Lightning protection spark gap assembly and method for operating a lightning protection spark gap assembly

Abstract

The invention relates to a lightning protection spark gap assembly. The lightning protection spark gap assembly comprises: a lightning protection spark gap (1); a safety fuse device (8) which can be triggered by a bridge initiator (7) and which is connected between a first or second voltage line (S1, S2) and a corresponding main connection (1, 1b) of the lighting protection spark gap (1); and an indicator device (4′) for detecting a secondary current flow connecting to a pulse current flow or a corresponding portion of the secondary current flow, and for triggering the safety fuse device (8) by activating the bridge initiator (7) when the detected secondary current flow or the corresponding portion of the secondary current flow fulfills a first predefined criterion, wherein the lightning protection spark gap (1) has a first and a second divergent electrode (21a, 21b) and an arcing chamber (25), and wherein the indicator device (4′) is electrically connected to the first or second divergent electrode (21a, 21b) and/or the arcing chamber (25) in such a way that it detects the secondary current flow or the corresponding portion of the secondary current flow in the area (L) in which the secondary current arc flows.

Claims

1. A lightning protection spark gap assembly having: a lightning protection spark gap (1; 1′) having a first main connection (1a) and a second main connection (1b); wherein a first voltage line (S1) of a supply network can be connected to the first main connection (1a) and a second voltage line of the supply network can be connected to the second main connection (1b); a fusible link device (8) which can be triggered by a bridge igniter (7) and is connected between the first or second voltage line (S1, S2) and the corresponding main connection (1, 1b) of the lightning protection spark gap (1; 1′); and an indicator device (4′; 4″; 4′″) for capturing a power follow current profile following a pulse current profile or a corresponding portion of the power follow current profile and for triggering the fusible link device (8) by activating the bridge igniter (7) if the captured power follow current profile or the corresponding portion of the power follow current profile satisfies a first predefined criterion, wherein the lightning protection spark gap (1; 1′) has a first and a second diverging electrode (21a, 21b) and a quenching chamber (25); wherein the indicator device (4′; 4″; 4′″) is electrically connected to the first or second diverging electrode (21a, 21b) and/or to the quenching chamber (25) in such a manner that it captures the power follow current profile or the corresponding portion of the power follow current profile in the running region (L) of the arc.

2. The lightning protection spark gap assembly as claimed in claim 1, wherein the quenching chamber (25) has a plurality of arc splitter plates (21c), and wherein the indicator device (4″) is connected between one of the arc splitter plates (21c) and the second main connection (1b).

3. The lightning protection spark gap assembly as claimed in claim 2, wherein a current limiting device (28) is connected in series with the indicator device (4″).

4. The lightning protection spark gap assembly as claimed in claim 2, wherein one arc splitter plate (21c) has an interruption point (22′) which is arranged in such a manner that an electrical connection to the indicator device (4″) is formed only after the power follow current arc has entered the quenching chamber (25).

5. The lightning protection spark gap assembly as claimed in claim 1, wherein the quenching chamber (25) has a plurality of arc splitter plates (21c), wherein the indicator device (4″; 4′″) is connected between a first and a second voltage probe (33a, 33b), and wherein the first and second voltage probes (33a, 33b) are arranged between two different adjacent arc splitter plates (21c) in each case.

6. The lightning protection spark gap assembly as claimed in claim 5, wherein the indicator device (4′; 4″; 4′″) has an indicator fuse (4′″) and the bridge igniter (7) is connected in parallel with the indicator fuse (4′″).

7. The lightning protection spark gap assembly as claimed in claim 6, wherein a current limiting device (28) is connected in series with the indicator device (4′″).

8. The lightning protection spark gap assembly as claimed in claim 1, wherein a further indicator device (4a) for capturing the pulse current profile or a corresponding portion of the pulse current profile and for triggering the fusible link device (8) by activating the bridge igniter (7) if the captured pulse current profile or the corresponding portion of the pulse current profile satisfies a second predefined criterion is connected in series with the fusible link device (8).

9. The lightning protection spark gap assembly as claimed in claim 8, wherein the further indicator device (4a) has a further indicator fuse (4a) which can be used to actuate the mechanical actuator (S) or a further mechanical actuator (S), wherein the switch device (11) for activating the bridge igniter (7) can be closed by the mechanical actuator (S) or a further switch device (S′) for activating the bridge igniter (7) can be closed by the further mechanical actuator (S′).

10. The lightning protection spark gap assembly as claimed in claim 9, wherein a further current divider (10a) is connected in parallel with the further indicator fuse (4a).

11. The lightning protection spark gap assembly as claimed in claim 9, wherein the mechanical actuator (S) or the further mechanical actuator (S′) is configured in such a manner that the activation of the bridge igniter (7) can be delayed by a predefined period which is selected in such a manner that the pulse current has substantially decayed before the bridge igniter (7) is activated.

12. The lightning protection spark gap assembly as claimed in claim 11, wherein the predefined period is in the range of 1 ms to 5 ms.

13. The lightning protection spark gap assembly as claimed in claim 8, wherein the switch device (11) or yet another switch device (11″) for activating the bridge igniter (8) can be closed by a capture device for secondary parameters (α, ϑ, p), in particular temperature (ϑ), pressure (p) and expansion (α).

14. The lightning protection spark gap assembly as claimed in claim 8, wherein the current level and the current duration of the pulse current profile or of the corresponding portion of the pulse current profile are included in the second predetermined criterion, in particular the current level is included quadratically and the current duration is included linearly in the second predefined criterion.

15. The lightning protection spark gap assembly as claimed in claim 1, wherein the indicator device (4′; 4″; 4′″) has an indicator fuse (4′; 4″) which can be used to actuate a mechanical actuator (S), wherein a switch device (11) for activating the bridge igniter (7) can be closed by the mechanical actuator (S).

16. The lightning protection spark gap assembly as claimed in claim 15, wherein a current divider (10) is connected in parallel with the indicator fuse (4′).

17. The lightning protection spark gap assembly as claimed in claim 1, wherein the current level and the current duration of the power follow current profile or of the corresponding portion of the power follow current profile are included in the first predetermined criterion, in particular the current level is included quadratically and the current duration is included linearly in the first predefined criterion.

18. The lightning protection spark gap assembly as claimed in claim 1, wherein the first diverging electrode (21a) has an interruption point (22), with the result that the first diverging electrode (21a) has an electrode region (23) which faces the quenching chamber (25) and can be reached only by the power follow current, and wherein the indicator device (4′) is connected between the first main connection (1a) and the electrode region (23).

19. The lightning protection spark gap assembly as claimed in claim 1, wherein the quenching chamber (25) has a plurality of arc splitter plates (21c), wherein the indicator device (4″) is connected between a voltage probe (33) and the second main connection (1b), and wherein the voltage probe (33) is arranged between two adjacent arc splitter plates (21c).

20. The lightning protection spark gap assembly as claimed in claim 1, wherein the quenching chamber (25) has a plurality of arc splitter plates (21c), wherein the indicator device (4″; 4′″) is connected between two arc splitter plates (21c).

21. A method for operating a lightning protection spark gap assembly having: a lightning protection spark gap (1; 1′) having a first main connection (1a) and a second main connection (1b); wherein a first voltage line (S1) of a supply network can be connected to the first main connection (1a) and a second voltage line of the supply network can be connected to the second main connection (1b); a fusible link device (8) which can be triggered by a bridge igniter (7) and is connected between the first or second voltage line (S1, S2) and the corresponding main connection (1, 1b) of the lightning protection spark gap (1; 1′); and wherein the lightning protection spark (1; 1′) has a first and a second diverging electrode (21a, 21b) and a quenching chamber (25); wherein the method has the steps of: capturing a power follow current profile following a pulse current profile or a corresponding portion of the power follow current profile and triggering the fusible link device (8) by activating the bridge igniter (7) if the captured power follow current profile or the corresponding portion of the power follow current profile satisfies a first predefined criterion, wherein the power follow current profile or the corresponding portion of the power follow current profile is captured in the running region (L) of the power follow current arc.

22. The method as claimed in claim 21, wherein the pulse current profile or a corresponding portion of the pulse current profile is captured and the fusible link device (8) is triggered by activating the bridge igniter (7) if the captured pulse current profile or the corresponding portion of the pulse current profile satisfies a second predefined criterion.

23. The method as claimed in claim 22, wherein the activation of the bridge igniter (7) is delayed by a predefined period which is selected in such a manner that the pulse current has substantially decayed before the bridge igniter (7) is activated.

24. The method as claimed in claim 23, wherein the predefined period is in the range of 1 ms to 5 ms.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a first embodiment of the present invention;

(3) FIG. 2 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a second embodiment of the present invention;

(4) FIG. 3 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a third embodiment of the present invention;

(5) FIG. 4 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a fourth embodiment of the present invention;

(6) FIG. 5 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a fifth embodiment of the present invention;

(7) FIG. 6 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a sixth embodiment of the present invention;

(8) FIG. 7 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a seventh embodiment of the present invention; and

(9) FIG. 8 shows a circuit diagram for explaining a lightning protection spark gap assembly according to an eighth embodiment of the present invention.

(10) In the figures, identical or functionally identical elements are provided with the same reference signs.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

(11) FIG. 1 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a first embodiment of the present invention.

(12) In FIG. 1, reference sign 1 denotes a lightning protection spark gap having a first main connection 1a and a second main connection 1b. The lightning protection spark gap also has a trigger connection 1c, connected upstream of which is a trigger circuit 2. The trigger circuit 2 is also connected to the first and second main connections 1a, 1b.

(13) In other embodiments (not illustrated), the trigger circuit 2 can be connected only to one of the main connections 1a, 1b.

(14) The lightning protection spark gap is, for example, a horn spark gap, as known from DE 10 2011 051 738 A1. In particular, this lightning protection spark gap 1 has a first and a second diverging electrode 21a, 21b. The distance between the first and second diverging electrodes 21a, 21b is kept short in an ignition region Z, whereas the distance between the first and second diverging electrodes 21a, 21b increasingly widens in a running region L.

(15) The first and second diverging electrodes 21a, 21b end in a quenching chamber 25 which has a plurality of arc splitter plates 21c arranged in a parallel manner.

(16) In other embodiments (not illustrated), the electrodes or baffles may already end at some distance below the quenching chamber. The arc then virtually bridges the distance to the quenching chamber through expansion of itself.

(17) A first voltage line S1 of a supply network can be connected to the first main connection 1a via a fusible link device 8 which can be triggered by a bridge igniter 7, and a second voltage line S2 of the supply network can be connected to the second main connection 1b.

(18) The bridge igniter 7 is connected, on the one hand, to the first main connection 1a and, on the other hand, to the second voltage line S2 via a current limiting resistor 12 and a controllable switch device 11.

(19) During operation of the lightning protection spark gap 1, the current load caused by the pulse currents which arise during a lightning strike is limited substantially to the ignition region Z of the first and second diverging electrodes 21a, 21b, whereas the power follow currents which arise on account of the voltage of the supply network run along the first and second diverging electrodes 21a, 21b in the direction of the quenching chamber in the running region L. The follow current arc is finally split and quenched in the quenching chamber 25.

(20) In this example, the inherent fusible function of the fusible link device 8 is used to disconnect the overvoltage protection device in the case of pulse current loads which exceed the proven nominal value of the device, for example a lightning current of 25 kA for a network arrester.

(21) The power follow currents are assessed or captured by an indicator device 4′ which is configured in such a manner that it triggers the fusible link device 8 by activating the bridge igniter 7 if the captured power follow current profile or a corresponding portion of the power follow current profile (partial current) satisfies a first predefined criterion. In particular, with this type of lightning protection spark gap 1, the power follow current can be assessed independently of the pulse current in the running region L or inside the quenching chamber 25 since the pulse current is locally restricted to the ignition region Z.

(22) In the present first embodiment, the first diverging electrode 21a has an interruption point 22, with the result that the first diverging electrode 21a has an electrode region 23 which faces the quenching chamber 25 and can be reached only by the power follow current since the power follow current can jump over the interruption point 22 on account of its intrinsic magnetic field.

(23) The indicator device 4′ is therefore connected between the first main connection 1a and the disconnected electrode region 23 facing the quenching chamber 25. In the present case, the indicator device 4′ has an indicator fuse 4′ which can be used to actuate a mechanical actuator S. The switch device 11 for activating the bridge igniter can be enclosed by the mechanical actuator S. Optionally, a frequency-dependent current divider 10 or a PTC thermistor, for example, may be connected in parallel with the indicator fuse 4′, as indicated using dashed lines.

(24) The indicator fuse 4′ is designed in this case in such a manner that, in the case of excessively high or excessively long power follow currents which are associated with excessively low power follow current limitation or an overload of the lightning protection spark gap 1, the fusible conductor of the indicator fuse 4′ fuses and the mechanical actuator S closes the switch device 11, which is in the form of a short-stroke button, for example, in order to activate the bridge igniter 7, as a result of which the fusible link device 8 is destroyed and the lightning protection spark gap 1 is electrically decoupled from the first voltage line S1.

(25) The first predetermined criterion is therefore preferably an I.sup.2t criterion of the power follow current profile, in which the current level is included quadratically and the current duration is included linearly.

(26) The exact stipulation of the first predetermined criterion, for example as an I.sup.2t criterion, depends on the respective design of the lightning protection spark gap 1 and the further boundary conditions and can be empirically and/or theoretically determined in the individual case.

(27) FIG. 2 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a second embodiment of the present invention.

(28) In the second embodiment, the lightning protection spark gap 1′ is designed without a trigger connection 1c and without a trigger circuit 2. However, this does not influence the assessment of the power follow current, which is carried out inside the quenching chamber 25 in the second embodiment.

(29) In particular, the indicator device 4″ is connected between one of the arc splitter plates 21c and the second main connection 1b in the second embodiment.

(30) A current limiting device 28, for example a non-reactive resistor, is connected upstream of the indicator device 4″. The arc splitter plate 21c which is connected to the indicator device 4″ has an interruption point 22′ which causes the electrical contact between the indicator device 4″ and the power follow current arc to be made only after the power follow current arc has completely entered and has been split in the quenching chamber 25.

(31) Like in the first embodiment, the indicator device 4″ in the second embodiment is also an indicator fuse 4″ which can be used to actuate the mechanical actuator S, as a result of which the switch device 11 for activating the bridge igniter 7 can be closed.

(32) As a result of the power follow current arc, the arc splitter plate 21c is connected to the counter-potential and the power follow current or a partial current thereof therefore loads the indicator fuse 4″. The level of the power follow current which is tapped off can be determined by the current limiting device 28 and the choice of the specific arc splitter plate 21c (voltage component). Like in the first embodiment, a frequency-dependent current divider may be provided in parallel with the indicator fuse 4″.

(33) Otherwise, the second embodiment is configured like the first embodiment.

(34) FIG. 3 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a third embodiment of the present invention.

(35) The third embodiment differs from the second embodiment by virtue of the arrangement and electrical contact with the indicator device 4″ in the form of the indicator fuse 4″.

(36) In particular, the indicator fuse 4″ is connected there between a first and a second voltage probe 33a, 33b, wherein the first and second voltage probes 33a, 33b are arranged between two different adjacent arc splitter plates 21c in each case. In the case of power follow current arc contact of the arc splitter plates 21c, the power follow current or a partial current thereof flows via the indicator fuse 4″ according to the driving power follow current arc voltage between the arc splitter plates 21c and triggers the activation of the bridge igniter 7 if the first predefined criterion is satisfied.

(37) Otherwise, the third embodiment is configured like the second embodiment.

(38) FIG. 4 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a fourth embodiment of the present invention.

(39) In the fourth embodiment, the indicator device 4″ in the form of the indicator fuse 4″ is connected between a voltage probe 33 and the second main connection 1b or the second voltage line S2, wherein the voltage probe 33 is arranged between two adjacent arc splitter plates 21c.

(40) Otherwise, the fourth embodiment is configured like the third embodiment.

(41) FIG. 5 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a fifth embodiment of the present invention.

(42) In the fifth embodiment, the indicator device 4″ in the form of the indicator fuse 4″ is connected between two arc splitter plates 21c at a distance from one another.

(43) Otherwise, the fifth embodiment is configured like the fourth embodiment.

(44) The first to fifth embodiments described above allow very good matching of the time and level of the current output of the power follow current or a partial current thereof to the behavior of the power follow current arc, as a result of which a functional deviation of the lightning protection spark gap 1 or l′ from the normal function can be detected very well via the destruction of the indicator fuse 4″.

(45) In contrast to the first to fifth embodiments described above, the bridge igniter 7 may also be ignited directly by the switching energy of the indicator device 4′″ in the form of the indicator fuse 4′″, as explained below in connection with the sixth and seventh embodiments.

(46) FIG. 6 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a sixth embodiment of the present invention.

(47) In the sixth embodiment, the lightning protection spark gap 1 is again a triggerable lightning protection spark gap, as in the first embodiment described above.

(48) At its two connections, the indicator device 4′″ in the form of the indicator fuse 4′″ is connected in parallel with the bridge igniter 7, on the one hand, and is connected to two arc splitter plates 21c, on the other hand. The required switching energy can be set by selecting the arc splitter plates 21c (voltage drop) and the current limiting resistor 28.

(49) If the follow current arc makes contact with the arc splitter plates 21c, there is a voltage drop across the indicator fuse 4′″ which is connected in parallel with the defined fusible wire in the bridge igniter 7. The current flow caused by this is split between the bridge igniter 7 and the indicator fuse 4′″.

(50) If the follow current load of the quenching chamber 25 exceeds a limit value according to the first predefined criterion, the current-carrying capacity of the fusible conductor is exceeded and the bridge igniter 7 initiates the triggering of the fusible link 8, as a result of which the lightning protection spark gap 1 is disconnected from the network.

(51) In addition to designing the fusible conductors of the indicator fuse 4′″ and of the bridge igniter 7 to control the current distribution, the current limiting resistor 28 may be optionally provided and can limit the current flow into the bridge igniter 7. This limitation not only makes it possible to avoid overloading of the triggering path but also makes it possible to set a time delay of the triggering of the bridge igniter 7.

(52) FIG. 7 shows a circuit diagram for explaining a lightning protection spark gap assembly according to a seventh embodiment of the present invention.

(53) In the seventh embodiment, in a similar manner to the third embodiment, the indicator fuse 4′″ is connected to two voltage probes 33a, 33b which are each arranged between two different adjacent arc splitter plates 21c.

(54) Otherwise, the seventh embodiment is configured like the sixth embodiment.

(55) FIG. 8 shows a circuit diagram for explaining a lightning protection spark gap assembly according to an eighth embodiment of the present invention.

(56) The eighth embodiment differs from the first embodiment in that the lightning protection spark gap 1′ cannot be triggered and a further indicator device 4a for capturing the pulse current profile or a corresponding portion of the pulse current profile and for triggering the fusible link device 8 by activating the bridge igniter 7 if the captured pulse current profile satisfies a second predefined criterion is connected in series with the fusible link device 8 and the lightning protection spark gap 1′.

(57) The further indicator device 4a has a further indicator fuse 4a which can be used to actuate a further mechanical actuator S′, wherein a further switch device 11′, which is connected in parallel with the switch device 11, for activating the bridge igniter 7 can be closed by the further mechanical actuator S′.

(58) In the eighth embodiment, the pulse currents and the power follow currents can therefore be monitored using independent, locally separate indicator fuses 4a and 4′.

(59) Like in the first predetermined criterion, the current level and current duration of the pulse current profile may be included in the second predetermined criterion, in particular in the form of an I.sup.2t criterion, which should be determined empirically or theoretically in the individual case.

(60) In the eighth embodiment, it is advantageous if the further indicator device 4a is a mechanical actuator S′ with an inherent delay which ensures, for example, that a pulse current profile can be discharged via the lightning protection spark gap 1′ before the bridge igniter 7 is ignited. Such a delay should be in the range of 1 ms to 5 ms, for example.

(61) Furthermore, one or more secondary criteria or parameters, for example pressure p, temperature ϑ, expansion α etc., can be optionally used to control yet another switch device 11″ which is connected in parallel with the switch devices 11, 11′.

(62) Although the present invention has been completely described above on the basis of preferred exemplary embodiments, it is not restricted thereto, but rather can be modified in various ways.

(63) Although, in the embodiments described above, the lightning protection spark gap has a quenching chamber with arc splitter plates, the present invention is not restricted thereto, but rather can also be used for meander quenching chambers and insulating web quenching chambers, for example.

(64) Similar indicator devices can be used in quenching chambers without arc splitting, for example insulating web or gap or meander chambers. These quenching chambers also first follow the arc running region and are reached substantially only by the power follow current. Voltage probes, for example, can be introduced into the chambers between the webs or in the gap region at different heights inside the chamber and also at different distances and allow a defined voltage difference to be tapped off in the case of arcs. The level of the voltage difference can be used by a defined fusible wire to assess the follow current, just like in quenching chambers with arc splitter plates.

(65) The invention is also not restricted to triggerable lightning protection spark gaps or the triggerable lightning protection spark gap described.

(66) The indicator device is also not restricted to the described embodiments, but rather can be varied in order to perform the defined functions.

(67) Although the above embodiments are therefore indicator devices in the form of mechanical switching devices, electronic or electrical switch devices and components can also be provided and can be used to implement the functions mentioned.