EP1959459B1 - Method for manufacturing a toroidal core - Google Patents

Description

The invention relates to a method for producing a multi-stage closed ring core, in particular for a distribution transformer, wherein a thin magnetically conductive material is wound into a multi-stage closed toroidal transformer core, wherein between the magnetically conductive material is an adhesive which mutually isolates the material and the toroidal core solidified.

From the WO 95/12887 A For example, a method and apparatus for winding a closed ring core for high power transformers and chokes is known, in which a winding apparatus is used to wind a closed ring core for high power transformers and chokes with electrical conductors, the winding apparatus for this purpose being a toroidal core to be wound -Shaft encompassing guide and several along this guide through the toroidal core transportable, unrolled winding rollers and has on these bobbins the preferably band-shaped winding material, ie conductor or intermediate insulation, which is wrapped in the circulation of the winding roll of this on the toroidal core is.

From the DE 10 16 377 B is a ferromagnetic sheets with magnetic preferred direction spirally wound, circular band ring core with stepped cross-section and distributed over the entire circumference of the ring applied winding for magnetic amplifiers, inductors or the like known, wherein the core cross-section in a plane containing the ring axis no axis of symmetry parallel to the ring axis has and the center of the ring facing part of this core cross-section has a larger (finite) Umkreishalbmesser than the ring center remote from the part.

From the US-A-3 465 273 For example, there is known a high performance inductor having a magnetic core of generally annular shape subdivided into a plurality of arcuate segments, wherein dielectric spacing means are disposed between adjacent core segments through which the core segments are spaced with relatively narrow gaps, one not magnetic tape means is provided along the periphery of the magnetic core to hold the core segments and spacer means in assembled position.

The invention has for its object to build a multi-stage closed ring core high strength, especially for a distribution transformer, which is electrically insulated to the outside, and to realize a rational production process.

The high strength of the ring cores, with a weight of 100 kg to over 2000 kg, is necessary so that the thin transformer sheets remain dimensionally stable, on the one hand during further processing, and later in continuous operation. The electrical insulation is required so that the transformer winding has a sufficient dielectric strength with respect to the core.

It is a further object to provide a closed multi-stage toroidal transformer transformer high strength, which after Electrically isolated on the outside, and to provide a rational, machine manufacturing process, so that the production of toroidal distribution transformers is made possible.

The solution according to the invention of the stated object is to provide, for each width of the magnetically conductive material, at least one supply roll device, a drive and brake device, a guide device, a cutting device and an adhesive spraying device, for each width of the magnetic material, a take-up device to use with a drive and brake device, as well as a common guide rail.

In other words, a solution of this invention is that a thin magnetically conductive material is wound into a multi-level closed toroidal transformer core, between the magnetically conductive material is an adhesive which mutually isolated (to avoid eddy currents) the material and solidifies the toroidal core and the electrical insulation is obtained with respect to the low-voltage winding with spacers or spacers made of electrically non-conductive material.

To increase the strength and electrical insulation to the outside, the toroidal transformer core can be completely cast with an electrically non-conductive casting resin high strength.

A further embodiment provides that the electrical insulation (core for undervoltage winding) is realized by at least three spacer rings or in each case three spacers per turn, which are fixedly mounted in the steps of the toroidal core. Subsequently, the toroidal core is coated with a varnish for insulation and protection against corrosion.

For the solution of the toroidal core winding method is a support frame for holding the devices, for each width of the magnetically conductive material at least one supply roll device, a drive and braking device, with a guide device, a cutting device and a Klebsprühervorrichtung, for each width of the magnetically conductive material at least one take-up device with a drive and brake device, as well as a common guide rail needed.

The winding process begins at a narrow, too wide and too narrow again. The winding height is monitored by a remote measuring device. When the setpoint value is reached, the winding process for the corresponding width is terminated, the magnetically conductive material is severed and supplied to the guide rail of the next width. During the winding process The magnetically conductive material is sprayed with adhesive. In this way, a closed stage ring core is formed, which has adhesive for insulating the magnetically conductive material and has sufficient strength for further processing. For each width of the magnetically conductive material, with the exception of the widest material, there must be two supply rolls, including all devices, and two take-up devices, including all devices, corresponding to the number of stages of the toroidal core. In the steady state, all stock roll units and all take-up units are in operation simultaneously.

The advantage of the toroidal core technology is that it allows toroidal distribution transformers to be realized in the highest power range, which are extremely low-loss and only about 50% of the operating costs of conventional distribution transformers in casting resin technology. As a result, the toroidal distribution transformer refinances in a few years and, in addition, a significant amount of primary energy, for the conservation of resources and the environment, can be saved.

With the toroidal core winding apparatus described above, rational production of toroidal transformers is achieved by, for example, eleven stages, eleven toroidal transformer cores can be wound simultaneously.

The object is also achieved by a transformer, in particular a spiral undervoltage winding high cross-section and their manufacture, a multi-stage closed toroidal transformer high stability, of magnetically conductive and mutually insulated material, electrically insulated for undervoltage winding, and its manufacturing process, preferably a support frame with at least 3 supply roll devices, each with a braking device, with at least 2 different widths of magnetically conductive material, at least three adhesive spraying devices, and at least three winding devices with a drive system, at least three guide devices, a guide rail, and a cutting device is provided.

In a preferred embodiment, a transformer is provided, wherein each supply roll device, as well as each take-up device is equipped with a drive and brake device.

In a preferred embodiment, a transformer is provided, wherein for each width of the magnetically conductive material, with the exception of the widest material, two winding devices, each with a drive and braking device are provided.

In a preferred embodiment, a transformer is provided wherein the magnetic material has been pretreated with an insulating layer.

In a preferred embodiment, a transformer is provided wherein the closed toroidal transformer core is wound in multiple stages with a thin magnetically conductive material which is pre-treated with adhesive or sprayed with adhesive during the winding process.

In a preferred embodiment, a transformer is provided, wherein at least three spacer rings or three spacers per turn, are firmly mounted in the steps of the toroidal core.

In a preferred embodiment, a transformer is provided, the toroidal core being coated with a varnish for insulation and for protection against corrosion.

In a preferred embodiment, a transformer is provided wherein the toroidal transformer core is encased in a high strength cast resin.

In a preferred embodiment, a transformer is provided, wherein the magnetically conductive material has an amorphous structure.

Fig. 1

zeigt in schematischer Darstellung einen seitlichen Schnitt durch einen Mehrphasentransformator mit drei in axialer Richtung benachbart angeordneten Ringkernen.

Figur 2 und 3

zeigen einen fünfstufigen Ringkern gemäß eines Ausführungsbeispiels der vorliegenden Erfindung.

Fig. 4

zeigt eine Anordnung zur Durchführung eines erfindungsgemäßen Verfahrens.

The invention is explained in more detail with reference to figures.

Fig. 1

shows a schematic representation of a lateral section through a multi-phase transformer with three axially adjacent arranged ring cores.

FIGS. 2 and 3

show a five-stage toroid according to an embodiment of the present invention.

Fig. 4

shows an arrangement for carrying out a method according to the invention.

In FIG. 1 is a generally designated with 101 polyphase transformer having three stacked axially in the axial direction of ring cores 102. In each case adjacent ring cores 102 carry phase windings of different phases, wherein the phase windings are respectively applied to the ring cores 102 annularly enclosing coil bobbins 103. In this case, bobbin 103 may be alternately arranged with primary and secondary windings next to each other or one above the other. It is also possible for primary and secondary windings to be applied together to a bobbin 103.

The ring cores 102 are arranged in a holding device 104 which has outer and inner guide rails 105a, 105b for forming a receiving region for the toroidal cores 102. The guide rails 105a, 105b each exist of insulating material, so that the ring cores 102 and the phase windings on the bobbin 103 of the ring cores 102 are laterally outwardly insulated.

The holding device 104 has on its underside a bottom part 107, which likewise consists of insulating material. On the bottom part 107 insulating support elements 108 are provided for the lower ring core 102. In this case, a plurality of spaced bearing elements 108 may be provided, or it is a continuous ring as a support element 108 is provided. Spacers 109 are respectively provided between the individual ring cores 102 with which the ring cores 102 or the coil cores 103 respectively assigned to the toroidal cores 102 are fixed relative to one another in their position. Insulating support elements 108 are again provided above the upper ring core 102, on which a cover part 110 rests and the toroidal cores 102 are also insulated on the upper side towards the outside.

The Indian FIG. 1 shown polyphase transformer 101 is formed as a three-phase transformer. The connection points of the individual phase windings of the toroidal cores 102 or of the spool bodies 103, which are not illustrated in more detail, are each offset by 120 ° relative to one another. The phase windings are thereby mechanically offset from one another by an angle which corresponds to the electrical phase shift or the electrical phase angle between the voltage signals of these phase windings.

In particular, in the region of the spacers 109, that is, where adjacent ring cores have the smallest distance from each other, there is practically no potential difference at two opposite regions of two ring cores 102 or bobbin 103. Voltage flashovers between adjacent toroidal cores 102 are thus not possible even if the toroidal cores 102 are arranged close together. The polyphase transformer 101 can thereby be compact and with reduced space requirements are built. In addition, between the individual ring cores 102, in the region of the spacers 109, no or only little insulation measures are required, whereby costs are saved and the construction is simplified.

The ring cores 102 are formed with their respective bobbins 103 like a module. In the event of a defect in one of these modules, the affected toroidal core can be exchanged for a replacement module or the defective module is electrically disconnected and a replacement module is provisionally connected to the multiphase transformer 101. Thus, it is not necessary to keep ready a complete transformer as a backup device, but it is sufficient to keep ready a ring core with the coil windings supporting the phase windings as a reserve module. As a result, costs are saved and the space required for a reserve device is reduced.

FIGS. 2 and 3 show a closed ring core 301, which is designed with five stages 302, 303, 304, 305 and 306. The steps are preferred so that an approximately round cross-section is formed. The more steps, the higher the degree of filling with magnetically conductive material. The steps consist of thin sheets, which are preferably sprayed with adhesive, for insulation and strength. So that a circular cross-section is formed, an insulation towards the outside and the high strength, the toroidal core is encapsulated with a casting resin 307. Another advantage of this casting resin is that no sharp edges can damage the windings of the transformer.

Sheet width of supply roll 402:

B1 100 mm Sheet height 0.23 mm B2 100 mm + x (Magnetic steel sheet) B3 100 mm + x1 B4 100 mm + x B5 100 mm

The first sheet width of 100 mm is fed via the guide device 403 of the winding device 406 and fixed. The winding process begins and at the same time the sheet is sprayed with the adhesive device 404 with adhesive. By means of the drive and braking device, a uniform train is achieved on the sheet to be wound. By a measuring device, the wound sheet height is compared with the target value and stopped the winding when reaching the default. Subsequently, the sheet is cut and fixed by the cutting device 405.

On the guide rail 407, the take-up device 406 of the second sheet width (B2) is now fed. At the same time, the first sheet width is fed to a further take-up device. In the steady state, five toroidal transformer cores are wound simultaneously.

Claims (15)

1. Method for manufacturing a multi-stage closed toroidal core (301), particularly for a distribution transformer, in which a thin, magnetically conductive material (302, 303, 304, 305, 306) is wound to form a multi-stage closed toroidal transformer core (301), while between the magnetically conductive material (302, 303, 304, 305, 306) is provided an adhesive that insulates the material from itself and strengthens the toroidal core (301), characterised in that at least one supply roller device (402), a driving and braking device, a guide device (403), a cutting device (405) and an adhesive spray device (404) is used for each width (B1, B2, 83, B4, B5) of the magnetically conductive material (302, 303, 304, 305, 306), and a winding device (406) with a driving and braking device and a common guide rail (407) is used for each width of the magnetic material.
2. Method according to claim 1, characterised in that the winding process for each core (301) starts at narrow (B1) and goes to wide (B3) and then back to narrow (B5) again.
3. Method according to claim 1 or 2, characterised in that the winding height is monitored by a remote measuring device.
4. Method according to one of claims 1 to 3, characterised in that when the desired value is reached the winding process for the con-esponding width (B1, B2, B3, B4, B5) is ended, magnetically conductive material (302, 303, 304, 305, 306) is separated off and fixed and fed into the next width (B1, B2, B3, B4, B5) on the guide rail (407).
5. Method according to one of claims 1 to 4, characterised in that the magnetic material (302, 303, 304, 305, 306) is sprayed with adhesive during the winding process.
6. Method according to one of claims 1 to 5, characterised in that for each width (B1, B2, B3, B4, B5) of the magnetic material (302, 303, 304, 305, 306), with the exception of the widest material (B3, 304), two winding devices (406) are provided, each having a driving and braking device.
7. Method according to one of claims 1 to 6, characterised in that for each width (B1, B2, B3, B4, B5) of the magnetic material (302, 303, 304, 305, 306), with the exception of the widest material (304, B3), there are two supply rollers (402) including all the devices and two winding mechanisms (406) including all the devices according to the number of stages (302, 303, 304, 305, 306) in the toroidal core.
8. Method according to one of claims 1 to 7, characterised in that in the steady state all the supply roller units (402) and all the winding units (406) are in operation.
9. Method according to one of claims 1 to 8, characterised in that in the steady state five or more stages, particularly eleven stages, are wound simultaneously.
10. Method according to one of claims 1 to 9, characterised in that a uniform tension on the sheet metal that is to be wound is achieved by means of the driving and braking device.
11. Method according to one of claims 1 to 10, characterised in that the toroidal core (301) is coated with a lacquer to insulate it and protect it against corrosion.
12. Method according to one of claims 1 to 11, characterised in that the toroidal core (301) is encased in a high-strength casting resin (307).
13. Method according to one of claims 1 to 12, characterised in that the magnetically conductive material has an amorphous structure.
14. Method according to one of claims 1 to 93, characterised in that the toroidal core (301) has a circular cross-section and/or the toroidal core (301) is of circular configuration.
15. Method according to one of claims 1 to 14, characterised in that the electrical insulation of the toroidal core (301) from an under-voltage winding is achieved by means of spacer rings or spacer members of electrically non-conductive material.

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