HK1245994A1 - Vacuum circuit breaker - Google Patents

Description

Vacuum circuit breaker

Technical Field

The present invention relates to a vacuum circuit breaker mounted in a gas insulated switchgear or the like, and more particularly to a main circuit structure of the vacuum circuit breaker.

Background

The gas insulated switchgear can make the equipment compact by utilizing the excellent insulating performance of sulfur hexafluoride (SF6) gas, thereby contributing to the reduction of the space of the electric room. In the vacuum circuit breaker incorporated in the gas insulated switchgear, the operating mechanism of the vacuum circuit breaker is generally disposed outside the gas container, the main circuit portion of the vacuum circuit breaker is disposed inside the gas container, and the operating mechanism and the main circuit portion are connected by a shaft that can be driven while maintaining airtightness between the inside and the outside of the gas container.

Here, the main circuit portion of the vacuum circuit breaker is constituted by the insulating operating rod, the movable-side terminal, the vacuum valve, and the fixed-side terminal, but the constituent members of the main circuit portion need to be supported in the gas container while being insulated from the gas container at the ground potential. Therefore, the main circuit portion of the vacuum circuit breaker is generally configured to be supported in the gas container by an insulator or an insulating support.

In the case where the main circuit portion of the vacuum circuit breaker is supported by the insulating support as described above, for example, when a structure is adopted in which the insulating support is formed in a cylindrical shape and covers the periphery of the vacuum interrupter, the withstand voltage performance is deteriorated because the electric field outside the vacuum interrupter is increased. Further, although the vacuum valve generates heat when energized, when the surroundings are covered, the convection of air is deteriorated, and therefore, there is a problem that the temperature around the vacuum valve is increased, and the energization performance is deteriorated.

As a solution to the above-described problems, for example, a vacuum circuit breaker as shown in patent document 1 or patent document 2 is proposed.

That is, the vacuum circuit breaker disclosed in patent document 1 is configured, as shown in fig. 3: the first insulating frame and the second insulating frame having a U-shaped cross section are disposed with a gap therebetween so as to cover the vacuum valve from the left and right sides thereof, and the first insulating frame and the second insulating frame are fastened by a fixed-side conductor of the vacuum valve.

As shown in fig. 1 and 4, the vacuum circuit breaker disclosed in patent document 2 includes a pair of insulating support plates disposed so as to sandwich a vacuum interrupter from above and below, and an upper electrode fixed to one end of the insulating support plate and to a fixed side of the vacuum interrupter.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-131440 (especially refer to FIG. 3)

Patent document 2: japanese patent laid-open publication No. 2013-149579 (especially referring to FIGS. 1 and 4)

Disclosure of Invention

Technical problem to be solved by the invention

In the vacuum circuit breakers described in patent documents 1 and 2, although the opening is provided in the insulator around the vacuum interrupter to improve the air convection, since one vacuum interrupter is supported by two insulating frames, when the length of the two insulating frames is slightly different, one of the insulating frames receives the impact load generated in the vacuum interrupter when the circuit breaker is closed. Therefore, there is a problem that the strength of the insulating frame is unstable, and the reliability of the withstand voltage performance and the energization performance of the vacuum valve is impaired.

Further, when a vacuum circuit breaker is configured to support one vacuum valve by two insulating frames as in the vacuum circuit breaker shown in patent document 1, six insulating frames are required in the case of a three-phase circuit breaker, which has a problem of increasing the cost.

In addition, when the insulating frames are combined three-phase as in the vacuum circuit breaker shown in patent document 2, there is a problem that assembling performance of the phase positioned in the middle is poor in the case where the vacuum valves are arranged in three phases.

Further, the fixing plate for supporting the fixed side of the vacuum interrupter is required to have a strength capable of withstanding an impact load generated in the main circuit when the vacuum interrupter is closed or opened and a function of supplying current to the main circuit of the vacuum interrupter, and therefore, a material having high current-supplying performance such as copper or aluminum and a thickness capable of withstanding the impact load are required. Therefore, there is a problem that the fixed plate becomes large and the cost increases.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a main circuit structure of a vacuum circuit breaker capable of improving stability and suppressing cost without lowering withstand voltage performance and energization performance.

Technical scheme for solving technical problem

The vacuum circuit breaker of the present invention comprises: a main circuit structure including a vacuum valve having a fixed contact and a movable contact, a fixed side terminal connected to the fixed contact of the vacuum valve, a movable side terminal connected to the movable contact of the vacuum valve, and an insulating rod connected to the movable contact of the vacuum valve and opening and closing the fixed contact and the movable contact; and an insulating support member for supporting the main circuit structural member, wherein the insulating support member is a frame structural member having openings on upper and lower surfaces and both side surfaces of a portion where the vacuum valve is disposed and a portion where the insulating rod is disposed.

Effects of the invention

According to the present invention, the insulating support member supporting the main circuit structural member having the vacuum interrupter is used as the frame structural member, and thus the vacuum circuit breaker capable of improving air convection without increasing an electric field outside the vacuum interrupter and improving reliability of withstand voltage performance and energization performance around the vacuum interrupter of the vacuum circuit breaker can be provided at low cost.

Drawings

Fig. 1 is a side sectional view showing a switchgear provided with a vacuum circuit breaker according to embodiment 1 of the present invention.

Fig. 2 is a perspective view showing an insulating support according to embodiment 1 of the present invention.

Fig. 3 is a view showing a side shape of the insulating support member in fig. 2.

Fig. 4 is a view showing the shape of the upper surface of the insulating support in fig. 2.

Fig. 5 is a side view showing a structure of a single pole section of a vacuum circuit breaker according to embodiment 1 of the present invention.

Fig. 6 is a view showing a cross-sectional shape along the line a-a in fig. 5.

Fig. 7 is a view showing a cross-sectional shape along the line B-B in fig. 5.

Fig. 8 is a side view showing a main part structure of a vacuum circuit breaker according to embodiment 1 of the present invention.

Fig. 9 is a plan view showing the shape of the upper surface of the vacuum circuit breaker in fig. 8.

Fig. 10 is a perspective view showing a main part structure of a vacuum circuit breaker according to embodiment 2 of the present invention.

Fig. 11 is a side view showing a main part structure of a vacuum circuit breaker according to embodiment 3 of the present invention.

Detailed Description

Embodiment mode 1

A switchgear according to embodiment 1 of the present invention will be described below with reference to fig. 1 to 9.

Fig. 1 is a side sectional view showing a switchgear provided with a vacuum circuit breaker according to embodiment 1 of the present invention, fig. 2 is a perspective view showing an insulating support according to embodiment 1 of the present invention, fig. 3 is a view showing a side surface shape of the insulating support in fig. 2, and fig. 4 is a view showing an upper surface shape of the insulating support in fig. 2. Fig. 5 is a side view showing the structure of a single pole section of a vacuum circuit breaker according to embodiment 1 of the present invention, fig. 6 is a view showing a cross-sectional shape taken along line a-a in fig. 5, and fig. 7 is a view showing a cross-sectional shape taken along line B-B in fig. 5. Fig. 8 is a side view showing a main part structure of a vacuum circuit breaker according to embodiment 1 of the present invention, and fig. 9 is a plan view showing a shape of an upper surface of the vacuum circuit breaker in fig. 8.

In fig. 1, the switching device includes: a case CS having a door DR and housing the respective portions; and a vacuum circuit breaker VB, an instrument current transformer CT, an instrument transformer VT and a disconnecting switch DS which are arranged in the shell CS.

Here, one terminal of the vacuum circuit breaker VB is connected to the cable CB via the connection conductor CD and the cable head CH, and the other terminal is connected to the horizontal bus bar HB. In the vacuum circuit breaker VB, the instrument current transformer CT and the instrument transformer VT are connected to a path connected to the cable CB, and the disconnecting switch DS is connected to a path connected to the horizontal bus HB. In addition, the switching device includes: a disconnecting switch operating mechanism section LP in which a disconnecting switch operating mechanism that operates the disconnecting switch DS is housed; and a circuit breaker operation mechanism portion BP in which a circuit breaker operation mechanism that operates the vacuum circuit breaker VB is housed.

As shown in fig. 5, the main circuit structural member forming the vacuum circuit breaker VB is configured by a vacuum interrupter 8, a fixed-side terminal 9, a movable-side terminal 7a, and an insulating rod 6, and is fixed to the insulating support 1 via a fixed plate 10 and a fixed plate fixing portion 4, wherein the vacuum interrupter 8 has a fixed contact and a movable contact, the fixed-side terminal 9 is connected to the fixed contact of the vacuum interrupter 8, the movable-side terminal 7a is connected to the movable contact of the vacuum interrupter 8, and the insulating rod 6 is connected to the movable contact of the vacuum interrupter 8 to perform an opening and closing operation of the movable contact.

The vacuum valve 8 has a fixed contact and a movable contact inside a vacuum container formed of an insulating cylinder. Here, the fixed contact of the vacuum valve 8 is fixed to the tip of a fixed electrode rod fixed to a fixed-side end plate provided on one end surface of the insulating cylinder. The movable contact is fixed to the tip of a movable electrode rod driven by the insulating rod 6, and performs opening and closing operations with respect to the fixed contact in accordance with the movement of the movable electrode rod. The movable electrode rod is inserted through a movable end plate provided on the other end surface of the insulating cylinder, and the insertion portion is sealed by a sealing member formed of a bellows. Further, a fixed-side terminal 9 connected to the fixed contact is fixed to the fixed-side electrode rod, and a movable-side terminal 7a connected to the movable contact is fixed to the movable-side electrode rod.

Next, the structure of the insulating support 1, which is a main part of the present invention, will be described in detail.

That is, as shown in fig. 2, the insulating support 1 includes a movable conductor fixing portion 2, a fixing portion 3, and a fixed plate fixing portion 4, in which the movable conductor fixing portion 2 fixes the movable conductor of the vacuum circuit breaker VB, the fixing portion 3 fixes the insulating support 1, and the fixed plate fixing portion 4 fixes a fixed plate 10 to which the main circuit component is attached.

To explain in more detail, as shown in fig. 4, the insulating support 1 is configured as a frame structure as follows: as shown in fig. 3, the U-shaped frame 101 having the innermost end portions (right side in the drawing) connected thereto is arranged in two upper and lower stages, one side of the opening side 102 of the upper frame 101a and the lower frame 101b of the frame 101 is integrally connected to each other by the vertical insulating support fixing portions 3, and the intermediate portions of the U-shaped upper frame 101a and the lower frame 101b are integrally connected to each other by the vertical intermediate frame 103. The insulating support member 1 is formed by integrally molding an insulating resin material.

The vacuum circuit breaker VB shown in fig. 5 is formed by arranging the insulating rod 6 in a space surrounded by the insulating holder fixing portion 3 of the insulating holder 1, the intermediate frame 103, and the insulating holder fixing portion side of the U-shaped frame 101, and arranging the vacuum valve 8 in a space surrounded by the front end side 104a of the U-shaped frame 101a, the front end side 104b of the U-shaped frame 101b, and the intermediate frame 103. When there is a margin in strength, the intermediate frame 103 may be omitted.

Here, as shown in fig. 5, when the vacuum circuit breaker single pole is disposed on the insulating support 1 of the vacuum circuit breaker VB, the insulating rod side opening 5a (see fig. 3) and the insulating rod upper surface opening 5b (see fig. 4) are provided at a position where the insulating rod 6 is disposed, and the vacuum valve side opening 5c (see fig. 3) and the vacuum valve upper surface opening 5d (see fig. 4) are provided at a position where the vacuum valve 8 is disposed.

In this way, when the vacuum circuit breaker single pole is disposed on the insulating support 1, the movable side terminal 7a and the movable conductor 7b of the vacuum valve are attached to the movable side of the vacuum valve 8, and the movable conductor 7b is fastened to the movable conductor fixing portion 2. Further, a fixed-side terminal 9 is attached to the fixed side of the vacuum valve 8, and the fixed-side terminal 9 is fastened to the frame 101 of the insulating holder 1 via the fixed plate 10 and the fixed plate fixing portion 4.

Fig. 6 shows a cross section along the line a-a of fig. 5, showing the electrode 13 of the vacuum valve 8, the electrode rod 14, the insulating cylinder (insulating cylinder) 15, and the electrode shield 16 disposed on the insulating support 1. Fig. 7 shows a cross section along the line B-B of fig. 5, showing the insulating rod 6 of the vacuum valve 8 disposed in the insulating support 1 and the operating rod 17.

Fig. 8 and 9 show an example of the vacuum circuit breaker VB applied to three phases, fig. 8 shows a state in which the fixed side conductor 11 is attached to the vacuum valve fixed side terminal 9 of the single pole structure of the vacuum circuit breaker in fig. 5, and fig. 9 shows a structure in which the fixed side conductor 11a and the fixed side conductor 11b are fastened to both side surfaces of one fixed side terminal 9 of the vacuum valve 8, and a wide portion is arranged so as to be positioned in the vertical direction.

By directly attaching the fixed-side conductors 11(11a, 11b) to both side surfaces of the fixed-side terminal 9 of the vacuum circuit breaker VB without passing through the fixed plate 10 that fixes the vacuum valve 8 and the insulating support 1 in this way, the current-carrying performance can be improved due to the increase in the conductor cross-sectional area, and the heat-dissipating performance of the conductor portion can be improved without hindering air convection because the fixed-side conductors 11a and the fixed-side conductors 11b, which are flat conductors, are arranged in the vertical direction (vertical direction). In addition, although an example in which two conductors (11a, 11b) are used as the fixed-side conductor 11 is shown, in a case where the flowing current is not large, only one of the conductors may be used.

As described above, since the insulating support 1 is formed of the frame structure having the opening portions on the upper surface and the side surface, the main circuit structure having high heat dissipation performance can be formed without preventing the air convection around the vacuum valve 8. Further, since the insulating support 1 is provided with a large opening, the bolt fastening work at the time of assembly can be facilitated. Further, since the insulating support 1 is configured to have independent phases, when the vacuum circuit breaker VB is arranged in three phases, only the central phase can be first installed and then the phases on both sides can be installed, thereby improving the workability of the installation.

Further, since the vacuum circuit breaker VB is a device that closes or breaks an electric current by operating the movable electrode of the vacuum interrupter 8, the insulating holder 1 that supports the vacuum interrupter 8 is required to have a strength that can withstand an impact load generated when the vacuum circuit breaker is closed or opened, and the fixing plate 10 that fixes the insulating holder 1 and the vacuum interrupter 8 is also required to have a strength that can withstand an impact load, but in embodiment 1, as shown in fig. 5 and 8, the fixing plate 10 has a function of supporting the vacuum interrupter 8 by withstanding an impact of the vacuum circuit breaker, and the fixing side terminal 9 has a function of connecting to and energizing the main circuit of the vacuum circuit breaker, and the fixing side terminal 9 and the fixing plate 10 are configured to separate the functions of energizing and energizing. Therefore, the fixing plate 10 does not need to use expensive metal such as aluminum or copper having electrical conductivity, and the fixing plate 10 can be made of inexpensive metal such as iron.

Further, as shown in fig. 5, since the fixing plate 10 is disposed so as to extend between the end portions of the U-shaped frame 101, the fixing plate 10 has a size larger than the diameter of the vacuum valve 8, and also needs to have a necessary thickness in order to achieve strength necessary for supporting the vacuum valve 8. Although the fixing plate 10 is large in size and increased in material, cost increase can be suppressed by using an inexpensive material such as iron. In addition, although the fixed-side terminal 9 needs an expensive material having an electrical conduction performance, such as copper or aluminum, the material cost is not so much increased as long as the size is about the same as the diameter of the vacuum valve 8.

Embodiment 2.

Next, a vacuum circuit breaker as a main part of a switchgear according to embodiment 2 of the present invention will be described with reference to fig. 10.

In embodiment 2, as shown in fig. 10, a heat radiation fin 12 is disposed between a fixed side conductor 11a and a fixed side conductor 11b of a main circuit structural member of a vacuum circuit breaker. The configuration other than the heat radiating fins 12 is the same as that of embodiment 1, and therefore, the description thereof is omitted.

By providing the heat radiation fins 12 between the fixed side conductor 11a and the fixed side conductor 11b in this way, the heat generated in the fixed side conductors 11a and 11b is easily discharged out of the space by air convection. Further, since the heat radiation fins 12 are disposed in the space sandwiched between the fixed side conductor 11a and the fixed side conductor 11b, the electric field around the heat radiation fins 12 hardly rises, and the withstand voltage performance does not decrease.

Embodiment 3.

Next, a vacuum circuit breaker according to embodiment 3 of the present invention will be described with reference to fig. 11.

In embodiment 1 described above, the fixed-side terminals 9 are formed of a metal having good conductivity and the fixed plate 10 is formed of an inexpensive iron or the like, thereby providing a structure having both functions of energization and strength, but as shown in fig. 11, both the fixed-side terminals 9 and the fixed plate 10 may be formed of a metal having good energization performance such as copper or aluminum, and the fixed-side conductor 13 may be directly fastened to the fixed plate 10.

With the above configuration, the cost of the main circuit component increases by a factor of more expensive metal such as copper or aluminum than iron, but the fixed-side conductor 13 can be directly fastened to the fixed plate 10, and the work efficiency of assembly can be improved.

In addition, in embodiments 1 to 3, the description has been given of the case where the fixing plate fixing portions 4 provided at the distal end portion of the insulating support 1 are arranged horizontally above and below the distal end of the insulating support 1, but the present invention is not limited thereto. For example, the same effect can be exhibited by a main circuit structure of a vacuum circuit breaker configured such that the vertical direction of the insulating support 1 shown in fig. 1 is rotated by 90 degrees in the vertical direction, and the fixing plate fixing portions 4 provided at the front end portion of the insulating support 1 are respectively arranged in the vertical direction on the left and right sides of the front end portion of the insulating support 1, that is, such that fig. 2 is a plan view and fig. 3 is a side view.

In the present invention, a part or all of the embodiments may be freely combined, or the embodiments may be appropriately modified or omitted within the scope of the invention described above.

(symbol description)

1: an insulating support; 2: a movable conductor fixing part of the vacuum circuit breaker;

3: an insulating support member fixing portion; 4: a fixed plate fixing part of the circuit breaker;

5 a: an insulating rod side opening part of a main circuit of the vacuum circuit breaker;

5 b: an opening part on the upper surface of an insulating rod of a main circuit of the vacuum circuit breaker;

5 c: a vacuum valve side opening part; 5 d: an opening part on the upper surface of the vacuum valve;

6: an insulating rod; 7 a: a vacuum valve movable side terminal;

7 b: a movable conductor; 8: a vacuum valve; 9: a vacuum valve fixing side terminal;

10: a fixing plate; 11. 11a, 11b, 13: fixing the side conductor;

12: a heat dissipating fin; 101: a U-shaped frame of insulating support members;

103: an intermediate frame of the insulating support.

Claims (7)

1. A vacuum interrupter, comprising:

a main circuit structure including a vacuum valve having a fixed contact connected to the fixed contact of the vacuum valve and a movable contact, a fixed side terminal connected to the movable contact of the vacuum valve, a movable side terminal connected to the movable contact of the vacuum valve, and an insulating rod connected to the movable contact of the vacuum valve and opening and closing the fixed contact and the movable contact; and

an insulating support supporting the main circuit structural member,

it is characterized in that the preparation method is characterized in that,

the insulating support is a frame structure having openings on the upper and lower surfaces and both side surfaces of a portion where the vacuum valve is disposed and a portion where the insulating rod is disposed.

2. Vacuum interrupter according to claim 1,

the insulating support is configured by arranging two layers of U-shaped frames to form an insulating support fixing portion, the insulating support fixing portion connects one side of the opening side of the U-shaped frames, and the insulating rod is arranged in a space surrounded by the insulating support fixing portion and a portion of the U-shaped frames near the insulating support fixing portion side.

3. Vacuum interrupter according to claim 1,

the insulating support is configured by arranging two layers of U-shaped frames to form an insulating support fixing portion, the insulating support fixing portion connects one sides of opening sides of the U-shaped frames to each other and forms a shape that respective intermediate portions of the U-shaped frames are connected to each other by an intermediate frame, the insulating rod is arranged in a space surrounded by the insulating support fixing portion, the intermediate frame and a portion of the U-shaped frames on the side of the insulating support fixing portion, and the vacuum valve is arranged in a space surrounded by a front end side of the U-shaped frames and the intermediate frame.

4. Vacuum interrupter according to one of the claims 1 to 3,

the insulating support member has three portions at which the vacuum valves are arranged and three portions at which the insulating rods are arranged, and is formed by integrating the three portions at which the vacuum valves are arranged and the three portions at which the insulating rods are arranged.

5. Vacuum interrupter according to one of the claims 1 to 4,

a fixing plate made of an inexpensive metal having low electric conductivity is attached to a fixing portion provided at a front end of the insulating support, and a fixing side terminal made of a metal having high electric conductivity is attached to the vacuum valve, and the fixing side terminal is fastened to the fixing plate to support the main circuit structure, and a conductor on a fixing side is directly connected to the fixing side terminal of the main circuit structure.

6. Vacuum interrupter according to one of the claims 1 to 5,

the conductor connected to the fixed side of the fixed side terminal has a wide shape, is directly connected to both side surfaces of the fixed side terminal, and is disposed so that the wide portion is positioned in the vertical direction.

7. The vacuum interrupter of claim 6,

and a heat radiation fin is arranged between at least two conductors on the fixed side fastened on two side surfaces of the fixed side terminal.