EP2953216B1 - Spark gap with a cooling and/or damping device - Google Patents

Description

The invention relates to a spark gap with cooling and / or damping device.

Numerous arrangements for spark gaps are known in the prior art. It should be noted that spark gaps are not trivial arrangements, but for a reliable ignition and for the cooling of the resulting plasma arc a not to be underestimated effort must be driven. Previous spark gaps were characterized by a specific to be taken pulse energy.

However, this turns out to be disadvantageous because now there is an optimized solution for a given pulse energy, but the switched-on at other pulse energies are sub-optimal.

For example, from the generic state of the art, the European patent application EP 1 542 323 A2 known. This shows a spark gap with a starting aid with a voltage-switching element.

Although one could now try to operate different Ableitorgane parallel, but there are problems with respect to a tuned switching behavior. In addition, such parallel arrangements are also considerably more expensive.

It would therefore be desirable to be able to provide a more flexible, cost effective solution.

The object is achieved by the features of independent claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

The invention will be explained in more detail with reference to the accompanying drawings with reference to preferred embodiments.

Fig. 1

eine erste Anordnung gemäß Ausführungsformen der Erfindung in einem ersten Zustand,

Fig. 2

die erste Anordnung gemäß Ausführungsformen der Erfindung in einem zweiten Zustand,

Fig. 3

beispielhafte Ausführungen von Scheiben gemäß Ausführungsformen der Erfindung,

Fig. 4

eine weitere beispielhafte Ausführungsform von Scheiben in Draufsicht und Schnittdarstellungen,

Fig. 5

ein weiteres illustratives Ausführungsbeispiel nicht Teil der Erfindung

Fig. 6

einen Aspekt des weiteren illustrativen Ausführungsbeispiels

Fig. 7

Noch ein weiteres illustratives Ausführungsbeispiel nicht Teil der Erfindung

Fig. 8

einen Aspekt des noch weiteren illustrativen Ausführungsbeispiels und

Fig. 9

noch einen Aspekt des noch weiteren illustrativen Ausführungsbeispiels.

Show it

Fig. 1

a first arrangement according to embodiments of the invention in a first state,

Fig. 2

the first arrangement according to embodiments of the invention in a second state,

Fig. 3

exemplary embodiments of discs according to embodiments of the invention,

Fig. 4

another exemplary embodiment of slices in plan view and sectional views,

Fig. 5

another illustrative embodiment is not part of the invention

Fig. 6

an aspect of the further illustrative embodiment

Fig. 7

Yet another illustrative embodiment is not part of the invention

Fig. 8

an aspect of the still further illustrative embodiment and

Fig. 9

yet another aspect of the still further illustrative embodiment.

The FIGS. 1 and 2 show a first arrangement according to embodiments of the invention in two different states.

In this case, the spark gap 1 an adaptive cooling and / or damping device, which will be explained in more detail below.

The spark gap 1 has at least a first spark gap electrode FS ₁ and a second spark gap electrode FS _2. The spark gap can also have further electrodes for different purposes. For example, measuring electrodes may be provided to measure, for example, the degradation of insulating components within the spark gap in a capacitive, inductive or resistive manner.

Furthermore, the spark gap 1 has at least one auxiliary ignition electrode ZE for connection to an ignition circuit. Such arrangements are for example from the EP 1423894 B1 the applicant known. In this case, the auxiliary ignition electrode ZE is spatially adjacent to the first spark gap electrode FS ₁ and spaced from the second spark gap electrode FS ₂ . As a rule, that is Ignition auxiliary electrode ZE, based on the direction of the first spark gap electrode FS ₁ and second spark gap electrode FS _{2 arranged} laterally to this direction.

Between the auxiliary starting electrode ZE and the first spark gap electrode FS ₁ , a low-conductivity material BRZ is introduced for ignition assistance. That is, in the event of an overvoltage, ionization will first take place via the auxiliary starting electrode and the first spark gap electrode FS ₁ , and then the main spark gap between the first spark gap electrode FS ₁ and the second spark gap electrode FS ₂ will be ignited.

In the invention, a plurality of slices S ₁ , S ₂ ,... S _n are now introduced between the auxiliary starting electrode ZE and the second spark gap electrode FS ₂ . These plurality of disks S ₁ , S ₂ ,... S _n are electrically insulated from the auxiliary starting electrode ZE and the first spark gap electrode FS ₁ by means of an electrical insulator ISO ₁ .

In this case, the slices S ₁ , S ₂ , ... S _n each have an opening, wherein the openings of the slices S ₁ , S ₂ , ... S _n are arranged so that they form an arc channel between the second spark gap electrode FS _second and the first spark gap electrode FS ₁ .

These plurality of disks S ₁ , S ₂ , ... S _n serve as cooling and / or damping device.

In the case of FIG. 1 is the spark gap in the off state, ie the spark gap 1 does not conduct electricity. If there is now a current flow, ie the spark gap ignites, then an arc plasma is formed.

Depending on the strength of the pulse event that has led to the ignition of the spark gap 1, the spark gap 1 can now adjust to the event.

If a strong impulse event occurs, the arc plasma will build up a correspondingly higher heat and pressure, so that now through the pressure effect the disks in the lateral direction as in FIG. 2 shown can be pushed apart. This extends on the one hand the spark gap channel, because at the same time On the other hand, now at least a portion of the arc plasma and the resulting heat to the environment can be derived according to the arrows in the interstices of the discs. Since now at least a portion of the ionized gas is removed from the spark gap channel, the conductivity of the arc plasma decreases. Since energy is needed to move the disks and at least a portion of the pressure escapes when the disks are pushed apart, the pressure increase is damped.

If a less strong impulse event occurs, the arc plasma will build up a correspondingly lower heat and pressure, so that the discs can not be pushed apart laterally due to the pressure effect.

Thus, different strong pulse events can be derived while at the same time achieved by the special design that for different pulse events and the network follower currents can be suppressed by a reliable extinguishing.

Due to the design of the spark gap 1 with particularly thick layers of material also a large thermal mass can be provided, whereby a high energy absorption is provided, which has a positive effect on the plasma cooling and extinguishing the spark gap 1. For example, the spark gap electrodes may be made of WCu or other preferably arc-resistant materials.

It will be readily understood by those skilled in the art that the discs S ₁ , S ₂ , ... S _{n are} made of a suitable material.

Although it is possible in principle to produce the slices S ₁ , S ₂ ,... S _n from a hard-gasifying material such as polyoxymethylene (POM) or from polyetheretherketone (PEEK), the slices S ₁ , S ₂ , _n preferably made of an arc-resistant material such as WCu (tungsten-copper), so that usually a variety of pulse events can be derived.

For example, at least part of the plurality of slices S ₁ , S ₂ ,... S _{n may comprise} an electrically conductive material. Here, for example, the heat capacity for the Selection should be a criterion. For example, the disks may comprise copper or tungsten or compounds thereof.

On the other hand, at least a portion of the plurality of slices S ₁ , S ₂ ,... S _{n may comprise} an electrically nonconductive material. Here too, for example, heat capacity for the selection can be a criterion. For example, the discs may have ceramic.

However, it is also readily possible to provide arrangements in which disks of electrically conductive materials as well as disks of electrically non-conductive materials are used.

Depending on the predicted lifetime of the spark gap, the plurality of electrically conductive panes S ₁ , S ₂ ,... S _{n can have} a more or less temperature-resistant material.

Without further, at least a portion of the plurality of slices S _1, S _2, ... S _n grooves or electrically conductive / non-conductive spacers have R as shown in FIG. 4 shown.

Without limiting the generality, it can also be provided that one or more of the (electrically conductive or electrically insulating) disks S ₁ , S ₂ ,... S _{n have} a porous material. For example, a porous or sintered material may be used. An essential aspect of a porous material is that this material forms channels, so that a plasma of the spark gap can be derived attenuated. For example, porous material may include (sintered) sand (resulting in a solid shape), and / or spheres made of, for example, steel, POM, ceramic and / or flux or fibers, for example of ceramic material.

Both the grooves and the spacers as well as the grooves R allow plasma to escape directly at the beginning of an impulse event. If a stronger pulse event occurs, then the slices S ₁ , S ₂ ,... S _n can be pushed apart in order to further assist the outflow under the influence of the further increasing pressure. However, this is not absolutely necessary. The spacers or grooves R in the individual panes can be introduced into the surface, for example, by stamping, pressing or embossing. If several discs are stacked, depending on the position of the spacers or grooves to each other a free volume between the discs are generated. The plasma has the possibility to flow outward through this free volume. The same applies to spacers which can be applied to the surface of the slices S ₁ , S ₂ ,... S _n alternatively or additionally.

Although a hard gas insulating material is not mandatory for insulation ISO ₁ adjacent to the first spark gap electrode FS ₁ , it is advantageous for effective cooling of the arc plasma because hard gas materials have the property of narrowing the arc channel.

Furthermore, the low-conductive material BRZ and / or the auxiliary ignition electrode ZE may have an annular opening, wherein the openings of the slices S ₁ , S ₂ , ... S _n are arranged so that they form an arc channel between the second spark gap electrode FS ₂ and the form the first spark gap electrode FS ₁ . As a result, parts that are particularly easy to produce can be used for the spark gap, so that the mechanical structure can be implemented quickly and inexpensively.

Depending on the shape of the openings in the individual panes, the spark gap channel can now also be designed in the connecting direction from the first spark gap electrode to the second spark gap electrode.

If e.g. does not use circular apertures in the disks, or the aperture in the disks is not centered, a slight rotation of disks relative to each other can alter the arc channel.

While results in similar circular openings in the discs a cylindrical channel, for example, a slightly eccentric opening arranged as in Fig. 3 On the right side shown in the discs cause that at a certain angular displacement of the discs to each other results in a helical path. Similarly, with a slot-like opening as in FIG. 3 can be reached on the left side. The openings can in principle take all possible forms. It is also possible to use a part of the disks in one mold and another part in another mold.

Of particular advantage, however, circular openings, since they are particularly simple and therefore inexpensive to produce.

In order to use the adaptive feature, it may be sufficient that the individual elements are held only by their own weight, in which case it is expedient to provide guide devices so that the individual elements return to their previous position after being pushed apart.

However, it may also be provided that the adaptive property can only be used once, e.g. in that the elements are suitably pressure-releasably connected. For this, e.g. Use a suitable adhesive or a solder.

However, it can also be provided that the spark gap 1 has an elastic element D, so that the spark gap electrodes FS ₁ , FS ₂ and the slices S ₁ , S ₂ , ... S _{n are} held. Such an elastic element D may be a pressurization by means of a spring or a circumferential elastic element, for example, of an elastomer similar to a rubber band or the like.

Furthermore, the spark gap 1 may also have a encompassing housing G. But particularly advantageously, the housing G can also combine the function of the elastic element. Depending on the shape of the housing G, an outflow is now either possible only in the intermediate regions of the disks or, as far as the housing G has openings, plasma can continue to escape into the environment.

In order to direct the arc plasma targeted can also be provided that between the slices S ₁ , S ₂ , ... S _n and the auxiliary ignition electrode ZE an arc diaphragm ISO _{2 is} attached.

In a particularly advantageous embodiment of the spark gap 1, the spark gap has an elastic element D, so that the spark gap electrodes FS ₁ , FS ₂ and the disks S ₁ , S ₂ , ... S _n (pressure-displaceable) are held and that the electrically conductive disks S ₁ , S ₂ , ... S _n can be displaced in the direction of the first spark gap electrode and the second spark gap electrode.

Without further ado, the spark gap according to the invention can also be used in a spark gap arrangement with an ignition circuit, the ignition circuit connecting the second spark gap electrode FS ₂ and the auxiliary ignition electrode ZE via a voltage-switching and / or voltage-limiting element. For example, this can be done as in FIG. 1 and 2 a varistor and a gas discharge tube may be provided.

Hereinafter, such an arrangement will be described again by way of example. The second spark gap electrode FS ₂ is contacted with the auxiliary ignition electrode ZE by a voltage-switching element and / or a voltage-limiting element (for example a varistor), whereby a continuous current flow through the ignition circuit can be prevented.

If a surge current is impressed by a pulse event, the upper potential is conducted to the auxiliary starting electrode ZE via the voltage-switching and / or the voltage-limiting element. In the region of the low-conductivity material BRZ, at least part of the surface burns to the first spark gap electrode FS ₁ and ionizes the combustion channel. The plasma creates a main discharge between the two spark gap electrodes. Insulation material ISO ₁ or ISO ₂ gasifies and cools the arc. At the same time, the temperature and the pressure increase. From a certain threshold value of the pressure, the disks S ₁ , S ₂ , ... S _{n are} pressed apart and thus form several large blow-off volumes, through which the ionized gas can escape.

The plasma can be strongly cooled by the large surfaces between the discs.

The structure thus forms a self-regulating system, since the pressure build-up and the pressure reduction depend on each other and simultaneously counteract each other.

Particularly advantageously, the distance between the discs is dimensioned so that the flow of the plasma is inhibited so much that outside the arrangement no or only very small amounts of ionized gas escape. As a result, a sufficiently high pressure is maintained in the arc combustion channel, and the plasma emerging from the channel is optimally cooled. The spacing of the cooling surfaces can be achieved by insulating or non-insulating and resistive, as well as a combination of insulating as non-insulating and resistive spacers. By suitable combination, the flow of the plasma, the cooling effect and the formation of the conductivity of the plasma can be adjusted so that conductivity with low Energy conversion is achieved while network follower currents are severely limited or completely suppressed.

As a result, the invention makes it possible to adjust the outflow area adaptively to different requirements by means of different pulse energies. The arrangement according to the invention is simple to realize mechanically. In particular, the invention allows to provide a high discharge capacity by a large thermal mass. The high thermal mass also has a large surface, resulting in a high energy absorption. By adaptively opening the outflow region, the plasma channel can be deionized and thus the conductivity of the plasma can be reduced. Other cooling mechanisms can be used to achieve efficient cooling and removal of the plasma. Thus, an optimal derivation of transient currents is achieved and effectively suppressed a Netzfolgestrom.

In FIG. 5 is another illustrative embodiment, which is not part of the invention shown. This differs initially only in the shape of the disc S. ₁ The disc of FIG. 5 and FIG. 6 is not a disk of solid material but rather resembles (in plan view) a snail.

Suitable screws - indicated in FIG. 6 - Can be made of sheet-metal material wound (particularly simple and inexpensive production) or milled from solid material or produced as such, for example by casting-like process. In this case, the properties of the winding, ie the number of windings and the geometry of the channel created thereby, the properties such as flow behavior and cooling behavior can be specifically influenced. Without limitation of generality, the material may be insulating or electrically conductive.

It is essential that can be provided by the helical arrangement, a channel through the plasma of an arc can escape steamed. If the screw is constructed of a suitable material, then this can be used in addition to the cooling. In this case, the channel may be both uniform and irregular, such as in FIG. 6 indicated. The walls of the screw S ₁ can run parallel to each other over the entire length, converge toward one another or diverge.

The material in a worm shape S ₁ may consist of one or more layers and different materials. For example, material in a worm shape S ₁ may comprise a conductive material such as copper or non-conductive material such as ceramic (as a flux or as a solid material).

In a multilayer structure, different materials may be suitably connected to each other. For example, a layer structure may be comprised of one or more layers of ceramic and / or metal adjacent to an outgassing material, such as e.g. Polyoxymethylene (POM) be constructed. In this case, in order to make use of the cooling effect of the outgassing material, openings may also be provided in the other layers, which are either given by the material property itself and / or are particularly provided. Is e.g. the outgassing material is arranged in a (coarse) porous ceramic or in a wire-like grid is given a good access to the outgassing material with simultaneous stability.

For example, the number of openings can be distributed differently, so that, for example, in order to realize a smaller material removal in the multilayer material in a screw shape S ₁ , the openings can be selectively attached, for example to minimize outgassing close to the spark gap. the number of holes (voids) increases with respect to the length of the channel. Thus, in the region of the main electrode, the risks of increased burn-up and possibly a breakthrough to the second turn of the material in a screw shape S _{1 are} avoided.

The (electrically conductive) material in a screw shape S ₁ forms an opening, wherein the openings are arranged so that it forms an arc channel between the second spark gap electrode FS ₂ and the first spark gap electrode FS ₁ .

The (electrically conductive) material S ₁ can also be embodied as part of the second spark gap electrode FS ₂ . In this case, the material S _{1 is} usually made in one piece and electrically conductive with the spark gap electrode FS ₂ .

On the other hand, if the (electrically conductive) material S ₁ is a separate component, then it may, if necessary, also be configured in such a way that, under the pressure of a plasma, an expansion of the channel formed can also take place. Ie similar to the Embodiment before, the spiral configuration can change their properties depending on the pressure.

As in FIG. 5 shown further, the housing G may have areas in which plasma could also escape to the outside. These areas are shown, for example, as a dotted housing G.

Although in the FIG. 5 only a single disc S _{1 is} shown, it is obvious to the person skilled in the art that a plurality of discs can also be mounted one above the other in a corresponding arrangement. In this case, mixed forms can also be used. For example, individual discs can be used accordingly FIG. 6 be executed while other discs according to Figures 3 or 4 are executed.

Furthermore, as in FIG. 5 may be provided that in the material in a worm shape S ₁ further openings Ö1 are provided so that plasma of the ignited spark gap can enter at more than one point in the channel.

Likewise, as in FIG. 7 shown alternatively or additionally provided that the second spark gap electrode FS _{2 has} at least one further opening Ö ₁ , so that plasma can enter laterally into the channel formed by the material in a screw shape S ₁ . A possible sectional view through the second spark gap electrode FS and the material in a screw shape S ₁ is shown in FIG FIG. 8 shown.

The present invention provides a large thermal mass and surface in which the plasma has the opportunity to cool. In addition, the spiral shape and the imperfections to the partition wall dampening the plasma flow, resulting in a reduction of the thermal energy. With appropriate dimensioning of the spiral damper, a back pressure is generated, so that during the high-current phase, the conductivity in the combustion chamber is increased and the energy conversion in the spark gap decreases. In the case of the low-current phase in the area of reconsolidation, the back pressure and the conductivity in the spark gap decrease. As a result, a higher arc burn voltage is produced, resulting in improved line follow current extinguishing capability.

As far as a worm shape is described above, it is to be understood within the meaning of the invention that more than one turn of material is present, i. that at least one overlapping area arises.

The material described above in a worm shape S ₁ may comprise a conductive material and / or a non-conductive material.

In particular, the material described above in a worm shape S ₁ as well as other formations of the spark gap 1, such as housing G at least partially a multi-layer structure as it is exemplified in FIG. 9 is shown. Here, for example, an inner wall W _I and an outer wall W _{A can be} made of a rather massive material with holes or a net-like material, which together include a porous material W _Z located therebetween. For example, porous material may include (sintered) sand (resulting in a solid shape), and / or spheres made of, for example, steel, POM, ceramic and / or flux or fibers, for example of ceramic material.

Insofar as reference has previously been made to low-conductivity material BRZ, it may be any suitable material. In particular, the low conductivity material BRZ may be made of, for example, FR4, a material used for printed circuit boards consisting of an epoxy resin-filled glass fiber fabric, with a suitable surface coating such as graphite. In principle, for the material with low conductivity BRZ any material made of plastic or ceramic is suitable, which has a certain conductivity, be it that the respective material corresponding conductive materials such as electrically conductive ceramics or graphite (embedded) or coated with these is. LIST OF REFERENCE NUMBERS radio link 1 Spark gap electrode FS ₁ , FS ₂ auxiliary ignition ZE low conductive material BRZ (electrically) conductive disk S ₁ , S ₂ , ... S _n insulation ISO ₁ elastic element D casing G Arc aperture ISO ₂ Spacers, grooves R connection A ₁ , A ₂

Claims (13)

1. A spark gap (1) having a cooling and/or damping device, having

   • at least one first spark gap electrode (FS₁) and one second spark gap electrode (FS₂),

   • at least one auxiliary ignition electrode (ZE) for connection to an ignition circuit, the auxiliary ignition electrode (ZE) being arranged spatially adjacent to the first spark gap electrode (FS₁) and spaced from the second spark gap electrode (FS₂), the auxiliary ignition electrode (ZE) being arranged laterally with respect to the direction of first spark gap electrode and second spark gap electrode,

   • a plurality of discs (S₁, S₂, ... S_n), which are insulated (ISO₁) with respect to the auxiliary ignition electrode (ZE) and the first spark gap electrode (FS₁), are attached between the auxiliary ignition electrode (ZE) and the second spark gap electrode (FS₂), characterized in that

   the discs (S₁, S₂, S_n) have openings, wherein the openings of the discs are arranged in such a manner that the openings form an arc channel between the second spark gap electrode (FS₂) and the first spark gap electrode (FS₁),
   and in that a slightly conductive material (BRZ) for supporting ignition is introduced between the auxiliary ignition electrode (ZE) and the first spark gap electrode (FS₁),
   and in that the plurality of discs (S₁, S₂, ... S_n) can be pushed apart under the action of pressure.
2. The spark gap according to Claim 1, characterized in that at least a portion of the plurality of discs (S₁, S₂, ... S_n) have grooves or electrically conductive/non-conductive spacers, which are used as spacers.
3. The spark gap according to one of the preceding claims, characterized in that the spark gap has an elastic element (D), so that the air gap electrodes (FS₁, FS₂) and the discs (S₁, S₂, ... S_n) are held.
4. The spark gap according to one of the preceding claims, characterized in that at least one of the plurality of discs (S₁, S₂, ... S_n) has a conductive material and/or a non-conductive material.
5. The spark gap according to one of the preceding claims, characterized in that the insulation (ISO₁) has a strongly gassing material adjacent to the first spark gap electrode (FS₁).
6. The spark gap according to one of the preceding claims, characterized in that at least one of the plurality of discs (S₁, S₂, ... S_n) has an arc-resistant material.
7. The spark gap according to one of the preceding claims, characterized in that the slightly conductive material (BRZ) and/or the auxiliary ignition electrode (ZE) has an annular opening, wherein the openings are arranged in the discs (S₁, S₂, ... S_n) in such a manner that they form an arc channel between the second spark gap electrode (FS₂) and the first spark gap electrode (FS₁).
8. The spark gap according to one of the preceding claims, characterized in that at least one of the plurality of discs (S₁, S₂, ... S_n) has a temperature-resistant material.
9. The spark gap according to one of the preceding claims, characterized in that the arc channel has a cylindrical or helical or slot-shaped or elliptical shape.
10. The spark gap according to one of the preceding claims, characterized in that the spark gap has an elastic element (D), so that the air gap electrodes (FS₁, FS₂) and/or the discs (S₁, S₂, ... S_n) are held.
11. The spark gap according to one of the preceding claims, characterized in that an arc screen (ISO₂) is attached between one of the plurality of discs (S₁, S₂, ... S_n) and the auxiliary ignition electrode (ZE).
12. A spark gap arrangement having a spark gap according to one of the preceding claims, characterized in that an ignition circuit is furthermore provided, which connects the second spark gap electrode (FS₂) and the auxiliary ignition electrode (ZE) by means of a voltage-switching and/or a voltage-limiting element.
13. The spark gap according to one of the preceding claims, characterized in that the spark gap has a surrounding housing (G).

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