DE1513721A1 - Spark gap for surge arrester with magnetic blowing of the arc - Google Patents

Description

Spark gap for surge arresters with magnetic flashing of the arc.

For this application the priority of the corresponding USA application serial no. 430 274 claimed from February 4, 1965.

The present invention relates to a spark gap for surge arresters, in which the arc through Magnetic field is blown.

It is an essential feature of the operation of surge arresters, that the arc is extinguished after an overvoltage shock, i.e. the Polgestron, which is also fed to the network, is

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ORIGINAL INSPECTED

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is broken. With surge "dee valve type is" \ the resistance in Ableiterkreis for the "überspannungsßtoö so high that the arc in the spark gap sun British is brought. Spark gaps with air blowing

r ■

ken ionize the extinction of the arc by | dead distance The gases from the interelectrode space are known from this doorway by the release of non-ionized oases as a result of the arc heat, those on insulating material inside or around the arc chamber acts, are accelerated. In each case the essential cause for the final isc When the arc is extinguished, the direct or indirect generation of a resistance for the arc in one or several parts of the entire Ableiterstrowkreiaes.

The invention relates to a spark gap for surge arresters with magnetic release of the arc and is characterized by two ring-shaped electrodes between where there is a ring-shaped arc chamber that is delimited by insulating walls and penetrated by a magnetic field As a result of the ring-shaped arrangement of the electrodes and the arc chamber the arc has an extensive path, in which it is driven by the magnetic field.

This makes it possible to remove the electrode surfaces during the light

* ·· ■ '■■■ * to keep the arch hike cool. The cross-section of the arc chamber advantageously forms a narrow rectangle that extends in the direction

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tung dos electrical spacing extends; this causes the arc laterally narrowed and cooled. DiQ the arc chamber isolating wall are preferably made of a mat «-«

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4 «r arc heat gives off gas, 11 is deionized.

1 liifi 6 share an exemplary embodiment of the

e top view of the spark gap;

eeigt öino ndng

not on the lower half of the

Figure 3 shows a cross section length of the line III-III in Fi

Figure 4 shows schematioch a development in the arrangement self-contained electrodes used according to FIG. 1;

Figure 5 shows schematically a development of modified electrical

■ ■■:! ■■

those used in the arrangement of FIG «

can;

FIG. 6 shows a side view of a large number of spark gaps which are used to form an arrester series circuit for a predetermined nominal voltage are arranged in a stack.

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In detail, Figure 1 shows a spark gap 10, the alIoin '* or in combination with other similar arrangements alti Surge arrester works. The arrangement 10 can "if eic. used alone or in a stack, in a poreellan housing (not shown) or other suitable material housing to be included.

The spark gap 10 is essentially circular in shape; it consists of an outer, cylindrical liMteÜH

housing .12, in which a pair of »Jwgfttr ·» Migen electrodes 14 and 16 (Figure 3) are arranged, twiechen An arc gap 18 is located between electrodes 14 and 16. The electrodes 14 and 16 are held directly by the inner and outer, insulating walls 20 and 22, whose side surfaces 24 and 26 delimit the arc gap 18 and open in this way an annular arc chamber cwikehetfWfr electrodes 14 and 16 form.

V ι - * The outer housing 12 consists of similarly designed upper and lower halves 28 and 30 having inwardly directed flanges 32; the outer wall 22 of the arc chamber is enclosed by the flanges 32. The holding together of the outer housing halves 28 and 30 is therefore Boleen

secured. '. ^;

Similarly, walls 20 and 22 are the

chamber formed by the same halves 36 and 38, «says wall ..

part 36 or 38 is betf with an annular cavity 40. 42

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provide in what means for generating a magnetic Fluaaes, preferably permanent magnotes 44 and 46, are arranged are. Each permanent magnet 44 or 46 can be formed by a self-contained ring; in the present example are a plurality of curved Teilraagne- ■ th 48 and 50 (Figure 2) arranged side by side in the annular, cavities 40 and 42, respectively. The magnets £ 8 and £ 50 can- ■ non be formed from a metallic, ceramic or other type of magnetic material.

The wall parts 36 and 38 are preferably made of vulcanized fiber so that non-ionized gas (usually water vapor) is generated in the arc chamber 18 when an arc is ignited between the electrodes 14 and 16. In the spark gap 10, the extinction of the arc is therefore partly promoted by means which, as already explained, have already been used in spark gaps with gas blowing. However, other materials can also be used for the wall parts 36 and 38, depending on the need for non-ionized gas to suppress the arc. Must have the essential properties, the dac wall material of the arc chamber, are: sufficient strength with respect to the expected pressure in the arc chamber, sufficient insulating properties to electrically isolate the electrodes 14 and 16, appropriate magnetic permeability for the transmission of an appropriate magnetic flux $ transversely to Arc chamber 18. An example of a suitable fabric for walls 20 and 22 is polyester resin with an aluminum trihydrate filler. · '-5-

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The upper and lower ring electrodes H and 16 are provided with terminals 15 and 17; they consist of a suitable. ' Neten conductive material, e.g. red-free steel. Farther the electrodes 14 and 16, preferably with relative close fit, held in grooves 49 and 51 which are formed by shoulders 52 and 54 of wall parts 36 and 38. the upper electrode 14 is covered with a suitable filling and adhesive compound 56, which also the upper part 36 of the inner Wall can secure against axial movements relative to the outer wall 22, -üer lower part of the inner wall 36 can with the the upper part of the same wall can be glued or clamped to it in a manner not shown. If desired, special interlocking means can be provided which secure both inner wall parts 36 with respect to the outer wall 22, so that the strength of the arrangement in relation to the pressure generated in the arc chamber is not solely dependent on the

strength of the filling compound 56 depends.

A pressure equalization or an escape of double-arc gases From the arc chamber 18, the lower electrode 16 is provided with spaced holes 58 (Figure 2). An annular insulating layer 60 (FIG. 3), which is glued to the adjacent wall parts 36 and 38, supports the underside of the lower electrode 16. The vent holes 58 also extend through the insulating layer

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Vie from the development of Figure 4 can be seen, have Electrodes 14 and 16 have opposite, annular electrode surfaces 5f and 61 with rollover surfaces 62 and 64 »which form limited styles of the electrode surfaces.

The arcing chamberwoito, i.e. the. Distance between the electrode surfaces 59 and 61, preferably increases with the angle1 deviation to, starting with the flap surfaces 62 and 64 and ending at 180 °. The Veite of the arc chamber 18 takes then down again until the angular position of the rollover surfaces 62 and 64 is reached again. For the formation of the arc chamber 18 other profiles can also be used between the electrode surfaces 59 and 61; for example a uniformly increasing electrode spacing along the circumference σ the chamber with the overlap surfaces 62 and 64 as the start and End point be provided. However, as shown in FIG. 5, a constant electrode spacing 66 can also be used in conjunction with a reduced electrode spacing on the flashover surfaces 62 and 64. One is preferred Arc chamber ends / ends with increasing electrode spacing; The extinction of the arc is then obeyed by increasing arc resistance achieved in connection with increasing arc length.

Venn is! Arc ignited and through the river 0 length of the Übersch2Eg8region the closed loop formed by the electrodes is driven, is an essential factors *

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tor for extinguishing the arc the cooling effect that is on the arc acts and caused in particular by the low temperature of the electrode surfaces 59 and 61 will. The electrodes 14 and 16 therefore preferably have one relatively large mass (and preferably a relatively large depth in the direction of the electrode gap ^), in order to cause rapid heat dissipation from the surfaces 59 and 61 BU. Maintaining a low temperature at the arc roots has a limiting effect on the arc current off in the sense that large parts of the arc energy are then required to maintain the arc and that re-ignition of the arc after passage through the Hull the line voltage is made more difficult.

If, as preferred, the walls 20 and 22 are made of a material such as Vulcanized fiber and if the arc chamber has a suitable geometry, i.e. if the wall surfaces are relatively close, lie together so that they under the action of the arc-> heat take on a sufficiently high temperature, the deionization of the arc chamber by generating non-ionized Gas promoted j the production of non-cooled gas Stein is therefore another important factor in arc extinguishing In any case, it is desirable that the total extinguishing effect is sufficient to erase the light arc. is effected before or at the first Kuli passage of the line tromeo. This can be done by arc cooling alone or by such a cooling in connection with the influence of the

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th non-ionized Ga3es and additionally by the effect of the Arc extension can be achieved. The combined influence of these factors determines the voltage level, up to which overvoltage protection is effective.

The extinguishing of the arc and the preferred time for it are essentially achieved through suitable arc cooling, in particular in that it is of sufficient size for the self-contained arc path between electrodes 14 and 16, which have a relatively high mass, is provided. The inner diameter of the electrodes 14 and 16 is therefore relatively large, so that one is sufficient long, loop-shaped arc-line is formed, which together with the electrode mass causes an arc cooling, which is necessary to dissipate the energy of the arc and interrupt the follow-tron before the temperature of the electrode surfaces significantly above the ambient temperature increases and before the normal current zero crossing is reached. In In this context it is noted that the speed with which the arc length of the closed, loop-shaped Running distance is driven, it is decisive which cooling is achieved by the electrodes 14 and 16, as well as like ^ violent heat through the atmosphere of the arc chamber is dissipated while the arc moves into it. The fact that the inside diameter of electrodes 14 and 16 is relatively large, has an advantageous side effect in that the spark gap 10 has such a large central opening 68 ('# * -

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gur 1) that they have high-voltage bushings '.

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electrical Auarüatun paaa't, such as box transformers.

In FIG. 6, a stack 70 of point stripes 10 is shown, which are connected in series and form a surge arrester for a higher nominal voltage, alo 3io with a single arrangement 10 can be reached. For example, if a single Funkenatrekke 10 has a nominal voltage of 2000 V, the arrester stack contains 70 seven sparks stretch 10 to achieve line tension from H kV.

As can be seen from the illustration, there is between the knitted Lines 74 indicating the outer surfaces of the walls 20 and 22, a space 72. Released gases can escape from the Gaps 72 removed, as shown schematically by the Suction system 76 indicated i3t. The stack 70 can be arranged in a porcelain housing (not shown) or the like, if so desired.

The spark gap 10 or the stack 70 provide a reliable one Surge protection, without special resistance blocks to be required in the arrester housing. Furthermore, the overvoltage protection can also be used without the use of gas-emitting material in the vicinity of the arc chamber, although such Materials reinforce the extinguishing effect.

6 figures

12 claims

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Claims (12)

«E-Caae 3G 095 Claims Spark line for surge arresters with magnetic blowing of the arc, characterized by two ring-shaped electrodes, between which one is delimited by insulating walls and penetrated by a magnetic field also annular arc chamber is located. 2.) spark gap according to claim 1, characterized in that that the cross section of the arc chamber is a narrow α. ! Is a rectangle whose longitudinal direction is in the direction of the distance between electrodons lies. 3.) spark gap according to claim 1, characterized in that the magnetic field by annularly arranged permanent magnets is generated. 4.) Spark gap according to claim 1, characterized in that the insulating walls delimiting the arc chamber consist of gas-released material. 5.) spark gap according to claim 4, characterized in that that the insulating walls are made of vulcanized fiber. -11- BATH 0980Ü / ÜÜ6G WE Caoe 36 095 6.) Spark gap according to Anopruch 4, characterized in that the Ioolierwand are made of polyeoter resin with the addition of aluminum trihydrate. 7.) spark gap according to claim 3, characterized in that the insulating parts delimiting the arc chamber, form annular cavities for receiving the Penatmentmagnete. 8.) emergency spark gap according to claim 1, characterized in that the arc chamber delimiting Ioolierteile 'form grooves in which the electrodes are located * 9.) Spark gap according to claim 8, characterized in that the electrodes are glued in the grooves. 10.) Spark gap according to Anopruch 1, characterized in that the electrode gap iat, eo defl the arc after ignition at a tunnel ge i'ingaten Abotandea at its Uev / ogung extended · 11.) Funk eius track α according to Anopruoh 1, characterized in that wenißijtono «ine electrode with holes for venting the arc chamber iat. ^ ₁ P_ BADOBIGtNAL 009808/0466 WE-CAse 36 095 12.} spark gap according to claims 7 and 8, characterized in that that the to form the arc chamber and to accommodate the permanent magnets and electrodes provided insulating parts aua two ring-shaped halves are composed by two outer, interrelated screwed flanges held together 3ind. BATH ORIGINAL 9808/0466