EP2330603A1 - Transformer with tape coil - Google Patents

Abstract

The transformer has a spool (10) with a winding made of strip material (14), and a primary voltage winding part radially attached to a secondary voltage winding part, where the winding parts have electric terminals. The terminals have pipe-like formed shaft areas (26) arranged inwards and outwards parallel to a winding axis such that channels (24) are formed in the shaft areas, and cooling fluid flows through the channels. A winding strip (18) is formed in the shaft areas similar to a sine wave, where amplitude and wavelength of the sine wave corresponds to dimensions of the transformer.

Description

description

The invention relates to a transformer, for example a dry-type transformer, having at least one coil which has a strip winding formed from strip material, which coil is formed in each case of an undervoltage and a radially adjoining high-voltage winding, each having an inner and an outer electrical connection is provided alternately inwardly and outwardly parallel to the winding axis with tube-like shaped corrugations in which the winding band is corrugated, so that channels are formed in the thus provided corrugations, through which cooling fluid can be flowed.

In particular, the invention relates to the cooling of windings in transformers, especially in dry-type transformers.

From the DE 10 2008 031 746 is a winding for a transformer, in particular a strip conductor formed tape winding for a cast resin transformer has been known, which is provided with at least one provided for guiding a cooling fluid axially extending cavity which is bounded radially inwardly and outwardly by winding layers of the winding conductor, wherein a plurality of eccentrically arranged, axially extending cavities is provided, which serve as cooling channels, and the cavities are arranged along a winding layer and the cavities are formed by Wellformgebung the winding conductor in this winding layer.

From the DE 10 2008 033 125 a transformer is known with a wound with conductor material coil, are introduced in the cooling channels through which a cooling fluid flows, wherein corrugated components are formed in the coil to form the cooling channels, the waveform of the outer surface, in particular to the outer contour in corner regions of the coil is adapted, these components may also be formed by suitable conductor material.

However, the variants described are only given for cooling channels and explained accordingly with regard to their cooling effect. In addition, the measures described in the prior art have no effect on the outer surface of the winding.

Based on this prior art, it is an object of the invention to provide a transformer of the type mentioned, which is improved in terms of cooling its winding to simple and with little effort.

This object is achieved by the features of claim 1. Accordingly, it is provided that both the low voltage and the high voltage winding are each made smooth-band, that at least in the region of the main scattering channel between the upper and lower voltage winding, a first well region is provided and that a second wave region is provided, which is formed by an attached to the last winding layer of the outer winding further layer corrugated winding tape. Here and in the following, smooth band is understood to mean a band conductor which is undecorated and runs flat in the development.

By these features provided by the invention is achieved in the course of manufacturing a transformer without significant overhead, at the same time with the winding structure and required for cooling the transformer winding cooling channels to include in a simple manner and to integrate into the winding structure.

As a result, according to the relevant transformer or according to its operational heat generation provided in a simple manner for cooling by cooling fluid can flow through the inventively provided cooling channels.

According to an advantageous embodiment of the transformer according to the invention, the mentioned further winding layer, which is provided from corrugated winding tape, integrally attached to the largely smooth-band winding tape, for example by means of welding.

As a possible welding process in this case offer laser welding, gas-shielded welding, spot welding or electric arc welding, the selection of the used joining method depends essentially on the respective manufacturing capabilities and the material of the material, since for example in electrically good conductive conductor material required for electrical resistance welding specific electrical Resistance may be too low or requires significant currents.

According to a preferred embodiment of the transformer according to the invention it is provided that the mentioned further winding layer of corrugated winding tape is attached to the outer electrical connection, which is provided in principle in band-shaped winding conductors.

According to an advantageous embodiment of the transformer according to the invention may further be provided that the attached further winding layer of corrugated winding tape in the region is made smooth-band in the region to an adjacent winding so as to compensate for the increased by the Wellverformung the winding tape space requirements, that is, the distance each Coil to the adjacent winding coils despite increased Diameter of the coil winding coil according to the invention and thus to comply with the usual dimensions of three-phase transformers.

An expedient development of the transformer according to the invention provides that the winding band in the first and / or in the second well region, that is formed on the one hand in the region between the upper voltage and lower voltage windings as well as on the other side on the outside similar sine waves, the amplitude and the Wavelength of this sine wave-like tape winding is adjusted according to the intended dimensions or the required cooling capacity of the relevant transformer.

In an advantageous embodiment of the transformer according to the invention, the radially inner winding is integrally connected upon reaching the intended number of turns with the inner electrical connection, wherein a further winding layer corrugated winding tape is attached to the inner terminal, so in the area between the lower and upper voltage winding, the cooling channels according to the invention to build.

According to a further preferred embodiment, however, it can also be provided that the radially inner winding is extended by a further winding layer corrugated winding tape upon reaching the number of turns provided for the transformer in question, being attached to the one end of this turn of corrugated winding tape to the inner Ausleitungsschiene , preferably by welding.

Alternatively, however, it may also be provided instead that the first winding layer of the outer winding, which adjoins the inner winding radially, is corrugated, that is to say that the first winding of the outer winding comprising the inner winding is formed from a sine wave-like shaped winding strip.

In a further improvement and embodiment of the transformer according to the invention, it is provided that the end of each corrugated winding layer is electrically insulated from the winding.

According to a further advantageous variant of the transformer according to the invention but can also be provided that it is formed with a coil consisting of a strip material consisting of strip material and a wire coil consisting of wire, that is, that only one of the two windings of each coil as a tape winding is executed, while the respective other radially adjacent winding is designed as a wire winding.

The further embodiment of this variant corresponds to the transformer already described above, each having an undervoltage and a radially subsequent high-voltage winding with electrical connections. Between the inner and the radially outer adjoining winding at least partially a region with alternately inwardly and outwardly parallel to the winding axis is provided with tube-like shaped corrugations, so that channels are formed in the thus provided corrugations, through which cooling fluid can be flowed.

In detail, the variant given above differs from the transformer described in the introduction in that, in the case of internal wire winding, the tube-like-shaped corrugated regions between the two windings are formed by the band winding adjoining radially on the outside.

In a variant with an external wire winding, the tube-like shaped regions are accordingly formed by the inner band winding on its outer side.

Finally, a variant with external wire winding may be provided, in which the tube-like shaped areas are formed by the inside adjacent tape winding. In this case, however, another layer of wave-shaped tape is added to the outside of the wire winding, wherein this attached tape has no electrically conductive connection to the winding.

In particular, in order to ensure the cooling of the outer surface of the transformer according to the invention, on the outside of the outer winding also a sine wave-like shaped winding layer may be provided, which adjoins the end of the smooth-band tape winding.

According to the main purpose of the transformer according to the invention, namely the improvement of the cooling and thus the removal of the heat loss is provided according to a preferred development that at least partially the corrugated winding layers are provided with recesses in the waves. It proves to be particularly advantageous that at least partially recesses are formed in the corrugated surfaces of the winding layers.

A further advantageous embodiment of the transformer according to the invention provides that the outer surface of the outer corrugated winding layer is executed in a darker color and thus radiates the heat of dissipation reaching the surface.

These and other advantageous features and advantages and improvements are the subject of further claims.

Reference to an embodiment schematically shown in the accompanying drawings, the invention, particular advantageous refinements and improvements of the invention and particular advantages of the invention will be explained and described in detail.

Fig. 1

eine schematische Darstellung eines Querschnittes durch eine Ausgestaltung der erfindungsgemäßen Bandwicklung;

Fig. 2

eine schematische Darstellung eines Querschnittes durch eine alternative Ausgestaltung der erfindungsgemäßen Bandwicklung;

Fig. 3

eine schematische Darstellung einer ausschnittweisen Draufsicht auf Ausnehmungen im Wellenbereich einer Ausgestaltung der erfindungsgemäßen Bandwicklung.

Show it:

Fig. 1

a schematic representation of a cross section through an embodiment of the tape winding according to the invention;

Fig. 2

a schematic representation of a cross section through an alternative embodiment of the tape winding according to the invention;

Fig. 3

a schematic representation of a fragmentary plan view of recesses in the shaft region of an embodiment of the tape winding according to the invention.

In Fig. 1 is a schematic representation of a circular cross-section through a first embodiment of the tape winding 10 of the invention for a transformer not shown in detail. The tape winding exists here from a number of first turns 12 of smooth conductor strip 14 and an additional turn 16 of wavy conductor strip 18th

The waveform of the corrugated conductor strip is formed according to the invention similar sine waves, with their amplitude and respective wavelength are tuned to the thermal requirements of the relevant transformer and its size and power.

Of the first turns 12 is in Fig. 1 symbolically but only one turn shown, said single turn shown 12 is connected at its inner end with an inner terminal rail or outlet 20 and is connected at its outer end to an outer terminal rail or outlet 22.

The mentioned additional turn 16 of corrugated conductor strip 18 in turn connects to the outer connecting rail or outlet 22 and ends after a complete circulation, so that the cylindrical belt winding 10 thus formed is surrounded on its outside by a coaxially arranged tube-like channels 24 through which Cooling fluid can flow.

As cooling fluid is mainly a cooling gas, for example, air, provided. Instead, as a cooling fluid but also another gas or a liquid may be provided, wherein in the case of the use of a cooling liquid further, familiar to the expert insulation and sealing measures are provided.

In Fig. 2 is a schematic representation of a circular cross-section through a second, reproduced to the first alternative embodiment of the tape winding 10 according to the invention. The tape winding here also consists of a number of first turns 12 of smooth conductor strip 14 and an additional turn 17 of at least partially wavy conductor strip 19th

Again, the waveform of the corrugated conductor strip according to the invention is similarly formed sine waves, their amplitude and respective wavelength are also matched to the thermal requirements of the relevant transformer and its size and performance.

Of the first turns 12 is in Fig. 1 symbolically shown here only one turn, this single turn shown 12 is connected at its inner end with an inner terminal rail or outlet 20 and is connected at its outer end to an outer terminal rail or outlet 22.

The mentioned additional turn 17 of at least partially corrugated conductor strip 19 in turn connects to the outer connecting rail or outlet 22 and also ends after a complete circulation.

However, this additional turn 17 is not waved over its entire circumferential length, so that the cylindrical band winding 10 thus formed is not completely surrounded on its outside by a coaxially arranged tube-like channels 24, through which cooling fluid can flow, but it is in the area , which is adjacent to a three-phase transformer another coil, smooth running so as not to exceed the construction dimensions of the transformer by maintaining the usual coil spacings as possible.

The limited due to the adjacent adjacent coil in this area cooling channels 24 possibility of heat dissipation is offset, for example, by appropriate design of the cooling measures on the rest of the circumference.

As cooling fluid, a cooling gas, for example air, is also provided here. Instead, as a cooling fluid, but also another gas or a liquid, because of their higher heat capacity than gas, be provided, in the case of using a coolant further, the skilled person generally familiar measures for electrical insulation and to provide sealing.

In Fig. 3 is a detail of a plan view of a corrugated surface 26 of a wavy strip conductor 16 and a partially corrugated strip conductor 17 reproduced, in which plan view recesses 28 are visible in the corrugated surface, which are preferably provided as punched 28. However, these recesses 28 can also be introduced, for example, by means of laser cutting in the corrugated surfaces 26.

The recesses 28 in the corrugated surface 26 serve to increase the residence time of the cooling medium, in particular cooling air, in the region of the cooling channels 24. The recesses 28 may be formed as cooling slots or in other geometry, through which the cooling fluid can enter and exit again. 30 with the inlet openings for the cooling fluid and 32 are the outlet openings for the cooling fluid, wherein the flow arrows shown indicate the flow direction.

The idea underlying the invention provides for improved cooling on the outer surface of an external tape winding 10 by the winding 10 is continued after welding to the winding 10 normally final Ausleitungsschiene 22 with a corrugated turn 18 around the winding 10. Thus, by the continuation of the winding 10, a good heat transfer from the winding 10 to the corrugated part 18 is achieved by heat conduction.

In order to avoid an enlargement of the core area by enlarging the coil 10, it may be useful to reduce the waviness of the corrugated conductor strip 19 in the area to adjacent coils or to omit altogether, as in Fig. 2 shown.

In Fig. 2 As an example, an outer coil of a three-phase transformer is shown, in which the corrugated strip conductor 19, which is corrugated to itself, has a smooth-banding to the adjacent coil.

Similarly, this cooling principle can also be applied to the main scattering channel, that is the main isolation region, between two band windings 10, each with a corrugated turn, especially when both windings are low-voltage windings. In the in Fig. 1 and Fig. 2 As shown, the main baffle channel is not shown, only external cooling.

For this purpose, either the conductor material of the inner winding is not cut off at the end of the winding before welding the second electrical connection, but continued for another turn in wavy form. The connection with the winding has the advantage of good heat conduction in the corrugated part. Alternatively, the corrugated component can also be produced by a turn of the second winding at the beginning before attachment of the first electrical connection.

In both cases, the end of the continued winding must be electrically isolated from the actual winding in order to avoid a short circuit winding.

In order to improve the cooling effect, it may also be provided to provide cut-outs in the corrugated surface, as in Fig. 3 shown in sections.

In addition, it is beneficial for improved radiation exchange to coat the outer surface dark, that is to perform dark colored.

LIST OF REFERENCE NUMBERS

10

Tape winding, winding, coil

12

first turn, winding position

14

Head band

16

additional winding, additional winding layer

17

additional winding, additional winding layer

18

wavy ladder tape

19

partially wavy ladder tape

20

inner connecting bar or outlet

22

outer connection bar or outlet

24

cooling channel

26

corrugated surface, corrugated area

28

Recess, punching

30

Inlets for the cooling fluid (flow arrows)

32

Outlets for the cooling fluid (flow arrows)

Claims (17)

Transformer, for example a dry-type transformer, having at least one coil (10) which has a band winding (10) formed from band material (14), which coil (10) consists in each case of an undervoltage and a radially adjoining high-voltage winding with electrical connections, at least In regions, alternately inwardly and outwardly parallel to the winding axis with tube-like shaped corrugated areas (26) is provided, so that in the thus provided corrugated areas (26) channels (24) are formed, through which cooling fluid can be flowed. Transformer according to claim 1, characterized in that both the low-voltage and the high-voltage winding are each made smooth-band, that at least in the region of the main scattering channel between the upper and lower voltage winding, a first wave region (26) is provided and that a second wave region (26) provided is, which is formed by a further layer attached to the last winding layer of the outer winding corrugated winding strip (18). Transformer according to claim 1, characterized in that the further winding layer (16, 17) of corrugated winding strip (18) to the smooth-band winding strip (14) integrally, for example by means of welding, is added. Transformer according to claim 1 or 2, characterized in that the further winding layer (16, 17) of corrugated winding strip (18) is attached to the outer electrical connection (22). Transformer according to one of the preceding claims, characterized in that the attached further turn (17) made of corrugated winding strip (19) in the area to an adjacently arranged winding (10) is made smooth-band. Transformer according to one of the preceding claims, characterized in that the winding band in the first and / or in the second wave region is shaped similar sine waves, wherein the amplitude and wavelength is adapted according to the intended dimensions of the transformer. Transformer according to one of the preceding claims, characterized in that the radially inner winding is extended upon reaching the intended number of turns to a further winding layer corrugated winding strip and that electrically connected to the end of this turn of corrugated winding strip of the inner electrical connection. Transformer according to one of claims 1 to 5, characterized in that the radially inner winding is connected upon reaching the intended number of turns with the inner electrical connection and that a further winding layer corrugated winding strip is added to the terminal. Transformer according to one of claims 1 to 5, characterized in that the first winding layer of the radially adjoining the inner winding outer winding is performed wavy. Transformer according to one of the preceding claims, characterized in that the end of each corrugated winding layer is electrically insulated from the winding. Transformer according to one of the preceding claims, characterized in that at least partially the corrugated winding layers are provided with recesses in the waves. Transformer according to one of the preceding claims, characterized in that the corrugated surfaces of the winding layers are at least partially provided with recesses. Transformer according to one of the preceding claims, characterized in that the outer surface of the outer corrugated winding layer is designed in dark colors. Transformer according to Claim 1, having a coil formed from a strip winding (10) consisting of strip material (14) and a wire winding consisting of wire, which coil (10) has in each case an undervoltage and a radially adjoining high-voltage winding with electrical connections, and which is at least partially alternately inwardly and outwardly parallel to the winding axis with tube-like shaped corrugated areas (26), so that in the thus provided corrugated areas (26) channels (24) are formed, through which cooling fluid can be flowed. Transformer according to claim 14, characterized in that, in the case of internal wire winding, the tube-like shaped wave regions between both windings are formed by the band winding which adjoins radially outside. Transformer according to claim 14, characterized in that in the case of external wire winding, the tube-like shaped regions are formed by the inner band winding on the outside thereof. Transformer according to claim 14, characterized in that in the inner band winding, the tube-like shaped portions between the two windings are formed by the inner band winding, wherein on the outside of the wire winding, a further layer of wavy executed band is added, which no electrically conductive connection to the winding Has.

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