EP2277183B1 - Modular ring-shaped core - Google Patents

Abstract

The disclosure relates to a ring-shaped core for a power transformer. The ring-shaped core extends about an imaginary center axis in the form of a closed toroidal structure and is constituted of a plurality of adjacent layers of sheet metal. The ring-shaped core, along the length of the toroidal structure, is constituted of at least three core section modules that can be connected to and detached from each other, the core section modules being interconnected by an overlap of individual sheet layers and/or sheet layer sections. The disclosure also relates to the arrangement of ring-shaped cores having winding modules. The latter can be arranged in a common connecting structure and every ring core having winding modules arranged therein can be separately introduced into the connecting structure and removed therefrom in a non-destructive manner.

Description

The invention relates to a toroidal core for a power transformer, wherein the toroidal core extends in the form of a closed torus-like structure about an imaginary central axis and wherein this is formed from a plurality of adjacent layers of sheet metal. The invention also relates to an arrangement of a plurality of toroidal cores with winding modules.

It has long been known to use transformers in the distribution of electrical energy by transforming or switching AC voltage from a high level to a low voltage level or vice versa. Power distribution networks are usually constructed in 3-phase, i. there are three mutually associated individual conductors in each case by 120 ° phase angle shifted voltages whose in-phase mathematical summation in the symmetrical state of the energy distribution network always gives the value zero. Power ranges of such power transformers range from a few kVA up to several 100 MVA, the operating voltages are usually between 6kV and 380kV.

A 3-phase power transformer usually has at least one primary and one secondary winding for each phase, so that a total of at least 6 individual windings result. There are 3-phase power transformers are known in which all windings are arranged around a common transformer core having a plurality of legs, wherein one leg is then wrapped, for example, each of a primary and a secondary winding of a phase.

There are also known 3-phase power transformers, which are formed by suitable electrical interconnection of three single-phase transformers in which the primary and secondary windings are each a phase wrapped around a separate annular transformer core.

In such a 1-phase winding arrangement with annular core, it proves to be advantageous for reasons of compactness of the arrangement, the single-phase primary and / or secondary winding also in the form of several separate winding segments, for example along a circular path, wherein all winding segments are penetrated by the annular core, as for example in the European patent specification EP 0 557 549 B1 described.

A disadvantage of the prior art described there is in particular that the arrangement does not allow a modular exchange of winding segments of such a ready assembled transformer, without also further winding segments also at least temporarily remove from the transformer core.

Based on this prior art, it is an object of the invention to reduce the expense of replacing a winding segment in a transformer with an annular transformer core and a plurality of winding segments for a ring core for a power transformer of the type mentioned.

This object is achieved by a toroidal core having the features specified in claim 1.

Accordingly, the ring core according to the invention is characterized in that it is formed along the torus-like structure of at least three mutually connectable and detachable core section modules and that the connection of the core section modules is provided by toothing individual sheet metal layers or sheet metal layer areas.

The modular design of a ring core according to the invention of at least three, preferably identical, core section modules, which are also detachable from each other, allows selective disassembly of the individual transformer components, such as winding modules or winding segments, switches are arranged along the ring core and are penetrated by this. The maintenance effort when replacing a winding module is thereby reduced in an advantageous manner.

The detachable connection of the individual core section modules takes place according to the invention by toothing and / or overlapping a plurality of sheet metal layers or sheet metal layer areas between adjacent core sections. Thus, a sufficient guidance of a magnetic flux in the transition region of adjacent core sections is ensured.

In a further embodiment of the ring core according to the invention, this has at least in sections a core cross-section, which is approximated to an ellipse or a circle. Such an approximation is possible, for example, by a layering of the core of a plurality of laminated core layers, each having a different rectangular cross-section per laminated core layer.

In a particularly preferred embodiment of the toroidal core according to the invention, each core section module is assigned exactly one winding module, each having at least one electrical winding.

Winding module and core section module are then easily replaced together in a fault, without having to remove another, not faulty winding module from the toroidal core. Preferably, all winding and core section modules are identical. These advantages arise both for a circular and for a polygonal ring core, for example, with 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 corners.

According to a further embodiment of the ring core according to the invention at least two galvanically separated electrical windings are arranged in a winding module.
As a result, for example, the joint arrangement of a portion of a primary and a secondary winding of a power transformer within a winding module is possible. The production cost is thereby advantageously reduced.

By casting such a winding module with a suitable insulating material, for example based on an epoxy resin, also the susceptibility of the winding module is reduced, since it is better protected in this case from mechanical influences. In addition, the use of an insulating material allows a reduction in the required isolation distance between adjacent arranged winding modules.

In a variant of the ring core according to the invention, a core section module is non-positively and / or positively connected to the respective associated winding module, so that this results in a transformer module.

The joint disassembly and subsequent assembly of a corresponding replacement transformer module, ie a replacement core section module with a replacement winding module, thereby further simplified.

According to a preferred embodiment of the ring core with associated winding modules, the winding modules can be electrically coupled to one another. It is also envisaged that common electrical connections are led out for groups of electrically coupled winding modules.

By a suitable such electrical coupling, for example by a series and / or parallel connection of windings of several winding modules, the functionality of a 1-phase power transformer can be achieved, which can be coupled to the common terminals with an electrical power supply network.

The object of the invention is also achieved by an arrangement of toroidal cores with winding modules according to one of claims 3 to 7, wherein the respective toroidal cores with winding modules can be arranged in a common connection structure and can be introduced separately therefrom and non-destructively.

As a connection structure, a device is to be considered by means of which at least two ring cores with winding modules or two complete toroidal transformers are mechanically connected to each other. In addition, such a connection structure may also include electrical conductors and parts of electrical coupling devices, such as plugs, sockets or terminals, using one or more of the windings or winding modules Toroidal transformers are connectable. The electrical connections of a winding or of a winding module expediently have a corresponding counterpart of the coupling device.

Power distribution networks are usually constructed in 3-phase. The functionality of a previously described arrangement of inventive ring core with associated and suitably electrically interconnected windings corresponds to the functionality of a 1-phase power transformer. To achieve the functionality of a 3-phase power transformer, an arrangement and the electrical connection of three single-phase transformers are suitable, which also represents a preferred embodiment of the arrangement according to the invention.

According to the invention, a likewise modular arrangement of three already inventively modular ring cores with connected winding modules in a common connection structure (s.o.) Is provided. The effort to exchange a single defective winding module of such a connected arrangement of multiple 1-phase transformers is further simplified.

In a particularly preferred embodiment of the arrangement according to the invention, the connection structure has devices for the electrical coupling of individual winding modules and / or common electrical connections of the winding modules. Such an electrical connection can be realized for example via a plug connection. The connection of such an arrangement to a power supply network is thereby simplified.

According to further embodiments of the arrangement according to the invention, at least two toroidal cores with winding modules are arranged axially along a common central axis or also on a common plane transversely to the respective central axis. The construction of the common connection structure is thereby simplified and the space required is reduced.

In further preferred variants of a ring core according to the invention or arrangements according to the invention of such ring cores, this ring core has 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 core section modules.

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

ein erstes Kernabschnittsmodul mit zugeordnetem Wicklungsmodul,

Fig. 2

einen Ringkern mit Wicklungsmodulen sowie

Fig. 3

eine Anordnung von Ringkernen mit Wicklungsmodulen

Show it:

Fig. 1

a first core section module with associated winding module,

Fig. 2

a toroidal core with winding modules as well

Fig. 3

an arrangement of toroidal cores with winding modules

Fig. 1 shows a first transformer module 10 having a first core section module 11 with associated winding module, wherein the winding modules having a first 14 and a second 16 electrical winding, which are wound around a winding axis. Core section module and winding module are mechanically connected to a transformer module, so that it can be raised or moved as a component.

Several preferably identical transformer modules 10 are the starting point for a modular transformer core. The structural identity is essential for the interchangeability of the respective transformer modules with each other. For geometrical reasons, depending on given boundary conditions such as transformation ratio of the transformer, voltage level, etc., in particular a number of 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 core section modules per ring core are suitable. According to the invention, at least 3 core section modules are required, a higher number than 12 is increasingly unfavorable from a constructive point of view, since the respective winding modules turn out to be correspondingly narrower and thus lead to more outlay in production. In addition, the manufacturing effort also increases with an excessive number of Kernabschnitts- or winding modules.

Fig. 2 shows a hexagonal ring core with six transformer modules 10, 20, 30, 40, 50, 60, which are arranged in a circular orbit about a central axis 70. This in Fig. 1 shown transformer module 10 and the five identical other transformer modules 20, 30, 40, 50, 60 are an integral part of the illustrated ring core with winding modules.

Each core section module 11 is connected by a suitable connection, for example, a mutual interlocking respectively adjacent core packages forming the core section modules, with further core section modules adjacent to each other. Such a toothing improves the guiding of the magnetic flux along the extension of the toroidal core, in particular in the connecting regions. In addition, further connection mechanisms are provided, which increase the mechanical strength of the connection of adjacent core section modules, for example a screw connection through the toothing region of adjacent core section modules.

The gaps between the respective core section modules shown in the figure are merely intended to graphically show the boundary area between adjacent core section modules. In a real arrangement, such a gap is not provided, moreover, the sheets, which form the ring core in its main thing, interlocked in the border areas.

Fig. 3 shows an arrangement 100 of three ring cores or toroidal transformers in a side view. Each toroidal transformer has six transformer modules in this example, of which only three are visible in this lateral perspective. Each of the illustrated transformer modules 101, 102, 103, 111, 112, 113, 121, 122, 123 each has an identical core section module and a winding module, similar to that in FIG Fig. 1 shown transformer module.

The transformer modules 101, 102, 103 are in this illustration the visible part of a first toroidal transformer, which is formed in the main of these three transformer modules and three further located in the rear area imaginary transformer modules. Analogously, the transformer modules 111, 112, 103 in this illustration are the visible part of a second toroidal transformer and the transformer modules 121, 122, 123 in this illustration the visible part of a third toroidal transformer.

All three toroidal transformers are arranged vertically above one another along a common central axis, not shown.

Between the toroidal transformers insulation blocks 130 are arranged, which remove the load of each located above toroidal transformers down. These preferably have an electrical insulation capability and also have vibration-damping properties. The insulation blocks 130 are here to be regarded as part of a common connection structure of the three toroidal transformers. In this way, moreover, the operating noise of such an arrangement can be reduced.

In the case of the replacement of a defective transformer module, for example the transformer module 112, the third toroidal transformer could be slightly raised with a first mobile lifting device and the second toroidal transformer could be removed from the connecting structure with a second mobile lifting device. Here are the electrical connections of the second toroidal transformer, which are preferably designed as easily detachable connections such as a connector to solve. Also to be solved are the electrical connections of the transformer module 112 to be exchanged with the other transformer modules of the same toroidal transformer.

Now, the respective transformer module 112 is to be removed from the toroidal core, wherein the toroidal core must be located during this process in a safe parking position, so that it is the mechanically separated part of the toroidal core 111, 113 is not damaged.

Subsequently, a replacement transformer module of identical design is to be inserted into the separated ring core and to produce the electrical connections of the replacement transformer module with the other modules of the second ring core. Thereafter, the second toroidal transformer is to be returned to the original position within the connection structure, the electrical connections to the first and the third toroidal transformer and the third toroidal transformer with the first mobile lifting device on the insulation blocks 130 set down.

A further embodiment according to the invention - not shown in a figure - of a connection structure for a plurality of modular toroidal transformers consists of a shelf-like storage device with several superimposed planes, wherein in each plane a toroidal transformer can be positioned and electrically and mechanically connected to this. A lifting operation of over that toroidal transformer with a transformer module to be replaced further toroidal transformers is eliminated. In further embodiments of a connection structure according to the invention, the levels of the shelf-like storage device, on which a toroidal core is to be positioned, with the aid of telescopic rails from the storage device movable. The removal process of a toroidal transformer is thereby further simplified.

LIST OF REFERENCE NUMBERS

10

First transformer module with core section module and winding module

11

Core section module

14

First electrical winding

16

Second electrical winding

18

Toroidal core with winding modules

20

Second transformer module

30

Third transformer module

40

Fourth transformer module

50

Fifth transformer module

60

Sixth transformer module

70

central axis

100

Arrangement of transformer modules

101

Tenth transformer module

102

Eleventh transformer module

103

Twelfth transformer module

111

Thirteenth Transformer Module

112

Fourteenth transformer module

113

Fifteenth transformer module

121

Sixteenth transformer module

122

Seventeenth transformer module

123

Eighteenth transformer module

130

isolation block

Claims (14)

1. Ring-shaped core for a power transformer (18), Ring-shaped core extending in the form of a closed toroidal structure around an imaginary mid-axis (70), said power transformer being formed from a large number of mutually adjoining layers of laminate, characterized in that the ring-shaped core is formed along the toroidal structure by at least three core section modules (11) which are connected releasably to one another, and in that the connection of the core section modules is provided by means of meshing of individual laminate layers and/or laminate layer regions.
2. Ring-shaped core according to Claim 1, characterized in that at least sections of said ring-shaped core have a core cross section which is close to an ellipse or circle.
3. Ring-shaped core according to either of Claims 1 and 2, characterized in that a winding module with in each case at least one electrical winding (14, 16) is associated with each core section module (11).
4. Ring-shaped core according to Claim 3, characterized in that at least two DC-isolated electrical windings (14, 16) are arranged in a winding module.
5. Ring-shaped core according to either of Claims 3 and 4, characterized in that a core section module (11) is connected in a force-fitting and/or form-fitting manner to the respectively associated winding module, and a transformer module is formed therefrom.
6. Ring-shaped core according to one of Claims 3 to 5, characterized in that the winding modules can be coupled to one another electrically.
7. Ring-shaped core according to Claim 6, characterized in that electrical terminals which are common to all of the winding modules are passed out.
8. Arrangement of ring-shaped cores with winding modules (100) according to one of Claims 3 to 7, characterized in that said ring-shaped cores can be arranged in a common connecting structure, and in that each ring-shaped core arranged therein with winding modules (101-103, 111-113, 121-123) can be introduced separately into the connecting structure and can be removed therefrom without being destroyed.
9. Arrangement according to Claim 8, characterized in that the connecting structure has apparatuses for electrically coupling individual winding modules and/or common electrical terminals of the winding modules.
10. Arrangement according to either of Claims 8 and 9, characterized in that the ring-shaped cores with winding modules (101-103, 111-113, 121-123) are interconnected using the connecting structure to form an electrical function group, which has the functionality of a three-phase power transformer.
11. Arrangement according to one of Claims 8 to 10, characterized in that at least two ring-shaped cores with winding modules (101-103, 111-113, 121-123) are arranged axially along a common mid-axis (70).
12. Arrangement according to one of Claims 8 to 10, characterized in that at least two ring-shaped cores with winding modules (101-103, 111-113, 121-123) are arranged on a common plane transversely with respect to the respective mid-axis.
13. Arrangement according to one of Claims 8 to 12, characterized in that electrical terminals which are common to at least two ring-shaped cores with winding modules are passed out at the connecting structure.
14. Arrangement according to one of the preceding claims, characterized in that the number of core section modules per ring-shaped core is 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12.

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