporting the displacement portion at a fixed position in a state where the pressure of the first insulating medium is maintained at the initial pressure, in a state where the pressure of the first insulating medium has changed from the initial pressure, by displacing the displacement portion along the path portion in response to the pressure acting on the displacement portion, the pressure of the first insulating medium can be measured in real time, and by displacing the displacement portion along the path portion based on the measurement result, the pressure of the first insulating medium can be adjusted to the initial pressure. The insulating structure of the vacuum valve according to claim 1.

3. The third insulating medium has non-compressibility. The insulating structure of the vacuum valve according to claim 1.

4. The third insulating medium has the same breakdown voltage as the second insulating medium, or a breakdown voltage higher than that of the second insulating medium, or a breakdown voltage lower than that of the second insulating medium. The insulating structure of the vacuum valve according to claim 3.

5. The path portion forms a hollow cylindrical shape, the displacement portion is displaceably inserted inside the cylindrical path portion, and the third insulating medium is housed inside the path portion so as to be adjacent to the displacement portion without a gap. The insulating structure of the vacuum valve according to claim 1.

6. The path portion forms a hollow cylindrical shape, the displacement portion is disposed so as to cover a protruding tip protruding into the first container among the cylindrical path portions, and is configured to be elastically deformable, and the third insulating medium is housed inside the path portion so as to be adjacent to the displacement portion without a gap. The insulating structure of the vacuum valve according to claim 1.

7. The path portion forms a hollow cylindrical shape, the displacement portion is displaceably inserted along the inside of the first container, The third insulating medium is housed inside the path portion so as to be adjacent to the displacement portion without a gap. The insulating structure of the vacuum valve according to claim 1, wherein the path portion is provided with a medium storage tank for preliminarily securing an amount of the third insulating medium required when displacing the displacement portion along the inside of the first container.

8. The path portion has a hollow cylindrical shape. The displacement portion is displaceably inserted inside the cylindrical path portion. The third insulating medium is housed inside the path portion so as to be adjacent to the displacement portion without a gap. The insulating structure of the vacuum valve according to claim 1, wherein inside the first container, the vacuum valve is covered with a fourth insulating medium that is solid except for its movable-side end face.

9. The path portion has a hollow cylindrical shape and is configured to be distributed between the inside of the first container and the outside of the second container. The displacement portion is displaceably inserted into the path portion distributed between the inside of the first container and the outside of the second container, respectively. The non-compressible third insulating medium is provided between the displacement portion inserted inside the first container and the displacement portion inserted outside the second container so as to be adjacent to both displacement portions without a gap. The insulating structure of the vacuum valve according to claim 3.

10. The path portion has a hollow cylindrical shape. The displacement portion is displaceably inserted inside the cylindrical path portion. The third insulating medium is housed inside the path portion so as to be adjacent to the displacement portion without a gap. The second insulating medium filled in the second container is composed of a liquid. The first container is provided with a liquid reservoir portion capable of storing the leaked second insulating medium when the second insulating medium leaks from the second container to the first container. The insulating structure of the vacuum valve according to claim 1, wherein the liquid reservoir portion is configured in a space region below the first container when viewed in the direction of gravity.

11. The first insulating medium is filled in the first container at a preset initial pressure so that the vacuum state inside the vacuum valve is maintained constant. The second insulating medium has a higher dielectric breakdown voltage than the first insulating medium. The insulating structure of the vacuum valve according to claim 1, wherein the third insulating medium is provided along the path portion and has a higher dielectric breakdown voltage than the first insulating medium.

12. The first container and the second container each have insulation properties. The pressure adjustment means has insulation properties and can measure and adjust the pressure of the first insulating medium inside the first container. The displacement part is provided so as to block the path part without allowing the first insulating medium to leak from the first container. The insulation structure of the vacuum valve according to claim 1.

13. A switchgear including the insulation structure of the vacuum valve according to any one of claims 1 to 12, An operating rod for opening and closing the vacuum valve, A high-voltage conductor for electrically connecting the vacuum valve to an external power system, and having The operating rod and the high-voltage conductor extend through the second container from the first container. Switchgear.

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