EP2600367A1 - Switching device for DC applications - Google Patents

Abstract

The device has switching chambers (8, 9) for respective current paths (5, 6), and switching contact arrangements comprising contacts (15, 18). The contacts are connected in a switched-on condition of the device and arranged at a distance from each other in a switched-off condition of the device. Extinguishing devices are formed for the respective paths for extinguishing an arc occurring between the contacts. An arc driver arrangement is arranged in one of the chambers, generates a magnetic field in the area of the arrangements and drives the arc into the extinguishing device.

Description

The invention relates to a switching device for DC applications. The switching device comprises at least a first switching chamber for a first current path and a second switching chamber for a second current path, each current path at least one switching contact arrangement having a first contact and a second contact, wherein the two contacts in an on state of the switching device in contact and in a disconnected state of the switching device forming an isolating distance are kept out of contact with each other, and each current path at least one quenching device for erasing an arc occurring between the contacts.

Such a switching device is from the EP 2 061 053 A2 known. To provide a switching device for DC applications there is proposed to use the housing of a switching device for AC applications, in addition, at least two permanent magnets are provided which have a magnetic field with substantially transverse to the separation distance of the current paths field lines. In the housing, three switching chambers are provided in each case for a current path, each current path being assigned a movable switching contact element and two mutually opposite stationary switching contact elements. The three movable switching contact elements are in this case jointly movable between a closed position, which corresponds to the switched-on state of the switching device, and an open position, which corresponds to the switched-off state of the switching device. The individual current paths are each associated with two arc quenching devices, which are each in the form of individual stacked, electrically insulated from each other quenching plates are formed. In addition, each current path has two separating sections, which, when the movable switching contact elements are open, extend between the ends thereof and the first and second stationary switching contact elements assigned to these ends form. When the switching contact elements are opened, an arc forms along the separating sections, which arc can be extinguished with the aid of the arc-extinguishing devices. In DC applications, since erasure of an arc can not be achieved due to current zero crossing, as in AC applications, DC applications require the provision of a magnetic field which drives the arc into one of the arc quenching devices. As a result of the magnetic field formed by the permanent magnets, a Lorentz force acts on a arc forming along the separation path, which drives the latter in the direction of one of the arc extinguishing devices. At low currents, therefore, the arc is safely deleted in the arc quenching device. At very high currents, however, there is a risk that the arc on one of the permanent magnets overturns and burns this.

It is therefore an object of the present invention to provide a switching device that can equally be used for both low currents and high currents of a DC application.

The invention is achieved by a switching device for DC applications, which has at least a first switching chamber for a first current path and a second switching chamber for a second current path. At least one switching contact arrangement is provided for each current path, which has a first contact and a second contact, wherein the two contacts are kept in contact with one another in an on state of the switching device and in an off state of the switching device an isolating distance is formed. For each current path, at least one extinguishing device is furthermore provided for extinguishing an arc occurring between the contacts. In this case, an arc runner arrangement is provided which is arranged in one of the two switching chambers and at least in the region of the switching contact arrangement of the respective current path generates a magnetic field in order to drive the arc into the respective extinguishing device.

Thus, the switching device has a switching chamber in which a Lichtbogentreiberanordnung is provided, and a switching chamber in which no arc running arrangement is provided. The switching device is therefore suitable for both lower currents and high currents. The switching chamber with arc runner arrangement is suitable for lower currents, in which the risk is low that an arc on the arc guide assembly rolls over. The magnetic field of the arc runner assembly is also strong enough to drive arcs of a smaller current quickly into the quenching device. The switching chamber without arc runner arrangement is particularly suitable for high currents, since no arc runner arrangement is arranged in this switching chamber and thus the arc can not overturn on such an arc runner arrangement. This ensures that only small carbon deposits form by burning of a permanent magnet or adjacent housing walls, which would make it difficult to extinguish an arc. Depending on the geometry of the switching contact arrangement, the arc can already receive an independent pulse, which drives them in the extinguishing device. On the other hand, the two switching chambers of the switching device are arranged side by side, so that the magnetic field of the arc runner assembly also radiates to the switching chamber without arc runner assembly and generates a Lorentz force on a resulting there arc. In this case, the current paths are preferably arranged next to one another and parallel to one another. The switching chambers can be formed separately from each other, in particular in a housing of the switching device by intermediate walls, wherein the intermediate walls are preferably made of an electrically insulating but magnetically permeable material.

The two current paths can be used depending on the application, ie at low currents occurring the current path is used with arc runner assembly and at high currents occurring the current path is used without the arc runner assembly. On the other hand, the current paths can also be electrically connected in parallel or in series so that in principle current flows through both current paths and effects the extinction of an arc, depending on the occurring current intensity and the resulting quenching behavior of one of the two current paths. As a result, the maintained by the arcs Current flow interrupted at one point, so that all other arcs go out.

In principle, a third switching chamber can also be provided for a third flow path. If the arc runner arrangement is then arranged in the second switching chamber, this can be arranged between the first switching chamber and the second switching chamber. Thus, the magnetic field of the arc runner assembly of the second switching chamber radiates to the other two, namely, the first switching chamber and the third switching chamber. In principle, however, it is also conceivable that an arc runner arrangement is arranged in the first switching chamber and the third switching chamber, and the second switching chamber, which is located between the first and the third switching chamber, is free of an arc runner arrangement.

The arc runner assembly may include two permanent magnets disposed on opposite sides of the switch contact assembly that generate a magnetic field with field lines across the gap. In principle, however, the arc runner arrangement may consist of a permanent magnet, which is provided above the switching contact arrangement, and which is arranged between two pole plates, which are located laterally on opposite sides of the switching contact arrangement.

Preferably, at least one arc guide arrangement is provided per switching contact arrangement, by means of which the arc is directed to the extinguishing device of the respective switching contact arrangement. Such an arc guide arrangement usually consists of baffles which extend from the contacts in the direction of the respective extinguishing device.

Each switching arrangement may basically consist of a fixed contact and a movable contact, wherein the first contacts are each arranged on a fixed contact carrier fixed in the switching chamber and the second contacts each arranged on a movable in the switching chamber Bridge arrangement are arranged. The bridge arrangement serves to actuate the second contact.

In principle, a double interruption with two contact pairs can also be provided per current path, two contact arrangements being provided for each current path and the second contacts being arranged on a movable bridge contact piece and the second contacts being electrically connected to one another via the bridge contact element. The two contact pairs, each consisting of a first contact and a second contact, are thus connected in series. Here arcs are formed between each contact pair.

In principle, the bridge switching pieces of all current paths can be actuated by a common bridge arrangement, so that by actuation of an element, namely the bridge arrangement, all contact pairs or switching contact arrangements are actuated.

Figur 1

einen Teillängsschnitt durch ein erfindungsgemäßes Schaltgerät und

Figur 2

eine Draufsicht in das Schaltgerät gemäß Figur 1.

A preferred embodiment of the invention is explained below with reference to the drawings. Herein shows

FIG. 1

a partial longitudinal section through an inventive switching device and

FIG. 2

a plan view in the switching device according to FIG. 1 ,

FIG. 1 shows the switching device 1 according to the invention in a partial longitudinal section with a housing 2, which comprises a lower part 3 and an upper part 4. FIG. 2 shows a view into the switching device 1, wherein the upper part 4 is omitted so that you can look into the lower part 3. The two Figures 1 and 2 will be described together below.

The switching device 1 has three poles, ie three switching paths, namely a first switching path 5, a second switching path 6 and a third switching path 7. Each switching path 5, 6, 7 is in a separate switching chamber, namely a first switching chamber 8, a second switching chamber 9 and a third switching chamber 10th arranged. The switching chambers 8, 9, 10 are electrically separated from each other by partitions 11, 12 of the housing 2, wherein the intermediate walls 11, 12 are preferably magnetically permeable. The three current paths 5, 6, 7 are identical in terms of their structure, wherein the structure of the current paths 5, 6, 7 is explained in more detail by way of example with reference to the middle second current path 6 in the following.

The second flow path 6 within the second switching chamber 9 is in FIG. 1 shown in longitudinal section. The second switching path 6 is formed twice interrupting and has a first switching contact arrangement 13 and a second switching contact arrangement 16. The two switch contact arrangements 13, 16 are identical and mirror images of each other.

The first switching contact arrangement 13, which in FIG. 1 is shown on the left side, comprises a contact pair with a first contact 14 and a second contact 15. Accordingly, the second switch contact arrangement 16 with a second contact pair comprising a first contact 17 and a second contact 18 is formed.

The first contact 14 of the first switching contact arrangement 13 is arranged on a first fixed contact carrier 19. The first fixed contact carrier 19 is fixed and thus arranged immovably in the housing 2 of the switching device 1. The first contact 17 is arranged at a first free end of the first fixed contact carrier 19. At a this end facing away from the end of the first fixed contact carrier 19, a first terminal 23 is provided for the connection of the first current path 5 in a DC circuit.

The second contact 15 of the first switch contact arrangement 13 is located on a bridge contact piece 20 of a bridge arrangement 21 and is movably arranged in the housing 2. The bridge contact piece 20 is in the in FIG. 1 Oriented orientation vertically adjustable between a raised and a lowered position. In the raised position, the second contact 15 of the first switching contact arrangement 13 is in contact with the first contact 14. In a lowered position, the two contacts 14, 15 are out of contact. In this position, an isolating distance is formed between the first contact 14 and the second contact 15 along which an arc can form.

The second switching contact arrangement 16 is identical to the first switching contact arrangement 13. The first contact 17 of the second switching contact arrangement 16 is located on a second fixed contact carrier 22 and is arranged at a first end of the second fixed contact carrier 22. At a this end remote from the end of the second fixed contact carrier 22, a second terminal 24 is provided.

The second contact 18 of the second switching contact arrangement 16 is likewise arranged on the bridge contact piece 20, specifically on an end remote from the second contact 15 of the first switching contact arrangement 13. The bridge switching piece 20 is electrically conductive and connects the two second contacts 15, 18 electrically to each other. In the raised state of the bridge switching piece 20, the second contact 18 of the second switching arrangement 16 is in contact with the first contact 17, wherein in the lowered position of the bridge switching piece 20, the two contacts 17, 18 are kept out of contact and forms an insulating gap between them, along which can also form an arc.

In the raised state of the bridge switching element 20, a current can thus flow from the first terminal 23 via the first fixed contact carrier 19 to the first contact of the first switching contact arrangement 13, then on to the second contact 15 of the first switching contact arrangement 13 via the bridge contact piece 20 to the second contact 18 of the second switching contact arrangement 16 , From there, the current continues to flow to the first contact 17 of the second switching contact arrangement 16 via the second fixed contact carrier 22 to the second connection 24.

For adjusting the bridge switching piece 20, a switching bridge 30 is provided, which is arranged vertically displaceable in the housing 2 and the bridge switching piece 20 adjusted. In the raised state of the bridge contact piece 20, which the switched state of the switching device 1 corresponds, the bridge switching piece 20 is pressed with its second contacts 15, 18 via a spring 31 against the first contacts 14, 17, wherein the spring 31 is supported between the bridge switching piece 20 and the switching bridge 30.

In the second switching chamber 9, two erasing devices, namely a first erasing device 27 and a second erasing device 28 are provided. The first erasing device 27 is assigned to the first switching contact arrangement 13 and the second erasing device 28 to the second switching contact arrangement 16. The two erasing devices 27, 28 are each arranged on a side of the respective switching contact arrangement 13, 16 facing away from the switching bridge arrangement 21.

In order to drive resulting arcs between the contact pairs in the quenching devices 27, 28, in the second switching chamber 9, two Lichtbogentreiberanordnungen are provided, namely a first Lichtbogentreiberanordnung 32 and a second Lichtbogentreiberanordnung 33, wherein the first Lichtbogentreiberanordnung 32 of the first switching contact arrangement 13 and the second Lichtbogentreiberanordnung 33rd the second switching contact arrangement 16 is assigned. The first arc runner arrangement 32 comprises two first permanent magnets 25, which are arranged within the second switching chamber 9 on the intermediate walls 11, 12 and receive the first switching contact arrangement 13 between them. The first permanent magnets 25 are designed plate-shaped and arranged parallel to the intermediate walls 11, 12. The two first permanent magnets 25 are arranged rectified with respect to their magnetization, so that forms an approximately homogeneous magnetic field with field lines transverse to the separation direction between them. Thus, the field lines of the magnetic field also extend transversely to an arc, which forms between the first contact 14 and the second contact 15 of the first switching contact arrangement 13. As a result, a Lorenz force is generated by the magnetic field, which acts on the arc and drives it in the direction of the first extinguishing device 27.

The second arc driver assembly 33 is constructed similar to the first arc driver assembly 32 and includes two second ones Permanent magnets 26 which receive the second switching contact arrangement 16 between them. The magnetic field is in this case aligned in opposite to the magnetic field of the first permanent magnet 25. An arc, which forms between the first contact 17 and the second contact 18 of the second switching contact arrangement 16, has a current direction which is spatially opposite to the current direction of an arc between the contacts 14, 15 of the first switching contact arrangement 13. If an arc as shown in FIG. 1 between the contacts 17, 18 of the second switching contact arrangement 16 has a current direction vertically downward, an arc between the contacts 14, 15 of the first switching contact arrangement, a current direction vertically upwards. In order to ensure a safe erasure of the arcs regardless of the current direction in the respective current path, therefore, in a first current direction of the arc on the first switching contact assembly 13 to the left in the first erase device 27 and an arc on the second switching contact assembly 16 to the right in the second Extinguishing device 28 are driven. To achieve this, therefore, the magnetic fields must be aligned in the opposite direction.

The first flow path 5 and the third flow path 7 as well as the first switching chamber 8 and the third switching chamber 10 are identical to the second flow path 6 and the second switching chamber 9, but with the difference that in the first switching chamber 8 and the third switching chamber 10 no arc drive arrangements are arranged. In the first switching chamber 8 and in the third switching chamber 10 thus no permanent magnets are arranged. The arc runner arrangements 32, 33 of the first current path 6 radiate to the adjacent switching chambers, namely the first switching chamber 8 and the third switching chamber 10, in order to be able to exert a Lorentz force on a developing arc there as well.

LIST OF REFERENCE NUMBERS

1

switchgear

2

casing

3

lower part

4

top

5

first current path

6

second current path

7

third current path

8th

first switching chamber

9

second switching chamber

10

third switching chamber

11

partition

12

partition

13

first switching contact arrangement

14

first contact

15

second contact

16

second switch contact arrangement

17

first contact

18

second contact

19

first fixed contact carrier

20

Bridging contact member

21

bridge arrangement

22

second fixed contact carrier

23

first connection

24

second connection

25

first permanent magnets

26

second permanent magnets

27

first extinguishing device

28

second extinguishing device

29

splitter

30

jumper

31

feather

32

first arc driver assembly

33

second arc driver assembly

Claims (12)

Switching device (1) for DC applications comprising at least a first switching chamber (8) for a first current path (5) and a second switching chamber (9) for a second current path (6), at least one switching contact arrangement (13, 16) per current path (5, 6) ), which has a first contact (14, 17) and a second contact (15, 18), wherein the two contacts (14, 17, 15, 18) in an on state of the switching device (1) in contact and in an off Condition of the switching device (1) forming an isolating distance out of contact with each other, and each flow path (5, 6) at least one erasing means (27, 28) for erasing an arc occurring between the contacts (14, 17, 15, 18), characterized in that at least one arc runner arrangement (32, 33) is provided, which is arranged in one of the two switching chambers (9) and generates a magnetic field at least in the area of the switching contact arrangement (13, 16) of the respective current path (6) n arc in each extinguishing device (32, 33) drives. Switching device according to claim 1, characterized in that the current paths (5, 6) are arranged side by side and parallel to each other. Switching device according to one of the preceding claims, characterized in that the switching chambers (8, 9, 10) in a housing (2) by partition walls (11, 12) are formed separately from each other. Switching device according to claim 3, characterized in that the intermediate walls (11, 12) are made of an electrically insulating but magnetically permeable material. Switching device according to one of the preceding claims, characterized in that the current paths (5, 6, 7) are connected in parallel or in series. Switching device according to one of the preceding claims, characterized in that a third switching chamber (10) for a third current path (7) is provided. Switching device according to claim 6, characterized in that the at least one arc runner arrangement (32, 33) in the second switching chamber (9) is arranged and that the second switching chamber (9) between the first switching chamber (8) and the third switching chamber (10) is. Switching device according to one of the preceding claims, characterized in that the at least one arc runner assembly (32, 33) comprises two permanent magnets (25, 26) which are arranged on opposite sides of the switching contact arrangement (13, 16) and a magnetic field lines with transverse to the separation path produce. Switching device according to one of the preceding claims, characterized in that each switching contact arrangement (13, 16) at least one arc guide arrangement is provided, by means of which the arc to the quenching device (27, 28) of the respective switching contact arrangement (13, 16) is directed. Switching device according to one of the preceding claims, characterized in that the first contacts (14, 17) of the switching contact arrangements (13, 16) each on a fixed in the switching chamber (8, 9, 10) fixed contact carrier (19, 22) are arranged and that the second contacts (15, 18) of the switching contact arrangements (13, 16) are each arranged on a bridge arrangement (21) movably arranged in the shaking chamber (8, 9, 10). Switching device according to one of the preceding claims, characterized in that two contact arrangements (13, 16) are provided per current path (5, 6, 7), wherein the second contacts (15, 18) are arranged on a movable bridge contact piece (20) and wherein the second contacts (15, 18) are electrically connected to each other via the bridge contact piece (20). Switching device according to claim 11, characterized in that the bridge switching pieces (20) of all current paths (5, 6, 7) of a common bridge arrangement (21) are actuated.

Images