JP2008218001A - Electrode arrangement of gas-blast load-break switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode arrangement of a gas switch, capable of improving heat insulating performance for a permanent magnet, and suppressing deterioration of magnetic force of the permanent magnet. <P>SOLUTION: A stationary contact 1 and a movable contact 2 are provided coaxially each other in the inside of the arc-extinguishing chamber of a gas-blast circuit-breaker. An arc A is generated between both contacts 1, 2 by a breaking current when parting the contacts. First and second doughnut-shaped heat insulating support pieces 3, 4 made of a heat insulating material of an insulator, and a cylindrical permanent magnet 5 to apply magnetic force to the ark A are provided in the stationary contact 1. An intermediate gas space C is formed between the inner wall of the intermediate part of the stationary contact 1 and the side face of the permanent magnet 5 facing the inner wall by the first and second heat insulating support pieces 3, 4. An arc-extinguishing gas is filled in the end side gas space B and the intermediate gas space C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrode device for a gas switch used for a gas switch such as a gas circuit breaker, a gas disconnect switch, and a ground switch for opening and closing an electric circuit of an electric power system.

In the conventional gas switch, a permanent magnet is arranged inside the fixed electrode, and when the movable electrode is separated from the fixed electrode and an arc is generated between the electrodes, the arc is magnetically driven by the magnetic force of the permanent magnet. Then, the arc is extinguished by SF ₆ gas flowing between the electrodes (see, for example, Patent Document 1).

JP-A-2-21522

  In the conventional gas switch as described above, the entire permanent magnet is covered with a heat insulating material made of tetrafluoroethylene resin. However, the temperature of the arc generated at the time of electrode separation is about 20000 K, and the temperature of the arc generation point on the fixed electrode rises rapidly. Therefore, even if a heat insulating material is used, the heat of the arc is transmitted to the permanent magnet. The heat changes the magnetic properties of the permanent magnet, and the magnetic force is permanently reduced. For this reason, while the current interruption is repeated, the magnetic driving action of the arc by the permanent magnet cannot be obtained.

  The present invention has been made to solve the above-described problems, and can improve the heat insulation of the permanent magnet and can suppress the decrease in the magnetic force of the permanent magnet. The purpose is to obtain.

  An electrode device for a gas switch according to the present invention is provided by a cylindrical first electrode having a hollow portion, provided along the axial direction of the first electrode, and driven by an opening / closing drive unit for opening / closing an electric circuit of a power system. A hollow cylindrical second electrode that is brought into contact with and separated from the first electrode, a permanent magnet that is provided inside the first electrode and magnetically drives an arc generated between the first and second electrodes, and a heat insulating material. In addition to supporting the permanent magnet from the inner wall of the first electrode, a heat insulating support that forms a gas space between the permanent magnet and the inner wall of the first electrode is provided.

  Since the gas space is formed between the permanent magnet and the inner wall of the first electrode by the heat insulating support that supports the permanent magnet from the first electrode, the electrode device of the gas switch according to the present invention is generally solid. The thermal conductivity of the gas is smaller than the thermal conductivity of the gas, so that the heat insulation of the permanent magnet can be improved, the change in the temperature characteristics of the permanent magnet due to the arc heat is suppressed, and the magnetic force of the permanent magnet is reduced. The decrease can be suppressed.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a cross-sectional view showing an electrode device of a gas disconnector according to Embodiment 1 of the present invention.
In the figure, a cylindrical fixed contact 1 as a first electrode and a hollow cylindrical movable contact 2 as a second electrode are coaxially provided inside the arc extinguishing chamber main body of the gas disconnector. Yes. Both contacts 1 and 2 are made of metal.

  The fixed contact 1 is fixed to the inner wall of the arc extinguishing chamber and is electrically connected to one end of the electric circuit of the power system. Further, the internal shape of the fixed contact 1 is hollow. Further, the distal end surface of the fixed contact 1 (the end surface on the movable contact 2 side) is curved toward the radial center of the movable contact 2. The movable contact 2 is electrically connected to the other end of the electric circuit of the power system. The movable contact 2 can be brought into and out of contact with the fixed contact 1 and is separated from the fixed contact 1 by driving of an opening / closing drive unit (operation device; not shown) for opening and closing the electric circuit of the power system. At the same time, the fixed contact 1 is contacted. An arc A is generated between the contacts 1 and 2 due to a breaking current that flows when the contacts are opened.

  In the fixed contact 1, doughnut-shaped first and second heat insulating support pieces 3, 4 made of an insulating heat insulating material (for example, Teflon; registered trademark) and a columnar shape (or a rectangular parallelepiped for applying a magnetic force to the arc A) ) Permanent magnets 5 are provided. The 1st and 2nd heat insulation support pieces 3 and 4 comprise the heat insulation support body. The thermal conductivity of the first and second heat insulating support pieces 3 and 4 is smaller than the thermal conductivity of the fixed contact 1. Furthermore, the 1st and 2nd support body notch parts 3a and 4a are provided in the inner peripheral part of the 1st and 2nd heat insulation support pieces 3 and 4 over the perimeter. The first heat insulating support piece 3 is fixed to the tip surface side in the fixed contact 1. The second heat insulating support piece 4 is fixed to the middle portion in the length direction in the fixed contact 1. A corner of one end of the permanent magnet 5 is joined to the first support notch 3a. Moreover, the corner | angular part of the other end of the permanent magnet 5 is joined to the 2nd support body notch part 4a. That is, the permanent magnet 5 is supported by the first and second heat insulating support pieces 3 and 4 at the corners (four corners of the cross section in the length direction) at both ends in the length direction from the fixed contact 1. The arc A is magnetically driven in the circumferential direction of the distal end surface of the fixed contact 1 by the magnetic force of the permanent magnet 5.

Furthermore, the arc extinguishing chamber is filled with an arc extinguishing gas such as SF ₆ gas and air. The arc extinguishing chamber is provided with a medium ejecting portion (not shown) for blowing arc extinguishing gas to the arc A, and the arc extinguishing ejected from the medium ejecting portion when both the contacts 1 and 2 are opened. The arc A is cooled by the gas. Furthermore, the arc A is deformed so that its entire length extends in the radial direction of the fixed contact 1 by the magnetic drive by the magnetic force of the permanent magnet 5. The arc A is cooled and extinguished by the arc extinguishing gas from the medium ejection part, and the contacts 1 and 2 are electrically disconnected. That is, the full length of the arc A is extended by the magnetic force of the permanent magnet 5 and the contact area of the arc A with the arc extinguishing gas is increased, so that the arc A is extinguished.

  Here, between the inner wall on the front end surface side of the fixed contact 1 and the end surface (the top of the head; right side in the figure) of the permanent magnet 5 facing the inner wall, the inner peripheral portion of the second heat insulating support piece 3 An end face side gas space B is formed. Further, between the inner wall of the intermediate portion in the length direction of the fixed contact 1 and the side surface of the permanent magnet 5 facing the inner wall, the intermediate gas space C is formed by the first and second heat insulating support pieces 3 and 4. Is formed. The end face side gas space B and the intermediate part gas space C are filled (accommodated) with an arc extinguishing gas. The thermal conductivity of the arc extinguishing gas is further smaller than the thermal conductivity of the first and second heat insulating support pieces 3 and 4.

  When the arc A is generated when the contacts 1 and 2 are opened, the arc A itself has a temperature of about 20000 K. Therefore, the arc on the tip surface of the fixed contact 1 is heated by the heat of the arc A. The location where A is generated is rapidly heated, and the heat is transmitted to the entire fixed contact 1. Along with this, heat is transferred from the inner wall of the fixed contact 1 to the corners (four corners in the longitudinal direction) of the permanent magnet 5 through the first and second heat insulating support pieces 3, 4. Due to the heat insulating action of the heat insulating support pieces 3, 4, the temperature rise width at the corners of the permanent magnet 5 becomes slight. Further, in the intermediate portion in the radial direction of the end surface of the permanent magnet 5 on the movable contact 2 side and the intermediate portion in the length direction of the side surface of the permanent magnet 5, the heat of the fixed contact 1 is obtained by the end surface side gas space B and the intermediate portion gas space C. Is almost cut off, so that the temperature hardly rises.

  In the electrode device of the gas disconnector as described above, the gas space is formed between the permanent magnet 5 and the inner wall of the fixed contact 1 by the first and second heat insulating support pieces 3 and 4 that support the permanent magnet 5 from the fixed contact 1. Since B and C are formed, the thermal conductivity of the gas (gas) is generally smaller than the thermal conductivity of the solid, so that the heat insulation of the permanent magnet 5 can be improved, and the arc A The change of the temperature characteristic of the permanent magnet 5 due to the heat of is suppressed, and the decrease in the magnetic force of the permanent magnet 5 can be suppressed.

  Further, since the decrease in the magnetic force of the permanent magnet 5 can be suppressed, the attenuation of the magnetic drive action of the arc A by the permanent magnet 5 can be reduced, and the magnetic drive action of the arc A by the permanent magnet 5 can be reduced over a long period of time. Can be stabilized across. At the same time, the temperature increase of the permanent magnet 5 due to the current flowing between the contacts 1 and 2 in the normal state can be suppressed.

  Furthermore, since the corners of the permanent magnet 5 are supported from the inner wall of the fixed contact 1 by the first and second heat insulating support pieces 3 and 4, the permanent magnet 5 can be prevented from swinging due to vibration or the like and fixed. Chipping and cracking of the entire permanent magnet 5 and corners due to the collision of the contact 1 and the permanent magnet 5 can be prevented.

  Furthermore, the 1st and 2nd heat insulation support pieces 3 and 4 are divided | segmented in the location of the intermediate part gas space C, and the 1st and 2nd support body notch parts are divided into the 1st and 2nd heat insulation support pieces 3 and 4. Since 3a and 4a are provided, the 1st and 2nd heat insulation support pieces 3 and 4 and the permanent magnet 5 can be easily attached to the inside of the fixed contact 1. FIG. At the same time, the first and second heat insulating support pieces 3 and 4 can be easily processed.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. FIG. 2 is a cross-sectional view showing an electrode device of a gas disconnector according to the second embodiment. In the first embodiment, the shape of the first and second heat insulating support pieces 3 and 4 is a donut shape, and the radial center portions of the first and second heat insulating support pieces 3 and 4 are open. In the second embodiment, the first and second heat insulating support pieces 3 and 4 have blocking portions 3b and 4b that close the respective radial center portions. That is, the end face side gas space B is formed so as to be covered by the closed portion 3 b of the first heat insulating support piece 3. Other configurations are the same as those in the first embodiment.

  In the electrode device of the gas disconnector as described above, the end face side gas space B is formed so as to be covered with the closed portion 3b of the first heat insulating support piece 3, so that the heat of the front end surface of the fixed contact 1 is the first heat insulating. After being absorbed by the closing portion 3b of the support piece 3, it is transmitted to the permanent magnet 5 through the end face side gas space B having a lower thermal conductivity than the first heat insulating support piece 3, thereby As compared with the electrode device of the gas disconnector, the heat insulating property for the permanent magnet 5 can be improved, and the temperature rise of the permanent magnet 5 can be further suppressed.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. FIG. 3 is a cross-sectional view showing an electrode device of a gas disconnector according to Embodiment 3. The first heat insulating support piece 3 is fixed from the inner wall on the front end face side of the fixed contact 1 to the side opposite to the movable contact 2, and the end face side gas space B in Embodiment 2 is the first heat insulating support piece. 3 is divided into a permanent magnet side gas space D and a stationary contact inner wall side gas space (first electrode inner wall side gas space) E. Other configurations are the same as those in the second embodiment.

  In the electrode device of the gas disconnector as described above, the two gas spaces D and E and the first gap between the distal end surface of the fixed contact 1 and the radial intermediate portion of the end surface of the permanent magnet 5 on the movable contact 2 side. Since the heat insulating support piece 3 is interposed, the heat insulating property for the permanent magnet 5 can be improved as compared with the electrode device of the gas disconnector according to the second embodiment, and the temperatures of both end surfaces in the length direction of the permanent magnet 5 can be improved. The rise can be kept lower.

Embodiment 4 FIG.
In the second and third embodiments, the fixed contact 1 has the tip surface. However, as shown in FIG. 4, the tip surface of the fixed contact 1 may be opened, and the shape of the fixed contact 1 is hollow. It may be cylindrical. In this case, direct contact of the arc A with the permanent magnet 5 can be prevented by the closing portion 3 b of the first heat insulating support piece 3. At the same time, the transmission of the temperature of the arc A to the permanent magnet 5 is suppressed by the end face side gas space B, and a decrease in the magnetic force of the permanent magnet 5 can be suppressed.

Embodiment 5. FIG.
Next, a fifth embodiment of the present invention will be described. FIG. 5 is a cross-sectional view showing an electrode device of a gas disconnector according to Embodiment 5. The first and second heat insulating support pieces 3, 4 of the fifth embodiment have cylindrical portions 3 c, 4 c along the inner wall in the length direction of the fixed contact 1, respectively. The end faces of the cylindrical portions 3c and 4c are joined to each other. That is, the intermediate gas space C is covered by the cylindrical portions 3c and 4c of the first and second heat insulating support pieces 3 and 4. Other configurations are the same as those in the second embodiment or the third embodiment.

  In the electrode device of the gas disconnector as described above, the intermediate part gas space C is formed so as to be covered with the cylindrical portions 3c, 4c of the first and second heat insulating support pieces 3, 4, so Is absorbed by the cylindrical portions 3c, 4c of the first and second heat insulating support pieces 3, 4, and then the intermediate gas space C having a lower thermal conductivity than the first and second heat insulating support pieces 3, 4 is used. Therefore, the heat insulation of the permanent magnet 5 can be improved compared to the electrode device of the gas disconnector according to the first embodiment, and the temperature rise of the side surface of the permanent magnet 5 can be further increased. It can be kept low.

Embodiment 6 FIG.
Next, a sixth embodiment of the present invention will be described. FIG. 6 is a cross-sectional view showing an electrode device of a gas disconnector according to Embodiment 6. In Embodiment 1-5, the notch parts 3a and 4a for supporting the corner | angular part of the permanent magnet 5 are provided over the perimeter of the inner peripheral part of the 1st and 2nd heat insulation support pieces 3 and 4. As shown in FIG. However, the first and second heat insulating support pieces 3 and 4 of the fifth embodiment have end face joining protrusions 3d and 4d that join the radial center of the end face in the length direction of the permanent magnet 5, and permanent parts. Side surfaces of the magnet 5 are provided with side surface projections 3e and 4e that are joined over the entire circumference. The first and second heat insulating support pieces 3 and 4 support, from the fixed contact 1, the intermediate portion (body portion) in the length direction of the side surface of the permanent magnet 5 and the intermediate portions in the radial direction of both end surfaces of the permanent magnet 5. ing. Further, the first and second heat insulating support pieces 3 and 4 form a corner gas space F adjacent to the corners (four corners in the longitudinal direction) of the permanent magnet 5. Other configurations are the same as those in the first embodiment.

  Here, at the start of opening of the contacts 1 and 2, an arc A is generated so as to connect the portions that have been in contact with the end of the contacts 1 and 2. That is, the arc A is likely to be generated at the edge between the tip surface and the side surface of the fixed contact 1, and the heat of the arc A extends from the edge of the fixed contact 1 to the entire surface of the fixed contact 1 and the fixed contact. The temperature is transmitted to the inside of 1. On the other hand, in the electrode device of the gas disconnector as described above, the corner gas space F is formed by the first and second heat insulating support pieces 3 and 4 so as to be adjacent to the corner of the permanent magnet 5. Therefore, the temperature rise at the corners of the permanent magnet 5 can be suppressed.

Embodiment 7 FIG.
Next, a seventh embodiment of the present invention will be described. FIG. 7 is a cross-sectional view showing an electrode device of a gas disconnector according to a seventh embodiment. In the first to sixth embodiments, the permanent magnet 5 is provided on the fixed contact 1, but in the seventh embodiment, the permanent magnet 5 is provided on the movable contact 2. Moreover, the heat insulation support body of Embodiment 7 is the donut-shaped 3rd heat insulation support piece 6 fixed to the stationary contact 1 side of the outer peripheral surface of a 1st electrode, and the anti-fixation contact 1 side from the 3rd heat insulation support piece 6 And a doughnut-shaped fourth heat-insulating support piece 7 fixed to the outer peripheral surface of the movable contact 2 at intervals.

  The shape of the permanent magnet 8 of the seventh embodiment is a donut shape (ring shape), and the inner peripheral surface of the permanent magnet 8 faces the outer peripheral surface (side surface) of the movable contact 2. The permanent magnet 8 is disposed across the outer peripheral surfaces of the third and fourth heat insulating support pieces 6 and 7. Further, the permanent magnet 8 is supported from the outer peripheral surface of the movable contact 2 by the third and fourth heat insulating support pieces 6 and 7. An inner peripheral gas space G is formed by the third and fourth heat insulating support pieces 6 and 7 between the inner peripheral surface of the permanent magnet 8 and the outer peripheral surface of the movable contact 2 facing the inner peripheral surface. ing. Other configurations are the same as those in the first embodiment.

  In the gas disconnector electrode device as described above, even when the permanent magnet 8 is disposed on the movable contact 2, the same effect as that of the gas disconnector electrode device of the first embodiment can be obtained.

  In addition, although Embodiment 1-7 demonstrated the electrode apparatus of the gas disconnector, this invention is applicable also to the electrode apparatus of a gas circuit breaker, and the electrode apparatus of a ground switch.

  In the first to seventh embodiments, the columnar fixed contact 1 is fixed to the inner wall of the arc extinguishing chamber, and the hollow cylindrical movable contact 2 is driven by the opening / closing drive unit. The electrode may be fixed to the inner wall of the arc extinguishing chamber, and the columnar first electrode may be driven by the opening / closing drive unit. That is, the fixed side and the movable side of both contacts may be opposite to each other.

It is sectional drawing which shows the electrode apparatus of the gas disconnection switch by Embodiment 1 of this invention. It is sectional drawing which shows the electrode apparatus of the gas disconnection switch by Embodiment 2 of this invention. It is sectional drawing which shows the electrode apparatus of the gas disconnector by Embodiment 3 of this invention. It is sectional drawing which shows the electrode apparatus of the gas disconnector by Embodiment 4 of this invention. It is sectional drawing which shows the electrode apparatus of the gas disconnector by Embodiment 5 of this invention. It is sectional drawing which shows the electrode apparatus of the gas disconnector by Embodiment 6 of this invention. It is sectional drawing which shows the electrode apparatus of the gas disconnector by Embodiment 7 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Fixed contact (1st electrode), 2 Movable contact (2nd electrode), 3 1st heat insulation support piece, 3d, 4d End surface joining protrusion part, 3e, 4e Side surface protrusion protrusion part, 4 2nd heat insulation support piece, 5, 8 Permanent magnet, 6 3rd heat insulation support piece, 7 4th heat insulation support piece, A arc, B end surface side gas space, C middle part gas space, D permanent magnet side gas space, E fixed contact inner wall side gas space ( 1st electrode inner wall side gas space), F 2 corner gas space, G 2 inner periphery gas space.

Claims (6)

A cylindrical first electrode having a hollow portion;
A hollow cylindrical second electrode which is provided along the axial direction of the first electrode and is brought into contact with and separated from the first electrode by driving an opening / closing drive unit for opening / closing an electric circuit of the power system;
A permanent magnet provided inside the first electrode for magnetically driving an arc generated between the first and second electrodes, and a heat insulating material, and supporting the permanent magnet from the inner wall of the first electrode. A gas switch electrode device comprising: a heat insulating support that forms a gas space between the permanent magnet and the inner wall of the first electrode. The heat insulating support includes a first heat insulating support piece fixed to an end of the first electrode on the second electrode side, and a length direction inside the first electrode spaced from the first heat insulating support piece. It is comprised by the 2nd heat insulation support piece fixed to the center part,
The shape of the permanent magnet is a columnar shape,
Each of the first and second heat insulating support pieces has a donut shape,
The said 1st and 2nd heat insulation support piece forms the said gas space in the radial direction center part of the end surface by the side of the 2nd electrode of the said permanent magnet, and the side surface of the length direction center part of the said permanent magnet. The electrode device for a gas switch according to claim 1. The second electrode side of the inner periphery of the first heat insulating support piece is closed,
3. The electrode device for a gas switch according to claim 2, wherein the first heat insulating support piece covers the gas space adjacent to the end surface of the permanent magnet on the second electrode side. The first heat insulating support piece is fixed at an interval from the second electrode side end face of the first electrode to the second electrode side, and
The gas space adjacent to the end surface on the second electrode side of the permanent magnet is partitioned into a permanent magnet side gas space and a first electrode inner wall side gas space by the first heat insulating support piece. The electrode device for a gas switch according to claim 3. The heat insulating support includes a first heat insulating support piece fixed to an end of the first electrode on the second electrode side, and a second heat insulating support piece fixed to a central portion in the length direction inside the first electrode. And consists of
The first and second heat-insulating support pieces are each an end surface joining protrusion that joins the radial center portion of the end surface in the length direction of the permanent magnet, and the longitudinal center portion and the entire circumference of the side surface of the permanent magnet. And a side joining projection that joins across
2. The gas switch according to claim 1, wherein the first and second heat insulating support pieces form the gas space so as to be adjacent to corners at both ends in the length direction of the permanent magnet. Electrode device. A cylindrical first electrode having a hollow portion;
A hollow cylindrical second electrode which is provided along the axial direction of the first electrode and is brought into contact with and separated from the first electrode by driving an opening / closing drive unit for opening / closing an electric circuit of the power system;
An inner peripheral surface is provided to face the outer peripheral surface of the second electrode, and is constituted by a donut-shaped permanent magnet for magnetically driving an arc generated between the first and second electrodes, and a heat insulating material, A heat insulating support for supporting a permanent magnet from the outer peripheral surface of the second electrode and forming a gas space between the inner peripheral surface of the permanent magnet and the outer peripheral surface of the second electrode; Gas switch electrode device.

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