JPS59230226A - Vacuum breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum breaker number ζ, and more particularly to a vacuum breaker that applies a magnetic field in the same direction as the arc generated during the breaker.

Conventionally, the arc that occurs between a pair of electrodes during interruption
There have been many proposals for vacuum circuit breakers in which the breaking ability is improved by applying a magnetic field in the same direction as the arc (so-called longitudinal magnetic field). Interrupters are generally equipped with a coil for generating a magnetic field,
Broadly speaking, such vacuum interrupters can be divided into those that have a coil inside the vacuum container as shown in Figure 1, and those that have a coil outside the vacuum container as shown in Figure 2. .

That is, in the vacuum interrupter shown in FIG. 1, a pair of conductive rods 2'#2b are introduced into a vacuum container 1 formed by closing both ends of a cylindrical cylinder with metal end plates so that they can approach and separate from each other. At the same time, an electrode 3 is provided at the inner end of each conductive rod 2a, 2b.
a, , 3 b insulating space 4a.

4b, each conductive rod 2a, 2b and each electrode 3a, 3b are arranged on the back of each electrode 3a, 3b, and conducts an axial current flowing through the conductive rod 2a, 2b. A coil 5a generates a longitudinal magnetic field by changing the current to a loop centered around the rods 2a and 2b.

They are configured to be electrically connected via 5b.

The vacuum interrupter is housed in an insulating frame (not shown), and each conductive rod 2a #2
Terminal conductors 6a and 6b that connect and separate from the main circuit conductor (not shown) are connected to the outer end of b, and an operating device (not shown) is attached to drive the movable conductive rod 2b via the bellows 7. It is configured as a vacuum breaker.

However, the vacuum interrupter shown in FIG. 1 has the following drawbacks.

(2) Since the coils 5a and 5b are provided within the vacuum vessel 1, it is difficult to dissipate the Joule heat generated in the coils 5a*5b due to the flowing current to the outside.

■ In addition to the electrodes 3a and 3b, multiple members such as insulating spacers 4a and 4b and coil #5a and 5'b are fixed to the inner end of the conductive rod by brazing, which reduces the weight of the movable parts. In particular, in the case of large-capacity devices, the operating force and impact during operation are large, and durability is reduced.

■ Since the coils 5a and 5b are provided on the back of the electrodes 3a*3b, the strength of the longitudinal magnetic field applied to the arc decreases as the electrodes 3a and 3b separate,
There is a problem in that the diffused arc becomes concentrated as the magnetic field strength decreases, which adversely affects the breaking ability.

As mentioned above, in the vacuum interrupter shown in Fig. 1,
It has been found that there is a natural limit to the blocking ability, and although it is suitable for relatively low capacity devices, it is not suitable for high capacity devices.

For this reason, as a vacuum interrupter for large capacity, the vacuum interrupter shown in Fig. 2, which has been proposed earlier than the vacuum interrupter shown in Fig. 1, has historically been proposed, that is, the coil that generates a longitudinal magnetic field. The technology of a vacuum interrupter in which a vacuum interrupter 8 is disposed outside the vacuum vessel 1 has been reviewed.

Next, the vacuum interrupter shown in FIG. 2 will be explained.
The same members as those in the figures are given the same reference numerals and detailed explanations will be omitted.

That is, only the II pole 3'tab is fixed to the inner end of each conductive rod 2a, 2b.

Further, a coil 8 that generates a vertical magnetic field is wound around the outer periphery of the vacuum container 1, and one winding end of this coil 8 is
It is connected to the terminal conductor 6& through the connection lead 9a, and the other end of the winding is connected to the fixed conductive rod 2 through the connection lead 9b! It is connected to L.

The vacuum interrupter configured in this way is
It is housed in an insulating frame and connected to an operating device (both not shown) to form a vacuum breaker.

The vacuum interrupter shown in FIG. 2 has the following advantages.

(2) Since the coil 8 is provided outside the vacuum vessel 1, Joule heat generated in the coil 8 can be easily dissipated.

(2) Since the coil 8 does not move together with the electrodes 3a and 3b, the strength of the longitudinal magnetic field applied to the arc does not change and is always constant.

■Movable parts are lightweight and have a simple structure.

However, in the vacuum interrupter shown in FIG. 2, the relationship between the arrangement position of the coil 8 disposed on the outer periphery of the vacuum vessel 1 and the axial length of the coil 4 is unspecified, so that the optimum strength cannot be achieved. It is not possible to obtain a vertical magnetic field of 100 mm, resulting in an excessively large vacuum breaker.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a vacuum breaker for large-capacity shutoff stations whose size is suitable for R.

In order to achieve the above object, the present invention introduces a pair of conductive rods into a vacuum container so that they can approach and separate from each other, and
In a vacuum breaker, a 'flL pole is fixed to the inner end of each conductive rod, and a coil that generates a magnetic field in the same direction as the moving direction of the conductive rod is disposed around the outer periphery of the vacuum container. By locating the axial center within a range of 50 mm in the axial direction from the center between the electrodes when the electrode is opened, the longitudinal magnetic field applied to the arc is made to have the optimum strength. It is.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings from FIG. 3 onwards. In the following description, the same members as in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

FIG. 3 is a longitudinal sectional view of a vacuum breaker showing an embodiment of the present invention. In the same figure, reference numeral 10 denotes a bottomed cylindrical insulating frame made of epoxy resin, etc. In this insulating frame 0, a vacuum interrupter 11 having a coil 8 arranged around the outer periphery of the vacuum container 1 is mounted on a conductive rod on the movable side. 2b to insulation frame 1
It is housed by being inserted into a through hole 12 provided at the bottom of 0. As shown in FIG. 4, the coil 8 of the vacuum interrupter 11 includes a ceded coil portion 8a (approximately one turn) and a coil portion 8a extending in parallel to each other in the axial and radial directions from each end of the coil portion 8a. The L-shaped 1st. Second connection lead part 8
b, 8c, 1st. Second connection lead portion 8b.

It consists of a cylindrical first contact holder part 8ct and part 3e having different diameters and integrally formed concentrically at the end of the contact holder 8C, and as shown in FIG. In this case, the axial center P of the coil portion 3a is located at the same position in the axial direction as the interelectrode center 0 at the time of opening (when the disconnection is completed), and a contactor such as a ring contact or a multi-contact is used. 13 and 14 as the first
Between the contact holder part 8d and the movable conductive rod 2b and between the second contact holder part 8e and the terminal conductor 6N+
The conductive rod 2b is electrically connected to the terminal conductor 6b by being interposed between the contact holder portion 6'b'.

In addition, the breaking ability by applying a vertical magnetic field is 50 g'ua/
It is known that there is no problem in practical use in the range of 40 to 60 gauss, but the coil part 8I of coil 8 is the highest when it is 200 gauss. Is the center P in the axial direction of L the center C between the electrodes when the electrodes are open? In addition to the case where the center P of the coil part 8a is located within the range of +5 Q m / m in the axial direction with respect to the center between the electrodes when the electrodes are opened, Also, the desired magnetic field strength (4Q −5Q g
aus/'kA).

Further, if the center P of the coil portion 8a of the coil 8 is set at the same position as the interelectrode center 0 as described above, the necessary longitudinal magnetic field can be obtained even if the width of the coil portion 8a is small. The lines of magnetic force of the magnetic field generated from this are the coil part 8.
Since it is curved along the outer shape of the coil part 8a, in order to apply an effective vertical magnetic field to the arc, in other words, to make the lines of magnetic force of the vertical magnetic field applied to the arc parallel to the axial direction, the axis of the coil part 8a The width in the direction is set to be approximately equal to the distance G between the poles when the poles are opened.

Furthermore, when the diameter of the coil portion 8& becomes large, the strength of the longitudinal magnetic field generated thereby decreases at the center of the coil portion 8a, and in order to prevent it from being impossible to obtain a uniform required magnetic field in the radial direction. , the diameter of the coil portion 8a is the electrode 3a.
, 3b so that the relationship D/A≦2 is satisfied.

As described above, according to the present invention, it is possible to make the coil disposed around the outer periphery of the vacuum container an optimal size.

[Brief explanation of drawings]

Figures 1 and 2 are longitudinal cross-sectional views of a conventional vacuum interrupter, respectively. Figure 3 is a vertical cross-sectional view of a vacuum interrupter according to an embodiment of the present invention. Figure 4 is an exploded perspective view of the main parts. be. 1... Vacuum container, 2a, 21)... Conductive rod, 3 a
, 3b... Electrode, 8... Coil, O... Center between electrodes, P... Center in axial direction of coil.

Claims (1)

[Claims] A pair of conductive rods are introduced into a vacuum container relatively close to each other and freely, electrodes are fixed to the inner ends of each conductive rod, and a magnetic field is applied to the outer periphery of the vacuum container in the same direction as the moving direction of the conductive rods. In a vacuum breaker, the axial center of the coil is set at an angle of ±50% in the axial direction from the center between the electrodes when the contacts are opened. To 1/! A vacuum breaker characterized in that it is located within a range of +1.