JPS5942717A - Electrode contact for breaker, electrode assembly and electrode contact material - 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] , 111-9 u The present invention relates to an electrical contact material used in a large current vacuum circuit breaker. Directive coagulation rate (directi) used for contact points
onally 5olidified materi
al).

If J3C is connected to the power transmission system, it is necessary to interrupt the current.
．． c Rima 1. : Often desirable. This effect is usually exhausted! This is done by two separate contacts within the housing. This configuration takes advantage of the desirable vacuum state dielectric property ↑4.

However, as with other barrier media,
In C, the current does not stop immediately after the contacts separate. Rather, contact separation initiates an arc that, especially in vacuum circuit breakers, is sustained by a hot plasma formed by localized heating, vaporization, and ionization of the contact metal. In an AC power system, contact separation is typically i′J at any (or random) time with respect to sinusoidal variations in current and voltage in that power system.When an arc is formed, the current in the power system is continues to flow for most of the remaining period of half the cycle of current started.

As the arc current approaches the sine wave 1211 (1lrj), the mechanism that sustains the discharge tends to become unstable, causing the arc to suddenly disappear. Depending on trA a3 and other various conditions (11), it falls in the range from a fraction of an ampere to several tens of amperes j1.

This transition to the current zero l-1 state is extremely l'9. it
Since the transition to 1 current occurs from a relatively high current value, the parasitic inductive effect can cause transient high voltage Wake up. As is well known in the electrical industry, the photogenic filtration voltage is determined by the relationship E=-L u/dt.

Therefore, the rapid transition to the current Z121 state is <' M
: It can be seen that the transient voltage is at a clearly high level. Therefore, it is desirable to generate a plasma arc that reduces the nonoke stability at the C1 altitude. That is, in an AC system, , Plasma arc (Sarut: &:J s
It is generally desirable to create conditions that allow the next current zero following contact separation to last for a longer period of time, but less time than it takes for one point to occur. If this is followed, the transition to the current value following arc extinguishment will occur from a relatively low level of arc current. This minimizes the occurrence of undesirable high level voltage transients.

Increasing arc stability at low levels of arc current is an important consideration in selecting contact materials for use in vacuum circuit breakers. High arc stability is usually achieved by choosing a metal with a low boiling point. Such a choice is a compromise, since this group of low-boiling metals also exhibits relatively low dielectric strength in the vacuum field fl 1''.

Other researchers in the industry have found that certain alloys have +1 arc stability.
It was observed that all of the C alloy components exhibited excellent properties. For example, copper can be used in certain circuits to
5 amperes (in 1 level), while tungsten alone exhibits a current cutoff level of 1 under similar conditions.
0 to 20 amperes - 0 However, it has been confirmed that copper-tungsten alloys have lower currents than these values J... 8, immediately), and some alloys are at issue here. It exhibits better properties than any of the C components with regard to arc stability at low current levels η.

In most circuit installations, the three or five contact points are mounted on a conductive base member. Such construction is often required for economic considerations, since it is generally undesirable to fabricate all electrode assemblies from fairly expensive contact materials. Further, the base member acts as a conductive body convenient for removing heat from the electrical contacts. Therefore, a desirable feature of the electrical contact material f1 is that the material has a high degree of thermal conductivity, especially from the electrode contact surface to the base member, i.e. fi <→ is shown in the h direction of the support body. Furthermore, this heat transfer and 7
In addition to the presence of a path, it is also extremely desirable to create a path with low electrical resistance between the electrode contact surface and the main body of the base member where the contact points are intersected. But cT, (7) Fish”C
11 Dissolution of one metal component into another metal component C number bar 1! It should be noted that the addition of one metal acid to another metal component lowers their electrical conductivity above or below that point. The thermal conductivity properties and low level of energy dissipation of the bulk contact material 1 are particularly important in vacuum. The reason for this is that the heat generated at the contact interface is mainly dissipated by heat conduction through the electrode support. For contacts operating in air or other atmospheres, additional cooling is provided by convection at the contact sides. There are other differences when comparing contact operation in air to operation in a vacuum.

In particular, the choice of contact materials for use in air is severely limited by the problem of oxidation and the resulting high contact resistance. This is especially true in the case of contacts using copper.
The choice of material A for use in a device is very different from the choice of material used in devices where the contacts are exposed to air.

Therefore, extensive attempts to form mixtures of metal components for electrode contacts have largely shown mutual solubility. Due to an undesirable increase in the electrical resistivity of the January interest rate (・, generally does not jeopardize complete success. Therefore,
It is F that the contact material 11 is provided as a separate monthly 71 ~ ricks in the wiring form C'! ' :J: Yes, there is. However, the 7 tricks of a certain scale (Sli +:
It has been confirmed that it is particularly desirable for metals with a relatively high i to have the characteristic of exhibiting a breakdown strength of 11 degrees C in vacuum. Furthermore, it is known that the stability v1 of the vacuum arc is limited by the electrode surface CO') boundaries between the phase C7 insoluble components.・Tungesuran J3, I, which Ritz is used in pure form
It has been found that C has a higher arc stability than both copper and copper.

In addition, it is also pointed out here that researchers in other fields have conventionally used the technique of 1j tropic solidification of materials in various ways. The method has generally never been used in the manufacture of vacuum contacts. However, the transformers and electrical equipment of the Raji Institute of Technology, located in Bohnon 1-Kunitsuji, and Ku Cross H (K, CI+rost) di of the Equipment Research Institute.
J, bi1s wojushi] uski (S, wo
, icicchowsk i), Proceedings of the 9th International Conference on Electrical Contact Phenomena (1) roccedir+
os of the 9 th l internal
ional Conference on
Ietric Contact
Paper in p 11 + child n (l me n a, 1978, 259-26/l shell) [Properties of directionally solidified silver-copper contact materials J' (1) roperticsof
1)ircctionally 5olidify
ed3i1ver-Copper Contact
Materials) Smell-(, Directional Coagulation A (J
The use of -CU mixtures for electrical contacts is still shown. In addition, other researchers have proposed the structure of m-male materials made from extruded wire A7. (o, st'6ckei) is
Article 1: “Abrasion converter of compound-containing contact abrasive material” (Material
l-transformer or Composi
te Co+1tact Materials
) discloses the use of a composite contact material in the form of a non-uniform fiber. .

However, Buch's tropic coagulation has not been investigated. Compositions containing copper in vanadium have also not been considered. Proceedings of the 8th International Conference on Electrical Contact Phenomena (1976, 353-
M. Bonia 1-Usky (tvl
, Poniatowski), Tour Sea+
'l', l-ku (K, H, S C11r8de
r) A5 Nibi E Shilz ([E, l)
, S hulz)'s paper 1 ``City Power 1 Gaku'' (13 Riru・
Opening/closing behavior of silver/metal oxide materials 1 (1301Ta
VIOI'at c losing O
r O+) ening of's 1l
vcr"-to4cLallic-□x'ide Ma
terials Into1OcLrlc i'0WO
If (I-like 81
107 inclusions are oriented perpendicular to the contact surface 1, = t4J
/Silver oxide monthly extrudates are accepted. The same j, - silver/silver oxide -I bound is the
Proceedings of the 3rd International Conference (1976, 350-ζ36 /
Manfred Boniatous in l Mi): l--
(M anrred Pon1a1.0WSki
), Sat Runst-no! E “J Le Schilz” (E
rnst l) 1eter 3 cb old l) OJ,
Biri79rel Wirths (Δxcl Wirths)
Paper 1 Replacement of silver/cadmium oxide with silver/tin oxide in a low current switching device (Rcplac
emcnt or 31lver /Cadmium
Oxide by S 1lvcr/l'
ir+ Oxyclcin low Voltag
e 5w1tcl+ing L') cviccs). However, none of these papers touches on the directional solidification of copper-vanadium and other similar materials. Furthermore, copper and vanadium mixtures have never been used in the production of electrical contact materials.

However, according to John W. Ranheim, US Special Edition No. 3, 514.557, non-refractory metals such as copper are used in the matrix of vanadium fluoride (V[32), a heat-resistant compound. It is recommended that
Ru. There is no mention of covering the material with a dendritic or fibrous structure, and l<apl+e
IM's teachings seem to be primarily concerned with the production of heat-resistant metals in the 21-mb type rather than in the C-element form using semimetals such as C, boron, or silicon.

Additionally, IJ3 points out that in some of the situations at issue here, it may be desirable to physically move the arc from its current location to another location or even to another electrode.
<Should. There has never been an example of an IC in which the transition phenomenon has been realized by applying a tropic solidification method or material to the manufacture of an electrical contact.

SUMMARY OF THE INVENTION - In a preferred embodiment of the present invention, the electrical contacts used in a commercial circuit breaker are as follows: 1. 111 ivy of electrically conductive material with contact surfaces of r
olidiricd m1xture). The invention! l' (In a preferred embodiment, the electrode contact material comprises a mixture of copper and vapdium containing about 1 to 92% vanadium by weight. Such electrical contacts are used in electrode assemblies (1, 2) There are two different ways to move the arc. In one embodiment of the invention, the direction of solidification is parallel to the contact surface of the arc. In this embodiment, the arc movement -A, /:
1.1 Particularly desirable in situations where it is necessary to carry out transfer1.
(Indeed, the direction of solidification of the electrode contact of the present invention is plasma
- It can be used in a 4-metal assembly, which is perpendicular to the contact surface. It is this latter embodiment that is most effective for thermal transfer F4A3 and electrical resistance properties.

The present invention also encompasses the use of directionally coagulated contacts in vacuum circuit breakers. In particular, a preferred form of contact consists of a multicomponent mixture J: formed using at least two Phase H insoluble metal components. Furthermore, a mixture of copper and vapidium can be used, directionally solidified and electrically connected.

Accordingly, it is an object of the present invention to provide an electrical contact exhibiting high arc stability at low arc current levels.

There is a particular thing.

Another object of the present invention is to provide directionally solidified electrical contacts and materials thereof that have particularly enhanced vacuum Te thermal and electrical contact properties.

Another object of the present invention is to facilitate the transition of a plasma arc from one position to another by a tropic solidification electrode contact J5.
The purpose of this project is to provide the necessary materials for the construction.

Yet another object of the invention is to provide an electrical contact J5 and contact material suitable in particular for vacuum circuit breakers, consisting of a mixture of copper and vanadium, not only as a mixture but also in directionally solidified form. .

Finally, it is an object of the present invention to provide an Iζ electrode assembly using the electrical contacts and features of the present invention.

All matters deemed to constitute an invention are as set forth in the claims. However, the present invention has a structure J3 J, and a Buddhist painting lJ k,-,"'
The purpose and effect of the invention will be better understood by reading the following explanation, which follows the accompanying drawings.

(The graph in Figure 1 shows one complete cycle of the current waveform interrupted by 1°. The 99701 curve shown is the period).A typical U.S. line voltage is 1. For frequency, 1'=16
．． It takes 6 milliseconds. In order to electrically interrupt the circuit carrying the sine wave, it is customary to initiate the separation of the contacts of an electrical circuit interrupter at any time, for example at I+). (In the case of a plasma arc, a plasma arc is generated between separated electrical contacts, and a continuous current flows through the ionized plasma material, which is mainly composed of metallic material, which is heated from the surface of the electrical contact.) Form a passage. The current is at its maximum value (・,
It continues to rise by 1, then suddenly T at time [2;
Ni l! Until the current reaches the first point in the descending range, C,
The current continues to fall in a sinusoidal manner. This critical current (co1
Then, the current drops at the lowest CC speed. As mentioned above,
This rapid current change causes large voltage transients to occur. Therefore, it is generally desirable to set the threshold (threshold 1 hold) current level at which this rapid transition begins to occur as low as possible. The timing increase current (11i) associated with this current drop is a result of the lack of stability at lower current levels.

This sudden disappearance of current is called current severance (current c
hoppina). The cutting current is determined primarily by the electrode contact material used. Under ideal conditions, the arc will die out at time t3, corresponding to a point 1/2 second after the previous zero crossing.

The phenomenon of current interruption can be seen at time t3 in the graph shown in FIG.
Figure 2C is an enlarged view of the part just before . In particular, three possible annihilation transitions are shown at times t2a, C2b, and t2c. When current chopping occurs at time t2 a'c, the arc is said to be relatively unstable. However, if the current rubbing occurs for a time cU, then i' is said to be relatively stable C.

In general, high arc stability f(
is an electrical circuit; there are desirable features of the circuit breaker, and this is a major advantage of the present invention.

FIG. 3 shows another advantage obtained by the directionally solidified electrode contact material 11 of the present invention. Specifically, the ζ-shaped electrode contact ring 10 is electrically conductive 12.More specifically, between the contacts 10)'-ri1
The electrode assembly structure shown in FIG. In particular, it is generally desirable for this type of device to facilitate transfer from between the electrodes 10 to the conductive base member 12.According to the present invention, the annular The electrode contact 10 is made of a composite material which is oriented in the radial direction J as indicated by the horizontal hatching at the rear end 10 shown.

11 Physically, this J, solidification causes the arc 13 to be larger and further away from the contact points 10.
It becomes easy to transfer to the current transport M+1 body 12 questions. The structure 12, as best seen in the plan view of FIG. 4, consists of a substantially disk-shaped structure to which the annular electrode contact 10 is secured. In general, it is preferred that the conductive base member 12 is provided with a long groove or spiral recess 14 to control the arc rotation. I am a connoisseur.

5 and 6 show other electrode assemblies that can be used with the directional solidification method of the present invention. Specifically, in FIG. 5, the conductive base member 16 not only functions as a current conducting portion, but also functions as a thermal sink. However, the electrode contact 20 breaks the arc and forms a major surface 21. Contact 20 determines the arc stability of C3 in the circuit breaker.
It is. In particular, as indicated by the vertical hatching,
The contact 20 exhibits directional solidification in a direction perpendicular to the surface without breaking the arc. Accordingly, the embodiment of the present invention shown in FIG. 5 has three important advantages over previously used electrode contacts. First, by directional solidification in the direction shown,
The heat transfer rate between the arcing surface 21 and the conductive base member 16 is high. Second, due to lj-tropic solidification in the direction 15 shown in the figure, the conductivity if of 111- between the surface 21 of the nonok 41 and the base part 16 becomes 12'':1.

This results from the presence of a large number of conductive channels at the contact 20. Third, JJ to IX +:λ20 t
The resulting directional solidification creates a silk weave between the elemental metals (dark blue).”
, 'i -LJ, which maintains arc stability. In general, the electrodes have excellent dielectric strength.
J Lll. FIG. 5 shows a preferred embodiment of the invention.

Arc movement or transition is desired
This migration can be easily accomplished by using a pseudo-obligate slant. LJ 1' like this! The shapes of L and J are shown in Figure 6. The contact 30 used in Fig. 6 is the arc generation surface 2.
1. Reduce the solidification in the direction parallel to 1.3. Since the arc tends to move along the direction of the elongated composition (l), this directional solidification controls the movement of the arc at the contact surface, that is, the arc generation surface. This feature of the invention is also illustrated in FIG. 3, where it is generally desirable to "direct radially outward motion to the rasin arc."

In general, the electrode material of the present invention comprises a directionally solidified mixture of at least two mutually insoluble metal components.

A material that has been identified for use in particular is a mixture of copper and vanadium containing about 1 to 92% by weight of panodium. The copper-vanadium directional solidification A material of the present invention is described in rough detail below and illustrated in FIGS. 7 and 8. By month, insoluble in aluminum, silver and copper, copper and bismuth, copper and lead, copper and chidium 11, aluminum and lilium, silver and niracle, aluminum, aluminum and chromium, aluminum and titanium, d3 and aluminum and vanodium. The following Table 1 shows a list of materials that can be used in the present invention (~J3 and composition range 1, but is not limited to these only).

8g -Ni 1-98%N1Af-Be
1-98%AA Aj! B+ Cover Cσ) Navy 11 Brother] f11ΔA
-C'r ES O-99%〇AJ-311
1~82%S11 8E-'l'i 63□~99% A pcu
-13i (composition of fa utl )C
LJ -L, 1 ell -pt> cu-v 1~92%V The method of directional solidification itself is well known in the metallurgical industry. However, noj tropism 16 adventure 01 appetizer"'+g +
7V 421 to 43 C arc movement promotion
J? ``'History 111 ZatL/What is the matter now?-C
do not have. Sara(ko, puno li + J' p, lδ spear 1-・
Arc stability at 1h\1m arc current level:
X-) (IJ (+' ,, /j 1f11 In the bamboo coagulation method, the desired mixture of in-r and so-1 is passed through a high-heat region j, and the in-bo-1 is passed through a high-heat region i)-)< ) As the mountain passes, the material locally becomes Sakata 1 (2, [1f 1f
-・1 zuru.

The orientation of the tissue obtained is as follows: resolidification 111σ) 1iil
ri: t'i I≦j 'li'σ) It depends on the mutual affinity.In terms of L1 of Mizumoto's 1, the directional solidification method is used. l;L Consists of two components, one of which is woody and insoluble in the remaining components. Preferably, one component is a relatively high conductivity metal. In this respect as well, it has been discovered that copper and vanadium in particular exhibit desirable degrees of insolubility, boiling point, and electrical conductivity. Furthermore, the present inventor discovered that copper and vanadium exhibit extremely directional solidification.3 However, the present inventors have discovered that the contact point of copper and vanadium, which is made of copper and vanadium, is in a non-J directional solidification state. It is also important to note that it exhibits excellent arc stability characteristics.

The amenability of copper-vanadium mixtures to directional solidification is illustrated in Figures 7 CI'i and 8. Both figures are scanning electron micrographs of copper-vanadium.

Figure 7 shows a longitudinal cross section of a directionally solidified copper-vanadium inclusion. FIG. 8 is the same as FIG. 7 except that it includes a cross-section of the copper-vanadium mixture. In these figures, copper appears as the brighter IJ of the two substances present. Each of the scanning electron micrographs shown in Figures 7 and 8 was taken from the same sample and is a photograph of a metallographically polished surface. Furthermore, in Figure 7, there are many
t1Ja'<'j, lfi are combined, but these are artificially formed [1'J +,,m. is 47-)"C but seen 3, these +7)]
] TA ■ Point - 6 Dance image overculm C artificially C came 1].

Each micrograph shows a comparison of 150 microliters of 11 moss cutters (
1) /j (=i). As is clear from Figures 7 and 8, copper is a vanadium mixture on one surface or L) on the other hand (L) and has the form of multiple extending columnar stripes. C
: (j ?+: lru1, Therefore, the directional solidification phenomenon extends to the entire material O'31 (a3su, A (it can be seen that this phenomenon does not occur only on this surface. In addition to defining boundaries between the electrode surface 'C components, the direction of the invention is to stabilize the electrode surface 'C.
contains one component, such as copper fiber IIt* or dendritic I
J: It is attached along the axis of symmetry of the lfi contact, and is given the additional property of promoting the conductivity and heat transfer of the contact surface IJX. 7th and E3 Figure 1-
The material used is a mixture of 50% vanadium by volume and 50,000% copper. Furthermore, the micrographs in Figures 7 and 8 (see C 1.niji on the surface perpendicular to 1i).

As can be understood from the above, the electrode material of the present invention improves arc stability at low current levels and improves conductivity at the arcing surface! 1. Increases the heat conduction between the base parts and increases the electrical conductivity in roughly the same direction. Furthermore, it is recognized that according to the present invention, directionally solidified electrode contact materials can be used in a large number of electrical circuit breakers, and that arc transition can be easily prevented by appropriate selection of the solidification method. sea bream.

Finally, it can be seen that the present invention significantly enhances the performance of vacuum circuit breakers.

Although the invention has been described in detail with respect to several preferred embodiments thereof, many modifications and changes will occur to those skilled in the art. It is therefore intended that the appended claims cover all such modifications and variations that fall within the scope of the invention.

[Brief explanation of the drawing]

Figure 1 is a graph of current versus time illustrating a current interruption cycle, Figure 2 is an enlarged graph of a portion of Figure 1 illustrating a stable low current arc, and Figure 3 is a graph of electrode H material of the present invention. established (
FIG. 4 is a plan view of the electrode assembly of FIG. 3, and FIG. 1 is an embodiment of the present invention illustrating an example of the use of the y-notropically solidified electrode contact material. The longitudinal cross-sectional view of FIG. 6 is similar to FIG. The vertical cross-sectional view of the electrode assembly, Figure 7, shows copper-vanodium. Microscope 77° cross-section in the length l/j direction of Iit% contact material Explanation of symbols 10.20.30... Electrode contact 51, light, 12.16.
...Conductive base member, 13... Arc, 21... Arc! 1 surface. patent applicant

Claims (1)

[Scope of Claims] 1. At least one contact surface is connected to a conductive plate 1 of a pair of insoluble metal components: copper. and vanadium (however, vanadium \ about 1 to 92%), copper and bismuth, copper and lithium, copper and lead,
Aluminum and titanium (however, aluminum approx. 63-99
%〉, aluminum and antimony (however, antimony approx. 1
~82%), aluminum aluminum (aluminum approximately 8o-99%), aluminum and beryllium (aluminum approximately 1-98%), aluminum and bismuth, and silver and nickel (nickel approximately 1-98%)
An electrical contact for a vacuum circuit breaker, characterized in that it is a directionally solidified mixture selected from the group consisting of: 2. The electrode contact according to claim 1, wherein said electrode comprises a circular disk. 3. The electrode is a special crystal which has 4 f from the annular ring. 1. The electric current t→(contact point) according to claim 1. 5) An electrode assembly consisting of the electrode set forth in claim 1 fixed to the surface of the base portion of the conductive base portion JjJ and J. 16. Directionality An electrode assembly according to claim 5, in which the solidification is at a tit <' right angle C' to the surface, and the directional solidification is in the surface ifu at line q'
[The electrode assembly according to claim 5. 8. An electrode contact for a high-current circuit kneeling device made of a solidified mixture of copper and vanadium, characterized in that vanadium accounts for about 1 to 92,000% of the electrode contact. 9. Coagulated mixture J of copper and vanadium, linari, vanadium accounts for about 1-92% by weight, 14. Monthly rate suitable for electrical contacts.