JPS6319969B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vacuum shear breaker that improves the shearing performance by applying a magnetic field parallel to the arc generated during the shearing. .

Conventionally, many vacuum shield breakers have been designed to improve the shearing performance by applying a magnetic field in the same direction as the arc (so-called axial magnetic field) to the arc that occurs between a pair of electrodes during shearing. Although this type of vacuum interrupter is proposed, it is common that a coil for generating a magnetic field is attached integrally to the vacuum interrupter that serves as the opening/closing part. Then, they can be divided into those that have a coil inside the vacuum container as shown in FIG. 1, and those that have a coil outside the vacuum container as shown in FIG.

That is, the vacuum interrupter 1 shown in FIG. 1 includes a pair of lead rods 2a and 2b that hermetically penetrate through a vacuum container 10 comprising an insulator 11, and a high resistance wire is attached to the inner end of each of the lead rods 2a and 2b. The body 21 is provided with electrodes 3a and 3b, and the lead rod 2
a, 2b and electrodes 3a, 3b, and converts the current into a loop current surrounding the lead rods 2a, 2b to generate a magnetic field parallel to the arc.
a and 4b, and at least one lead rod 2b has a bellows 22 between it and the vacuum container 10 so that it can move in the axial direction (vertical direction in the figure).

The vacuum interrupter 1 configured as described above is held by an insulating frame (not shown),
In addition, lead-out conductors 5a and 5b each having a terminal portion 51 on one end side that can be freely connected to and separated from the main circuit conductors 9a and 9b are connected to the outer ends of the lead rods 2a and 2b, respectively, and an operating device (not shown), etc. The device is equipped with a necessary vacuum shield and disconnector.

Furthermore, the vacuum interrupter 1 shown in FIG. 2 does not provide a coil body behind the electrodes 3a and 3b, but is provided with a coil conductor 4 wound around the outside of the vacuum container 10 to generate an axial magnetic field. can be,
One winding end side of this coil conductor 4 has a connection lead 6
a to the outer end of the fixed lead rod 2a, and the other winding end is connected to the lead-out conductor 5a via a connecting lead 6b. The vacuum interrupter 1 configured in this way is
It is held by an insulating frame (not shown) and constitutes a necessary vacuum shield and disconnector. Note that the same reference numerals are given to the same members as in FIG. 1, and the explanation thereof will be omitted.

By the way, in the conventional axial magnetic field application type vacuum interrupter mentioned above, the pair of electrodes 3a,
The axial magnetic field of the arc generated by the contact and separation of the electrodes 3b is used to confine it in the electrode space and stabilize it, thereby improving the strength and cutting performance. There was a problem in that the arc spots on the top were concentrated and distributed near the center of the electrode or on concentric circles around the center, making it impossible to utilize the electrode surface effectively.

This phenomenon is caused by the diameter of the axial magnetic field, as is clear from Figure 3, which shows the experimental results of measuring the radial distribution state of the axial magnetic field due to the coil by changing the outer diameter (average diameter) of the coil. This seems to be due to the non-uniform distribution of directions.

In other words, in Fig. 3, the outer diameter R of the coil is plotted on the horizontal axis,
The vertical axis shows the magnetic field strength H, and the outer diameter R of the coil.
The distribution state of the radial direction of the axial magnetic field when changing is shown by curve A, curve A,
They are shown as B, C and D. According to this, when the outer diameter R of the coil is small, the magnetic field strength H takes on a convex shape with the highest value at the center point O, as shown by curve A, and as the outer diameter R of the coil increases sequentially, As shown by curves B, C, and D, the magnetic field strength H is lowest at the center point O of the coil and highest near the inner circumference of the coil, forming a concave shape. Furthermore, as the outer diameter R of the coil increases, the highest and lowest points of the magnetic field tend to decrease, and the distribution of the magnetic field in the radial direction, that is, the distribution of magnetic flux density, becomes uneven, resulting in local concentration of arc spots. It can be seen that this is causing a distribution.

The magnetic field distribution in the vacuum interrupter 1 as shown in FIG. 1 is as shown by curve A or B, and the magnetic field distribution in the vacuum interrupter 1 as shown in FIG. 2 is as shown in curve D.

The present invention has been made in view of the above points, and
A small diameter coil and a large diameter coil are combined, the small diameter coil is positioned between at least one lead rod and an electrode to form a vacuum interrupter, and the large diameter coil is fixed to an insulating frame. At the same time, the vacuum interrupter is arranged so as to surround the vacuum interrupter to form a vacuum interrupter, thereby uniformizing the radial distribution of the axial magnetic field and uniformly dispersing the arc spots. The object of the present invention is to provide a vacuum shear disconnector which is designed to improve the shear cutting performance by making effective use of the vacuum sheathing.

Next, an embodiment of the present invention will be described in FIGS. 4 to 14.
This will be explained based on the diagram.

First, FIG. 4 is a sectional side view of the main part of the vacuum shield breaker, showing the configuration for one phase. 1 is a vacuum interrupter (details of its configuration will be described later based on FIG. 5), and this vacuum interrupter 1 is
It is housed in a substantially cylindrical insulating frame 8 with a gap therebetween, and a pair of lead-out conductors 5a, 5.
It is held and fixed to this insulating frame 8 via b.

That is, one of the lead-out conductors 5a is fixed to the upper end of the insulating frame 8, and the lead rod 2a of the vacuum interrupter 1 on the fixed side is connected to the connecting portion 52 at one end of the lead-out conductor 5a (on the right side in the figure). The outer end of is connected and fixed. The other lead-out conductor 5b is fixed to a partition wall 81 located at an intermediate portion within the insulating frame 8, and a ring contact 53 provided at a connecting portion 52 of this lead-out conductor 5b is connected to a ring contact 53 on the movable side of the vacuum interrupter 1. A lead rod 2b is inserted through the lead rod 2b so as to be movable (in the vertical direction in the figure).

The pair of lead-out conductors 5a, 5b are both provided extending in the same direction (to the left in FIG. 3), and are provided at the tip of the terminal portion 51, which is the left end side of each lead-out conductor 5a, 5b. are each fitted with a contact 54 so as to be able to engage and come into contact with the ends of the main circuit conductors 9a and 9b.

The lead-out conductor 5b located on the lower side has a terminal portion 51 and a connecting portion 52 integrally formed in a uniaxial shape and made of a good conductive material such as copper material. On the other hand, in the lead-out conductor 5a located on the upper side, a terminal portion 51 and a connecting portion 52 are formed of a good conductive material such as copper material, and both are provided with a spacer (not shown) that electrically separates them. are integrally connected via the (Details will be described later based on FIGS. 7 to 9.) Furthermore, the vacuum interrupter 1 (particularly a pair of In the area surrounding the electrode portion), the sixth
A coil conductor 4 formed as shown in the figure is provided. Connection leads 6a and 6b, one end of which is fixed to the coil conductor 4, are attached to an insulating frame 8.
The other end (the upper end in the figure) is connected to a predetermined portion of the lead-out conductor 5a.

Further, the insulating frame 8 includes a pedestal frame 91.
One end (lower end) of the lead rod 2b on the movable side of the vacuum interrupter 1 is erected above the stand frame 9.
The other end (upper end) of an operating rod 92, which is interlocked and connected to an operating device (not shown) in 1, constitutes a so-called vacuum shield breaker. Note that 93 in the figure is a surface plate erected on the pedestal frame 91.

Next, the configurations of the vacuum interrupter 1, the coil conductor 4, the lead-out conductor 5a, and the insulating frame 8 will be explained in detail based on FIGS. 5 to 12.

First, FIG. 5 shows the vacuum interrupter 1. As shown in FIG. The vacuum container 10 includes a cylinder 1 made of non-magnetic metal (for example, austenitic stainless steel).
2, and end plates 13a and 13b made of an insulator (for example, alumina ceramics) that seal both ends of the cylinder 12 in the axial direction. A lead rod 2a is passed through one end plate 13a and fixed in an airtight manner, and a coil electrode 4a is provided at the inner end of the lead rod 2a. A disk-shaped electrode 3a is provided via a spacer made of stainless steel, for example. The coil electrode 4a has a plurality of arms 41 (for example, 2, 3, 4) whose inner end is connected to the lead rod 2a and extends radially outward, and each of these arms 41. One end side is connected to the outer end of 41,
The other end of the lead rod 42 extends in the same direction and is connected to the back of the electrode 3a through a connecting fitting 43.
The current between the lead rod 2a and the electrode 3a is divided into multiple circuits (for example, divided into 1/2, 1/3, and 1/4), and is formed into a loop current surrounding the lead rod 2a, creating an axial magnetic field (electrode surface This generates a magnetic field that is perpendicular to the arc and parallel to the arc.

The other lead rod 2b, which is disposed opposite to the lead rod 2a, is provided on the end plate 13b via a bellows 22 so as to be airtight and movable. A plate-shaped electrode 3b is provided. By moving this electrode 3b in the axial direction (in the vertical direction in the figure) via the lead rod 2b, it connects and separates from the mating electrode 3a to open and close the electric circuit. 14 and 15 are shield bodies fixed to the lead rods 2a and 2b;
6 and 17 are shield bodies fixed to both ends of the cylinder 12 or to the end plates 13a, 13b so as to cover the end plates 13a, 13b.

Note that the vacuum container 10 is not limited to the case where the cylinder 12 is made of metal and the end plates 13a, 13b are made of an insulating material as described above. There is no problem even if it is something that has been formed.

FIG. 6 shows the coil conductor 4, which consists of a coil body 44 formed by winding a rectangular conductor made of, for example, a copper material into a ring shape of approximately one turn; It is comprised of a pair of connection leads 6a and 6b fixedly installed near the winding ends 45 and 46 and on the outer circumferential side by brazing or the like. This pair of connection leads 6a, 6b
are made of, for example, a round bar-shaped copper material, and a notch 61 is provided at one end (lower end in the figure) of the connection leads 6a, 6b to increase the bonding surface with the conductor 44. There is. Note that this coil conductor 4 may be formed by bending a rectangular or round bar-shaped conductor to integrally form the pair of connection leads 6a, 6b and the coil body 44.

7 to 9 show the structure of the lead-out conductor 5a and the connection structure with the coil conductor 4. FIG.
The lead-out conductor 5a has a terminal portion 5 made of a rectangular rod-shaped body.
1, a connecting portion 52 made of a rectangular plate, and a spacer 7 that connects both together and electrically separates them. These terminal parts 51
and the connecting portion 52 are both made of a highly conductive material (e.g. copper material), while the spacer 7 is made of an insulating material (e.g. plastic or alumina ceramic) or a high resistance metal (e.g. stainless steel or Inconel alloy). It consists of A rectangular notch 521 is provided on one side of the connecting portion 52.
is provided in the notch 521, and the end portion 51 of the terminal portion 51 is inserted through the U-shaped spacer 7.
1 is fitted and connected, and the three members are integrated.

Further, the end portion 511 of the terminal portion 51 has a stepped hole 51.
2 is provided, and an elastic contactor 62 (for example, a ring contact or a multi-contact) is mounted and fixed, and this elastic contactor 62 has one connection lead 6 provided on the coil conductor 4.
The tip of a (the upper end in FIG. 6) is inserted and joined. On the other hand, the connecting portion 52 is provided with a protrusion 522 having a stepped hole 523.
An elastic contactor 63 is attached and fixed to the coil conductor 4 so that the tip of the other connection lead 6b of the coil conductor 4 is inserted and joined. Also, this connection part 5
A protrusion 524 having a through hole is provided at approximately the center of the vacuum interrupter 1, and is connected to the outer end of the fixed lead rod 2a of the vacuum interrupter 1. In addition, through holes 5 are provided at the four corners of the connection portion 52.
25, through which a mounting bolt is inserted when connecting portion 52, that is, lead-out conductor 5a, is attached and fixed to the upper end portion of insulating frame 8.

In FIG. 7, the arrows indicate the flow of the current I. The current flows downward through one connection lead 6a from the terminal portion 51 of the lead-out conductor 5a, flows in a loop shape through the coil conductor 4, and then flows through the other connection lead 6a. The connection lead 6b flows upward, and then the connection lead 52
The lead rod 2a on the fixed side of the vacuum interrupter 1 is reached through the lead rod 2a.

Note that the lead-out conductor portions 5a, 5b (Figs. 4 and 7)
(see figure), it is not necessary to provide a contact 54 at the end of the terminal portion 51 that can be freely connected to the main circuit conductors 9a, 9b; There is no problem even if the ends of the terminal portions 51 are provided on the sides 9a and 9b and are left in a rectangular state. Furthermore, the connection between the terminal portion 51 and connection portion 52 of the lead-out conductor 5a and the connection leads 6a and 6b is not limited to the case where the elastic contacts 62 and 63 are interposed, but may be connected by bolts or nuts. There is no problem.

10 and 11 show the insulating frame 8, and FIG. 12 shows the state in which the coil conductor 4 is embedded in the insulating frame 8. Insulating frame 8
is formed into a substantially cylindrical shape, has a partition wall 81 approximately in the center, has a cavity 83 on the upper side in which the vacuum interrupter 1 can be accommodated, and has a lead-out conductor 5 on the lower side.
A vacuum interrupter 1 is provided in the center of the partition wall 81.
The lead rod 2b on the movable side is provided with a through hole 82 through which the movable lead rod 2b can be inserted.

And a vacant room 83 that accommodates the vacuum interrupter 1.
a ring-shaped groove 86 in which the coil conductor 4 can be buried concentrically with the partition wall 85 having a predetermined thickness;
is provided. This groove 86 is formed by the insulating frame 8
As is clear from FIG. 11, which is a plan view of
and opposing ends 86a of the divided groove 86,
The portion 86b is formed as a groove cavity that is larger than the other portions. At these end portions 86a, 86b, connection leads 6a, 6 provided on the coil conductor 4 are provided.
It is inserted and placed so that b is in the same position.

Further, the upper end surface 87 of the insulating frame 8 is provided with an insert fitting 88 having a screw hole, into which a mounting bolt is screwed when attaching and fixing the connecting portion 52 of the lead-out conductor 5a.

As shown in FIG. 12 (and FIG. 4), the insulating frame 8 and the coil conductor 4 configured as described above have the coil conductor 4 housed in the groove 86 of the insulating frame 8, and the connecting lead 6a. , 6b are disposed so as to protrude from the upper end surface 87 of the insulating frame 8 by a predetermined dimension, and further, in order to stably fix the coil conductor 4, an insulating material 8a (for example, polyurethane rubber, polybutadiene rubber, or cast liquid rubber such as silicone rubber) is filled and solidified. Note that if the coil conductor 4 can be reliably fixed simply by storing the coil conductor 4 in the groove 86, it is not necessary to fill the groove 86 with the insulator 8a.

To explain an example of the assembly work of the lead-out conductor 5a, the coil conductor 4 insulating frame 8, and the vacuum interrupter 1 configured as described above, first, the lead-out conductor 5a
The protrusion 524 at the connecting portion 52 and the lead rod 2a on the fixed side of the vacuum interrupter 1 are connected with a mounting bolt, while the coil conductor 4 is housed and fixed in the insulating frame 8 as shown in FIG. 12, for example. .
In this state, the vacuum interrupter 1 is inserted into the empty space 83 of the insulating frame 8, and the lead-out conductor 5
The tips (upper ends) of the connection leads 6a and 6b of the coil conductor 4 are inserted and bonded to the elastic contacts 62 and 63 of the coil conductor 4, respectively, and then the connecting portion 52 of the lead-out conductor 5a is connected to the upper end surface 87 of the insulating frame 8.
Mutual assembly and connection is achieved by providing a mounting bolt that is brought into contact with the connecting portion 52 and penetrated through the through hole 525 of the connecting portion 52, and screwed into the insert fitting 88 provided in the insulating frame 8.

FIGS. 13 and 14 show the operation of the vacuum interrupter equipped with the vacuum interrupter 1 configured as described above.
This will be explained based on the diagram.

First, in the closing state, a pair of electrodes 3
a and 3b are in contact, and the current I from the main circuit conductor flows in a loop from the terminal portion 51 of the outgoing conductor 5a to the coil conductor 4 via the connection lead 6a, generating an axial magnetic field, and then connecting. It reaches the connecting portion 52 of the lead conductor 5a via the lead 6b.

The current flowing through the lead rod 2a is divided into a plurality of electric paths in the coil electrode 4a (as many as the arms 41 in the radial direction...see FIG. 5), and flows in a loop surrounding the lead rod 2a (the current flows through the coil conductor). 4) to generate an axial magnetic field, which reaches the electrode 3a, and further reaches the main circuit conductor via the mating electrode 3b, the lead rod 2b, and the lead conductor 5b.

Thus, when the electrodes 3a, 3b are separated and disconnected, an arc spot is generated on the electrodes 3a, 3b, and a composite magnetic field as shown in FIG. 14 is applied to the generated arc. That is, in FIG. 14, the horizontal axis represents the coil outer diameter R, the vertical axis represents the axial magnetic field strength H, and curve A shows the magnetic field due to the coil electrode 4a, which is divided into a plurality of parts provided on the back of the electrode 3a. , curve B represents the magnetic field generated by the coil conductor 4 provided outside the vacuum interrupter 1, and curve C represents the composite magnetic field obtained by combining both magnetic fields.

Therefore, as is clear from FIG. 14, the composite magnetic field (curve C) becomes an axial magnetic field that is substantially uniform in the radial direction, so the arc spot is formed by the electrodes 3a,
It can be uniformly diffused over almost the entire surface of 3b, thereby improving the shearing performance.

In addition, in the embodiment described above, the lead rod 2a on one side (fixed side) of the vacuum interrupter 1
Although the case has been described in which the coil electrode 4a is provided between the lead rod 2b and the electrode 3a, the present invention is not limited to this.
Further, it may be provided only on the movable side. However, the coil electrode 4 is attached to the back of the movable side electrode 3b.
Providing b increases the weight of the movable side and increases the impact force, which is not very preferable in terms of durability. However, there is no particular problem for small-sized items or items that do not require much durability.

Further, although the coil conductor 4 provided outside the vacuum interrupter 1 is connected to one (upper) lead-out conductor 5a, the present invention is not limited to this, and the coil conductor 4 provided outside the vacuum interrupter 1 may be connected to the lower lead-out conductor 5b, or both lead-out conductors. 5
There is no problem even if two coil conductors 4 are provided to be connected to a and 5b.

As is clear from the above description, the present invention has various effects as described below.

(1) The vacuum interrupter 1 is equipped with a coil electrode 4a between the lead rods 2a, 2b and the electrodes 3a, 3b.
Since the vacuum interrupter 1 is formed with a coil conductor 4 outside the vacuum interrupter 1 to constitute a vacuum interrupter, the axial magnetic fields generated by the coil electrode 4a and the coil conductor 4 are combined. Moreover, the coil electrode 4a (small diameter coil) is 1/2, 1/3,
Or, since the magnetic field is generated by the loop current divided into 1/4, the magnetic field strength is correspondingly smaller than the magnetic field generated by the outer coil conductor 4 (large diameter coil), which has a substantially one-turn shape. be. Therefore, the composite magnetic field becomes uniformly distributed in the radial direction of the electrodes 3a and 3b, and thereby the distribution of arc spots on the electrode surface can be made uniform, and the electrode surface can be used effectively. Therefore, it is possible to improve the chopping performance.

(2) Since the coil conductor 4 is fixed to the insulating frame 8, its mounting position in the axial direction can be easily changed, and thereby the distribution state of the composite magnetic field can be adjusted. This makes it possible to achieve an optimal magnetic field distribution state according to the outer diameter and separation dimension of the electrodes 3a and 3b, thereby further improving the shearing performance.

Furthermore, the coil conductor 4 is inserted into the groove 8 of the insulating frame 8.
If the coil conductor 4 is housed and fixed within the coil conductor 6, there is an advantage that the fixing and insulation treatment of the coil conductor 4 becomes simple.

(3) Connect the lead conductors 5a and 5b connected to the lead rods 2a and 2b of the vacuum interrupter 1 to the terminal portion 51.
If the connecting portion 52 and the spacer 7 that electrically separates the two are integrally connected, both winding ends of the coil conductor 4 fixed to the insulating frame 8 side and the drawer The conductors 5a and 5b can be connected to the terminal portions 51 and the connecting portions 52 at the time of assembly of the vacuum shield breaker, and a vacuum shield breaker that applies a synthetic axial magnetic field can be easily obtained. It is something.

[Brief explanation of the drawing]

1 and 2 are schematic explanatory diagrams of a conventional vacuum interrupter, FIG. 3 is an explanatory diagram showing the radial distribution state of the axial magnetic field with respect to changes in the outer diameter of the coil, and FIG. 4 is an explanatory diagram of the present invention. FIG. 5 is a cross-sectional side view of a main part of a vacuum interrupter according to an embodiment of the present invention. FIG. 6 is a cross-sectional perspective view of a main part of a vacuum interrupter according to an embodiment of the present invention. 7 is an assembled perspective view of the lead-out conductor and coil conductor in FIG. 4, FIGS. 8 and 9 are a plan view and a sectional view of the main part of FIG.
1 is a cross-sectional perspective view and a plan view of the main part of the insulating frame in FIG. 4, FIG. 12 is a cross-sectional perspective view of the main part of the insulating frame and the coil conductor in a combined state,
FIG. 14 is an explanatory diagram showing the flow of current in the vacuum shield breaker according to the present invention, and FIG. 14 is an explanatory diagram showing the radial distribution state of the axial magnetic field of the vacuum shield breaker according to the present invention. be. 1... Vacuum interrupter, 10... Vacuum container,
2a, 2b... lead rod, 3a, 3b... electrode,
4a, 4b...Coil electrode, 41...Arm, 43...
... Arc part, 4 ... Coil conductor, 5a, 5b ... Output conductor, 51 ... Terminal section, 52 ... Connection section, 7 ...
...Spacer, 8...Insulating frame, 9a, 9b...
...Main circuit conductor.

Claims (1)

[Claims] 1. A pair of opposing fixed-side lead rods 2a and movable-side lead rods 2b are provided, which hermetically penetrate the vacuum container 10 and can approach and separate from each other, and the inner ends of these lead rods 2a, 2b inside the vacuum container 10 A vacuum interrupter 1 comprising electrodes 3a and 3b, respectively, and a vacuum interrupter 1 connected to the outer ends of a pair of lead rods 2a and 2b provided in the vacuum interrupter 1, respectively, and the ends of main circuit conductors 9a and 9b. a pair of lead-out conductors 5a, 5b that can be connected to the vacuum interrupter 1 and the lead-out conductors 5a, 5b;
In a vacuum shield breaker comprising a coil body that generates a magnetic field parallel to an arc generated between the electrodes 3a or 3b, at least one of the pair of electrodes 3a or 3b and the lead rod 2a or 2b. A coil electrode 4a consisting of a plurality of arms 41 extending in the radial direction and a plurality of arcuate parts 42 extending in the same direction from the outer ends of the arms 41 is provided between the vacuum interrupter 1 and the vacuum interrupter 1. A coil conductor 4 is fixed to the insulating frame so as to surround the vacuum vessel 10, and one winding end of the coil conductor 4 is electrically connected to one of the lead rods 2a or 2b, and the other winding end is electrically connected to one of the lead rods 2a or 2b. A vacuum shield disconnector characterized in that its end is electrically connected to one of the lead-out conductors 5a or 5b.