JPS6341176B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum shear breaker, and more particularly to a vacuum sheath breaker in which means for generating an axial magnetic field parallel to the shear arc is provided at the back of the electrode.

In recent years, by applying an axial magnetic field parallel to the arc, it is possible to disperse the arc on the electrode surface and prevent its concentration, thereby improving the shearing ability by preventing excessive melting of the electrode. A so-called arc dispersion type vacuum cutter is known.

Such an arc dispersion type vacuum shield disconnector is
As shown in the figure, an insulating cylinder 1 is generally made of glass or ceramic and has a cylindrical shape.
A vacuum container 3 is formed by airtightly closing both ends with disk-shaped end plates 2, 2 made of metal and evacuating the inside to a high vacuum. In order to bring the electrodes 5, 4 into contact with and away from each other, the pair of electrode rods 5, 5 can be moved relatively toward and away from the center of each end plate 2 via an operating device (not shown) while maintaining the airtightness of the vacuum container 3. At the same time, the current flowing in the axial direction (up and down direction in FIG. 1) flowing through the electrode rod 5 is connected to the center of the back of each electrode 4 and the inner end of each electrode rod as a loop current centered on the electrode rod 5. The coil bodies 6, 6 are connected to each other to generate an axial magnetic field.

However, since the electrode 4 is usually formed of a copper-based material with high conductivity, the coil body 6
As a result of the interlinkage of the axial magnetic fields generated by the has been reduced.

In order to deal with this problem, as shown in FIG. 2, a plurality of slits 7 are provided in the body of the electrode 4 that extend radially from near the center toward the periphery.
Electrodes 4 that suppress the generation of eddy currents are known, but in the case of such electrodes 4, the mechanical strength of the electrode 4 itself decreases and the arc tends to stagnate at the corners of the slit 7. In the case of high-voltage vacuum shields and disconnectors, there are problems such as a decrease in withstand voltage.

The present invention has been made in view of the above-mentioned problems, and its object is to form an electrode from an alloy material mainly composed of iron with low conductivity, and to form a contact surface of the electrode made of the alloy material. By sufficiently reducing the length in the axial direction between the coil body and the connection part, it is possible to suppress the generation of eddy current without reducing the mechanical strength of the electrode, and improve the connection and disconnection performance. It is an object of the present invention to provide an arc dispersion type vacuum shield breaker which is capable of reducing the loss of current flowing when the electrodes are in a closed circuit state.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings from FIG. 3 onwards. In the following description, the same reference numerals are given to the same constituent members as in the previous one described above, and redundant explanation thereof will be omitted.

3 and 4 are a longitudinal sectional view and a plan sectional view of the first embodiment of the present invention, in which a circular recess 8 is formed at the inner end shaft center of the electrode rod 5 introduced into a vacuum container (not shown). As shown in FIG. 5, in the cylindrical body portion 5a formed by providing the recess 8, the recesses are equally distributed in the circumferential direction and have a depth about half of the recess 8. A plurality of (four in the embodiment) grooves 9a, 9b, 9c, and 9d are provided. A coil insulating support 10 whose base portion is joined by brazing to the bottom of the recess 8 is concentrically housed therein. As will be described later, the coil insulating support 10 supports the coil body 6 connected to the cylindrical portion 5a of the electrode rod 5 at one end while electrically insulating the electrode rod 5 from the other end, and is made of an insulating material or It is made of a high-resistance metal such as stainless steel and has a length of about half the depth of the recess 8, a diameter smaller than the inner diameter of the recess 8, and a cylindrical shape with a partition wall at the end. and electrode rod 5 on the partition wall.
Hole 11 for degassing when joining with etc.
12 are provided.

A shunt type coil body 6 is insulated and supported at an end of the coil insulating support 10 via a center conductor 13 at one end thereof. That is, the coil body 6
As shown in FIGS. 3 and 4, the central conductor 13 is formed into a cylindrical shape having approximately the same diameter as the coil insulating support 10 but longer than that, and the distance from the outer periphery of the central conductor 13 to the electrode rod 5. Each groove 9 of the cylindrical body part 5a
a, 9b, 9c, 9d in the radial direction (third
The first arm 1 extends outward (left-right direction in the figure)
4a, 14b, 14c, 14d, and circular arc portions 15a, 15b that curve in an arc shape from the end of each first arm 14a, 14b, 14c, 14d to the same direction along the outer periphery near the back of the electrode 4. 1
5c, 15d, and each arc portion 15a, 15b, 15
c, 15d to the respective arcuate portions 15a,
15b, 15c, 15d and the cylindrical body portion 5a of the electrode rod 5
The adjacent arcuate portion 15b to electrically connect the
1st arm 14b, 1 of 15c, 15d, 15a
4c, 14d, 14a, and a second arm 16a, 16 extending radially inward in parallel with the second arm 4c, 14d, 14a.
b, 16c, and 16d, and by fitting the base of the center conductor 13, which is the other end, to the end of the coil insulating support 10 and joining by brazing, the electrode rod 5 is insulated and supported. and the second arms 16a, 16b, 16 which serve as one end thereof.
By joining the inner end portions of c and 16d to the cylindrical portion 5a of the electrode rod 5, they are supported while being electrically connected to the electrode rod 5. Note that the ends of the center conductor 13 of the coil body 6 are connected to the first arms 14a, 14b, 1
4c, 14d and second arms 16a, 16b,
It protrudes as if positioned above 16c and 16d in FIG. At the end of the center conductor 13 of the coil body 6, there is a cap-shaped disk-shaped electrode 4 with a flat circular contact surface 4a in the center, and a circular recess 1 provided in the center of the back.
7, and are joined by brazing. The depth of the recess 17 is defined as the axial length between the end of the center conductor 13 of the coil body 6, which is the connection part with the electrode 4, and the contact surface 4a of the electrode 4, in other words, the depth of the recess 17 is defined as the depth of the recess 17. The wall thickness e of the electrode 4 between the electrode 4 and the contact surface 13 is set to 2 mm or less and other than that of the electrode 4 in order to reduce the loss of the current flowing during the closing of the electrode 4 made of an alloy material with low conductivity as described later. It is sufficiently small compared to the wall thickness of the part.

The electrode 4 is made of an alloy material having an electrical conductivity of 3 to 15% of copper and having iron as a main component, for example, 3% of copper.
Fe-Cr-Ni alloy, copper with conductivity below 10
Fe-Cr-Cu alloy with conductivity of ~15%, 0.5~
Fe-18Cr-8Ni alloy powder with a particle size of 500μ is sintered in a vacuum into a porous material with a pore (void) diameter of 0.5 to 500μ, and a metal such as Cu having a lower melting point than this is sintered into the porous material. 5 of copper infiltrated in vacuum
Those with conductivity of ~15%, or 0.5~500μ
It is formed by sintering Fe-18Cr-8Ni alloy powder with a particle size of ing.

With the above configuration, the current generated at the contact 4a of the electrode 4 is transmitted to the center conductor 13, each of the first arms 14a, 1
4b, 14c, 14d, each arc portion 15a, 15
b, 15c, 15d and each second arm 16a,
16b, 16c, 16d to the electrode rod 5, and each circular arc portion 15a, 15b, 15 of the coil body 6
The arc is dispersed on the electrode surface by generating an axial magnetic field by the current flowing in the same circumferential direction through the electrodes c and 15d. When the axial magnetic field generated by the coil body 6 interlinks with the electrode 4, an eddy current is generated in the electrode 4, but since the electrode 4 has a conductivity of 3 to 15% that of copper, this generation is prevented. significantly suppressed. Therefore, it is possible to efficiently insulate and break large currents with less loss in the axial magnetic field, and it is possible to improve insulation recovery characteristics with less phase lag, which in turn improves insulating and breaking performance. . In addition, the electrode 4 has a conductivity of 3 to 15% that of copper, in other words, has a relatively high resistance.
Since the length in the axial direction between the contact surface 4a and the connecting portion of the coil body 6 is made sufficiently small, current loss during energization can be reduced.

The relationship between the electrical conductivity and magnetic flux density of the electrode 4 described above is expressed by the sixth equation, where the horizontal axis is the electrical conductivity (%) for copper, and the vertical axis is the ratio (%) of the magnetic flux density to the case where no eddy current occurs. As shown in the figure, the relationship between the electrical conductivity of the electrode 4 and the phase delay is shown by the horizontal axis representing the electrical conductivity (%) for copper, and the vertical axis representing the relationship between the electrical conductivity of the electrode 4 and the phase delay.
Figure 7 shows the ratio (%) of the phase lag of the axial magnetic field to the phase lag of the axial magnetic field. Therefore, by reducing the electrical conductivity of the electrode 4 relative to copper, it is possible to reduce the loss of the axial magnetic field, and when the electrical conductivity is in the range of 3 to 15% of that of copper, the magnetic flux density hardly changes. It is possible to secure a value close to 100%, and the generation of eddy current is small, phase shift delay is extremely small, and test and break performance is improved.

In addition, since the electrode is made of an alloy material whose main component is iron, it is possible to obtain an electrode material that is inexpensive and has a high resistance value, and because there is little generation of eddy current, there is no need to provide slits like in the past. Coupled with the absence of cracks, an electrode with high mechanical strength can be obtained.

Further, in the embodiment described above, the coil body 6
Although the case is described in which the coil body 6 is of a shunt type, the present invention is not limited to this. For example, the coil body 6 may be formed into an annular arc portion with an end disposed around the electrode rod 5, and each end of the arc portion. and first and second arms connecting the electrode 4 and the electrode rod 5, or as in the second embodiment shown in FIGS. A center conductor 13 connected to the bottom of the recess 8 of the electrode rod 5 via the coil insulating support 10 and having the electrode 4 connected to the end thereof.
Then, the electrode rod 5 surrounds the center conductor 13.
Inner circular arc portions 19a, 19b, 19c, 19d that are joined to the end of the cylindrical body portion 5a and have one or more cut portions 18a, 18b, 18c, 18d.
and each inner circular arc portion 19a, 19b, 19c, 19
outer arcuate portions 20a, 20b disposed along the outer peripheral edge near the back of the electrode 4, facing d;
20c, 20d, and each outer arc portion 20a, 20
Inner arc portions 19a, 19b, 19c, 1 to connect one end of b, 20c, 20d and the center conductor 13
The first arms 21a, 2 extend in the radial direction through the cut portions 18a, 18b, 18c, 18d of 9d.
1b, 21c, 21d, and each outer arc portion 20a,
Each inner circular arc portion 19a, 19 is connected to the cylindrical body portion 5a via the other end and one end of 20b, 20c, 20d.
a second arm 2 extending in the radial direction in parallel in the same plane as the first arms 21a, 21b, 21c, 21d to connect the other ends of the arms 21a, 19c, 19d;
Consisting of 2a, 22b, 22c, 22d,
The polarity of the axial magnetic field generated by the inner circular arc parts 19a, 19b, 19c, 19d and the outer circular arc parts 20a, 20b, 20c, 20d may be made different in the radial direction.

As described above, the present invention introduces a pair of electrode rods into a vacuum container so that the pair of electrodes can approach and separate from each other on its axis, and also In a vacuum shield disconnector, the electrode is connected to the inner end thereof by a coil body that generates an axial magnetic field by changing the axial current flowing through the electrode into a loop current centered around the electrode. Since the electrode is made of an alloy material that has a conductivity of 3 to 15% that of copper and whose main component is iron, the mechanical strength of the electrode can be dramatically increased compared to conventional electrodes. In addition, since the generation of eddy current can be suppressed, the loss of the axial magnetic field is reduced and large currents can be efficiently cut off, and the phase delay of the axial magnetic field is reduced, improving insulation recovery characteristics. This makes it possible to improve the shearing and cutting performance.

In addition, since the electrode is made of the above-mentioned alloy material and the axial length between the contact surface of the electrode and the connection part of the coil body at the center of the back of the electrode is made sufficiently small, the current flow during energization is reduced. This has effects such as reducing loss.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a general arc dispersion type vacuum shield breaker, Fig. 2 is a plan view of the main part of the conventional technology, Fig. 3 is a longitudinal sectional view of the first embodiment of the present invention, Figures 4 and 5 are cross-sectional views along the - line and - line in Figure 3, Figure 6 is an explanatory diagram of the relationship between the conductivity and the ratio of magnetic flux density, and Figure 7 is the relationship between the conductivity and the phase delay ratio. FIG. 8 is a plan view of the second embodiment of the present invention, and FIG. 9 is a sectional view taken along the line -- in FIG. 3... Vacuum container, 4... Electrode, 5... Electrode rod,
6...Coil body, e...Thickness.

Claims (1)

[Scope of Claims] 1. A pair of electrode rods are introduced into a vacuum container so that they can approach and separate from each other on the axis of the vacuum container, and the center of the back of each electrode and each electrode rod In a vacuum shield disconnector, the electrode is connected to the inner end thereof by a coil body that generates an axial magnetic field by changing the axial current flowing through the electrode into a loop current centered around the electrode. 1. A vacuum shield breaker characterized in that it is made of an alloy material having an electrical conductivity of 3 to 15% that of copper and whose main component is iron. 2. The vacuum shear breaker according to claim 1, characterized in that the alloy material is an Fe-Cr-Ni alloy. 3. The vacuum shear breaker according to claim 1, characterized in that the alloy material is an Fe-Cr-Cu alloy. 4. The vacuum chamber according to claim 1, wherein the alloy material is a porous material made by sintering Fe-Cr-Ni alloy powder and infiltrated with a metal having a lower melting point than the porous material. Or disconnection. 5. The vacuum shear disconnector according to claim 1, wherein the alloy material is a sintered Fe-Cr-Ni alloy powder and a metal powder having a lower melting point than the Fe-Cr-Ni alloy powder. 6 Introduce a pair of electrode rods into a vacuum container so that they can approach and separate from each other on the axis of the vacuum container, and also insert the electrode rods into the vacuum container so that they can approach and separate from each other, and connect the central part of the back of each electrode and the inner end of each electrode rod. In a vacuum shield disconnector connected by a coil body that generates an axial magnetic field by changing the axial current flowing through the electrode rod into a loop current centered around the electrode rod, the electrode is It is made of an alloy material having an electrical conductivity of 15% and whose main component is iron, and the axial length between the contact surface of the electrode and the connection part of the coil body at the center of its back is made sufficiently small. A vacuum cutter characterized by: 7. The vacuum shear breaker according to claim 6, characterized in that the alloy material is an Fe-Cr-Ni alloy. 8. The vacuum shear breaker according to claim 6, characterized in that the alloy material is an Fe-Cr-Cu alloy. 9. The vacuum chamber according to claim 6, wherein the alloy material is a porous material made by sintering Fe-Cr-Ni alloy powder and infiltrated with a metal having a lower melting point than the porous material. Or disconnection. 10. The vacuum shear breaker according to claim 6, characterized in that the alloy material is made by sintering Fe-Cr-Ni alloy powder and metal powder having a lower melting point than the Fe-Cr-Ni alloy powder.