EP3834260A1

EP3834260A1 - Arrangement for firing spark gaps

Info

Publication number: EP3834260A1
Application number: EP19768780.9A
Authority: EP
Inventors: Uwe Strangfeld; Sebastian Haas
Original assignee: Dehn and Soehne GmbH and Co KG
Current assignee: Dehn SE and Co KG
Priority date: 2018-10-15
Filing date: 2019-09-11
Publication date: 2021-06-16
Anticipated expiration: 2039-09-11
Also published as: DE102019101448B3; US12015249B2; AU2019362453A1; EP3834260C0; US20210351572A1; KR20210076006A; EP3834260B1; AU2019362453B2; CN112868151A; WO2020078622A1; JP7268145B2; JP2022515695A; KR102691276B1

Abstract

The invention relates to an arrangement for firing spark gaps with a trigger electrode which is located on or in one of the main electrodes and is insulated with respect to this main electrode, wherein the trigger electrode can be electrically connected to a further main electrode via at least one voltage-switching or voltage-monitoring element, and there is an air gap between the trigger electrode and the further main electrode, wherein the trigger electrode forms a sandwich structure together with an insulating layer and a layer made of a material with lower conductivity than the material of one of the main electrodes. Furthermore, the insulating layer is embodied as a thin film or layer of coating agent and the layer is composed of the material with the lower conductivity is in contact with one of the main electrodes or rests on said electrode. According to the invention, in order to conduct away energetically weak overvoltage events without triggering the spark gap formed between the main electrodes, the insulating layer of the sandwich structure is interrupted outside the firing region and/or an electrical component which influences the triggering behaviour is connected between the trigger electrode and the associated main electrode.

Description

Arrangement for the ignition of spark gaps

description

The invention relates to an arrangement for igniting spark gaps with a trigger electrode located on or in one of the main electrodes and insulated from this main electrode, the trigger electrode being electrically connectable to the further main electrode via at least one voltage-switching or voltage-monitoring element and between the main electrode and the further There is an air gap in the main electrode, the trigger electrode with an insulation layer and a layer made of a material with a lower conductivity than the material of one of the main electrodes forms a sandwich structure, the insulation layer is formed as a thin film or lacquer layer and the layer with the material with lower conductivity one of the main electrodes is in contact or rests on this according to the preamble of claim 1.

Spark gaps can be differentiated in terms of their behavior as breakdown or sliding spark gaps. Such spark gaps

are triggered, but can also be executed without a trigger. With triggered

There are at least one spark gap in addition to the main electrodes

Trigger electrode. The ignition in the case of triggered spark gaps is carried out either by using an ignition transformer with the consequence of a high response voltage of the correspondingly well-insulated trigger electrode or, in an alternative, by a special arrangement of the

Trigger electrode with respect to the main electrode without ignition transformer.

Triggered spark gaps generally have a controllable response behavior.

In the pressure-tightly coupled spark gap arrangement for deriving harmful disturbance variables from overvoltages according to DE 200 20 771 U l, a conductive housing is provided there directly to form a Partial spark gap a trigger voltage can be applied in the discharge space. The main spark gap between the main electrodes is ignited via the partial spark gap. An ignition transformer, which is part of the trigger device, is also used there.

However, ignition transformers require a not inconsiderable installation space. In addition, the size of the ignition voltage generated in the ignition transformer on the secondary side depends on the primary-side current change di / dT. If such a current pulse does not have a sufficient steepness, the voltage occurring on the secondary side is not sufficient to achieve the

Ignite spark gap safely.

If the trigger electrode is connected to one of the main electrodes, an ignition transformer can be omitted. In the case of such solutions, a sliding discharge is triggered between one of the main electrodes and the trigger electrode during the ignition process, which reaches the further main electrode after a certain time and triggers the ignition process.

Such a solution is disclosed for example in DE 101 46 728 B4.

Such trigger electrodes have permanent electrical contact with one of the two main electrodes. This means that there is no electrical isolation of the main potentials. For this reason, a voltage-switching element, for example in the form of a

Gas discharge tube, can be switched.

DE 10 2011 102 937 A1 describes an arrangement for igniting

Known spark gaps, which has a trigger electrode located on or in one of the main electrodes, insulated from these main electrodes and with which the response behavior is in a large range

can be specified.

In this regard, the generic solution has a trigger electrode, which has an insulation layer and a layer made of a material with a lower conductivity than the material of one of the main electrodes

Sandwich structure forms. The insulation layer is preferably designed as a thin film or lacquer layer. The layer of material less Conductivity is in contact with or on one of the main electrodes.

The layer dielectric of the sandwich structure turns out to be one

Series connection of a first partial capacitance with the dielectric of the

Isolation stretch and a second partial capacitance with the material of lower conductivity than dielectric, the partial capacities are chosen to be very low.

The material M of the sandwich structure has a much worse one

Conductivity as the material of one of the main electrodes. The ignition arc is lengthened over the thickness of the layer of material M.

The thin insulation gap between the trigger electrode and the layer of poorly conductive material can preferably be realized by printed circuit boards. The trigger electrode then corresponds to the applied conductor track and the insulation layer to the lacquer layer above, with an end section remaining free of lacquer layer.

The previously known solution according to DE 10 2011 102 937 A1, the disclosure content of which is declared the subject of the present application, creates a plasma jet or plasma beam in the base region of an arrangement which is preferably designed as a horn spark gap. This beam leads to a strong and fast targeted movement of ionized gases and charge carriers. This transport is used to significantly accelerate the ignition of the main path between the main electrodes, whereby the load on the trigger electrode and the sandwich structure can be reduced and the residual voltage of the spark gap decreases.

The plasma jet effect explained above is characterized by the expression of a preferred direction of the ionized gas flow. According to the state of the art, measures can be taken which on the one hand influence the formation of the beam, but also the direction, so that the effect of a rapid ignition of the main line arises. The proposed beam with its very effective ionization of air distances is used to overcome the air gap between the main electrodes particularly suitable, which in turn ensures effective operation of the preferred horn spark gap. Due to the electrode arrangement and the insulation layer and the layer made of the material with lower conductivity, a preferred orientation is otherwise only stochastic

Plasma jets. In particular, the material with a lower conductivity can be suitable for gas emission, which enables a further targeted generation of the plasma jet.

The solution according to DE 10 2011 102 937 Al offers the advantage of a very fast ignition of the main spark gap compared to classic, non-insulated current triggering methods, as a result of which all other components of the spark gap arrangement are subjected to less energy and can therefore be designed in a miniaturized manner.

A disadvantage, however, is the fact that even the smallest, relatively low-energy pulses from overvoltage events are sufficient to ignite the entire spark gap. This results in a possible disadvantageous aging of the corresponding surge arrester arrangement.

From the above, it is therefore an object of the invention to provide a further developed arrangement for the ignition of spark gaps using a trigger electrode, the basic principle of plasma jet ignition being used in this regard in order to utilize the advantages provided thereby, on the other hand but it must also be ensured that there is no premature aging of appropriately equipped surge arresters with such spark gaps by preventing the actual overload area between the main electrodes, in particular the main electrodes of a horn spark gap, from being activated with low energy contents of overvoltage events.

The object of the invention is achieved with an arrangement according to the combination of features according to claim 1, the subclaims representing at least expedient refinements and developments.

Accordingly, an arrangement for igniting spark gaps with a trigger electrode located on or in one of the main electrodes and insulated from this main electrode is assumed. The trigger electrode can be electrically connected to the further main electrode via at least one voltage-switching or voltage-growing element.

There is an air gap between the main electrode and the further main electrode.

The trigger electrode forms a sandwich structure with an insulation layer and a layer made of a material with a lower conductivity than the material of one of the main electrodes.

The insulation layer is preferably a thin film or lacquer layer

educated. The layer made of the material of lower conductivity is in contact with or lies on one of the main electrodes.

According to the invention, the arrangement is now developed in such a way that an energetic limit or an energetic threshold value can be defined, energetically weak overvoltage events being derived below the defined limit or threshold value without the spark gap responding between the main electrodes. If the limit or threshold value is exceeded, the correspondingly triggered derivation process takes place by igniting the main spark gap.

The basic idea of the invention is now to only use those for the limit or threshold value determination and the means to be provided for this purpose, those that can be integrated spatially and structurally into the spark gap itself. An additional external circuit for any necessary housing penetrations and other structural measures must be explicitly excluded.

Accordingly, according to the invention, the insulation layer of the sandwich structure is interrupted outside of the ignition area in order to discharge weakly energetic overvoltage events without responding to the spark gap formed between the main electrodes. Alternatively or additionally, an electrical component influencing the response behavior is integrated between the trigger electrode and the main electrode in the spark gap. The interruption of the insulation layer forms an electrical connection between the trigger electrode and the layer of lower conductivity, the derivable energy content of the .through the limited conductivity or the resistance of the layer of lower conductivity

Overvoltage event can be determined. This in turn allows the aforementioned limit or threshold value to be set.

In one embodiment, the aforementioned electrical component is an integrable, miniaturized resistor.

Surge events with the lowest energy levels, for example

Burst pulses generally no longer lead to the ignition of the entire spark gap, since the low or minimal pulse energy is reduced in the layer of lower conductivity.

If the energy content of the overvoltage or the overvoltage event is higher, the total spark gap ignites with a delay. Exceeds that

Energy of the pulse a predetermined amount, such a high voltage drops at the layer of lower conductivity that the auxiliary ignition spark gap ignites and thus the main spark gap can be ignited. The degree of deceleration can be influenced via the structural design and the material sizes or material properties. The ignition auxiliary spark gap is ignited by a flashover of the insulation gap in the

Ignition range.

With all the overvoltages with greater energy contents, for example with direct or indirect lightning impulses, the main spark gap ignites comparatively quickly, as is known from the prior art.

In a preferred embodiment, the trigger electrode is a

The conductor track of a film circuit board and the insulation layer are formed by an insulating cover, in particular a lacquer layer on the conductor track.

The insulating cover is exposed for the interruption, so that the exposed section of the conductor track can be connected to the layer of lower conductivity. The layer of lower conductivity can preferably consist of a conductive plastic material or of a material with a

Carbon fiber content are formed.

The invention will be explained in more detail below using an exemplary embodiment and with the aid of figures.

Here show:

Fig. 1 is an equivalent circuit diagram with the basic arrangement of

Main electrodes of a spark gap and a sandwich structure, comprising a trigger electrode with an insulation layer and a layer made of a lower material

Conductivity as the material of one of the main electrodes and parallel connection of an electrical component in the form of a resistance between the trigger electrode and the associated main electrode as well

Fig. 2 is a representation similar to FIG. 1, but with a hinted

Interruption of the insulation layer, so that the trigger electrode comes into contact with the layer with the material of lower conductivity outside of the ignition area, in order to reduce

Energy contents of an overvoltage event can be directly derived without responding to the total spark gap.

The illustration according to FIGS. 1 and 2 comprises an electrically conductive trigger electrode T which extends from an insulation layer I in the direction of the

Main electrode H2 is covered.

The insulation layer I is followed by a layer made of a material M with a lower conductivity.

The layer of material M lies on the surface of the second

Main electrode H2 on.

Via a connection A, external elements can be connected between trigger electrode T and the main electrode H1. The funds provided there can for example include gas arresters, varistors, diodes or similar electrical components.

The spark gap formed by the main electrodes Hl and H2 can be used as

Horn spark gap can be formed and is electrically connected between the paths L and N / PEN.

The configuration shown corresponds in principle to the arrangement for plasma - jet generation according to DE 10 2011 102 937 A1 and the explanations there regarding the structural design. In this respect, on the disclosure side, reference is made to the relevant statements in DE 10 2011 102 937 A1, which embody the knowledge of the person skilled in the relevant art.

According to the invention according to FIG. 1 an electrical component R influencing the response behavior is connected between the trigger electrode T and the main electrode H2. The value of the resistance R determines that

Response behavior and thus an energetic limit value related to the ignition process of the corresponding spark gap.

At low energy contents of corresponding overvoltage events, the voltage drop resulting via the resistor R is insufficient to enable ignition in the ignition area of the arrangement. By arranging the resistor R, low-energy overvoltage events can be derived directly without the main spark gap responding and thereby unnecessarily aging.

2, instead of the parallel connection of the resistor R, a fully integrated solution is shown.

In this regard, the thin insulation layer I is interrupted outside the ignition and flashover area, so that the trigger electrode T is conductively connected to the material of lower conductivity M.

This is due to the resistance value of the material M one

Possibility created, overvoltage events via the path trigger electrode, material of lower conductivity M and main electrode H2

to be derived without the main spark gap responding between the electrodes H 1 and H2. In such a case, the energy content of the overvoltage is so low that only a very small current flows and the voltage drop in the poorly conductive material M is not sufficient to flash over the insulation layer I. This means that the rollover range does not respond and the overvoltage is derived solely from the energy mapping range.

If, on the other hand, the current rises very sharply due to an overvoltage event, so that the voltage falling in the material M flashes over the insulation layer I and generates an ignition spark, the entire spark gap is ignited.

In this embodiment of the invention, the layer of material M not only has the task of extending the ignition arc by extending the direct flashover distance from the trigger electrode T to the main electrode H2, but rather the resistance value of the poorly conductive material via the contacting of the trigger electrode with the Layer M used to derive weak surge events. This configuration makes it possible to completely dispense with any separate electrical or electronic components for controlling the response behavior, in particular in the case of very weak overvoltage events.

Claims

1. Arrangement for the ignition of spark gaps with a trigger electrode (T) located on or in one of the main electrodes (H2) and insulated from this main electrode (H 2), the trigger electrode (T) with the further main electrode (H 1) via at least one voltage-switching or voltage-monitoring element (A) is electrically connectable and there is an air gap between the trigger electrode (T) and the further main electrode (H l), the trigger electrode (T) having an insulation layer (I) and a layer made of a material (M) with lower conductivity than the material of one of the main electrodes (H 1, H2) forms a sandwich structure, the insulation layer (I) is designed as a thin film or lacquer layer and the layer of material (M) with lower conductivity with one of the

Main electrodes (H2) are in contact or resting on them,

characterized in that

for deriving energetically weak overvoltage events without

Response of those formed between the main electrodes (H 1; H2)

Spark gap the insulation layer (I) of the Sandwi ch structure is interrupted outside the ignition area and / or an electrical component influencing the response behavior is connected between the trigger electrode (T) and the main electrode (H 2).

2. Arrangement according to claim 1,

characterized in that

by interrupting (U) the insulation layer (I) an electrical one

Connection is formed between the trigger electrode (T) and the layer (M), the limited conductivity or the resistance of the layer (M) determining the derivable energy content of the overvoltage event.

3. Arrangement according to claim 1,

characterized in that

the electrical component is a resistor (R).

4. Arrangement according to one of the preceding claims,

characterized in that

at low energy content of the surge event by the

electrical component (R) and / or the layer (M) a current for Main electrode (H 2) flows, the measure of the voltage drop at the electrical component (R) and / or at the layer (M) determining whether the overvoltage is derived directly or whether the voltage drop leads to a flashover of the insulation gap (I) in the ignition area or .

Arcing range (Z) and thus leads to the ignition of the spark gap between the main electrodes (H l and H2).

5. Arrangement according to one of the preceding claims,

characterized in that

the trigger electrode (T) through a conductor track of a foil circuit board and the insulation layer (I) through an insulating cover, in particular

Lacquer layer, is formed on the conductor track, wherein the insulating cover is exposed for the interruption (U), and the exposed area is connected to the layer (M).

6. Arrangement according to one of the preceding claims,

characterized in that

the layer (M) consists of a conductive plastic material.

7. Arrangement according to one of claims 1 to 5,

characterized in that

the layer (M) consists of a material with a carbon fiber content.