JPH09200915A - Gas insulated disconnector, and earth device of gas insulated disconnector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lighten the electric field of an electrode and scale down the whole shape by having a pair of insulating layers Which have apertures in interpole direction in opposition to the mounting plate of a box, a conductive layer provided inside the insulating layer, and an electrode accommodated in the space part made between the insulating layers. SOLUTION: On the side of a fixed electrode, the earth side is fixed to an insulating cylinder 16 being roughly tubular and having an aperture on the side of a main circuit. The earth side is fixed by bolt 23b to the buried electrode 22b buried in the insulating tube 16 through the spacer 25 fixed to a mounting board 24. An aperture 16a is provided on the earth side of the insulating tube 16. For the main circuit side of the insulating tube 16, the sections of an electrode 21b on fixation side and a contact 20a are open. In short, the insulating layers 31 are constituted in two sheets in parallel. What is more, with the outer and inner radii of curvature of the end of the insulating layer 31 of the insulating tube 16 as R2 and R1 (R1< R2), a conductive layer 32 is made as far as a curve 33 at the inner face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulation disconnector and a grounding device for the gas insulation disconnector.

[0002]

2. Description of the Related Art FIG. 6 shows a configuration diagram of a typical gas insulated switchgear. In the figure, the inside of the box 1 whose outer periphery is airtightly surrounded by a mild steel plate is formed by a partition wall 2 vertically provided near the front surface on the left side in the figure, and has a circuit breaker chamber 1a at the front and a busbar chamber 1b at the rear.
Each chamber 1a, 1b is filled with a sulfur hexafluoride gas (hereinafter, abbreviated as an insulating gas) at a gas pressure of about atmospheric pressure and sealed.

Of these, a circuit breaker 3 equipped with a vacuum interrupter 3a is housed inside the circuit breaker chamber 1a, and a partition wall 2
The circuit breaker 3 is connected to the insulating spacer 9 attached to the through hole (not shown). The insulating spacer 9 has the same structure on the upper and lower sides.

A disconnector 4A is provided at the ceiling of the bus room 1b.
Is attached, one terminal is connected to the upper insulating spacer 9 via the connection conductor 8, and the other terminal is connected to the connection conductor 8
It is connected to the busbar 5 fixed to the rear insulator 6 via. The bus 5 interconnects the adjacent boards.

On the other hand, a disconnector 4A is provided at the bottom of the bus room 1b.
A disconnector 4B having the same shape as the above was attached, one terminal was connected to the lower insulating spacer 9 via the connecting conductor 8, and the other terminal was vertically attached to the rear of the bottom plate via the connecting conductor 8. It is connected to the upper terminal of the cable head 7. The cable 7a connected to the cable head 7 receives the power.

Here, one of the disconnectors 4A and 4b having the same shape is shown in FIG. The movable side and fixed side support insulators 11a and 11b are fixed to the base plate 10 attached to the box body 1,
The following electrodes are fixed to the support insulators 11a and 11b, respectively. That is, the electrodes have metal shields 12a, 12b.
Are attached, and have predetermined withstand voltage characteristics. Here, the operation plate 13 is attached to the longer metal shield 12a, and the movable contact conductor 14 is opened and closed by horizontal movement. The contact plates 14 and 15 are
It is an electrode of a grounding switch that opens and closes with the contacts provided in the metal shields 12a and 12b. The operation of the disconnecting switch and the grounding switch is performed by an operation mechanism portion provided outside the box body 1 (not shown).

[0007]

In these structures, those used in the insulating gas such as the electrodes of the disconnecting switch 4A (or 4B) have a rounded shape as disclosed in, for example, JP-A-60-128807. It is made up of a metal shield that you have. This is because the electric field strength is suppressed by providing the roundness. That is, as the radius of curvature of the electrode is larger, the electric field strength is reduced and the withstand voltage characteristic is improved. In particular, since the breakdown voltage of the insulating gas depends on the electric field strength, suppression of the electric field strength leads to improvement in withstand voltage characteristics.

However, as the radius of curvature of the electrode is increased, the electric field strength is reduced accordingly, but the electrode itself is enlarged. Therefore, the gas gap between the electrode and the ground and between the electrodes, that is, between the phases is narrowed. As a result, the withstand voltage characteristic is deteriorated.

Further, as the size of the electrode becomes larger, the arrangement of the connecting conductors to be connected must be detoured so as not to contact the electrode. Thereby, the arrangement of each electric device is restricted, and the overall shape is enlarged. This goes against the recent trend of shrinking.

An object of the present invention is to provide a gas-insulated disconnector which is provided with an electric field relaxation means in the electrode portion to reduce the overall shape. Another object of the present invention is to provide a gas-insulated disconnector and a grounding device for the gas-insulated disconnector in which the space for moving the electrode is minimized to reduce the overall shape.

[0011]

In order to achieve the above object, a gas insulated disconnecting switch according to a first aspect of the present invention is a pair of gas insulating disconnectors which are mounted so as to face a mounting plate of a box body and have an opening in a direction between poles. The gist is to have an insulating layer, a conductive layer provided inside the insulating layer, and an electrode portion housed in a space formed between the insulating layers.

In such a structure, the electric field of the electrode portion can be relaxed by providing a pair of conductive layers of the insulating layers which face each other and make them both have the same potential. The outer side of the insulating layer, which is in contact with the insulating gas, is the part with the maximum electric field strength on the gas side, but the electric field strength is suppressed by the effect of the dielectric constant of the insulating layer, and from the conductive layer at the same potential as the electrode. The electron emission is suppressed, and the breakdown voltage is improved as compared with the metal shield having the same shape.

Here, if the insulating layer serving as the end of the conductive layer is provided with a curved portion that is directed inward to form the conductive layer, the electric field at the end of the conductive layer can be relaxed, and the insulating layer If the radius of curvature is made larger than the radius of curvature of the curved portion, the electric field can be further relaxed, so that the breakdown voltage is improved.

The gas insulated disconnecting switch according to claim 6 is
A pair of electrodes provided so as to be separated from each other and opposed to each other, a movable contact which can be brought into contact with and separated from the other electrode fixed to one of these electrodes, and the movable contact which is connected to the movable contact and is connected to the movable contact. An insulating rod that rotates to bring the electrodes into contact with and separate from each other, and an operating rod that is connected to the insulating rod and protrudes into the central portion between the electrodes when the electrode is opened,
It has an opening hole provided in the central portion of the insulating layer up to the main circuit electrode and ground, and a contact bar penetrating the opening hole from the ground direction, and the operating rod and the contact bar move in the same direction. In such a configuration, which is characterized in that it is a linear movement, the operating rod for operating the insulating rod that contacts and separates the electrodes and the moving direction of the contact rod for grounding are the same direction and the linear movement. Therefore, the positional relationship between the operating rod and the contact rod can be minimized.

The grounding device for a gas insulated disconnector according to claim 8 is provided on the power source side and the load side, and an opening hole provided in the central portion of the insulating layer up to the main circuit electrode and ground, and an opening hole. It has a contact bar penetrating from the ground direction, and the moving direction of the contact bar on the power supply side and the load side is the same direction and linear movement.

In such a structure, the contact bar for grounding is designed to move linearly in the opening of the insulating layer, so that the space for moving the contact bar can be minimized. .

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a gas insulated switchgear disconnector according to an embodiment of the present invention. In the figure, on the fixed electrode side, the ground side is hollow in a substantially cylindrical shape and is fixed to an insulating cylinder 16 having an opening on the main circuit side, and is fixed to a spacer 17a on the ground side and a contactor 17b is attached. A penetrating ground electrode 18 is provided. Further, on the main circuit side, a contactor 17c with which the grounding electrode 18 comes into contact, an outer conductor 19a
A contactor 20a for connecting the electrodes, an electrode 21a for fixing the contactor 20,
Further, a fixed-side electrode 21b integrated with the electrode 21a is attached. The fixed electrode 21b and the like are attached to the embedded electrode 22a embedded in the insulating cylinder 16 at a substantially middle portion thereof by the bolt 23.
It is fixed at a.

The ground side is fixed by bolts 23b to the embedded electrode 22b embedded in the insulating cylinder 16 via the spacer 25 fixed to the mounting plate 24. Reference numeral 26 is an operation mechanism portion, and 27 is a gas seal portion that maintains airtightness. In addition,
An opening 16a is provided on the ground side of the insulating cylinder 16.

The main circuit side of the insulating cylinder 16 is a fixed side electrode.
21b and contactor 20a are opened. That is, 2
It has a shape in which an insulating layer is formed substantially parallel to the sheet. The movable-side electrode has the same configuration as the fixed-side electrode, but the movable electrode 28 is fixed to the fixed electrode 21b in a movable state by a bolt 23c. An insulating rod 29 is connected to the operating rod 30 at approximately the middle of the movable electrode 28, and a gas seal portion 27 similar to the ground electrode 18 is provided in the operating mechanism portion 26.

A fixed contact 21b is attached to the fixed electrode 21c so as to face the contact 20a, and the outer conductor 19b is grounded. The fixed-side electrode and the movable-side electrode are separated from each other and are arranged substantially in parallel.

In such a structure, the main circuit can be grounded by horizontally moving the grounding electrode 18. Similarly, the horizontal movement of the operating rod 30 causes the movable electrode 28 to make a circular motion, so that the disconnecting switch is opened and closed. That is, the movements of the ground electrode 18 and the operating rod 30 are in the same direction.

Here, an enlarged view of the main part of the end portion of the insulating cylinder 16 is shown in FIG.
Shown in The outer side of the end of the insulating layer 31 has a radius of curvature R ₂ , the inner side has a radius of curvature R ₁ , and a conductive layer 32 coated with, for example, a conductive coating is formed on the inner surface up to the curved portion 33. Here, these radii of curvature are set to R ₁ <R ₂ . That is, the radius of curvature of the insulating layer 31 is increased. These configurations are the same for the movable side electrode and the fixed side electrode.

Further, FIG. 3 shows a sectional view when the disconnector is opened. The operating rod 30 moves to the right on the page, and the insulating rod 29
The movable electrode 28 connected to the is housed in the insulating cylinder 16 on the movable electrode side. This state is the opening of the disconnector, and the operating rod 30 at the ground potential is located between the electrodes of the disconnector. In this case, in the movable electrode 28, electric field relaxation is performed by the insulating cylinder 16 and the conductive layer 32 provided on the inner surface of the insulating cylinder 16.

In such a structure, the conductive layer 32 is formed on the inner surface.
FIG. 4 shows the impulse flashover voltage characteristics obtained by the present inventors using the insulating cylinder 16 provided with and the metal electrode having the same shape as the insulating cylinder 16. Here, the radius of curvature R ₂ of the insulating cylinder 16
Is 15 mm, the radius of curvature R ₁ of the curved portion is 4 mm, and R ₂ and R ₁
The ratio is almost four times. As this ratio increases, the electric field strength at the tip of the insulating layer 31 decreases.

From FIG. 4, it can be seen that the characteristic (a) of the insulating cylinder 16 is improved by about 50% as compared with the characteristic (b) of the metal electrode having the same shape. This is the same tendency in the calculated value by the electric field analysis and the measured value.

As described above, the cause of the increase in the flashover voltage is that the electric field strength is suppressed because the relative dielectric constant of the insulating layer 31 is larger than the relative dielectric constant of the insulating gas, which is about 1. The dielectric constant of the insulating layer 31 is about 5. In addition, the insulating layer 31 suppresses electron emission from the electrodes, which delays the formation of initial electrons due to dielectric breakdown.

From these facts, when the ratio R ₂ / R ₁ of the radii of curvature of the insulating layer 31 and the curved portion 33 is increased, the electric field strength is further lowered, so that the flashover voltage can be improved. That is, when the space around the insulating layer 31 has a margin, the electric field strength can be significantly suppressed by increasing R ₂ and increasing the insulating layer 31 itself. Here, R ₂ / R ₁ is 5
The above is considered preferable.

From the above, by appropriately selecting the size of the insulating layer 31 and suppressing the electric field strength, the disconnecting switch can be downsized. Further, if the disconnecting switch is downsized, the degree of freedom in the arrangement of the conductors is increased and the overall shape can be downsized.

Further, since the movements of the ground electrode 18 and the operating rod 30 are linear movements in the same direction, the positional relationship between the two can be minimized, and the disconnector can be downsized. In addition, a cylindrical opening is provided on the ground side of the insulating cylinder 16 to provide an electrode for grounding.
Since 18 is penetrated, downsizing as a grounding device can be achieved. That is, since the grounding electrode 18 moves linearly in the insulating cylinder 16, the space for moving the grounding electrode 18 becomes the minimum range. Therefore, as the grounding device of the gas insulation disconnector, it is possible to reduce the overall size of the insulation gas.

On the other hand, when the disconnecting switch is opened, the operating rod 30 at the ground potential connected to the insulating rod 29 is positioned substantially in the center between the electrodes, so that an unexpected overvoltage may enter. When dielectric breakdown occurs, it does not break between the
It is the destruction of 30 grounds. That is, the breakdown between the poles causes the overvoltage to enter the load circuit, but the overvoltage is suppressed between the ground. Furthermore, since the dielectric strength ratio between the poles and the ground is satisfied, insulation cooperation can be achieved.

As another embodiment, instead of the conductive layer 32 applied to the inside of the insulating layer 31, for example, a resistance layer of resistance paint containing carbon or a semiconductive layer containing antimony is formed. If so, the resistance becomes smaller than the surface resistivity of the insulating layer, and there is an effect of relaxing the electric field. Further, when the arc generated when the disconnecting switch is opened diffuses into the resistance layer or the like, the arc current is narrowed, so that damage to the insulating layer can be suppressed.

[0032]

As described above, according to the present invention, a pair of insulating layers, which are attached to the mounting plate of the box body so as to face each other and have an opening in the inter-electrode direction, are provided inside the insulating layers. Since the conductive layer and the electrode portion housed in the space formed between the insulating layers are provided, the electric field of the electrode portion can be relaxed and the overall shape can be reduced.

Further, a pair of electrodes provided so as to be separated from each other and opposed to each other, a movable contact which can be brought into contact with and separated from the other electrode fixed to one of these electrodes, and a movable contact which is connected to the movable contact. An insulating rod that rotates the movable contact to bring the electrodes into contact with and separate from each other, an operating rod that is connected to the insulating rod and protrudes in the central portion between the electrodes when the electrode is opened, and the center of the insulating layer between the main circuit electrode and ground. Since there is an opening hole provided in the part and a contact rod penetrating the opening hole from the grounding direction, the operating rod and the contact rod move in the same direction and in a linear movement, so The positional relationship between the bar and the contact bar can be minimized, and the overall shape can be reduced.

Further, it has an opening hole provided on the power supply side and the load side, provided in the central portion of the insulating layer up to the main circuit electrode and ground, and a contact bar penetrating the opening hole from the ground direction. Since the contact rods on the power source side and the load side are moved in the same direction and are linearly moved, the space for moving the contact rods can be minimized and the overall shape can be reduced. Can be planned.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of a gas insulation disconnecting switch showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of an essential part of an insulating cylinder 16 of FIG.

FIG. 3 is a cross-sectional view showing an open state of the gas insulation disconnector of FIG.

FIG. 4 is a characteristic diagram showing the relationship between gas pressure and impulse flashover voltage.

FIG. 5 is a side view of a conventional gas insulated disconnector.

FIG. 6 is a block diagram of a typical gas insulated switchgear.

[Explanation of symbols]

16 ... Insulating cylinder, 17, 20 ... Contact, 18 ... Grounding electrode, 21 ... Fixed electrode, 28 ... Movable electrode, 29 ... Insulating rod, 30 ... Operating rod, 31
… Insulating layer, 32… Conductive layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Masaki No. 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Corporation Fuchu factory

Claims (8)

[Claims] 1. A pair of insulating layers attached to the mounting plate of the box body so as to have openings in the interelectrode direction, conductive layers respectively provided inside the insulating layers, and the insulating layers. A gas insulated disconnecting switch having an electrode portion housed in a space formed therebetween. 2. A curved portion is formed at an end of a conductive layer provided inside the insulating layer, and the conductive layer is also provided on an inner surface up to a region where the curvature of the curved portion ends. 1
The gas-insulated disconnector described. 3. The gas insulated disconnector according to claim 2, wherein a radius of curvature R ₂ of a portion of the insulating layer that contacts the insulating gas is larger than a radius of curvature R ₁ of a curved portion of the conductive layer. 4. The gas insulated disconnector according to claim 3, wherein the ratio of the radii of curvature R ₂ / R ₁ is 5 or more. 5. A resistance layer or a semiconductive layer is provided inside the insulating layer, a curved portion is formed at an end portion of these layers, and an inner surface of a region until the curvature of the curved portion ends. The gas-insulated disconnecting switch according to claim 1, further comprising either a resistance layer or a semi-conductive layer. 6. A pair of electrodes, which are spaced apart from each other and are opposed to each other, a movable contact which can be brought into contact with and separated from the other electrode fixed to one of these electrodes, and is connected to this movable contact. An insulating rod for rotating and moving the movable contactor to bring the electrodes into contact with each other, an operating rod which is connected to the insulating rod and protrudes in the central portion between the electrodes when the electrode is opened, and an insulating layer up to the main circuit electrode and ground. Has an opening hole provided in the center of the contact hole and a contact bar penetrating the opening hole from the ground direction, and the operating rod and the contact bar move in the same direction and in a straight line. A gas-insulated disconnecting switch. 7. A pair of electrodes that are spaced apart from each other and face each other, a movable contactor that can be brought into and out of contact with the other electrode fixed to one of these electrodes, and connected to this movable contactor. And an operating rod that rotates the movable contact to bring the electrodes into contact with and separate from each other, and an operating rod that is connected to the insulating rod and protrudes in the central portion between the electrodes when the electrodes are opened. A gas-insulated disconnecting switch, characterized in that 8. An opening hole provided in the power source side and the load side, provided in the central portion of the insulating layer from the main circuit electrode to the ground,
A contact bar that penetrates these opening holes from the ground direction, and the moving directions of the contact bar on the power supply side and the load side are the same direction and linear movement. Grounding device.