DE2040053A1 - Arrangement to increase the arc voltage in relation to the number of spark gaps that are decisive for the response behavior in magnetically blown surge arresters - Google Patents

Description

51/70 Hw / Gu

Public limited company Brown, Boveri & Cie., Baden (Switzerland)

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Arrangement to increase the arc voltage in relation to the Number of spark gaps that are decisive for the response behavior with magnetically blown surge arresters.

The invention relates to an arrangement for increasing the arc voltage in Lieh z., With respect to the number of decisive for the Änsprechverhalten spark gaps in magnetic beblassnen surge arresters.

It is already known to equip modern arresters with a magnetic blowing of 4 arcs, whereby a relatively high arc voltage is made possible. In order to achieve a sufficiently strong Bla ^ effective, are in series with the arrester furfkenstrecken '..-. a · or more blowout coils connected "which are" The short time high current Leakage Etrom has the blowout coil were guided by these Ueberbrückungselemente through a radio link or a resistance state Bridges, and then sclinellstens, as so-called folic "- power to the blowout coil to commute, so that a safe blowing effect is guaranteed.

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At the same time, with modern arresters, the individual Spark gaps controlled so that a defined irregular Stress distribution forced and with it; the response voltage can reasonably be reduced.

The disadvantage, however, is the fact that at a very low relative protection level, which means that the arrester nominal voltage related maximum voltage occurring at the arrester is understood, these measures are not yet sufficient are. In this case, each individual spark gap must be provided with a complex pre-ionization device, so that the response voltage and its spread can be kept sufficiently small. However, the control and ionization elements mentioned are essential for the end product Price increase.

The protection level of the arrester can be set lower, the higher the ratio between the arc voltage and response voltage is. On the one hand, this ratio can be increased by, apart from the above defined uneven stress distribution, the inherent The response voltage of the individual spark gaps is lowered by reducing their striking distances. This solution way however, it is problematic in that it increases the spread the response voltage increases. On the other hand, the mentioned can

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Ratio can be increased by putting the arc in the arrester spark gap cannon is extended in a new way and thus the arc voltage is increased extraordinarily.

The invention is based on the object, the arc voltage per spark gap by a new arc extension according to the invention up to a hitherto unknown Measure to increase.

The resulting decrease in the number of spark gaps required enables the protection level of the arrester to be reduced on the one hand, and control and ionization elements on the other to save and thus the end product; to cheaper.

These advantages could basically be achieved through the enlargement of the diameter of the arcing chamber can be achieved, whereby the maximum arc length is also lengthened and the This would increase the arc voltage. In this case would, however, with the same subsequent terror and the same number of turns the magnetic induction, which is decisive for the blowing of the arc, accordingly decrease as the path of the magnetic field lines increases of the blowing coil diameter would increase. Since the blow coil would have to enclose a larger area at the same time the inductance of a coil also increases, and

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the KoraraautierungsVorgang the follow current from the bridging spark gap or from the bridging resistance to the blowing coil would be decisively delayed. The increase in inductance could be canceled out by a smaller number of turns, but this would further decrease the magnetic induction, which is proportional to the number of turns, and the This would jeopardize the mechanism of magnetic blowing.

The aforementioned object is achieved according to the invention by that the arc is lengthened by suitable means that he is from a first chamber, cie from bottom, lid and consists of a cylindrical wall connecting these two, merges into a second or more subsequent chambers, with these chambers are preferably arranged one above the other.

The chambers have openings for the production of an electrical one Provide a connection to the next chamber.

The arrangement according to the invention achieves »that the Arc after going up to the bounding walls of the The first karamer has pre-grown and thereby lengthened into the second, preferably above or below it

■ ti. Chamber is drawn, in which it then also expands to the edges, depending on the construction the chamber to end here, or in a third or

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to expand further chamber. The arc voltage jaro contact point is now many times higher than if, for example, each chamber had its own spark gap. By eliminating a number of spark gaps the number of control and ionization elements can also be reduced accordingly.

According to a preferred embodiment, these chambers exist from an insulating material, preferably from one known per se porous and therefore beneficial in terms of cooling; at inner circumference of the edge delimiting the chambers, they are preferably provided with a large number of recesses known per se, which cause a high arc voltage, while openings are provided in the chamber through which a electrical connection to the next chamber is made possible, and furthermore, the tongues of one of the response voltage are in the first chamber determining collector spark gap between which the arc ignites first.

Furthermore , electrically conductive auxiliary ignition plates are arranged in the next, adjoining chamber, to which, for example two, likewise electrically conductive cams protruding into the chamber in front of it through the openings thereof, which are preferably located at the edge of the chamber, are attached. Furthermore, an ionization channel ending between the auxiliary ignition plate is arranged, which is from

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this chamber leads back to the one in front of it. The stress gradient The extended arc causes between the cams and thus also between the auxiliary ignition plates a potential difference occurs, which, however, is generally not sufficient for the response point of the auxiliary ignition plates to ignite in the second chamber. However, as a result of up to the bounding walls the first chamber of the pre-grown arc through the ionization channel, enough charge carriers to reach the point of contact reach the auxiliary ignition plate in order to make a breakthrough causing the arc part in the first chamber, which is between the protruding into this chamber Cam is located, extinguished. The arc can now be released from the ignited contact point of the auxiliary ignition plates expand further in the second chamber, so that it is greatly extended? Three-part arc at this stage consists, of which two in the first chamber each between a tongue of the collector spark gap and an esa protruding into this chamber of the auxiliary ignition plates of the continue burning in the next chamber. The third part of the arc is identical to the one mentioned above, from the ignited response point of the auxiliary ignition plates to the next Chamber further expanding arc. This arc extension by passing from the first chamber to the next, it can be repeated as desired until the recovery limit reaches confused. To increase the flashback resistance therefore the level of the chamber floors and ceiling »in performed arched in a known manner.

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The aforementioned ionization channel leading from one channel to the next enables the auxiliary ignition plates to be ignited if the voltage between them is not too high, without
later, with further expansion of the arc into the next chambers, the savings resistance of this response point would be too low.

By the aforementioned spark gap cascade arrangement with
successive chambers will therefore be greatly increased
Arc voltage reached, whereby only the first
Spark gap of def * spark strike cascade is decisive for the response voltage of the arrester.

According to a further embodiment of the invention, dehfti
the arc does not radiate out, but rather burns, starting from the ignited tongues of the arrester spark gap between svrei
concentric circular chimney walls. It expands between these concentric circular walls in a semicircular manner in a plane which, in order to increase the resistance to backfire between the parallel arc parts, is preferably arched in such a way that there is no line of sight between the concentric arcuate parts of the semicircular expanding arc. By a
similar arrangement as the one already mentioned is the
Arc from one chamber to the next, not open

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The chamber lying on the same level is drawn to turn there to expand further between two concentric circular walls.

A drawing of the arc into the next chamber can be avoided by placing the preferably curved plane between the two concentric circular walls formed helically will.

The inner concentric circular wall can be scaled down as far that in extreme cases only one of the two tongues of the collector spark gap takes its place. These Tongue is then axially, preferably cylindrical, formed in the center of the helical arc widening plane.

According to a further preferred embodiment of the invention, 1st; one of the two tongues of the response point of the first chamber is cylindrical, and the other tongue of the response point is arranged so that it partially encloses the first concentric i: i at a distance.

Usually the arc burns the longest in the vicinity » of the chamber edge. Therefore the energy absorption is the Chamber relatively limited because the chamber material heats up quickly at this point and the arc is less well cooled and the arc voltage therefore drops. Will

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the contact point between the tongues of the collector spark gap, after the arc has reached the edge of the last chamber, is triggered by a new one, then the already extended arc is extinguished and the new arc in the first chamber must. from the contact point of the collector spark gap * to Hike to the chamber wall of the last chamber. In this way, the heat capacity of the entire chamber, and not just that of its peripheral area, can be used. By heating up the whole. Chamber surface, and not only the border area, may * the energy absorption capability of each chamber siege much gestei. The mentioned re-ignition of the response point ier collector spark gap can therefore be achieved according to a further embodiment of the invention that an ionization channel is arranged in the last chamber from the edge of the chamber to the response point of the collector spark gap of the first chamber, through which the ignition of the response point in this chamber er.ieut is triggered.

It is particularly advantageous to have a / pre-ionization element only to be arranged at a contact point of the cascade connection.

Self-extinguishing DC voltage arresters require an extVen high arc voltage, which is why the arrangement according to the invention through extraordinary lengthening of the arc with regard to it This apparatus is of particular importance.

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In the drawings, embodiments according to the invention are for example shown.

Show it:

1 shows a diagram of a spark gap arrangement with 2 chambers and a blowing coil with a bridging resistor;

Fig. 1 a: a blowing coil arrangement with bridging spark gap »

Fig. 2-5: various exemplary embodiments of spark gap arrangements j

Fig. 6: a section through a Ki.mmer along the cutting line A - A in Fig. 3.

The same parts in the individual figures have been given the same reference numbers.

All design features that are not necessary for a direct understanding of the invention have been omitted from the figures. According to FIG. 1, in a diagram of a spark gap arrangement in which the chambers are arranged one above the other, 1 denotes a first chamber and 2 denotes a second chamber. These chambers 1 and 2 have edge recesses 3 on the inside of their chamber walls Ik to enlarge the edge surface. Tongues 4 of the arrester spark gap are arranged in chamber 1, between which a contact point 12 of the arrester spark gap is located. In the second

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Chamber 2 are auxiliary ignition plates 5 with cams 6, which in Openings 7 in the first chamber 1 for the cams 6 of the auxiliary ignition plates 5 of the second chamber 2 when stacking the. Fit chambers. An ionization channel 8 leads from the first chamber 1 into the second chamber 2.

A blowing coil 9 with a bridging resistor 10 is also connected to the first chamber 1. However, this blowing coil arrangement can also consist of a blowing coil 9 g and a bridging spark gap 11 according to FIG. "Between the auxiliary ignition plates 5 of the second chamber 2 there is a contact point 13 of the auxiliary ignition plates 5.

2 shows an embodiment of the arrangement of the tongues k of the collector spark gap and ler auxiliary ignition plates 5 with cams 6 and the associated openings 7, as well as the ionization channel 8, which runs from the first chamber 1 into the second

Chamber 2 leads. m

In Fig. 3 is a part of the chamber wall, .I ¹ J of the chambers 1 and 2 to pulled to its center and a circular shape in the center and also with peripheral openings 3 for the enlargement of their surface have been provided.

In FIGS. 4 and 5, one of the tongues k of the arrester shape is cylindrical f-.assoMl ·! - * and extends in front of it. the first. Chamber 1 to the second chamber 2. Also with this arrangement

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a part of the chamber wall I ¹ J has been pulled up to the cylindrical tongue k at one point of the arrester spark gap.

In FIG. 5, one of the two tongues is k in the first camera 1 so formed that they partially unschliesst the second, cylindrically shaped tongue ¹ I in a certain distance. The contact point 12 of the collector spark gap is located between these two tongues H.

The Fig. (> Shows how the Karcnerboden between the chamber walls I ¹ J is arched.

The mode of operation of the inventive arrangement of an arrester spark gap emerges from the following:

Parallel to an object to be protected from overvoltages are the chambers 1, which are preferably arranged one above the other, 2, connected via lead 15. The ones that are still required Discharge resistors, control elements, etc., are omitted since they are known to the person skilled in the art and for the invention are not of fundamental importance. Part of the voltage is applied to the object to be protected the tongue. 4 of the collector spark gap of the first chamber 1. If a sufficiently high overvoltage occurs, then speaks

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the first chamber 1, i.e. it forms at the point of contact 12 between the tongues 4 of the arrester spark gap initially a short arc, which is followed by a short-term electric arc Leakage current through the short arc and the bridging element 10 or 11 of the blowing coil 9 flows as quickly as possible commuted to the blow coil as a so-called follow-up tora. If the follow-up current now passes through the blowing coil 9, a strong magnetic blowing effect is created on the arc between the tongues 4 of the collector spark gap.

Due to the magnetic blowing effect on the arc, it is continuously extended from both tongues 4, and finally goes along the recesses 3 of the chamber wall 14 to the cams 6 protruding through the openings 7. The auxiliary ignition plates attached to the cams 6 in the second chamber 2 5 are now under a voltage which is equal to the voltage of the arc in the first chamber 1, between the openings 7 for the cams 6. However, this voltage is not sufficient to cause the response point 13 between the auxiliary ignition plates 5 in the second chamber 2 to ignite. However, through the ionization channel 8, which leads from the first chamber 1 into the second chamber 2, enough charge carriers reach the response parts 13 of the auxiliary ignition plates 5 in the second chamber 2 to cause a breakdown here, whereby the arc part in the first chamber 1 , which is located between the protruding into this chamber 1 cam 6, extinguishes. Now it can be in front of the ignited contact point

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13 of the auxiliary ignition plates 5 from the arc in the second. Expand chamber 2 so that the greatly lengthened arc at this stage consists of 3 parts, two of which continue to burn in the first chamber 1 between a tongue h of the arrester radio link and a cam 6 protruding into this chamber ier auxiliary ignition plates 5 of the next chamber, and the third part differs from the ignited one. Contact point 13 lev auxiliary ignition plates 5 from in the chamber 2 further expands.

If, for example, as shown in Fig. 6, the chamber floor of the '{poor 1 and 2, has a bulge 16, the retraction strength becomes elevated. The arc does not expand radially in this example, but between the two concentric circular ones Walls 14, starting from the tabs 4 of the lead. * - spark gap (like Fig. 3, Ί and 5). The vault 16 of the Ka.ir floor is designed so that there is no line of sight between the concentric arc parts of the semicircular expanding arc. This increases the backfire resistance stitched between the parallel arc parts. .

If the preferably arched Karr.merbogen 16 between the zv: ei concentric circular camr.erwnien 1Ί v.'endelfcmig formed i'ird, drawing the arc into the next chamber can be avoided.

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Claims (12)

Claims 1 «) / Spark gap nano-size of a magnetically blown cover voltage arrester, consisting of individual chambers, these chambers made of an insulating material, preferably made of consist of a porous substance known per se and therefore favorable in terms of cooling, and those on their inner circumference the edge delimiting it preferably with a large number of recesses, known per se, which have a high arc voltage effect, are provided, characterized in that means for lengthening the arc of fire and for increasing it the backfire resistance in these, preferably one above the other arranged chambers (1, 2), which are made of soil, Cover and a wall connecting these two are made, are arranged, and the chambers nothing, openings (7) for Establishing an electrical connection to the nearest Kanmer are mistaken. 2.) Spark gap arrangement according to claim 1, characterized in that that both the chamber bottom (l6) and the chamber lid are arched. 3.) spark gap arrangement according to claim 1 and 2, characterized in that in the first chamber (l) tongues (4) an arrester spark gap that determines the response voltage are arranged. 109848/1105 - yt - 51/70 4.) Spark gap arrangement according to claims 1 to 3> characterized in that in the further chambers (2) following the red chamber (1) electrically conductive Auxiliary ignition plates (5) are arranged to which, for example two, also electrically conductive, in each in front of the chamber arranged through their openings (7) protruding cams (6), which are preferably located on the edge of the chamber are located. 5) spark gap fixing according to C5n claims 1 to 4, characterized by £; e denotes that each one of a chamber (1) to the next (2) leading, between the auxiliary ignition plates (5) ending ionization channel (8) is arranged. 6.) spark gap arrangement according to claim 1, characterized in that that the spark gaps are formed in a cascade shape in successive chambers. 7.) Spark gap arrangement according to claims 1 to 6, characterized in that cie arc path between zv / egg concentric circular?: Ammerwilden (14) is in a plane in 3-chamber (1, 2). 8.) Funke.'istrecKenordnung according to claims 1, 2, 5 and 7 »characterized in that the plane between the two concentric circular walls (14) is designed in a vrendelförrr.ig. 109848/1105 ■■ ... ■ 51/70 Air 204Q053 9.) 'spark gap arrangement according to claims 1 to 5, characterized in that the inner concentric circular wall (14) consists of a tongue (4) of the arrester spark gap consists. 10.) Spark gap arrangement according to claims 1, 7 and 8, characterized in that the in the middle of the helical Tongue (4) arranged axially on a flat arch is preferably cylindrical. 11.) Spark gap arrangement according to claims 1 and 9 * characterized in that in the last chamber of de.ren At the edge an ionizing channel (8) leading to the contact point of the collector spark gap of the first chamber is arranged 12.) The spark gap arrangement according to claims 1 to 11, characterized in that eir.e the two tongues (4) of the point of contact of the first Kammei (1) is cylindrical and the other tongue (4) is arranged of the point of contact so that they the first partially encloses concentrically at a distance. 13 ♦) The spark gap arrangement according to claims 1 to 10, characterized in that a Vorionisationseinrichtu: ig arranged only at a point of contact of the Kaskandenschaltung Public company Brown , Boy en &. Cie. 109848/1105