JP4601203B2 - Switchgear - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a switchgear in which main circuit switching means for connecting / separating a bus-side terminal and a load-side terminal and grounding switching means for connecting / separating a load-side terminal and a ground-side terminal are integrated.
[0002]
[Prior art]
In general, a switchgear (closed switchboard) receives power from a bus and distributes power to various load devices and other electrical rooms. Therefore, together with the bus side conductor for connection to the bus and the load side conductor for connection to the power transmission cable to the load, the main circuit switch for connecting and separating the bus side terminal and the load side terminal, the load side terminal A grounding switch for grounding and a control device necessary for monitoring control are disposed in a grounded metal container.
FIG. 3 is a configuration diagram showing a main part of a conventional switchgear described in, for example, Japanese Patent Publication No. 7-28488, and FIG. 4 is an electrical connection diagram of FIG.
3 and 4, an open / close function that serves as a disconnect switch for disconnecting from the bus-side terminal 2 and a ground switch for grounding the output electrode in a disconnected state of the vacuum switch 3 in a container 1 in which an insulating gas is sealed. Switches 4 and 7 for grounding the load terminals 4 and the load side terminals 5a and 5b are arranged, and are configured to connect to an external bus and a power transmission cable (not shown).
[0003]
Branch conductors 8 corresponding to each of the three phases connected to an external bus (not shown) via the bus-side terminal 2 are disposed in the container 1 and supported by an insulating support insulator 9. Each branch conductor 8 is connected to an intermediate conductor 11 supported by an insulating support insulator 10 via a vacuum switch 3 and a switch 4. Further, it is branched in two directions by the intermediate conductor 11 and connected to the load side terminals 5a and 5b via the switches 6 and 7, respectively. And it connects to an external power transmission cable (not shown) via the load side terminals 5a and 5b.
The swing electrode 4a of the switch 4 swings around the shaft 4e via a lever 4c and an insulating link 4d fixed to the drive shaft 4b. The swing electrode 4a is in a closed position in contact with the fixed electrode 4f connected to the intermediate conductor 11, a ground position in contact with the grounding conductor 12, and an intermediate disconnection position away from the fixed electrode 4f and the grounding conductor 12. And works.
The swing electrodes 6a and 7a of the switches 6 and 7 swing around the shafts 6e and 7e via levers 6c and 7c and insulating links 6d and 7d fixed to the drive shafts 6b and 7b, respectively. The oscillating electrodes 6a and 7a are in a closed position in contact with the fixed electrodes 6f and 7f connected to the intermediate conductor 11, a ground position in contact with the grounding conductors 13 and 14, and the fixed electrodes 6f and 7f and the grounding conductor. 13 and 14 move to an intermediate position.
[0004]
[Problems to be solved by the invention]
Since the conventional switchgear is configured as described above, the switches 4, 6 and 7 are operated from the closed position to the disconnected position or the ground position after the vacuum switch 3 opens the bus terminal 2. Therefore, it is necessary to arrange two switches 4 and 6 or switches 4 and 7 in series between the bus terminal 2 and the load terminals 5a and 5b. For this reason, there is a problem that it is difficult to reduce the size of the container 1.
An object of the present invention is to provide a switchgear that can be miniaturized and can improve the reliability of withstand voltage performance.
[0005]
The switchgear according to the present invention forms a vacuum state by forming an insulating storage chamber integrally connected to a metal container with a jacket of a solid insulator, and connects and separates the bus-side terminal and the load-side terminal in the insulating storage chamber. The circuit switch is housed, the fixed electrode of the main circuit switch is formed at the tip of the fixed electrode rod, the fixed electrode is disposed in the insulating housing chamber, and the fixed electrode rod is placed on the outer cover of the solid insulator. To hold between the fixed electrode bar and the outer cover of the solid insulator, and form the movable electrode of the main circuit switch at the tip of the movable electrode bar to fix the main circuit switch. In the switchgear disposed in the insulating storage chamber so as to face the electrode, an arc shield is disposed around the main circuit switch and is held by an insulating member provided with a predetermined vacuum gap from the arc shield , the outer periphery of the metal container and the insulating housing chamber Capacitors respectively the same capacity to the solid insulator in between the fixed electrode rod of the envelope formed to between the fixed electrode rod of the arc shield and the main circuit switches and the arc shield and the grounding switch of the solid insulator A metal container-side electric field relaxation ring is disposed in the metal container so as to face the arc shield, and an insulating storage chamber-side electric field relaxation ring is disposed in the insulating storage chamber on the opposite side of the metal container. The distance between the arc shield and the electric field mitigating ring on the metal container side is made smaller than the distance between the arc shield and the electric field mitigating ring on the insulating storage chamber side.
In addition, the outer diameter of the tip of the arc shield facing the metal container side electric field relaxation ring and the outer diameter of the tip of the arc shield facing the insulating storage chamber side electric field relaxation ring is set to the metal container side electric field relaxation ring and the insulating container side electric field relaxation. It is smaller than the outer diameter of the ring.
Further, the distance between the arc shield and the insulating storage chamber side electric field relaxation ring is 1.5 times or more than the distance between the arc shield and the metal container side electric field relaxation ring.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing the configuration of the first embodiment. In FIG. 1, 15 is a metal container, and electric field relaxation rings 15a to 15d are formed in the openings, respectively. Reference numeral 16 denotes an outer covering made of epoxy resin or the like in which the metal container 15 is embedded, and an insulating storage chamber 17 integrally connected to the metal container 15 is formed on the side of the metal container 15 facing the electric field relaxation ring 15a. Furthermore, openings 16 a and 16 b are formed in the outer cover 16 on the side opposite to the insulating storage chamber 17. Reference numeral 18 denotes a fixed electrode bar having a fixed electrode 18 a of a main circuit switch 20 (described later) formed at the tip, and the fixed electrode 18 a is held by the jacket 16 so as to be disposed in the insulating storage chamber 17. Further, a bus-side terminal 18b is formed on the opposite side of the fixed electrode rod 18 from the fixed electrode 18a so as to protrude from the jacket 16. Reference numeral 19 denotes a movable electrode rod having a movable electrode 19a of a main circuit switch 20 (described later) formed at the tip thereof, and is disposed to face the fixed electrode 18a so that the movable electrode 19a is disposed in the insulating storage chamber 17. In addition, the main circuit switch 20 is comprised by the fixed electrode 18a and the movable electrode 19a.
[0007]
Reference numeral 21 denotes an insulating rod connected to the movable electrode rod 19, and 22 denotes an operation rod connected to the insulating rod 21, which is connected to a drive mechanism (not shown). Reference numeral 23 denotes an electric field relaxation shield disposed on both sides of the insulating rod 21, and 24 denotes a bellows attached to the operation rod 22, which is held by the outer cover 16 via a metal sealing member 25. An insulating member 26 such as ceramic is disposed between the sealing member 25 and the metal container 15. 27 is a sealing member that seals between the insulating member 26 and the metal container 15, and 28 is an insulating member that is disposed between the metal container 15 and the fixed electrode rod 18, and a protrusion 28 a is formed. 29 is a sealing member that seals between the insulating member 28 and the metal container 15, 30 is a sealing member that seals between the insulating member 28 and the fixed electrode rod 18, and 31 is a periphery of the main circuit switch 20. The metal arc shield disposed on the projection member 28 is supported by the protrusion 28 a so that a predetermined vacuum gap 32 is formed between the metal arc shield and the insulating member 28. Note that the electric field strength between the arc shield 31 and the electric field relaxation ring 15a on the metal container 15 side is the maximum when the arc shield 31 is charged and the arc shield 31 reaches a charging potential. The shape and position are set based on experiments and experience. An electric field relaxation ring 33 is held by the sealing member 30 and is formed so as to cover a joint portion between the insulating member 28 and the sealing member 30. The opposing distance between the electric field relaxation ring 33 and the arc shield 31 is set to 1.5 times or more the opposing distance between the metal container 15 and the arc shield 31.
[0008]
Reference numeral 34 denotes a fixed electrode rod of a later-described ground switch 36 formed with a fixed electrode 34 a of a later-described ground switch 36 at the tip, and is held by the outer cover 16 so that the fixed electrode 34 a is disposed in the metal container 15. ing. Further, a load-side terminal 34b is formed on the opposite side of the fixed electrode bar 34 from the fixed electrode 34a so as to protrude from the jacket 16. Reference numeral 35 denotes a movable electrode bar of a later-described grounding switch 36 having a movable electrode 35a of a later-described grounding switch 36 formed at the tip thereof. The movable electrode 35a faces the fixed electrode 34a so that the movable electrode 35a is disposed in the metal container 15. Are arranged. The fixed switch 34a and the movable electrode 35a constitute a ground switch 36. A bellows 37 attached to the movable electrode rod 35 is held by the outer cover 16 via a sealing member 38. An insulating member 39 is disposed between the sealing member 38 and the metal container 15. Reference numeral 40 denotes a sealing member that seals between the insulating member 39 and the metal container 15, and reference numeral 41 denotes an insulating member that is disposed between the metal container 15 and the fixed electrode bar 34. 42 is a sealing member sealed between the insulating member 41 and the metal container 15, 43 is a sealing member sealed between the insulating member 41 and the fixed electrode rod 34, and 44 is held by the sealing member 43. The electric field relaxation ring is formed so as to cover the joint between the insulating member 41 and the sealing member 43.
[0009]
Reference numeral 45 denotes a grounding layer formed on the outer surface of the jacket 16 and is coated with zinc or the like. A connection conductor 46 connects the movable electrode bar 19 of the main circuit switch 20 and the fixed electrode bar 34 of the ground switch 36.
Next, the operation will be described. In FIG. 1, the arc shield 31 is normally at a floating potential. Here, when the main circuit switch 20 is opened, an arc is generated between the electrodes 18a and 19a, and metal vapor is generated from the electrodes 18a and 19a. The arc shield 31 suppresses scattering of metal vapor. Furthermore, when a discharge to the arc shield 31 occurs, the arc shield 31 becomes a charging potential. At this time, since the electric field strength between the arc shield 31 and the electric field relaxation ring 15a of the metal container 15 is maximized, the arc shield 31 discharges to the metal container 15.
Further, in order to limit the discharge between the arc shield 31 and the electric field relaxation ring 33 on the insulating storage chamber 17 side, the distance between the arc shield 31 and the electric field relaxation ring 33 is the arc shield 31 and the metal container 15 side. Since the distance is set to 1.5 times or more of the distance to the electric field relaxation ring 15a, the electric field relaxation ring 15a on the metal container 15 side can be discharged from the arc shield 31.
When the arc shield 31 reaches a charging potential, the electric field concentrates in the vacuum gap 32 between the arc shield 31 and the insulating member 28 due to the difference in the relative permittivity between the jacket 16 and the vacuum. Therefore, the outer diameters of the tip 31a of the arc shield 31 facing the electric field relaxation ring 15a on the metal container 15 side and the tip 31b of the arc shield 31 facing the electric field relaxation ring 33 on the insulating storage chamber 17 side are the electric field relaxation ring. Since the discharge from the arc shield 31 to the insulating member 28 can be suppressed by making it smaller than the outer diameter of 15a and the electric field relaxation ring 33, damage to the insulating member 28 can be reduced.
[0010]
Further, each electric field relaxation ring 15a, 15b, 15c, 15d, 33, 44 is an electric field at the junction between each insulating member 26, 28, 39, 41 and each sealing member 27, 29, 30, 40, 42, 43. Along with the relaxation, the contamination by the metal vapor generated when the electrodes 18a and 19a are opened is suppressed.
As described above, the arc shield 31 is arranged around the main circuit switch 20, the insulating member 28 is opened with a predetermined vacuum gap 32 and held by the insulating member 28, and the electric field relaxation ring is opposed to the arc shield 31. 15a is disposed in the metal container 15, an electric field relaxation ring 33 is disposed on the insulating storage chamber 17 side, and the distance between the arc shield 31 and the electric field relaxation ring 15a is determined by the distance between the arc shield 31 and the electric field relaxation ring 33a. the distance to the smaller kites, the electric field strength between the arc shield 31 and the field relaxation ring 15a is maximized, to discharge from the arc shield 31 to the metal container 15 is a floating potential, the inter-electrode flashover and ground It is possible to suppress and achieve a high withstand voltage performance.
[0011]
In addition, since the outer cover 16 is formed of a solid insulator on the outer periphery of the metal container 15 and the insulating storage chamber 17, the strength of the outer periphery can be reinforced.
Further, the outer diameters of the tip 31a of the arc shield 31 facing the electric field relaxation ring 15a on the metal container 15 side and the tip 31b of the arc shield 31 facing the electric field relaxation ring 33 on the insulating storage chamber 17 side are as follows. Since the discharge from the arc shield 31 to the insulating member 28 can be suppressed by making it smaller than the outer diameter of the electric field reducing ring 15a on the side and the electric field reducing ring 33 on the insulating storage chamber 17 side, damage to the insulating member 28 can be reduced. Can do.
Furthermore, the distance between the arc shield 31 and the electric field relaxation ring 33 on the insulating storage chamber 17 side is 1.5 times or more than the distance between the arc shield 31 and the electric field relaxation ring 15a on the metal container 15 side. Thus, the electric field relaxation ring 15a on the metal container 15 side can be discharged from the arc shield 31.
In the first embodiment, the case where the jacket 16 is formed has been described. However, the metal container 15, the insulating members 26, 28, 39, 41 and the sealing members 25, 27, 29, 30, 38, 40, 42, By setting 43 to a predetermined strength, the same effect can be expected without forming the jacket 16.
Further, although the arc shield 31 is supported by the protrusion 28a of the insulating member 28, the insulating member 28 and the outer cover 16 are integrated so that the arc shield 31 is directly supported by the outer cover 16. Similar effects can be expected.
[0012]
Embodiment 2. FIG.
FIG. 2 is a cross-sectional view showing the configuration of the second embodiment. In FIG. 2, 15 to 27, 29, 30, and 32 to 46 are the same as those in the first embodiment. Reference numerals 47 and 48 denote insulating members arranged at a predetermined interval between the metal container 15 and the fixed electrode rod 18, and 49 denotes an arc shield arranged around the main circuit switch 20, with the insulating members 47 and 48. It is supported by the jacket 16 so that a predetermined vacuum gap is formed therebetween. The metal container 15 side of the arc shield 31 is set so that the electric field strength between the arc shield 31 and the electric field relaxation ring 15a of the metal container 15 becomes maximum when the arc shield 31 reaches a charging potential. Reference numerals 51 and 52 denote sealing members which are sealed between the insulating members 47 and 48. 53 and 54 are capacitors of the same capacity embedded in the jacket 16, 55 is a connection conductor connecting the capacitors 53 and 54 and the arc shield 31, and 56 is a connection conductor. The capacitor 53 and the main circuit switch The 20 fixed electrode rods 18 are connected. A connection conductor 57 connects the capacitor 54 and the fixed electrode bar 34 of the ground switch 36.
[0013]
When the ground layer 45 is formed on the surface of the jacket 16 as in the above configuration, the floating potential of the arc shield 31 becomes a value close to the ground potential. Therefore, the insulation distance around the main circuit switch 20 needs to withstand the potential difference applied to the main circuit switch 20. However, since the potential of the arc shield 31 is 50 ± 10% between the electrodes 18a and 19a due to the partial pressure of the capacitors 53 and 54, the discharge to the arc shield 31 can be suppressed. Furthermore, since the distance between the electrodes 18a and 19a and the distance between the electrode rods 18 and 19 and the arc shield 31 can be shortened, the size can be reduced.
[0014]
【The invention's effect】
According to the present invention, an arc shield is disposed around the main circuit switch, a predetermined vacuum gap is formed between the insulating member and held by the insulating member, and the electric field relaxation ring on the metal container side is made of metal so as to face the arc shield. Place in the container and place the electric field relaxation ring on the side opposite to the metal container in the insulating storage room. From the distance between the arc shield and the electric field relaxation ring on the insulating container side, the arc shield and metal container side By reducing the distance between the electric field relaxation ring, the electric field strength between the arc shield and the metal container side electric field relaxation ring is maximized, and the arc shield discharges to the metal container that is at a floating potential. It is possible to suppress the tangling and grounding, and to realize a highly reliable withstand voltage performance.
Moreover, the outer periphery strength can be reinforced by forming a jacket with a solid insulator on the outer periphery of the metal container and the insulating storage chamber.
[0015]
In addition, the outer diameter of the tip of the arc shield that faces the metal container side electric field relaxation ring and the tip of the arc shield that faces the insulating container side electric field relaxation ring is set to the metal container side electric field relaxation ring and the insulating container side electric field relaxation. Since the discharge from the arc shield to the insulating member can be suppressed by making it smaller than the outer diameter of the ring, damage to the insulating member can be reduced.
In addition, the distance between the arc shield and the electric field relaxation ring on the insulating storage chamber side is 1.5 times or more than the distance between the arc shield and the electric field relaxation ring on the metal container side. The electric field relaxation ring can be discharged.
Furthermore, by connecting capacitors of the same capacity between the arc shield and the fixed electrode rod of the main circuit switch and between the arc shield and the fixed electrode rod of the ground switch, it is possible to suppress discharge to the arc shield. Since the distance between both electrodes and the distance between both electrode rods and the arc shield can be shortened, the size can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a configuration of a second embodiment of the present invention.
FIG. 3 is a configuration diagram showing a main part of a conventional switchgear.
4 is an electrical connection diagram of FIG. 3. FIG.
[Explanation of symbols]
15 metal container, 15a metal container side electric field relaxation ring, 17 insulating storage room,
18 Fixed electrode rod of main circuit switch, 18a Fixed electrode of main circuit switch,
18b Bus side terminal, 19 Movable electrode rod of main circuit switch,
19a movable electrode of main circuit switch, 20 main circuit switch, 28 insulating member,
31 arc shield, 32 vacuum gap,
33 Insulation storage chamber side electric field relaxation ring, 34b Load side terminal,
53, 54 capacitors.

Claims (3)

An insulation storage chamber integrally connected to the metal container is formed with a solid insulator jacket to create a vacuum state, and the main circuit switch that contacts and separates the bus side terminal and the load side terminal is stored in the insulation storage chamber. The fixed electrode of the main circuit switch is formed at the tip of the fixed electrode rod, the fixed electrode is disposed in the insulating storage chamber, the fixed electrode rod is held by the outer cover of the solid insulator, and the fixed electrode Sealing between the rod and the outer cover of the solid insulator , forming the movable electrode of the main circuit switch at the tip of the movable electrode rod and facing the fixed electrode of the main circuit switch the switchgear disposed in the chamber, by placing the arc shield around the main circuit switch and held by an insulating member provided at a predetermined vacuum gap and the arc shield, and the metal container and the insulating housing chamber periphery to form a jacket of said solid insulator of Serial arc shield and with a capacitor for each same volume to the solid insulator in between the fixed electrode rod between the fixed electrode rod of the main circuit switches and the arc shield and grounding switch, opposed to the arc shield The metal container side electric field relaxation ring is arranged in the metal container, and the insulating storage chamber side electric field relaxation ring is arranged in the insulating storage chamber on the opposite side of the metal container, and the arc shield and the insulating storage chamber side electric field relaxation are arranged. A switchgear characterized in that a distance between the arc shield and the metal container side electric field relaxation ring is made smaller than a distance between the ring and the ring.   The outer diameter of the tip of the arc shield facing the electric field relaxation ring on the metal container side and the tip of the arc shield facing the electric field relaxation ring on the insulating storage chamber side are the electric field relaxation on the metal container side electric field relaxation ring and the insulating container chamber side. The switchgear according to claim 1, wherein the switchgear is smaller than the outer diameter of the ring.   The distance between the arc shield and the electric field relaxation ring on the insulating storage chamber side is 1.5 times or more than the distance between the arc shield and the electric field relaxation ring on the metal container side. 2. Switchgear according to item 2.

Images