WO2009138099A1

WO2009138099A1 - Coupling of transformer winding modules

Info

Publication number: WO2009138099A1
Application number: PCT/EP2008/003824
Authority: WO
Inventors: Charles W. Johnson; Jan Leander; Karel Bilek; Benjamin Weber
Original assignee: Abb Technology Ag
Priority date: 2008-05-13
Filing date: 2008-05-13
Publication date: 2009-11-19
Also published as: DE112008003836A5

Abstract

The invention relates to a coupling system (30) of a plurality of transformer winding modules (12, 31 - 39, 71 - 78), a transformer winding module (12, 31 - 39, 71 - 78) comprising at least one first (12) and one second ((14) galvanically separate partial winding. The respective partial windings (12, 14) are arranged about a common imaginary winding axis (22, 81, 89). The respective first partial windings (12) of the transformer winding modules (12, 31 - 39, 71 - 78) are interconnected in series and the respective second partial windings (18) are interconnected in parallel.

Description

Coupling of transformer winding modules

description

The invention relates to a coupling arrangement of a plurality of transformer winding modules, wherein a transformer winding module each comprises at least a first and a second galvanically separated part winding, which are arranged about a common winding axis.

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 38OkV.

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 shading of three 1-phase transformers in which the primary and secondary windings of each phase are each penetrated by 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 to arrange the 1-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 partially described in European Patent EP 0 557 549 B1. According to this prior art, an annular transformer core is mechanically connected thereto along the transformer core around this helical first electrical winding. Around this transformer core with winding, a plurality of high-voltage winding segments of a second winding are arranged.

A disadvantage of this arrangement is in particular that only the second winding is segmented, while the first, core near winding is continuously guided spirally around the transformer core.

Based on this prior art, it is an object of the invention to provide a coupling arrangement of a plurality of transformer winding modules of the type mentioned, which have at least two mutually galvanically isolated part windings.

This object is achieved by a coupling arrangement with the features specified in claim 1.

Accordingly, the coupling arrangement according to the invention is characterized in that the respective first partial windings of the transformer winding modules in electrical series connection and the respective second partial windings are connected in electrical parallel connection with each other. Due to the electrical series connection of the respective first partial windings, the voltage load of the respective first partial winding advantageously decreases with the number of interconnected transformer winding modules.

Thus, the series connection of the respective first partial windings leads to a reduced electrical insulation effort and is preferably suitable for high voltage levels.

In contrast, a reduction of the current load in each second partial winding is achieved in an advantageous manner by the parallel connection of the respective second partial windings.

In this case, thinner winding conductors can be used than in series connection of the respective second partial windings, which also simplifies their mechanical electrical connectability. Thus, the parallel connection of the respective second partial windings is preferably suitable for high currents with a reduced electro-mechanical connection complexity.

When using such a coupling arrangement as a power transformer in a power supply network therefore the upper-voltage side (for example 3OkV - 11OkV) requirements for the insulation is taken into account by the series connection of the first partial windings with low insulation costs. The parallel connection of the respective second partial windings, on the other hand, takes into account the requirements of the higher currents on the low-voltage side (for example 6kV-3OkV) with little electrical-mechanical connection expense.

According to a further embodiment of the coupling arrangement according to the invention, the electrical connection of the transformer winding modules takes place at least in sections using electrical conductors encased with at least one electrical insulation layer.

The thickness of the insulating layer is dimensioned such that the voltage stresses occurring during operation can be held by the insulating layer. The risk of a voltage flashover within the coupling arrangement is thereby significantly reduced.

According to a particularly preferred embodiment of the coupling arrangement according to the invention, an electrical conductor sheathed by at least one electrical insulation layer also has a grounded conductive shield enclosing the same, which radially outwardly adjoins the at least one electrical insulation layer.

The thus defined distribution of the electrical potential within the coupling arrangement, the risk of electrical flashover is further reduced, or the distances between individual components such as transformer winding modules can be reduced, resulting in an advantageous manner to a more compact design and associated material savings.

In a further embodiment of the coupling arrangement, the transformer winding modules are provided for an operating voltage of at least 6 kV. The voltage of at least 6kV refers to at least one of the two partial windings. From this voltage range, the isolation advantages of the coupling arrangement according to the invention come especially to bear.

In an extended embodiment of the coupling arrangement, the partial windings in the respective transformer winding modules are cast together, for example with an insulating material based on epoxy resin.

The mechanical stability of a transformer winding module is thereby increased while increasing the insulation strength. In addition, this also allows a more compact construction of the arrangement, because the distances between individual components can be further reduced.

In a particularly preferred embodiment of the coupling arrangement, the transformer winding modules are arranged along a circular path about a common center axis. In such an arrangement, identical transformer winding modules are preferably space-saving and can be connected to one another with short lengths of the connecting conductors.

In a further embodiment of the coupling arrangement, the transformer winding modules are penetrated by a common closed annular or polygonal transformer core, so that during operation of the coupling arrangement occurring magnetic flux is passed through the transformer core.

The penetration of the transformer core is effected by a cylinder-like clearance around an imaginary winding axis of the respective part windings, around which they are wound.

Preferably, here is the polygonal configuration of the transformer core, that is, it has in the areas which pass through the respective transformer winding modules, straight legs, the legs are connected at buckling or bending points angularly interconnected or merge into each other.

According to a further preferred embodiment of the coupling arrangement, a barrier with electrical insulation material is at least partially disposed between adjacent transformer winding modules arranged along a circular path, wherein such a barrier is preferably designed in the form of a plate which has an approximately identical insulation resistance between its two sides.

Thus, it is possible to reduce the spacings between transformer winding modules and the size of the transformer core.

According to a further variant of the coupling arrangement, the barrier contains a glass fiber composite material. This combines good electrical insulation properties with high mechanical stability.

In addition, according to a particularly advantageous embodiment of the coupling arrangement, the barriers in a particularly space-saving manner, starting from the Mit- telachse arranged in the radial direction between adjacent transformer winding modules.

Preferably, the number of transformer winding modules is 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12. The specified number range covers approximately a typical gear ratio of a power transformer. So it is for example particularly favorable to select a number of transformer modules of 11 in a power transformer with a rated voltage of the lower side 10kV and upper side 11OkV. In this way, it is possible that the conductor cross-section of the primary and secondary windings is approximately the same due to the electrical interconnection of the transformer winding modules according to the invention, which leads to manufacturing advantages.

For reasons of construction, a similar number of transformer winding modules can also be selected, which results in a more favorable angle for the production between the arranged around the central axis transformer winding modules result, for example, in this case 8, 9 or 12.

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.

Show it:

1 shows an exemplary transformer winding module, Fig. 2 shows an exemplary coupling arrangement and

3 shows an exemplary arrangement of transformer winding modules, barriers and an octagonal transformer core

1 shows a transformer winding module 10 having a first partial winding 12 arranged radially about a winding axis 22 and a second partial winding 18 arranged radially inward of the first partial winding 12. The first partial winding 12, wel che is provided according to the invention for the electrical series connection with further first part windings, is provided at its two conductor ends with two electrical connection options 16, preferably suitable for the connection of shielded cables. However, it is also within the scope of the invention if, within a transformer winding module 10, the first partial winding 12 is arranged radially inward and the second partial winding 14 is arranged radially outwardly about the winding axis 22.

The second partial winding 14 is also provided at its two conductor ends, each with two corresponding electrical connection options 16. The transformer winding module 10 is potted by means of a potting material 20, so that the first partial winding 12 and the second partial winding 14 each form a rigid unit, which is particularly easy to handle. Preferably, the casting material 20 to be used is a suitable, electrically insulating material, for example based on epoxy resin. Such encapsulation with a suitable insulation material also allows an even more compact arrangement of the transformer winding modules, because insulation distances are thereby further reduced.

2 shows an exemplary coupling arrangement 30 with a total of nine electrically connected transformer winding modules 31, 32, 33, 34, 35, 36, 37, 38, 39, which are arranged along a circular path about a central axis 56. The respective first partial windings are connected to one another in series by means of electrical conductors, of which the first conductor, to which the first partial winding of the first transformer winding module 31 is connected to the first partial winding of the second transformer winding module 32, is provided with the reference symbol 42 in the FIGURE , Accordingly, the eighth conductor, with which the first partial winding of the eighth transformer winding module 38 is connected to the first partial winding of the ninth transformer winding module 39, is provided with the reference numeral 42.

As electrical conductors are particularly suitable shielded cable with a corresponding insulating layer between the actual conductor and the preferably grounded shield, which sheathed the conductor. The connection of a cable with the corresponding connection options to the transformer winding modules 31 - 39 is preferably clamped, screwed and / or pluggable. The respective other terminals of the respective first partial windings of the first 31 and the ninth transformer winding module 39 are - preferably also by means of a shielded cable connection - each led to a hunt group 46, by means of which the series connection of all first partial windings can be connected for example to an electrical power supply network.

Similarly, the respective second partial windings of the transformer winding modules 31-39 are connected in parallel by means of eighteen electrical conductors, with the two conductors, which connect the second partial windings of the first 31 and second 32 transformer winding modules, being identified by reference numerals 50 and 52 by way of example. These conductors are preferably each designed as a cable with grounded shield.

By means of the hunt group 56, the parallel connection of the nine transformer winding modules 31 - 39 can be connected to an electrical power supply network. Another electrical connection of such a 1-phase coupling arrangement with two other similar coupling arrangements to a 3-phase coupling arrangement with the functionality of a 3-phase power transformer is well within the scope of this invention.

It can be clearly seen that the arrangement of the transformer winding modules 31-39 along a circular path minimizes the cable lengths required to connect the respective part-windings.

Fig. 60 again shows a coupling arrangement of eight transformer winding modules 71-78, which are arranged in a star shape along a circular path around a central axis. The electrical connection of the transformer winding modules 71-78 corresponding to that shown in FIG. 2 is not shown here. The geometric configuration of the cross section of the radially outer partial winding of the respective transformer winding modules is triangular, so that the inner region of the arrangement around the central axis is better utilized than in a corresponding rectangular cross-section of the respective radially outer partial windings. The first and second sub-windings of the respective transformer winding modules 71-78 are arranged radially about a respective winding axis, of which the winding axis of the eleventh transformer winding module 71 is denoted by 81 and the winding axis of the eighteenth transformer winding module 78 by 88 in the figure.

Also shown are eight barriers 61-68, which are also positioned in a star shape about the central axis of the coupling arrangement between adjacent transformer winding modules 71-78. These barriers 61-68 are preferably predominantly made of a plate-shaped insulating material which, for example, also comprises a glass fiber composite and an epoxy resin compound. By arranging such barriers, the separation distance between adjacent transformer winding modules can be reduced and the size of the coupling arrangement according to the invention can be further reduced.

Also shown in FIG. 10 is an octagonal transformer core 80 around which the transformer winding modules 71-78 are disposed. This transformer core 80 has eight straight legs, each of which passes through a transformer winding module 71 - 78 along their respective winding axis. The geometric transition between the respective legs is arcuate. A transformer core 80 executed in sections in straight legs has the advantage that a respective transformer winding module 71-80 can be arranged nearer to the core and no increase in spacing between the winding and core caused by bending radii is produced.

LIST OF REFERENCE NUMBERS

Exemplary transformer winding module First partial winding Second partial winding Terminals of the first partial winding Terminals of the second partial winding Potting material Winding axis Exemplary coupling arrangement First transformer winding module Second transformer winding module Third transformer winding module Fourth transformer winding module Fifth transformer winding module Sixth transformer winding module Seventh transformer winding module Ninth transformer winding module Connecting the first winding of the first transformer winding module First electrical conductor connecting first partial windings Eighth electrical conductor for connecting first partial windings Hunt group of all first partial windings Connection of the second partial winding of the third transformer winding module First electrical conductor for connecting second partial windings Second electrical conductor for connecting second partial windings Sa Central connection of all second partial windings Central axis Exemplary arrangement of transformer winding modules, barriers and an octagonal transformer core First barrier Second barrier Third barrier Fourth barrier Fifth barrier Sixth barrier Seventh barrier Eighth barrier Eleventh transformer winding module Twelfth transformer winding module Thirteenth transformer winding module Fourteenth transformer winding module Fifteenth transformer winding module Sixteenth transformer winding module Seventeenth transformer winding module Eighteenth transformer winding module Transformer core Winding axle Eleventh transformer winding module Winding axle Eighteenth transformer winding module

Claims

claims

1. coupling arrangement (30) of a plurality of transformer winding modules (12, 31-39, 71-78), wherein a transformer winding module (12, 31-39, 71-78) each at least a first (12) and a second (14) galvanically from each other comprises separate sub-winding, which are arranged about a common winding axis (22, 81, 89), characterized in that the respective first part windings (12) of the transformer winding modules (12, 31-39, 71-78) in electrical series connection and the respective second Partial windings (18) are connected in electrical parallel connection with each other.

2. Coupling arrangement according to claim 1, characterized in that the electrical connection of the transformer winding modules (12, 31 - 39, 71 - 78) is provided at least in sections using at least one electrical insulation layer sheathed electrical conductors (42, 44, 50, 52) ,

3. Coupling arrangement according to claim 2, characterized in that a sheathed by an electrical insulation layer electrical conductor (42, 44, 50, 52) is also provided with this enclosing grounded conductive shielding.

4. Coupling arrangement according to one of the preceding claims, characterized in that the transformer winding modules (12, 31 - 39, 71 - 78) are provided for an operating voltage of at least 6kV.

5. Coupling arrangement according to claim 4, characterized in that the partial windings (12, 14) in the respective transformer winding modules (12, 31 - 39, 71 - 78) shed together (20).

6. Coupling arrangement according to one of the preceding claims, characterized in that the transformer winding modules (12, 31 - 39, 71 - 78) are arranged along a circular path about a common center axis (56).

7. Coupling arrangement according to claim 6, characterized in that the transformer winding modules (12, 31 - 39, 71 - 78) are wound around a common, closed annular or polygonal transformer core (80).

8. Coupling arrangement according to one of claims 6 or 7, characterized in that between adjacent transformer winding modules (12, 31 - 39, 71 - 78) at least partially a J3arriere (61 - 68) is arranged with electrical insulation material.

9. coupling arrangement according to claim 8, characterized in that the barrier (61 - 68) is formed predominantly plate-shaped.

10. Coupling arrangement according to one of claims 8 or 9, characterized in that the barrier (61 - 68) contains a glass fiber composite material.

11. Coupling arrangement according to one of claims 8 to 10, characterized in that the barrier (61 - 68), starting from the central axis (56) in the radial direction between adjacent transformer winding modules (12, 31 - 39, 71 - 78) is arranged.

12. Coupling arrangement according to a preceding claims, characterized in that the number of transformer winding modules 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 amounts.