EP3340390A1 - Cable connector for high current - Google Patents

Abstract

Cable connector for high current cables, with - A first and a second connector, each having a contact piece for connection to one end of the cable, and - fastening means for detachably connecting the connecting pieces to each other, in which - Each of the connecting pieces has an electrical contact surface which extends in a longitudinal direction and rises to a free end of the connecting piece in the manner of a ramp so that it transmits a force on the ramp of the other connector at a mechanical tensile load along the longitudinal direction.

Description

The present invention relates to a high current cable connector particularly suitable for use in harsh environments in which the cable connector is subjected to mechanical stresses such as vibrations, heat and the like. Preferably, the cable connector according to the invention is used in wind turbines, but also the use in shipbuilding and in particular in naval shipbuilding is advantageous.

High current is also referred to as high current in some branches of industry, with the following terms being synonymous with each other. High current here refers to currents as defined in the corresponding DIN standards, for example for the measurement of high currents, the high current usually has a current strength of more than 100 A.

Out EP 2 856 566 B1 is an electrical connection system has become known, which is designed in particular for use in a wind turbine. The connection system has two connecting pieces, which engage behind each other for securing with regard to tensile loads. In a tensile load of the connection system in the cable longitudinal direction so changes the electrically effective contact surface of the connection system.

Out EP 2 856 562 B1 An electrical connection system has become known in which one of the two connecting pieces has a longitudinally extending projection and the other has a corresponding receptacle for the projection. A security of the connectors against train in the longitudinal direction via a transverse to the longitudinal direction screw.

The invention has for its object to provide an improved cable connector for high current available, which can be used to the disadvantages of the known in a mechanically demanding environment.

The object of the invention is preferably achieved by a cable connector with the features of claim 1. Advantageous embodiments form the subject of the dependent claims.

The cable connector according to the invention is provided as a connector for high-current cables. The cable connector has a first and a second connector, each having a contact socket for connection to the cable. Furthermore, fastening means for releasably connecting the connecting pieces to each other are provided. According to the invention, it is now provided that each of the connecting pieces is provided with an electrical contact surface. The electrical contact surfaces each extend in a longitudinal direction and rise toward a free end of the connector in the manner of a ramp such that the connecting pieces transmit a force on the ramp-shaped contact surface of the respective other connector in a mechanical tensile load along the longitudinal direction. The inclination of the contact surfaces is such that when the cable connectors are pulled apart in the longitudinal direction, the contact surfaces are pressed flat against one another. By pressing the contact surfaces on each other, the contact surface always develops the same under tension and does not change. Another particular advantage of the sloped contact surfaces is that the fasteners that extend across the cable connector are not loaded with tension. The engaging tensile forces are each received by the other connector, so that shear forces on the guided transversely through the cable connector fastener can be avoided.

In a preferred embodiment, the connecting pieces in their connected form form a cylindrical connecting body which is held together by a pair of fastening means extending through the connecting body. Unlike known from the prior art, is not focused on a single fastener, but this applied in pairs.

In a preferred embodiment, the connecting pieces are designed as identical parts. The use of common parts for cable connectors has great advantages, especially in the manufacture and assembly of the cable connector. When using identical parts, it can not happen that during assembly, for example, a tower of the wind turbine, mating connectors are not matching or even pre-assembled on the tower sections. The production costs and the costs for storage are thereby significantly reduced.

In a preferred embodiment, the contact surfaces each extend over the preferably entire width of the connecting pieces and are formed as a surface. In the connected state of the connectors, the surfaces are flat over their width to each other and are secured by the connecting means to each other. By extending the contact surface over the entire width of the connector, the connectors can be easily merged even from very different positions and orientations.

In a preferred embodiment, each of the contact surfaces has a continuous, mutually parallel teeth whose orientation is equal to the connecting pieces and runs such that the teeth of the Contact surfaces of two interconnected connectors at an angle superimposed electrical contact points of the toothing create. The use of a toothing is based on the idea to create a defined contact surface by the juxtaposition of two teeth, having defined contact points, in which an electrically conductive contact occurs. The orientation of the toothings at an angle ensures that the effective contact surface has punctiform contact surfaces, in each of which higher parts of the teeth, for example a tooth tip or a dental plateau, lie on top of one another. Even with a tensile load or vibration of the interconnected connectors does not change the effective contact surface, there is always tooth on tooth in the contact surface and forms the electrically conductive contact surface.

In order to ensure that the use of two equal parts, which also have a similar orientation of their toothings, the serrations are at an angle to each other when connecting the dice, there are two preferred approaches. In a first approach, the contacts are divided in half into two sections, of which a first section has a toothing with a first orientation and the second section has a second, perpendicular to the first orientation toothing. If the connecting pieces are superimposed and connected to each other, the first portion of the one connecting piece comes to lie on the second portion of the other connecting piece and vice versa, so that the orientations are perpendicular to each other. In this configuration, it is possible, for example, to orient the toothing in one section in the longitudinal direction of the connecting piece, while it is oriented in the other section in the transverse direction. But also oblique orientations are possible.

In a second possible embodiment, each of the contact surfaces is provided with a uniformly continuous toothing, which has an oblique angle, in particular a 45 ° angle to a longitudinal axis of the associated connecting piece. In a juxtaposing and connecting the connectors, the two oblique angles then have a different orientation, which ensures that tooth comes to rest on tooth with a defined contact surface. If a 45 ° angle relative to the longitudinal direction is selected for the oblique angle, the serrations enclose a 90 ° angle with one another.

In a preferred development, the fastening means comprise two screws arranged one behind the other in the longitudinal direction, one of which is arranged captively in one of the connecting pieces. Even with the captive in the connector arranged screw pair, the connectors remain the same parts. When establishing the connection, the one screw is guided from one side through the connecting pieces, while the other screw is guided from the other side through the connecting pieces. The use of a captive arranged in the connector screw has great advantages for the assembly, since the fitter has to handle only a few parts. In addition, lost fasteners such as nuts and bolts pose a great risk of injury in the construction of the tower, as they fall from a great height and can continue to hurt working people. This is also avoided by the captive fastening means.

In a further preferred embodiment, the fastening means on a pair of nuts with an additional external thread, which are each screwed into one of the connecting pieces. External thread and internal thread of In this case, mothers have an opposite orientation, so that when the screw is screwed into the internal thread, the nut already screwed in the connecting piece does not unscrew and is therefore designed to be captive.

Alternatively, it is also possible to use nuts without external thread, which are held by clamping in the associated connector and can also be screwed in this state and thus are designed to be captive.

Preferably, the connecting piece has a first end face on its side facing the contact neck, standing transversely to the central longitudinal axis of the connecting piece. Depending on the inclination of the contact surface, the central longitudinal axis of the connector is not in the contact surface, but includes an inclination angle of the contact surface with this. The pointing to the contact piece end face may be perpendicular or inclined to the central longitudinal axis of the connecting piece, wherein the end face is pulled on a tensile load of a corresponding end face of the other connector away. Preferably, the connector also has at its free end a transverse to the central longitudinal axis of the second end face, wherein in the connected state of the formed as equal parts connecting pieces, the first and second end faces of the connecting pieces are arranged opposite to each other and parallel to each other.

Preferably, the contact piece has a conical transition section, which has a smaller diameter on its side facing the end face than on its side facing the contact surface. The conical transition section directs as a truncated cone of the diameter of the contact piece, whose end face can be connected to a cable to a larger diameter of the Connecting body over. The continuous transition has the advantage that an electrical insulation of the cable connector can be easily mounted and also the electrical resistance of the cable connector does not change abruptly along the connection of the end face to the contact surface within the connecting body.

In a preferred embodiment, which is particularly suitable for use on tower sections, each of the connecting pieces has an orientation mark indicating an intended fixing position. Due to the intended mounting position, the contact surfaces receive a desired orientation and the connecting means are also connected to each other in a desired direction.

For the connecting pieces, an aluminum alloy is particularly preferred as the material. The common disadvantages of aluminum alloys for connectors is that the aluminum tends to flow under heat and vibration. As a result, for example, the contact surfaces or the current-conducting cross section can change significantly. In the cable connector according to the invention such a flow movement is excluded both by the design of the contact surfaces and by the connection with the contact socket and it remains a consistently good electrical contact.

In a preferred embodiment, the contact surfaces and their teeth are provided with a metallic coating. Aluminum alloys can tend to oxidize, so that a consistently good electrical contact is ensured by a metallic coating, for example with tin, copper or silver.

With regard to the effective contact surface, tooth spacings of 300 μm to 600 μm have proven to be preferable for the teeth. Preferably flat teeth are used with a plateau, wherein the plateau then has a width of 50 microns to 150 microns to form the desired electrical contact surface.

A cable connector system which is very suitable with regard to installation has a cable connector according to the invention, of which a pair of connecting pieces are each connected at the end to a line section which can be fastened in a tower section. The line section with its connecting pieces can be preassembled, so that when the tower is erected, only the cable connectors must be connected to one another.

A preferred cable connector system additionally has an insulation sheath that electrically isolates the connected cable connector from the outside. Preferably, the Insolationshülle is designed as a tube and in particular as a shrink tube. The shrink tube is mounted on the interconnected connectors and shrunk onto the finished connected connectors. The shrinking process can be done warm or cold.

It has been found that the cable can be well connected to the contact studs via resistance butt welding. This connection is mechanically strong and produces a uniform electrical contact between cable and contact piece. In a preferred embodiment, the cable also has a longitudinally extending mark aligned with the orientation mark of the connectors. As a result, the orientation mark on the connectors with the aid of Marking on the cable clearly visible and recognizable during installation from a distance.

Fig. 1

eine schematische Ansicht einer Windenergieanlage mit einem im Turm entlang geführten Kabel,

Fign. 2a, b

zwei unterschiedliche Ansichten eines Kabelverbinders im verbundenen Zustand in einer ersten Ausgestaltung,

Fign. 3a, b

ein einzelnes Verbindungsstück in zwei verschiedenen Ansichten,

Fig. 4

ein Verbindungsstück mit zwei senkrecht zueinanderstehenden Zahnungen in der Kontaktfläche in einer Draufsicht,

Fig. 5

eine perspektivische Ansicht von zwei Verbindungsstücken aus Fig. 4,

Fig. 6

eine zweite Ausgestaltung eines Kabelverbinders mit einem konischen Übergang zum Kontaktstutzen und

Fig. 7

eine Ansicht der miteinander verbundenen Verbindungsstücke aus Fig. 6 mit angeschlossenem Kabel und Markierung.

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

Fig. 1

a schematic view of a wind turbine with a guided along the tower cable,

FIGS. 2a, b

two different views of a cable connector in the connected state in a first embodiment,

FIGS. 3a, b

a single connector in two different views,

Fig. 4

a connector with two mutually perpendicular toothings in the contact surface in a plan view,

Fig. 5

a perspective view of two connectors Fig. 4 .

Fig. 6

a second embodiment of a cable connector with a conical transition to the contact socket and

Fig. 7

a view of the interconnected connectors Fig. 6 with connected cable and marking.

For the reference numerals, a nomenclature is used, that a reference character X denotes a feature, and Xa and Xb, the occurrences of the feature X in FIG designate the two connectors. In this respect, the feature X is always included in an explanation of a feature Xa or Xb.

Fig. 1 shows a wind turbine 10 with a tower 12, a machine house 14 and a rotor 16. The rotor 16 has three rotor blades, of which, in the view from the side, the rotor blades 18a and 18b can be seen, the rotor blade 18b for clarity is shown cut in the figure.

The tower 12 consists of at least a lower portion of a plurality of tower sections 20a, 20b, 20c. Inside the tower leads an electrical line 22 which connects a arranged in the machine house 14 generator with an electrical device 27 in the base of the tower. Due to the individual tower sections 20a, 20b, 20c, the electrical line 22 is also divided into line sections 24d, 24c, etc. The line sections 24 are electrically conductively connected to one another both at their upper end 26 and at their lower end 28 via a cable connector 30.

FIGS. 2a and 2b show a first embodiment of the cable connector 30. The cable connector 30 consists of two connecting pieces 32a, 32b, which are designed as identical parts, ie as identically constructed parts. The connecting pieces 32 are connected by screws 34a, 34b which are secured by nuts 36a, 36b (cf. Fig. 2 ). The connecting pieces 32 each have a contact socket 38a, 38b. For connection to the cable this is connected to a nozzle end face 40a, 40b of the contact socket 38. Preferably, the cable to be connected is connected to the end faces 40 by resistance butt welding. The longitudinal direction of the cable connector 30 extends in the direction of the connecting piece 38 connecting the central longitudinal axis L.

In Fign 2a . 3a, 3b a Z-shaped separation point 42 between the connecting pieces 32a, 32b can be seen. The Z-shaped separation point 42 has two end faces 44, 45 and a contact surface 46. Here, in the contact surface 46, the contact surface 46b of the connecting piece 32b and the contact surface 46a of the connecting piece 32a come into electrical contact with one another. The end faces 44, 45 of the connecting pieces (see. FIGS. 3 ) are arranged opposite to each other, in which case a gap can remain without there being any contact of the end faces. It can be clearly seen that, based on the longitudinal axis L, the free end of the connecting piece 32 is located on one side of the longitudinal axis L, while the end of the contact surface 46 facing the contact socket 38 lies on the other side. The contact surfaces 46 are thus inclined relative to the central longitudinal axis L by an inclination angle α. The angle of inclination α can be 1 ° to 45 °, preferably 1 ° to 10 ° and particularly preferably 3 ° to 7 °.

Fig. 2b shows the cable connector rotated 90 ° clockwise about its longitudinal axis L. It can be seen that the nut 36b is held in a rectangular recess 50a on the connecting piece 32a. The dimension of the recess 50 a and the nut 36 b may be coordinated so that the nut 36 b is clamped in the connector 32. Also in the Fig. 2b It can be seen that the head of the screw 34a has a hexagon socket.

FIGS. 3a, 3b show a connector 32b in its disconnected state. The contact piece 38b are circular cylindrical and therefore in both views of FIGS. 3a and 3b equal. The recess 50b has a rectangular shape with a central throughbore 56b. For the screw head 34a a circular recess 52 is provided with a central through-hole 54b.

The connecting piece 32b has a contact surface 46b which is divided into two sections 58b and 60b by a groove 61 extending transversely to the longitudinal direction L.

Furthermore, in Fig. 3a to recognize an end face 45b, which is arranged closer to the contact piece 38b than the end face 44b from the free end. The contact surface 46b with its portions 58b and 60b is always inclined to the arranged near the contact piece 38b end face 45b out.

Fig. 4 shows the connector 32b with a view of the contact surface 46b. Clearly visible in the section 60b is a toothing transverse to the longitudinal direction L, while the toothing in the section 58b extends in the longitudinal direction L.

In Fig. 5 It can be seen that the connecting pieces 32a and 32b Fig. 4 when the contact surfaces 46 are connected to each other in a planar manner, the orientation of the payment in the sections 58b and 60b is perpendicular to one another.

Fig. 6 shows a second, improved embodiment of the cable connector 62 according to the invention, which has a conical transition section 64 to its contact stub 66. The conical transition section 64 makes it possible to better conduct the current from the contact piece via the connector and the contact surface. In addition, the conical transition section 64 allows a better application of a spaghetti and prevents air pockets under this.

Fig. 7 shows the cable connector 68 with connected lines 70, each having a extending in the longitudinal direction of the line marking 72. The lines 70 are attached to the contact socket 38a, 38b. The isolation of the Lines 70 extend along line 70a, as a line with insulation, and enter line 70b without isolation. The conduit 70b without insulation is welded to the contact stub 38a, 38b. The insulation of the leads 70, their connection to the contact piece 38a, 38b and the entire cable connector via a shrink tube 75, which is shown in its not yet shrunken state. The shrink tube 75 encloses the entire assembly, preferably without the inclusion of air bubbles. Alternatively, a plurality of heat shrink tubing may be provided (not shown), each enclosing only a portion and superimposed so that they enclose the entire assembly and safely isolate. On the cable connector 68 itself two orientation marks 74a, 74b are provided. In the illustrated embodiment, the marker 72 of the cable coincides with the orientation marks 74a, 74b. The advantage of the alignment marks 74 and the cable marking 72 is that they can define a clearly defined mounting position for the cable connectors in a tower section. Since the connecting pieces are formed as equal parts, it is irrelevant which connection piece is mounted in the top of the tower section and which is mounted in the tower section for connection to a bottom or top connecting piece.

The cable connector according to the invention consists of solidly formed connecting pieces, which are made of a metal alloy, preferably an aluminum alloy. The connecting pieces can be coated or bare, preferably tin-plated, copper-plated or silver-plated, and contact the respective cables via a welding method at their contact surfaces, to which they are materially connected. The connecting pieces are designed as identical parts, wherein the contact surface of each connector is provided with a toothing, so that always occur when merging two connectors point contacts of the toothings.

As a result, the teeth on the connectors are oriented accordingly. The tooth geometry is essential for the defined point contacts, preferably the distance between two teeth is in each case between 300 μm and 600 μm. The teeth have a plateau in a range of 50 microns to 150 microns.

The contact surface is inclined to the longitudinal axis and has an area which is greater than or equal to the cross section of the cable to be connected. Due to the inclination, the connecting pieces are compressed when screwing not only parallel to the biasing force of the screw, but also perpendicular to the screw, which increases the stability of the connection. The frictional attachment of the two connectors together, for example, by two screws. In order to facilitate handling in the assembly of the connectors, the screw can be arranged captive in the connector.

An embodiment of the fastening means, not shown, provides a tensioning device which, in its tensioned state, presses the connecting pieces transversely to one another against their longitudinal direction. The advantage of a tensioning device is that it can be quickly brought into a defined position in order to connect the connecting pieces together.

To facilitate assembly in the tower, an orientation mark is mounted on one side of the cable connector perpendicular to the contact surface. In conjunction with a longitudinal line on the cable to be connected can be ensured so that two cables can be connected to the same direction of the cable with the same orientation of the cable without torsion of the cable with two equally welded connectors.

LIST OF REFERENCE NUMBERS

10

Wind turbine

12

tower

14

power house

16

rotor

18a

rotor blade

18b

rotor blade

20a

tower section

20b

tower section

20c

tower section

22

electrical line

24c

line section

24d

line section

26

upper end of the pipe sections

27

electrical device

28

lower end of the line sections

30

cable connectors

32a

joint

32b

joint

34a

screw

34b

screw

36a

mother

36b

mother

38

Contact stub without transition area

38a

Contact stub without transition area

38b

Contact stub without transition area

40

Piece face

40a

Piece face

40b

Piece face

42

Z-shaped separation point

44

face

44a

face

44b

face

45

face

45b

face

46

contact area

46a

contact area

46b

contact area

50

recess

50a

recess

50b

recess

52

recess

54b

Through Hole

56b

Through Hole

58b

section

60b

section

61

groove

62

cable connectors

64

Transition section

66

Contact stub with transitional area

68

cable connectors

70

management

70a

Lead with insulation

70b

Cable without insulation

72

mark

74a

orientation mark

74b

orientation mark

75

shrinkable tubing

Claims (22)

Cable connector (30) for high current cables, with - A first and a second connector (32 a, 32 b), each having a contact piece (66) for connection to one end of the cable, and - fastening means (34, 36) for detachable connection of the connecting pieces (32a, 32b) to each other, characterized in that - Each of the connecting pieces (32a, 32b) has an electrical contact surface (40a, 40b) which extends in a longitudinal direction and rises to a free end of the connecting piece in the manner of a ramp such that it at a mechanical tensile load along the longitudinal direction of a Force on the ramp of the other connector transmits. A cable connector (30) according to claim 1, characterized in that the connecting pieces (32a, 32b) in their connected form form a cylindrical connecting body held together by a pair of fixing means (34, 36) extending through the connecting body. Cable connector (30) according to claim 1 or 2, characterized in that the connecting pieces (32a, 32b) are formed as equal parts. Cable connector (30) according to one of claims 1 to 3, characterized in that the contact surface (40a, 40b) extends over the connecting piece (32a, 32b) and forms a surface. Cable connector (30) according to one of claims 1 to 4, characterized in that the contact surface (40a, 40b) has a continuous parallel toothing whose orientation at the connecting pieces (32a, 32b) is the same and extends such that the serrations of Contact surfaces (40a, 40b) of two interconnected connecting pieces (32a, 32b) at an angle to each other create electrical contact points of the serrations. Cable connector (30) according to claim 5, characterized in that each of the contact surfaces (40a, 40b) is divided in half into two sections (58b, 60b), one of each of which a first portion (58b) has a toothing with a first orientation and the second Section (60b) has a second, perpendicular to the first orientation orientation. Cable connector (30) according to claim 5, characterized in that each of the contact surfaces (40a, 40b) has a continuous toothing, which has an oblique angle, in particular a 45 ° angle to the longitudinal direction of the associated connecting piece. Cable connector (30) according to one of claims 1 to 7, characterized in that the fastening means (34, 36) in the longitudinal direction of two consecutively arranged screws (34a, 34b), each of which a screw in one of the connecting pieces (32a, 32b ) is arranged captive. A cable connector (30) according to any one of claims 1 to 8, characterized in that the fastening means comprise a pair of externally threaded nuts (36a, 36b) threaded into one of the connectors (32a, 32b), respectively. A cable connector (30) according to any one of claims 1 to 8, characterized in that the fastening means comprise a pair of nuts (36a, 36b), each clamped in the associated connector (32a, 32b). Cable connector (30) according to one of the preceding claims, characterized in that a first end face (44a) is arranged standing on a side facing the contact socket (38a) transversely to the central longitudinal axis (L) of the connecting piece (32a). Cable connector (30) according to one of the preceding claims, characterized in that a second end face (44b) at a free end of the connecting piece (32b) transversely to the central longitudinal axis (L) of the connecting piece (32b) is arranged standing, wherein in the connected state, the first and second end surfaces (44a, 44b) of the connecting pieces (32a, 32b) are arranged opposite to each other and plane-parallel to each other. Cable connector (30) according to one of the preceding claims, characterized in that the contact socket (66) has a conical transition section (64) which, on its end face towards the nozzle (40) facing side has a smaller diameter than on its side facing the contact surface (46). A cable connector (30) according to any one of the preceding claims, characterized in that each of the connectors (32a, 32b) carries an orientation mark (74a, 74b) indicative of an intended mounting position. Cable connector (30) according to one of the preceding claims, characterized in that the connecting pieces (32a, 32b) are made of an aluminum alloy. Cable connector (30) according to any one of the preceding claims, characterized in that the contact surfaces (40a, 40b) and their teeth are provided with a metallic coating, for example of tin, copper or silver. Cable connector (30) according to any one of the preceding claims, characterized in that the teeth have a tooth spacing of 300 .mu.m to 600 .mu.m and flattened tooth heads having a plateau width of 50 .mu.m to 150 .mu.m. A cable connector system comprising a cable connector (30) according to any one of the preceding claims, characterized in that a pair of connectors are connected end-to-end to a conduit section (24c, 24c) mountable in a tower section (20b, 20c). Cable connector system according to claim 18, characterized in that in addition an insulating sheath is provided, which isolates the interconnected connecting pieces (32a, 32b). Cable connector system according to claim 18 or 19, characterized in that the insulation sheath is formed as a shrink tube (75). Cable connector system according to one of claims 18 to 20, characterized in that the cable is connected via resistance butt welding to the contact socket. A cable connector system according to any one of claims 18 to 21, characterized in that the cable carries a longitudinally extending marker (72) aligned with the alignment marks (74a, 74b) of the connectors (32a, 32b).

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