EP2184749A1 - Arrangement of coil segments - Google Patents

Abstract

The arrangement (80) has bus-bars (90, 92) concentrically arranged around a central axis (100). Coil segments comprise two coils arranged around a coil axis, and penetrated from a ring shaped transformer core (98) along the coil axis. The coil segments are arranged in an angle to each other around the central axis of the transformer core. The coil segments are electrically switched parallel to each other by the bus bars. The bus bars are arranged in a minimum clearance, which runs radial to the middle axis, to the transformer core.

Description

The invention relates to an arrangement of first winding segments of a transformer winding about a transformer core extending annularly about a center axis, wherein a respective first winding segment comprises at least two windings of a respective winding conductor arranged around a respective winding axis, wherein the first winding segments penetrate the transformer core along their respective winding axis and wherein the first winding segments are arranged at a respective angle to each other about the central axis

It is well known that transformers are used in electrical energy supply networks. Their task is to electrically couple network areas with different voltage levels together. Higher voltages, for example 10 kV or 110 kV, are suitable for transmission over longer distances because the electrical transmission losses are reduced by the lower current flow. Usually, however, consumers in an electrical network require a lower voltage, which results in a correspondingly higher current flow for the same electrical power.

The low-voltage winding of an electrical transformer must be able to carry a correspondingly high current, depending on the rated power and rated voltage of the transformer, for example, some 10A to several 1000A. One way of constructive simplification of such a power transformer is the modular construction of upper and lower voltage winding. A corresponding arrangement of winding modules for power transformers is in the PCT / EP2008 / 003824 described. In this case, a plurality of winding modules, each having a low-voltage winding segment and a respective high-voltage winding segment are arranged around an annular transformer core, wherein the lower-voltage winding segments are electrically connected in parallel and the high-voltage winding segments are electrically connected in series.

According to the teaching disclosed therein, an electrical connection of the winding modules by means of cable pieces is proposed. In the series connection of the annularly arranged undervoltage winding segments, this leads either to a ring-like juxtaposition of cable pieces with a disadvantageously high number of interruption points, namely one per winding segment. Alternatively, the terminals of the lower voltage winding segments can also be connected to one another in a star shape at a common point via corresponding lines, which accordingly has unnecessarily high line lengths.

A disadvantage of this approach, moreover, that the electrical parallel connection of the low-voltage windings with cable pieces requires a lot of effort in terms of electrical connections.

Based on this prior art, it is an object of the invention to provide an improved possibility of electrical parallel connection of the low-voltage windings.

The invention provides for this purpose that at least two concentrically arranged around the central axis busbars (are provided, by means of which the first winding segments are connected to each other electrically in parallel.

By following the ring-like structure of the transformer core structure of the busbars on the one hand, a nearly constant distance between the respective busbar and the respective terminals of the preferably identical lower voltage winding segments is achieved, whereby the connection to the busbars for each winding segment takes place in exactly the same way. Despite this simplified installation electrical connection points along the busbars are advantageously avoided.

In a preferred embodiment of the subject invention, the bus bars are each arranged in at least one radially to the central axis extending minimum distance to the transformer core and the respective winding conductor of a respective first winding segment is at least partially disposed between the transformer core and the respective busbar.

Due to the radially to the winding axis of a winding segment outer arrangement of the busbars, the installation of the corresponding transformer is simplified. First, the winding segments are applied to the transformer core and positioned. Subsequently, the connections between busbars and the respective terminals of the winding segments is produced with high accessibility.

Preferably, a busbar consists predominantly of copper or aluminum. Both materials can be correspondingly easily converted into the desired geometric shape of a corresponding busbar - for example, by bending and have good electrical properties as a conductor.

According to a preferred embodiment of the invention, a respective first winding segment is arranged together with at least one galvanically separated further winding segment in a respective common winding module. The manufacture of a transformer, which has a plurality of galvanically separated windings, thereby significantly simplified.

Preferably, the first and the at least one further winding segment of a winding module are encapsulated with one another, for example with a suitable one Insulating resin. The mechanical stability of the windings and the insensitivity to mechanical external influences as well as the handling are thereby further increased.

A further embodiment of the arrangement according to the invention is characterized in that the respective winding conductor of at least one first winding segment is a strip conductor, which in its respective radially innermost and / or its radially outermost position by means of a fold axially led out of the first winding segment and with the associated busbars electrically connected.

The use of a strip conductor increases the fill factor of a winding and thus leads to a more compact design. By a folding of the strip conductor and its lateral design made possible thereby, a particularly space-saving design of the winding segment and a particularly simple guiding of the winding conductor to the bus bars are made possible.

In an embodiment of the arrangement according to the invention, the electrical connection of at least one conductor end to the associated busbar is effected by means of a welded connection. This is particularly advantageous for a permanently reliable electrical connection, if the arrangement is not intended for a later partial disassembly, for example, for the replacement of a single winding segment and the complete assembly is cast in resin, for example.

However, if the arrangement is provided for such a partial disassembly, the execution of the electrical connection of at least one conductor end with the associated busbar by means of a screw connection is advantageous. This can be solved very easily.

A further embodiment of the arrangement according to the invention is characterized in that the band conductor between its respective connection to the respective busbar and the respective folding is at least partially surrounded by an electrical insulation layer. The minimum distances of the Strip conductor to other components of the arrangement and thus the size of the arrangement are thereby advantageously reduced. Of course, an envelope of winding conductors, which are not band conductors, with a suitable insulating material is also covered by the idea of the invention.

The cross section of a busbar can be made rectangular, round or trapezoidal according to a preferred embodiment. Such cross sections allow a particularly good contact, in particular with a strip conductor of a respective winding segment - due to the relatively large contact area of the components to be contacted in this case - and are also particularly easy to produce cross-sectional shapes. Rounded edges of a rectangular or trapezoidal cross-section of a busbar serve to reduce the maximum field strength occurring.

In a preferred form, a bus bar has a cavity extending along its length. Depending on the size of the arrangement is to be expected in their operation with a high electrical current through the busbars, as mentioned above, up to several hundred amps, so that then takes place by the then occurring effect of the current displacement of the current flow to the surface of the busbars. By such a cavity in the busbar, the required cost of materials can be advantageously reduced. Furthermore, this gives the possibility of flowing through the cavity with a suitable coolant.

First winding segment elements are preferably provided at least for an electrical voltage of at least 400V. This is the lowest typical rated voltage for electrical components in power distribution networks. Of course, higher rated voltages, such as 10kV, covered by the spirit.

Preferably, the further winding segment elements are electrically connected in series, an electrical voltage of at least 1000V being provided for the series connection. The series connection reduces the voltage load of each individual further winding segment in an advantageous manner. Corresponding The transmission ratio of a device operated as a transformer according to the invention results in a rated voltage of the series-connected further windings, which is for example between the factor 2 and the factor of 15 higher than the rated voltage of the parallel-connected.

Further advantageous embodiment possibilities can be found in the further dependent claims.

Reference to the embodiments illustrated in the drawings, the invention, further embodiments and other advantages will be described in detail.

Fig. 1

eine erstes Wicklungsmodul in dreidimensionaler Ansicht,

Fig. 2

einen Teil eines zweiten Wicklungsmoduls in einer Draufsicht,

Fig. 3

eine Schnittansicht auf eine erste erfindungsgemäße Anordnung sowie

Fig. 4

eine Draufsicht auf eine zweite erfindungsgemäße Anordnung

Show it:

Fig. 1

a first winding module in three-dimensional view,

Fig. 2

a part of a second winding module in a plan view,

Fig. 3

a sectional view of a first inventive arrangement and

Fig. 4

a plan view of a second arrangement according to the invention

Fig. 1 shows a first winding module 10 in a perspective view. To a winding axis 99, a first winding segment 12 of the first winding module is arranged. In the illustration, only the cross section of the first winding segment 12 is visible, but it has to be assumed to have a multiplicity of turns of a strip conductor, for example 5 or even 20. The winding layers of the strip conductor are insulated from each other, which is also not shown in the figure. Such insulation is conceivable, for example, by a sheathing of the electrical conductor before the winding process or by inserting a separate insulating interlayer during the winding process of the winding segment 12.

The first conductor end 16 of the strip conductor is led out at the radially outermost winding layer of the winding segment 12 axially laterally out of this and the second conductor end 18 corresponding to the radially innermost winding layer.

Radially outside of the first winding segment 12 adjacent another winding segment 14 of the first winding module is arranged, whose individual winding layers also not shown. Here, for example, the use of a wound round conductor is conceivable, which is enveloped by a suitable layer of insulating material.

First 12 and further 14 winding segment are arranged together in the winding module 10 and connected to each other, for example with a casting resin, whereby the mechanical stability of the module is increased.

Fig. 2 shows a second winding module 30 in a sectional plan view, which is substantially the first in Fig. 1 is similar to the first winding module shown. To a winding axis 99, a first winding segment 32 and another winding segment 36 are arranged.

Shown in detail is the fold 38 of the strip conductor designed as the coil conductor of the first winding segment 32 in its radially outermost winding layer. The embodiment of the winding conductor takes place axially laterally to the third conductor end 34. The embodiment of the winding conductor at its other end in the radially innermost winding layer is not shown in the figure.

Fig. 3 shows a section through a first inventive arrangement 40 of winding modules about a central axis 100, wherein for the sake of illustration only a sectional view through a third winding module 42 and a fourth winding module 44 is shown. Depending on the embodiment of the arrangement, however, a number of 4 to 10 winding modules is to be regarded as the preferred number, for example. The winding modules 42 and 44 substantially correspond to those in FIG Fig. 1 shown first winding module 10 and each have a first winding segment 48 and 50 and a further winding segment 52 and 54, respectively. The winding modules 42 and 44 are penetrated by a first transformer core 46, which is arranged annularly around the central axis 100. The winding axis, not shown in this illustration, of the respective winding modules extends longitudinally within the annular first transformer core 46 in the region of the respective winding module 42, 44.

Also arranged annularly around the central axis 100 are the first busbar 56 and the second busbar 58, which are for example made predominantly of copper or aluminum and which optionally have contacting possibilities, for example for screwing on a conductor. The radial distance of the respective winding axis of a winding module to a respective busbar 56, 58 is approximately the same for all modules, also for the modules not shown. In the example shown, the first winding segments 48, 50 and the second winding segments 52, 54 are arranged in sections between the busbars 56, 58. After mounting the winding modules 42, 44 on the first transformer core 46, the busbars 56, 58 can therefore be introduced into this arrangement in a particularly simple manner by placing them in a wreath-like manner. For reasons of saving space, the arrangement in one of the respectively existing corners of the approximately circular cross section of the respective winding modules 42, 44 is particularly advantageous. As an alternative to the illustrated arrangement of the bus bars 56, 58, an arrangement on or in the vicinity of the with the Reference numbers 60 and 62 indicated positions. Of course, all possible combinations of the arrangement of the busbars are conceivable, for example, and at the two radially arranged to the central axis positions 58 and 62. In this case, the claimed by the arrangement without busbars outer contour is not adversely increased by the arrangement of the busbars. The arrangement or the transformer can be made more compact.

At each first winding segment 48, 50 of each winding module 42, 44, the two terminals of the winding conductor, which is preferably designed as a strip conductor, led out axially to the respective winding axis and respectively connected to the associated bus bars 56 and 58 respectively. The connection 64, 66, 68. 70 of the winding conductor with the busbars may for example be both welded and screwed, depending on whether a subsequent dismantling of the arrangement, for example, for maintenance or repair purposes, is provided or not.

The design of the winding conductor as a strip conductor is particularly suitable for the electrical connection 64, 66, 68, 70 with a busbar, because the components to be connected are arranged in the connection area in each case flat against each other can and so a particularly good and low-loss electrical connection 64, 66, 68, 70 can be realized. But even with a vertical arrangement of a strip conductor to be contacted to the region of the busbar in the case of a welded joint results in an elongated weld, which is also characterized by an advantageously large contact area.

Fig. 4 shows a plan view of a second inventive arrangement 80, which substantially the in Fig. 3 similar to the first arrangement shown. A fifth 82, sixth 84, seventh 86 and eighth 88 winding module are arranged in a circle about a central axis 100, each of which essentially corresponds to that in FIG Fig. 1 Correspond to the first winding module 10 shown. The winding modules are penetrated by an annular second transformer core 98, wherein this can of course also be made with a polygonal or rectangular plan. In this case, preferably one winding module would be assigned to each leg of the transformer core. It is also a the basic shape of the transformer core corresponding polygonal configuration of the busbars conceivable.

The respective first windings of the winding modules 82, 84, 86, 88 are electrically connected in parallel to each other by means of the third 90 and fourth 92 busbars, the connections not being shown in this illustration. At each busbar 90, 92, a connection is provided for contacting the same with other electrical components.

For use of such an arrangement, which has the operation of a single-phase transformer, in a three-phase power distribution network, in each case three such arrangements are electrically connected to form a unit which has the functionality of a three-phase transformer. In particular, the modular design of such a transformer simplifies the respective manufacturing process.

LIST OF REFERENCE NUMBERS

10

first winding module

12

first winding segment of the first winding module

14

another winding segment of the first winding module

16

first conductor end

18

second conductor end

30

second winding module

32

first winding segment of the second winding module

34

third leader

36

another winding segment of the second winding module

38

folding

40

first inventive arrangement

42

third winding module

44

fourth winding module

46

first transformer core

48

first winding segment of the third winding module

50

first winding segment of the fourth winding module

52

another winding segment of the third winding module

54

another winding segment of the fourth winding module

56

first busbar

58

second busbar

60

first alternative position for busbar

62

second alternative position for busbar

64

first connection

66

second connection

68

third connection

70

fourth connection

80

second inventive arrangement

82

fifth winding module

84

sixth winding module

86

seventh winding module

88

eighth winding module

90

third busbar

92

fourth busbar

94

first busbar connection

96

second busbar connection

98

second transformer core

99

winding axis

100

central axis

Claims (13)

Arrangement of first winding segments (12, 32, 48, 50) of a transformer winding (10) about a transformer core (46, 98) extending annularly about a central axis (100), wherein a respective first winding segment (12, 32, 48, 50) at least two windings of a respective winding conductor arranged around a respective winding axis (99), wherein the first winding segments (12, 32, 48, 50) are penetrated along their respective winding axis (99) by the transformer core (46, 98) and wherein the first Winding segments (12, 32, 48, 50) at an angle to each other about the central axis (100) of the annular transformer core (10) are arranged, characterized in that at least two concentrically arranged around the central axis (100) busbars (56, 58, 90, 92) are provided, by means of which the first winding segments (12, 32, 48, 50) are connected in parallel with each other electrically. Arrangement according to claim 1, characterized in that the bus bars (56, 58, 90, 92) in each case at least one radial to the central axis (100) extending minimum distance to the transformer core (46, 98) are arranged and that the respective winding conductor of a respective first winding segment (12, 32, 48, 50) at least in sections between the transformer core (46, 98) and the respective busbar (56, 58, 90, 92) is arranged. Arrangement according to claim 1 or 2, characterized in that as material for at least one busbar (56, 58, 90, 92) copper or aluminum is provided. Arrangement according to one of the preceding claims, characterized in that a respective first winding segment (12, 32, 48, 50) together with at least one galvanically separated further winding segment (14, 36, 52, 54) each have a common winding module (10, 30, 42, 44, 82, 84, 86, 88). Arrangement according to claim 4, characterized in that the first (12, 32, 48, 50) and the at least one further (14, 36, 52, 54) winding segment of a winding module (10, 30, 42, 44, 82, 84, 86, 88) are shed together. Arrangement according to one of the preceding claims, characterized in that the respective winding conductor of at least one first winding segment (12, 32, 48, 50) is a strip conductor which in its radially innermost and / or its radially outermost position by means of a fold (38). axially led out laterally from the first winding segment (12, 32, 48, 50) and electrically connected to the associated bus bars (56, 58, 90, 92). Arrangement according to claim 6, characterized in that the electrical connection (64, 66, 68, 70) of at least one conductor end with the respective busbar (56, 58, 90, 92) is provided by means of a welded connection. Arrangement according to claim 6, characterized in that the electrical connection (64, 66, 68, 70) of at least one conductor end with the respective busbar (56, 58, 90, 92) is provided by means of a screw connection. Arrangement according to one of claims 6 to 8, characterized in that the band conductor between its respective connection (64, 66, 68, 70) with the respective busbar (56, 58, 90, 92) and the respective fold (38) at least in sections is surrounded by an electrical insulation layer. Arrangement according to one of the preceding claims, characterized in that the cross section of the busbar (56, 58, 90, 92) is rectangular, round or trapezoidal. Arrangement according to one of the preceding claims, characterized in that the busbar (56, 58, 90, 92) has a cavity extending over the length thereof. Arrangement according to one of the preceding claims, characterized in that the first winding Segmentente (12, 32, 48, 50) are provided for an electrical voltage of at least 400V. Arrangement according to one of claims 4 to 12, characterized in that the further winding Segmentente (14, 36, 52, 54) are electrically connected in series and that the series circuit is provided for an electrical voltage of at least 1000V.

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