EP2915174B1 - Dc voltage switching device - Google Patents

Description

The invention relates to a DC switching device according to the preamble of claim 1.

There are switching devices for switching DC currents known per se. However, the use of direct current for a long time was usually limited to the low power range in which there were hardly any problems in switching the direct currents.

Since the spread of photovoltaic applications as well as powerful battery back-up systems for computerized server systems, it is also necessary to switch DC currents, DC voltages of higher voltage and power. The known AC switchgear have proved unsuitable in many respects. For example, when switching DC currents with an AC switch, even at voltages and currents far below the maximum AC power limits of the AC switch concerned, it can result in its total loss. As a result, in addition to the failure of an electrical system, this can also lead to a fire.

The EP 892 415 A2 describes a DC switching device with an arc quenching chamber with identically formed quenching plates, each having a spiral shape in plan view to produce a Lorentz force.

The EP 619 592 B1 describes a switching device with a conductor loop on fixed contacts, which causes an electrodynamic force in case of short circuit in order to accelerate the contact opening.

The object of the invention is therefore to provide a DC switching device of the type mentioned, with which the mentioned disadvantages can be avoided, and with which DC currents high power can be switched safely.

This is achieved by the features of claim 1 according to the invention.

Thereby, a DC switching device can be provided, which has a high switching capacity at DC currents, and which is therefore suitable for switching DC currents of high power. Such a DC switching device has a high level of security, in particular against thermal destruction.

The subclaims relate to further advantageous embodiments of the invention.

It is hereby expressly referred to the wording of the claims, whereby the claims at this point are incorporated by reference into the description and are considered to be reproduced verbatim.

• Fig. 1 eine besonders bevorzugte Ausführungsform eines Gleichstromschaltgeräts in teilweise geschnittener Ansicht im Aufriss;
• Fig. 2 die Lichtbogenlöschanordnung für ein Gleichstromschaltgerät gemäß Fig. 1 in axonometrischer Darstellung;
• Fig. 3 ein Detail aus Fig. 1 im Schnitt;
• Fig. 4 ein weiteres Detail aus Fig. 1 in einem ersten Zustand des Lichtbogens; und
• Fig. 5 ein weiteres Detail aus Fig. 1 in einem zweiten Zustand des Lichtbogens.

The invention will be further described with reference to the accompanying drawings, in which a merely preferred embodiment is shown by way of example. Showing:

• Fig. 1 a particularly preferred embodiment of a DC switching device in a partially sectioned view in elevation;
• Fig. 2 the arc extinguishing arrangement for a DC switching device according to Fig. 1 in axonometric representation;
• Fig. 3 a detail from Fig. 1 on average;
• Fig. 4 another detail Fig. 1 in a first state of the arc; and
• Fig. 5 another detail Fig. 1 in a second state of the arc.

The Fig. 1 to 5 show a particularly preferred embodiment of a DC switching device 1, or parts of an arc extinguishing arrangement 6 of such a DC switching device 1, wherein the DC switching device 1 has at least one electrical input 2 and at least one electrical output 3, and at least a first switching contact 4 and a movable switching bridge 20, wherein the DC switching device 1 further comprises an arc extinguishing arrangement 6, wherein the arc extinguishing arrangement 6 comprises at least a first arc quenching chamber 7, which has a plurality of quenching plates 9, wherein at least a first quenching plate 27 of the quenching plates 9 so shaped, in particular bent such that - caused by a switching operation - arcs 11, in the first arc quenching chamber 7, a Lorentz force 12 in the direction of the quenching plates 9 acts.

Thereby, a DC switching device 1 can be provided which has a high switching capacity at DC currents, and which is therefore suitable for switching DC currents of high power. Such a DC switching device 1 has a high level of security, in particular against thermal destruction.

The subject invention relates to switching devices, which are provided for the switching of direct currents and specially designed. In particular, the invention relates to DC switching devices 1, which for the intended switching of high voltages in the range of several hundred volts, about 600V operating voltage, and currents in the two-digit ampere range provided and designed.

The invention will be described in more detail below with reference to a preferred embodiment of a DC switching device 1 with a single switching path. However, it is also possible to provide designs with a plurality of parallel switching paths, therefore switchable current paths.

An objective DC switching device 1 has an electrical input 2 and an electrical output 3, which are preferably designed as screw terminals, as well as in Fig. 1 shown. Furthermore, the DC switching device 1 has an insulating material housing.

The DC switching device 1 has in its illustrated and preferred embodiment, a single switching path, but a double interruption of this single switching path is provided. It is preferably provided that the DC switching device 1 next to the first switching contact 4 further comprises a second switching contact 5, which are both fixed to the housing, and can be electrically connected by a movable switching bridge 20, whereby an electrically conductive current path from the input 2 to the output 3 is formed becomes. It is provided that the position of the switching bridge 20 is manually controlled by the shift lever 19. It is preferably provided that the shift lever 19 acts on the switching bridge 20 via a snap-action switching mechanism in order to achieve a sudden opening and closing of the switching path. It can also be provided to carry out the subject DC switching device 1 as a so-called. Self-switch, which has one or more triggers, such as an overcurrent release and / or a short-circuit release. Furthermore, it is preferably provided that the DC switching device 1 has a switching mechanism, in particular when the same is carried out as a self-switch.

There are also - not shown - versions representational DC switching devices 1 are provided, which in addition to the first switching contact 4 only have the movable switching bridge 20, which - is connected - for example by a flexible conductor - to the output 3, to such a current path through the DC switching device 1 form.

In the case of closed switch contacts, the current flow through the DC switching device 1 shown is from the electrical input 2 to the first switching contact 4, from this via the switching bridge 20 to the second switching contact 5 and from there to the latter electrical output 3. Although the switching bridge 20 has two, designed as electrical contacts areas to contact with the first switching contact 4 and the second switching contact 5, this is referred to in the diction of the subject application only as a switching bridge 20. It can also be provided that also the first switching contact 4 and the second switching contact 5 are designed as movable electrical contacts.

The DC switching device 1 further comprises an arc extinguishing arrangement 6 in order to extinguish arcs 11, which arise in the course of a switching operation, to extinguish. This is to prevent that due to so-called "stationary" arcs 11 continues to flow through the DC switching device 1 and also due to the thermal effect of the arcs 11 damage to the DC switching device 1 takes place. Such arcs 11 occur in particular during a switch-off. "Switching off" here refers to the separation of the switching bridge 20 of the first and second electrical switching contact 4, 5 for preventing a current flow through the DC switching device 1. The physical relationships in the ignition of an arc 11 are described in the law of induction.

Fig. 2 shows a preferred embodiment of the arc extinguishing arrangement 6, in forming the DC switching device with a first and a second switching contact 4, 5. In the illustration according to Fig. 2 the first switching contact 4 and the second switching contact 5 are shown, but these are shown without any further contacting, only to illustrate their arrangement relative to the respective arc extinguishing chambers 7, 8. The same applies to the also in Fig. 2 shown switching bridge 20 to.

In the illustrated preferred embodiment, the arc extinguishing arrangement 6 has a first arc quenching chamber 7 and a second arc quenching chamber 8. It is preferably provided that the first arc quenching chamber 7 is assigned to the first switching contact 4, and that the second arc quenching chamber 8 is assigned to the second switching contact 5, wherein also embodiments are provided with only a first arc quenching chamber 7, if no second switching contact 5 is present. The term "assigned" refers in this context to an arrangement of the relevant arc quenching chamber 7, 8 with respect to the specified switching contact 4, 5 in such a way that an emerging at the switching contact 4, 5 arc 11 its way into or to the relevant arc quenching chamber 7, 8 finds. Fig. 2 shows the two switching contacts 4, 5 in Area of the respective arc quenching chamber 7, 8.

In the illustrated preferred embodiment, it is provided that the first arc quenching chamber 7 and the second arc quenching chamber 8 are arranged parallel to each other in the DC switching device 1, as in Fig. 2 shown.

In the first arc quenching chamber 7 and the second arc quenching chamber 8, a plurality of quenching plates 9 are arranged in each case. The quenching plates 9 are preferably arranged substantially normal to the arc guide rail 18, wherein between the side by side mounted quenching plates 9 is in each case a distance. In each case at least one quenching plate 9 of the first arc quenching chamber 7 is electrically conductively connected to a quenching plate 9 of the second arc quenching chamber 8, provided that a first and a second arc extinguishing chamber 7, 8 are provided.

The quenching plates 9 are preferably formed from an electrically and magnetically conductive metal, preferably comprising iron. Furthermore, it is preferably provided that the quenching plates 9 are formed substantially identical to each other. In particular, it may be provided that individual quenching plates 9 are formed larger than the vast majority of quenching plates 9. These quenching plates 9, which protrude from the overall composite of the quenching plates 9, in particular in a region next to the path of movement of the switching bridge 20 are arranged.

If the switching bridge 20 is moved away from the first switching contact 4 and the second switching contact 5 during a current flow via the DC switching device 1, an arc 11 is formed from the first switching contact 4 to the switching bridge 20, as well as a further arc 11 from the switching bridge 20 to the second switching contact 5th

At a certain length of the air gap to be bridged by the arcs 11 this jump to the quenching plates 9 of the arc extinguishing chambers 7, 8 via. It has been found that the present at this time arcs 11 have an astonishing stability, and it may be that these arcs 11 at the respective arcuate plates 9, where they contact, remain until it is for thermal destruction of the DC switching device. 1 comes. This problem is not known in the AC technique in the way it comes to quickly extinguishing occurring AC arcs due to the constant zero crossings of the applied voltage.

It is therefore provided that at least a first quenching plate 27 of the quenching plates 9 is shaped, in particular bent such that - caused by a switching process - arcs 11, in the first arc quenching chamber 7, a Lorentz force 12 in the direction of the quenching plates 9 acts. The first quenching plate 27 is here a quenching plate 9, which is formed differently from the other quenching plates 9. In this way, the - caused by a switching process - arcs 11 are driven in the direction of the quenching plates 9, whereby the energy of the arc 11 can dissipate quickly.

In particular, it is possible for the first quenching plate 27 to delimit a quenching plate stack of the quenching plates 9 of the first arc quenching chamber 7. According to Fig. 1 . 3 . 4 and 5 It can be provided that the first quenching plate 27 is arranged at one end of the quenching plate stack of the quenching plates 9. The first quenching plate 27 may in particular be part of the quenching plate stack of the quenching plates 9. Furthermore, it can be provided that the first arc splitter 27 is arranged at a first end of the splitter stack of quenching plates 9, which first end is arranged adjacent to a position switching bridge 20, which position assumes the switching bridge 20, when the switching bridge 20 of the switch contacts 4, 5 is disconnected. Thereby, the arc 11 can skip well on the first arc splitter 27, wherein the arc 11 is formed immediately after this skipping between the switching contact 4,5 and the first arc splitter 27.

Particularly preferably, it can be provided that the first quenching plate 27 is arranged adjacent to a movement path of the switching bridge 20. In particular, it can be provided that the first quenching plate 27 is arranged in the arc extinguishing arrangement 6, in particular in the first arc quenching chamber 7 and or the second arc quenching chamber 8 to a movement path of the switching bridge 20. When the switching bridge 20 is opened, that part of the switching bridge 20 which is intended to be in contact with the first switching contact 4 and / or the second switching contact 5 moves along this trajectory of the switching bridge 20. Upon opening, therefore, the arc 11 also initially moves Through the arrangement of the first quenching plate 27 to the movement path of the switching bridge 20, one end of the arc 11 can easily jump from the switching bridge 20 to the first quenching plate 27.

Furthermore, it can be provided, in particular, that the first quenching plate 27 has a receptacle 30, and that a contact abutment part 31 made of insulating material is arranged in the receptacle 30. The contact stop member 31 is in this case provided in particular a stop for form the switching bridge 20, so that it can be arranged immediately adjacent to the first splitter plate 27 in the open state.

In particular, it can be provided that the first arc splitter 27 is U-shaped. Due to the u-shaped configuration can, as in Fig. 4 shown, a particularly simple Lorentz force 12 are caused in the direction of the quenching plates 9. Furthermore, the local field strength can be increased by a U-shaped curved surface. In this case, the first quenching plate 27 can be divided by the U-shaped bent region into a first leg 28 and a second leg 29.

Furthermore, it can be provided, in particular, that a first leg 28 of the U-shaped first quenching plate 27 is conductively connected to a part of the DC switching device 1 which is at an electrical potential. As a result, a current flow of the arc 11 through the first arc splitter 27 can be derived. Furthermore, it can be dispensed with the additional use of magnets, since the magnetic field, which can be generated by the current flow of the Lichbogens 11 itself, the Lorentz force 12. Another advantage is that the stronger the current intensity of the arc 11, and therefore the more dangerous the arc 11, the strength of the Lorentz force 12 also increases, and the arc 11 can be deleted quickly and reliably in the quenching plates 9.

In particular, it can be provided that the first leg 28 of the U-shaped first quenching plate 27 is conductively connected to the electrical output 3. In this case, it may be provided, in particular, that essentially one end of the first leg 28 is conductively connected to the electrical output 3, as a result of which the current flow of the electric arc 11 flows at least partially through the first leg 28.

Furthermore, it can be provided that the second leg 29 of the U-shaped first quenching plate 27 is arranged substantially parallel to an adjacent arranged quenching plate 9. Thereby, a plane-parallel gap 32 between the second leg 29 and an adjacent arranged quenching plate 9 are formed. In this case, the arc 11 is pulled by the Lorentz force 12 in the gap 32, whereby the energy of the arc 11 can be well dissipated. Such a plane-parallel gap 32 can in particular cause a propagation direction 25 of the arc 11 away from the switching contacts 4, 5.

Furthermore, it can be provided that the first leg 28 and the second leg 29 of the U-shaped first quenching plate 27 are arranged substantially parallel to each other. When an end of the arc 11 has jumped over during switching-off of the switching bridge 20 to the first splitter plate 27, can by this arrangement, as in particular in Fig. 4 shown, a particularly strong Lorentz force 12 are formed in the direction of the quenching plates 9.

Fig. 1 shows a particularly preferred embodiment of a DC switching device 1, according to which a DC switching device 1 can be provided with at least one electrical input 2 and at least one electrical output 3, and at least a first switching contact 4 and a movable switching bridge 20, wherein the DC switching device 1 further a Arc quenching assembly 6, wherein the arc extinguishing assembly 6 has at least a first arc quenching chamber 7, which has a plurality of quenching plates 9, wherein the first quenching plate 27 is U-shaped, wherein the first leg 28 of the U-shaped first quenching plate 27 conductively connected to the electrical output. 3 wherein the second leg 29 of the U-shaped first quenching plate 27 is arranged substantially parallel to an adjacent arranged quenching plate 9, wherein the first leg 28 and the second leg 29 of the U-shaped first quenching plate 27th are arranged substantially parallel to each other. In such an arrangement, a particularly advantageous behavior of the arc 11 can be effected.

Fig. 4 shows the preferred embodiment in a first state of the arc 11, wherein one end of the arc 11 of the switching bridge 20, which is in particular potential-free, jumps on the first arc splitter 27, which is conductively connected to the electrical output 3. Here, as indicated by the arrow, flows over the U-shaped region and further through the first leg 28 of the current flow of the arc 11 in the direction of electrical output 3 from. By the current flow in the u-shaped region and in the first leg 28 in this case a magnetic field is generated, which causes a Lorentz force 12 in the direction of the quenching plates 9, and in particular away from the switching bridge 20.

Fig. 5 essentially shows Fig. 4 in a second state of the arc 11, which second state is the first state in Fig. 4 essentially immediately follows. Due to the penetration of the arc 11 into the gap 32 between the second leg 29 and the adjacent splitter plate 9, a current flow in the second leg 29 forms, wherein the path of the current flow in the second leg 29 increases with increasing penetration depth of the arc 11 into the gap 32. This further strengthens the Lorentz force 12, which drives the arc into the quenching plates, as a result of which a particularly rapid dissipation of the arc 11 can be achieved.

Preferably, it can further be provided that the arc extinguishing arrangement 6 has a second arc quenching chamber 8, comprising a plurality of quenching plates 9, and that in the second arc quenching chamber 8 also a first quenching plate 27 is arranged. In particular, the first quenching plate 27 of the second arc quenching chamber 8 may be formed equal to the first quenching plate 27 of the first arc quenching chamber 7.

Furthermore, it can be provided that the DC switching device 1 has at least one arc rail 18, which arc rail 18 is conductively connected to the first switching contact 4, and which arc rail 18 is disposed opposite the quenching plates 9 in the DC switching device 1. Depending on the structure of the DC switching device 1 can be provided that the arc runner 18 is part of the first arc extinguishing chamber 7. As a result, the arc 11 can be offered an electrotechnically attractive way. By the arc guide rail 18, the arc 11 is pulled away in a direction 26 from the first switching contact 4, which sweeps across the quench stack away, and thereby each loses energy.

Claims (8)

1. D.c. voltage switching device (1) with at least one electrical input (2) and also at least one electrical output (3), and also with at least a first switching contact (4) and a movable jumper (20), wherein the d.c. voltage switching device (1) has furthermore an arc quenching arrangement (6), wherein the arc quenching arrangement (6) has at least a first arc chute (7), which has a plurality of splitter plates (9), characterised in that only a first splitter plate (27) of the splitter plates (9) is U-shaped, and that a first limb (28) of the U-shaped first splitter plate (27) is conductively connected with the electrical output (3), wherein a Lorentz force (12) acts in the direction of the splitter plates (9) on arcs (11) caused by a switching operation in the first arc chute (7).
2. D.c. voltage switching device (1) according to claim 1, characterised in that a second limb (29) of the U-shaped first splitter plate (27) is disposed essentially parallel to a neighbouring splitter plate (9).
3. D.c. voltage switching device (1) according to claim 2, characterised in that the first limb (28) and the second limb (29) of the U-shaped first splitter plate (27) are disposed essentially parallel to each other.
4. D.c. voltage switching device (1) according to one of the claims 1 to 3, characterised in that the first splitter plate (27) delimits a splitter plate stack of the splitter plates (9) of the first arc chute (7).
5. D.c. voltage switching device (1) according to one of the claims 1 to 4, characterised in that the first splitter plate (27) is disposed adjacent to a movement path of the jumper (20).
6. D.c. voltage switching device (1) according to one of the claims 1 to 5, characterised in that the first splitter plate (27) has a holder (30), and that a contact stop part (31) made of insulating material is disposed in the holder (30).
7. D.c. voltage switching device (1) according to one of the claims 1 to 6, characterised in that this has a second switching contact (5), and that, to establish the conducting current path from the input (2) to the output (3), the first switching contact (4) and the second switching contact (5) are conductively connected by means of the jumper (20).
8. D.c. voltage switching device (1) according to one of the claims 1 to 7, characterised in that the arc quenching arrangement (6) has a second arc chute (8), comprising a plurality of splitter plates (9), and that a first splitter plate (27) is also disposed in the second arc chute (8).

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