WO2018068842A1

WO2018068842A1 - Electrical contact arrangement and method for establishing electrical contact

Info

Publication number: WO2018068842A1
Application number: PCT/EP2016/074412
Authority: WO
Inventors: Matthias Böhm; Daniel Schmitt
Original assignee: Siemens Aktiengesellschaft
Priority date: 2016-10-12
Filing date: 2016-10-12
Publication date: 2018-04-19
Also published as: EP3501063B1; EP3501063A1; CN210142727U

Abstract

The invention relates to an electrical contact arrangement (1) for high-voltage applications, the electrical contact arrangement (1) comprising a first and a second contact piece (2, 3). The invention is characterised in that by turning a rotatably mounted and at least partially eccentric clamping bar (4) connected to the first contact piece (2), the second contact piece (3) can be clamped between the first contact piece and the clamping bar so as to establish electrical contact. The invention also relates to an electrical device (15) comprising a switching module (16), which comprises at least one power semiconductor switch (191, 192), and comprising a storage module (23), wherein the switching module and the storage module are connected to each other via the contact arrangement according to the invention. The invention also relates to a method for establishing electrical contact by means of the contact arrangement.

Description

description

Electrical contact arrangement and method for producing an electrical contact

The invention relates to an electrical contact arrangement for high voltage applications with a first and a second contact piece. The two contact pieces are in known contact arrangements for making electrical contact with each other in a suitable manner associated, so that an electric current can flow through the contact pieces. According to a known method for connecting the contact pieces, these are screwed together. Especially in high-voltage applications, such a screw connection must be made relatively solid, because high currents in the higher kA range can flow through the contact arrangement. However, such a solid contact arrangement is associated with ei ^¬ nem high effort in the production and separation of the electrical contact. Such a separation is in ^¬ play, at a maintenance of two interconnected via the two contact pieces components of a high-voltage system necessary. In particular, the solution of the massive

Screw connection is expensive in this case. In addition, there is a need for secure stowage loose fasteners such as screws, nuts and washers, whereby the cost is further increased.

The object of the invention is to propose a contact arrangement according to the species, which is as reliable as possible in operation, and which allows the simplest possible production and separation of the electrical contact.

The object is achieved in a species-specific contact arrangement according to the invention in that for producing a elekt ^¬ step contact, the second contact piece by means of rotation of egg ner connected to the first contact piece and rotatably mounted, at least section-eccentric clamping rod between the first contact piece and the clamping bar

is clamped.

The term eccentric clamping rod is to be understood in the context of the invention such that the clamping rod ent ^¬ long its longitudinal direction at one or more points or sections or along the entire length has a cross-section such that a rotational movement of the clamping rod in a translational movement in the Type of crankshaft can be converted.

An eccentric clamp bar is in this sense to the case ^¬ play a clamp rod having an elliptical cross-section, a single- or multi-edged clamp rod, wherein a longitudinal edge of the clamp bar extends at least in sections along the longitudinal direction of the clamping rod or a clamping rod with one or more eccentrics.

The contact arrangement according to the invention is thus such out ^¬ staltet that the two contact pieces for the manufacture of the electrical contact may form a clamping connection with each other. The clamping connection is achieved by the rotation of the clamping rod and is thus detachable. By entge ^¬ gengesetzten rotation of the clamping rod, the jamming of the contact pieces can be reversed again.

A significant advantage of the contact arrangement according to the invention is the reduced effort in a separation of elekt ^¬ cal contact. The solution of massive screw connections is eliminated, which reduces the time required. No loose fasteners are used. The jamming of the contact ^¬ pieces is done by a simple and quick to be performed rotation of the clamping bar. In this way, the time required in the manufacture and separation of the electrical contact can be reduced. At the same time is through the clamp connection of Contact pieces ensures reliable electrical contact even at high currents through the contact arrangement.

A ^clamping force achieved in the jamming of the contact ^pieces is expediently to be selected such that it corresponds, for example, to the force of a corresponding screw connection. This results in a functional dependence on the surface, since a clamping connection normally has larger effective surfaces than a comparable Schraubverbin ^¬ tion.

According to one embodiment of the invention, the contacts are at least partially flat construction and lying in a jammed state of the contact assembly at least partially abut each other, wherein the clamping rod in such a ^¬ arranged that a longitudinal edge of the clamping bar an on ^¬ pressing force on the at least partially abut each other ^¬ lying contact pieces exerts, so that the second contact ^¬ piece between the first contact piece and the clamping rod is releasably clamped. Accordingly, the clamping bar is a kanti ^¬ ge clamping bar with a longitudinal edge along the longitudinal direction of the clamping bar. Accordingly, the second contact piece can be inserted between the first contact piece and the clamping bar for producing the electrical contact, so that the two contact pieces lie at least partially one above the other and abut one another flatly. The clamping bar can then be rotated by a predetermined angle. The longitudinal edge of the clamping rod, after the rotation, suitably points in the direction of the contact pieces and exerts the contact pressure on them. The clamping rod may be connected to the first clock Kon ^¬ piece, for example by means of suitable screw elements. The separation of the contact pieces can be done in a simple manner by opposite rotation of the clamping rod and pushing out the second contact piece.

Preferably, the pressing force is transferable via a spring element on the contact pieces. Accordingly, at least one spring element is provided which is arranged such that the Pressing force in the jammed condition of the clamping rod via the at least one spring element on the contact pieces over ^¬ wear. By using the spring element, the transmission of the contact force is particularly homogeneous. Own investigations have shown that in this way the electrical contact is particularly reliable. Even in the case of very high currents through the contact arrangement, essentially no marked current marks or weak points are produced at the contact pieces.

Is considered to be particularly advantageous when the Federele ^¬ element comprises at least one disc spring. The at least one disc spring can be arranged on a side of the clamping rod facing the first contact piece. In the jammed state, the longitudinal edge of the clamping rod presses on the Tellerfe ^¬ who transmits the contact pressure on the contacts. According to a variant, a plurality of disc springs are provided, which are arranged along the clamping rod. Belleville springs have the advantage of a particularly homogeneous power transmission.

According to one embodiment of the invention, a return spring is provided, which is arranged such that a spring ^¬ force of the return spring counteracts the contact force. The return spring can, for example, in an interior of the

Disc spring be arranged. The return spring has the function to establish a distance between the clamping rod or the plate spring and the first contact piece when the contact arrangement is not in the jammed condition. The distance between the clamping rod or Tellerfe ^¬ and the first contact piece is suitably dimensioned such that the insertion of the second contact piece between the first contact piece and the clamping bar or the plate spring is easily possible. In this way, a further simplification of the production and separation of the electrical contact is achieved. The return spring may be playing as a coil spring with ^¬. For high voltage applications with rated voltages of several kV, high rated currents of several hundred kA can occur. In addition, however, peak currents of more than 1 mA may occur. For this reason, the contact arrangement is preferably to be designed for at least short-term conducting of currents above 1 MA, particularly preferably above 1.5 MA.

Preferably, the longitudinal edge of the clamping rod has a chamfer. In other words, the longitudinal edge is provided with a flat. This prevents in particular that the clamping ^¬ rod laterally slipped or twisted in the jammed condition of the contact assembly, so that the clamping rod can no longer exert sufficient contact force. According to one embodiment of the invention, the clamping rod has a polygonal cross-section. For example, the clamping bar may be a square. A polygonal Aus ^¬ leadership of the clamping rod causes advantageous that the zuver ^¬- permissible rotation of the clamping rod is facilitated. The rotation of the clamping rod can be done for example by means of a suitable tool which has a corresponding cross section of the clamping ^¬ rod corresponding recess.

The invention further relates to an electrical device with a switching module comprising at least one Leistungshalblei ^¬ terschalter, and with a memory module.

Such an electrical device is used, for example, in systems for high-voltage direct current transmission (HVDC). There, so-called power modules are used, which are connected to one another, for example, in a series connection. Each power module is also connected to an energy storage ^{¬ ¬} , suitably a capacitor. In the event of a power module failure and maintenance work on the power modules, in particular the connection between the power module and the capacitor must be disconnected. The object of the invention is to provide an artful electrical device that is as reliable and easy to maintain. The object is achieved in an art-appropriate electrical device, characterized in that between the switching module and the memory module, an electrical contact by means of a erfin ^{¬ to the} invention contact arrangement can be produced. The advantages of the electrical device according to the invention result in particular from the advantages of the contact arrangement according to the invention described above. Due to the simple production and separation of the contact in particular, the maintenance time can be shortened.

All embodiments and variants of the contact arrangement according to the invention described above can also be realized in connection with the device according to the invention.

If the switching module and the memory module are to be connected to one another via more than one electrical contact, it is of course possible to produce one or more of the contacts by means of the contact arrangement according to the invention.

The switching module may comprise a plurality of power semiconductor switches which are interconnected in a half-bridge circuit. According to other variants, the switching module is known as the specialist full-bridge circuit, double-clamp

Realized circuit or other suitable circuits. A series connection of the switching modules can form a phase branch of a modular multistage converter known to the person skilled in the art, wherein the phase branch extends between a DC voltage pole and an AC voltage terminal of the multistage converter. The invention further relates to a method for producing an electrical contact between two at least teilwei ^¬ se area contact pieces. The invention here is the object of the invention to provide such a method to enable a reliable as possible and equal ^¬ simple to produce and to be separated electrical connection between the contact pieces. The object is achieved in such a method according to the invention in that the contact pieces are at least partially ^¬ applied to each other and connected to the first contact piece, rotatably mounted along a longitudinal axis, angular clamping rod is rotated by a predetermined angle of rotation, so that a longitudinal edge of the clamping bar a

Pressing force on the at least partially juxtaposed ^¬ lying contact pieces, wherein the second contact piece between the first contact piece and the clamping bar is clamped.

The advantages of the method according to the invention arise in particular from the use of the contact arrangement according to the invention. Particularly in the case of maintenance of the components which are electrically contacted by means of the method according to the invention, the already described advantages with regard to reduced maintenance time and maintenance expenditure result.

The method according to the invention is suitable for use with all embodiments and variants of the contact arrangement according to the invention described above.

The invention will be explained below with reference to Figures 1 to 5. Figure 1 shows an embodiment of a contact arrangement according to the invention in a schematic representation; Figure 2 shows the embodiment of Figure 1 in a schematic side view;

FIG. 3 shows a section of a further exemplary embodiment of the contact arrangement in a schematic representation;

Figure 4 shows the detail of Figure 3 in a jammed condition of the contact arrangement;

Figure 5 shows an embodiment of an electrical device according to the invention in a schematic representation.

In detail, an exemplary embodiment of a contact arrangement 1 according to the invention is shown in FIG. The contact arrangement 1 comprises a first contact piece 2 and a second contact piece 3. In the present exemplary embodiment, the first contact piece 2 forms one pole of a memory module (not shown in FIG. 1). The second contact piece 3 forms a busbar for connection to a likewise figuratively not shown switching module. Both contact pieces 2, 3 are at least partially planar and in the Dar ^¬ position of Figure 1 in sections superimposed. A quadrangular clamping rod 4 is connected via connecting means 51, 52 with the first contact piece 2. Between the clamping rod 4 and the first contact piece 2, two plate springs 61 and 62 are arranged. The second contact piece 3 has two recesses 71 and 72. An opening width of the recesses 71, 72 is each slightly larger than a diameter of the cylindrical connecting means 51 and 52, but smaller than a diameter of the disc springs 61 and 62. In this way, the second contact piece 3 between the disc springs 61, 62 and the first contact piece 2 are pushed, so that the two contact pieces abut each other in sections. FIG. 2 shows a side view of the arrangement from FIG. 1. For reasons of clarity, therefore, the same parts in FIGS. 1 and 2 are given the same reference numbers.

It can be seen that the connecting means 51 have a fastening foot 8, which ensures a firm closure with the first contact piece 2 (for example by screwing).

In the illustration of Figures 1 and 2, the contact assembly 1 is in a jammed condition. In this case, the two contact pieces 2 and 3 are clamped together, so that a reliable electrical contact for guiding high currents of several kA between the contact pieces 2, 3 is made. For this purpose, the clamping rod 4 is in a position in which a longitudinal edge 9 of the clamping rod 4 (one of four longitudinal edges in the present example) points in the direction of the second contact piece 3. In this position, the clamping rod 4 exerts a contact pressure on the plate spring 61. The plate spring 61 transmits this contact pressure on the two contact pieces 2 and 3 and ensures their jamming. The plate spring 61 also allows a surface homogeneous ^¬ ne force distribution on the contact pieces 2, 3rd

The principal functional principle of the production of the electrical contact is shown in more detail in FIGS. 3 and 4 ^using the example of a contact arrangement 10 according to the invention. For reasons of clarity, only a four-sided clamping rod 11 and a plate ^¬ spring 12 are shown in Figures 3 and 4. The remaining embodiment of the Kontaktanord ^¬ tion 10 corresponds to that according to the embodiment ^¬ example of Figures 1 and 2. In the illustration of Figure 3, the clamping rod 11 is in a position in which the plate spring 12 is relaxed. A side length L of the clamp rod is indicated with a double arrow ^¬. The clamping rod 11 is with respect to a Rotatably mounted longitudinal axis. The longitudinal axis is perpendicular to the plane of the drawing.

To produce an electrical contact between the contact pieces, the clamping rod 11 is rotated by a predetermined angle. Specifically, the clamping rod 11 is ge ^¬ rotates until a longitudinal edge 13 in the direction of the Kontaktstü ^¬ bridge or the plate spring 12 points. The rotation of the clamping rod 11 is indicated in FIG. 4 by an arrow W and, in the example shown, is at an angle of 45 °. A diagonal diameter of the clamping rod 11 is marked with a double arrow D.

The distance between a center of the clamping rod 11 and the first contact piece is constant, so that the clamping rod 11 in the position shown in Figure 4 exerts a contact pressure on the plate spring 12. The plate spring 12 is deformed due to the contact pressure and transmits this area to the contact pieces, so that the second contact piece between see the clamping rod 11 and the first contact piece is jammed. In an interior of the plate spring 12, a return spring 14 is arranged. The return spring 14 is a spiral spring. The contact assembly 10 is not in the jammed condition, the return spring 14 is relaxed. It ensures a distance between the first contact piece and the clamping rod 11 and thus facilitates the insertion of the second contact piece between them. In the jammed state of the contact assembly 10, which is shown in Figure 4, the return spring is compressed. Here, the spring force of the return spring counteracts the contact force.

The longitudinal edge 13 of the clamping rod 11 has a chamfer 131. Accordingly, the longitudinal edge 13 does not taper sharply but has a flattening. The chamfer 131 ensures in the jammed condition of the clamping arrangement 10 that the clamping rod 11 does not slip out of its position (as in FIG. 4) and thus increases the reliability of the electrical contact between the contact pieces. In the figure 5 an embodiment of a fiction, modern ^¬ electrical device 15 is shown. The electrical device 15 comprises a switching module 16, which has two external connections 17 and 18. The switching module 16 can be connected by means of the terminals 17 and 18 with other identical switching modules, for example, to form a series circuit. The switching module 16 comprises two power semiconductor switching units 19, 20, each having a IGBT switch (191, 192) and an antiparallel diode umfas ^¬ sen. The power semiconductor switching units 19, 20 are connected to each other in a manner known in the art as a half-bridge circuit. Furthermore, the switching module 16 comprises two terminals 21 and 22 for connection to a memory module 23.

The memory module 23 comprises a capacitor. Further, the memory module to the switching module 23 includes two terminals 24 and 25 for at ^¬ circuit 16. The connection terminal 21 of the switching module 16 with the

Terminal 24 of the memory module 23 by means of the contact ^¬ arrangement 1, which has the structure according to the embodiment of Figures 1 and 2. Accordingly, the connection of the terminal 22 of the switching module 16 to the terminal 25 of the memory module 23 by means of a further, identical contact arrangement. 1

Claims

claims

An electrical contact arrangement (1) for high-voltage applications having a first and a second contact piece (2, 3), characterized in that

for producing an electrical contact, the second contact piece (3) can be clamped between the first contact piece (2) and the clamping rod (4) by means of rotation of a clamping rod (4) connected to the first contact piece (2) and rotatably mounted, at least partially eccentric.

2. Contact arrangement (1) according to claim 1, wherein the contact pieces (2, 3) are at least partially flat and in a jammed condition of Kontaktanord ^¬ voltage (1) at least partially abut each other, wherein the clamping rod (4) is arranged such that a longitudinal edge (9) of the clamping rod (4) a Anpress ^¬ force on the at least partially together Toggle located contact pieces (2, 3) exerts, so that the second contact piece (3) (between the first contact piece (2) and the clamping bar 4) is releasably jammed.

3. Contact arrangement (1) according to claim 2, wherein the pressing force via a spring element (61, 62) on the contact ^¬ pieces is transferable.

4. Contact arrangement (1) according to claim 3, wherein the spring element (61, 62) comprises at least one plate spring.

5. Contact arrangement (10) according to claim 4, wherein a return spring (14) is provided, which is arranged such that a spring force of the return spring (14) ent ^¬ acts against the contact force.

6. Contact arrangement (1, 10) according to one of the preceding

Claims, wherein the contact arrangement (1, 10) is designed to carry currents above 1 mA. Contact arrangement (10) according to one of the preceding claims, wherein the longitudinal edge (13) of the clamping rod (41) has a chamfer (131).

Contact arrangement (10) according to one of the preceding claims, wherein the clamping rod (11) has a polygonal cross-section.

Electrical device (15) with a switching module (16) which comprises at least one power semiconductor switch (191, 192) and with a memory module (23), wherein an electrical contact between the switching module (16) and the memory module (23) by means of a contact arrangement (1) according to one of claims 1 to 8 producible ^¬ bar. A method for producing an electrical contact between two at least partially flat Kontaktstü ^¬ bridges (2, 3), in which

- The contact pieces (2, 3) are at least partially applied to each other and

- One connected to the first contact piece (2), rotatably mounted along a longitudinal axis, at least partially eccentric clamping rod (4) is rotated to ei ^¬ NEN predetermined rotation angle, so that a longitudinal edge of the clamping rod (4) a contact force on the at least partially Anlie ^¬ adjacent contact pieces (2, 3) exerts, wherein the second contact piece (3) between the first contact piece (2) and the clamping rod (4) is clamped.