EP2920855A1

EP2920855A1 - Ignition circuit

Info

Publication number: EP2920855A1
Application number: EP13811373.3A
Authority: EP
Inventors: Rainer Durth; Mario STOLZENBERG
Original assignee: Phoenix Contact GmbH and Co KG
Current assignee: Phoenix Contact GmbH and Co KG
Priority date: 2012-11-16
Filing date: 2013-11-08
Publication date: 2015-09-23
Also published as: CN104769792B; WO2014075782A1; US9906016B2; CN104769792A; DE102012022399A1; US20150288176A1

Abstract

The subject matter of the invention is an ignition circuit (Z) for a series circuit comprising at least two spark gaps for limiting overvoltages with medium and high power, in particular overvoltages corresponding to the pulse shapes 8/20 μs and 10/350 μs with amplitudes of approximately 10 kA to approximately 200 kA (Class I arrester), (FS₁, FS₂). The spark gaps (FS₁, FS₂) are each equipped with at least one auxiliary electrode (H₁, H₂). The ignition circuit (Z) has a first varistor (VAR₁) and a second varistor (VAR₂), wherein the ignition circuit (Z) is suitable for limiting overvoltages with a mean power, in particular overvoltages corresponding to the pulse shape 8/20 μs with amplitudes of approximately 10 to approximately 100 kA (Class II arrester). The ignition circuit (Z) is designed for connection to the auxiliary electrodes (H₁, H₂), wherein the ignition circuit (Z) has two ignition subcircuits (TZ₁, TZ₂). The first ignition subcircuit (TZ₁) has the first varistor (VAR₁) and is designed for igniting the first spark gap (FS₁). The second ignition subcircuit (TZ₂) has the second varistor (VAR₂) and is designed for igniting the second spark gap (FS₂). Further subjects of the invention are an overvoltage protection device comprising such an ignition circuit (Z) and the use of a multiple-contact varistor (M-VAR) for triggering a spark gap (FS₁).

Description

ignition circuit

The invention relates to a firing circuit. Spark gaps are known from the prior art.

These are connected, inter alia, for the protection of electrical systems parallel to these electrical systems. If an overvoltage event occurs, then the

Ignite the spark gap and the overvoltage at the

Derive electrical system over. The aim is to keep the voltage level at which the spark gap ignites as low as possible. This voltage level is also referred to as the protection level. In order to keep the protection level low, spark gaps are equipped with an ignition circuit.

The ignition circuits typically provide one

Vorionisierung the spark plug corner available, so that the spark gap at much lower voltages in

Compared to a spark gap ignites without Vorionisieren. That the voltage level necessary to ignite the spark gap is lowered. The pre-ionization is achieved by an auxiliary electrode, which is arranged either centrally or closer to one of the main electrodes of the spark gap. In this case, the auxiliary electrode together with at least one of the main electrodes of the spark gap is an auxiliary spark gap, while the spark gap between the main electrodes of the spark gap is often referred to as the main spark gap.

However, it may depend on the design of the

Spark gap some time, for example, take a few micro-seconds before the main spark gap ignites. Since usual overvoltage pulses with very high current increases it is during the

Stromstieges particularly critical of the required

To maintain the protection level. For this reason, another protective path can be provided parallel to the spark gap, keeping the protection level correspondingly low for short times. Since this additional protection path is needed only for a short time, it can be designed for lower requirements. For example, the spark gap can be a Abieiter according to Class I, while in the further protection path Abieiter according to Class II can be used.

Although the above arrangements have already become one

Reduction in the level of protection, these are still relatively high. Furthermore, the configuration of the further protective paths is often disadvantageous, as this often introduces a parasitic inductive component that should not be underestimated. The invention is based on the object to provide an ignition circuit that bypasses the disadvantages of the prior art in an inventive manner.

The object is achieved by the features of the independent claims. advantageous

Embodiments of the invention are specified in the subclaims.

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

1 schematic arrangements of spark gaps with a firing circuit,

Fig. 2 shows a detail of a spark gap with

Auxiliary electrode,

Fig. 3 shows a schematic structure of a

Multiple contact varistor with a tap,

4 shows spark gaps with an ignition circuit,

5 spark gaps with a firing circuit,

Fig. 6 series circuits of spark gaps with a

Ignition circuit according to embodiments of the invention,

Fig. 7 series circuits of spark gaps with a

Ignition circuit according to further embodiments of the

Invention, and

Fig. 8 series circuits of spark gaps with a

Ignition circuit according to still further embodiments of the invention.

FIG. 1 shows schematic arrangements of

Spark gaps FSi with an ignition circuit Z. The spark gap has a first supply line ZLi and a second supply line ZL ₂ . The ignition circuit Z is as the second protection path as

Series connection of two varistors VARi, VAR ₂ formed. In this case, the series circuit is operated as a kind of voltage divider, wherein the tap of the voltage divider is guided on the auxiliary electrode Hi a spark gap. Ie at an overvoltage event, the varistors VAR _X , VAR ₂ are first conductive, and thereby conditional on the

Auxiliary electrode Hi for a quick ignition of the spark gap FSi. That the time until ignition of the spark gap is bridged by the second protection path. An overload of the second protection path can by suitable

Dimensioning of the voltage divider and the auxiliary electrode can be avoided, in which the spark gap to a

early ignition by an existing pre-ionization is initiated. The simultaneous interpretation of the

Ignition circuit Z as a parallel discharge path leads to an advantageous reduction of required components.

As shown in Figure 1 on the left side, the

Assembled structurally, or as shown on the right side, the ignition circuit Z can be connected, e.g. pluggable, be executed.

FIG. 2 shows a detail of a spark gap FSi

Auxiliary electrode Hi shown. This spark gap FSi has a first spark gap terminal FSAx and a second spark gap terminal FSAi. The first

Spark gap terminal FSA ₂ is connected to a first (main) electrode of the spark gap, and second spark gap terminal FSA ₂ is connected to a second (main spark gap electrode)

Auxiliary electrode Hi may be arranged either centrally or closer to one of the two main electrodes, or may also be connected resistively to one of the main electrodes.

In Figures 4 and 5 further spark gaps are shown with an ignition circuit. In contrast to FIG. 3, these also have a gas-filled surge arrester English gas discharge tube (GDT), on. With such a gas-filled surge arrester GDT in the ignition circuit can be achieved that the overall arrangement further has a high insulation value. In a pure

Varistor circuit VARi, VAR _{2 of} the ignition circuit Z (as shown in Figure 1), this is not always the case. In this case, the arrangement according to Figure 5 is particularly advantageous, since in this arrangement, a particularly good setting of the respective ignition behavior is possible. Thus, by the variation of the operating voltage of

Gas-filled surge arrester GDT and a suitable choice of the varistors of the voltage divider with respect to the current through the ignition circuit are set so that the spark gap before overloading the varistors safely

is ignited. This also shows a favorable

asymmetrically arranged auxiliary electrode (as indicated in the figures) to use.

To the inductive influence of the ignition circuit to

can advantageously minimize

Multiple contact varistor M-VAR be used. Such a multi-contact varistor M-VAR is shown schematically in FIG. It has the

Mehrfachkontaktvaristor M-VAR, which by a

dashed frame is shown, a first

Mehrfachkontaktvaristoranschluss M-VARAi and a second Mehrfachkontaktvaristoranschluss M-VARA ₂ on.

Furthermore, the multi-contact varistor M-VAR has a tap A.

Although only one tap is shown, multiple taps may be provided. It represents the Mehrfachkontaktvaristor M-VAR circuitry an integrated series connection of a first varistor VARi and a second varistor VAR ₂ represents the use of

Mehrfachkontaktvaristoren M-VAR also has the advantage that for these components only a single

Temperature monitoring may be provided, while for a discrete series circuit usually several

Temperature monitoring must be provided. Furthermore, it is always ensured by the use of a Mehrfachvaristors that the Teilvaristoren come from a Baucharge. Furthermore, parasitic inductances are avoided by the integrated approach. This can do that

Switching behavior can be positively influenced. It should be noted that the tap does not necessarily have to lead to a symmetrical voltage division, but that the Teilvaristoren VARi and VAR _{2 can} also be chosen differently. Furthermore, the use of components is minimized, since now only a Mehrfachkontaktvaristor M-VAR for

Use comes.

This concept can also be applied to series connections of

Spark gaps are extended. By a

Series connection of spark gaps can be one

blit zstoßstromgestfähige and netzfolgestrombegrenzende overvoltage protection device 1 can be provided.

In the figures 6 to 8 are series circuits of

Spark gaps with an ignition circuit according to embodiments of the invention shown.

In each case, an ignition circuit Z for a series connection of at least two spark gaps FSi, FS ₂ for limiting overvoltages with medium and high power, in particular of overvoltages corresponding to Pulse shapes 8/20 and 10/350 s with amplitudes of about 10 kA to about 200 kA (Class I Abieiter) are shown. The

Spark gaps FSi, FS ₂ are each equipped with at least one auxiliary electrode Hi, H ₂ . The ignition circuit Z has a first varistor VARi and a second varistor VAR ₂ . The ignition circuit Z is particularly suitable for limiting overvoltages with medium power, in particular overvoltages corresponding to the pulse shape 8/20 with amplitudes of about 10 to about 100 kA (Class II Abieiter). The ignition circuit Z is designed for connection to the auxiliary electrodes Ηχ, H ₂ , wherein the ignition Z has two Teilzündkreise TZi, TZ ₂ , wherein the first

Teilzündkreis ΤΖχ the first varistor VAR _X and is designed to ignite the first spark gap FSi, and wherein the second Teilzündkreis TZ _2, the second varistor VAR ₂ and is designed to ignite the second spark gap FS ₂ .

The optional gas-filled surge arrester GDT shown in Figure 6 and Figure 7 provided isolation of the

Arrangement, in particular of the ignition circuit Z, is because the two ignition circuits (ignition electrode to the two respective lower main electrodes) have no isolation in a resistive connection.

About the three varistors of Figure 6 is a further

Protection path with low protection level, which limits the voltage until the two spark gaps FSi, FS ₂ ignite. At the same time, the varistors serve as ignition varistors for the spark gaps. It can be beneficial varistors with different

Rated voltages to use to ignite the

Spark gaps at low protection level of

Overall arrangement to optimize. The varistors of the ignition circuit can be provided with one or more thermal separation devices. In the embodiment according to FIG. 7, in contrast to FIG. 6, only one series connection of two varistors is used. Ie the ignition circuit can not be without

further be seen as an independent protection path. The two varistors VARi, VAR ₂ become the two

Auxiliary electrodes Ηχ, H _{2 of} the spark gaps FSi, FS ₂

driven. The waiver of the third varistor may have the consequence that the two spark gaps, in particular the lower spark gap, ignite earlier, since the entire initial current flows over the first spark gap. Since a quick ignition of the spark gaps is generally positive for the protection level, with suitable

Sizing the varistors an improved level of protection can be set. In the embodiments according to FIG. 6 and FIG. 7, the first partial ignition circuit TZi and the second partial ignition circuit TZ _{2 of} the ignition circuit Z represent a series connection.

These embodiments are particularly suitable for use with multi-contact varistors M-VAR. The use of multiple contact varistors M-VAR in turn leads to the advantages already described above. That the first

Varistor VARi and the second varistor VAR ₂ are part of a Mehrfachkontaktvaristors M-VAR with at least one tap A. The tap A is then designed to connect to the first auxiliary electrode H _x . In the embodiment of FIG. 6, a multi-tap multi-contact varistor M-VAR may also be used. A first tap is then for connection to the first auxiliary electrode Ηχ designed while another tap for connection to the second auxiliary electrode H _{2 is} designed. Of course, but here also a simple Mehrfachkontaktvaristors M-VAR can be used with a tap A in series with a discrete further varistor.

In the embodiments according to FIGS. 6 and 8, the second partial ignition circuit TZ _{2 is designed} for connection to a second supply line ZL _{2 of} the series connection of at least two spark gaps FSi, FS ₂ . This corresponds to the circuit concept of FIG. 4.

In further advantageous embodiments, the

Ignition circuit continues a gas-filled

Surge arrester GDT, with the first

Teilzündkreis TZi the gas-filled surge arrester GDT and the first varistor VAR _{X has} as a series circuit and is designed to ignite the first spark gap FSi. As a result, the overall insulation of the arrangement can be kept high.

Without further ado, the ignition circuit Z outlined above may be integrated (as shown on the left side of FIGS. 6 to 8) or connectable (shown on the right side of FIGS. 6 to 8). In the

integrated construction, it is possible to provide an overvoltage protection device 1 which has lightning current-carrying and network sequence current-limiting properties.

On the other hand, the pluggable variant to a

retrofittable protection with improved ignition behavior

be used. Thus, it is easily possible to offer a cost-effective combination product that

easiest way to adapt to the needs. In the embodiment shown in FIG. 8, the two partial ignition circuits are separate from each other

executed. In this case, the first Teilzündkreis TZi to

Connection with a first supply line ZLi the

Series connection of at least two spark gaps FSi, FS2 designed. In a corresponding manner, the second Teilzündkreis TZ _{2 is designed} for connection to a second supply line ZL _{2 of} the series connection of at least two spark gaps FSi, FS2. Finally, it should be noted in relation to Figure 8 that the arrangement of

Auxiliary electrodes in relation to the supply lines at

asymmetric arrangement or resistive coupling can be designed so that the electrodes, which have the smallest distance to the auxiliary electrodes,

electrically contacted. This is special

advantageous if the auxiliary electrodes are connected resistively to one of the main electrodes of the respective spark gap. By this arrangement, the respective non-resistively connected electrodes are on the outside

Supply side arranged and thus provide a

improved insulation available.

As far as above is spoken by Class I or Class II Abieitern only properties of the corresponding Abieiter are referenced. Actual standard compatibility is not important.

Furthermore, the varistors can also as

Multicontact varistors be executed. Such

Multicontact varistors are, for example, the subject of German Patent Application DE 10 2012 011 241, to which reference is explicitly made here. In this embodiment of the varistors, the varistor has a parallel connection of Teilvaristoren on, in which many individual contacts

side by side contact a common varistor ceramic in parallel. Thus, for example, a supply side of a varistor and / or a tap A with respect to one or both adjoining Teilvaristoren as

Be designed multi-contact.

These multicontact varistors allow to further reduce the protection levels while at the same time increasing the safety against alloying. Such a design may also be combined with a series connection as described above, so that a multiple multi-contact varistor is used.

Reference sign list

Tap A Spark gaps FS _X , FS ₂ Spark gap connection FSAi, FSA ₂ Gas filled surge arresters GDT Auxiliary electrode Hi, H2 Partial ignition circuits TZ _X , TZ ₂ Varistor VARx, VAR ₂ Ignition circuit Z Supply cable ZLi, ZL ₂

Multiple contact varistor M-VAR

Multiple contact varistor connection M-VARAi, M-VARA ₂

Overvoltage protection device 1

Claims

claims

1. ignition circuit (Z) for a series connection of at least two spark gaps to limit overvoltages with medium and high power, in particular of

Overvoltages corresponding to the pulse shapes 8/20 με and 10/350] are with amplitudes of about 10 kA to about 200 kA (Class I Abieiter), (FSi, FS ₂ ), the spark gaps (FSi, FS ₂ ) each having at least one Auxiliary electrode (Hi, H ₂ ) are equipped, the ignition circuit (Z) comprising a first varistor (VARi), a second varistor (VAR ₂ ), wherein the ignition circuit (Z) for limiting overvoltages with medium power, in particular overvoltages

corresponding to the pulse shape 8/20 s with amplitudes of about 10 to about 100 kA (Class II Abieiter), wherein the ignition circuit (Z) for connection to the auxiliary electrodes (Hi, H ₂ ) is designed, the ignition circuit (Z ) two

Teilzündkreise (ΤΖχ, TZ ₂ ), wherein the first

Teilzündkreis (TZi) has the first varistor (VARi) and is designed to ignite the first spark gap (FSi), and wherein the second Teilzündkreis (TZ ₂ ) the second

Varistor (VAR ₂ ) and to ignite the second

Spark gap (FS ₂ ) is designed.

2. ignition circuit (Z) according to claim 1, wherein the first

Teilzündkreis for connection to a first supply line (ZLi) of the series connection of at least two spark gaps (FSi, FS ₂ ) is designed.

3. ignition circuit (Z) according to claim 1 or 2, wherein the first Teilzündkreis and the second Teilzündkreis a

Show series connection.

4. ignition circuit (Z) according to any one of the preceding claims, wherein the first varistor and the second varistor part of a Mehrfachkontaktvaristor (M-VAR) with at least one tap (A), wherein the tap (A) for connection to the first auxiliary electrode ( Hi) is designed.

5. ignition circuit (Z) according to claim 1 or 2, wherein the second Teilzündkreis for connection to a second supply line (ZL ₂ ) of the series connection of at least two spark gaps (FSi, FS ₂ ) is designed.

6. ignition circuit (Z) according to one of the preceding claims, wherein the ignition circuit further comprises a gas-filled

Überspannungsabieiter (GDT), wherein the first

Teilzündkreis (TZi) the gas-filled surge arrester (GDT) and ^' the first varistor (VARi) as a series circuit and is designed to ignite the first spark gap (FSi).

7. ignition circuit (Z) according to any one of the preceding claims, wherein at least the first varistor (VARi) or the second varistor (VAR ₂ ) is a Multikontaktvaristor.

8. Overvoltage protection device with an ignition circuit (Z) according to one of the preceding claims.

9. Overvoltage protection device with an ignition circuit (Z) according to claim 8, characterized in that the spark gaps (FSi, FS ₂ ) are connected to each other in series so that the electrodes, which have the smallest distance to the auxiliary electrodes, are electrically contacted.

10. Use of a multi-contact varistor (M-VAR) designed to limit medium power surges, in particular of overvoltages corresponding to the pulse shape 8/20 s with amplitudes of about 10 kA to about 100 kA

(Class II arrester) is suitable for triggering a spark gap (FSi) of class I, wherein the

Mehrfachkontaktvaristor (M-VAR) at least one tap (A) of an internal series connection of varistors (VARi, VAR ₂ ) of the Mehrfachkontaktvaristors (M-VAR), and the tap (A) for triggering the spark gap (FSi) is used.

The use of a multi-contact varistor (M-VAR) according to claim 10, wherein the multi-contact varistor (M-VAR) includes at least one multicontact varistor.