WO2018033336A1 - Multi-storey transformer for a distribution network or operation with a converter - Google Patents

Abstract

The invention relates to a transformer (1) for a distribution network or for operation with a converter having: a core with a plurality of core sections (10); an undervoltage winding, which surrounds a core section (10) and has a plurality of undervoltage part-windings (9, 15), which are arranged one above the other and are each embedded in a cured insulation material; an overvoltage winding, which has a plurality of overvoltage part-windings (6, 7), which are arranged one above the other and are each embedded in a cured insulation material; and lower pressure plates (3, 4) for compressing the core sections (10), a bottom overvoltage part-winding being supported on the lower pressure plates (3, 4). According to the invention, to reduce the production costs of the transformer, all the overvoltage part-windings (4, 5) rest directly on one another and are connected to one another, wherein the overvoltage winding is not fixed by external compression.

Description

 description

Multi-level transformer for a distribution network or operation with one inverter

The invention relates to a transformer for a distribution network or for the power supply of a power converter having a core having several core sections, a core section enclosing undervoltage winding having a plurality of stacked and embedded each in a cured insulating lower voltage sub-windings, a high-voltage winding having a plurality of superposed and each having embedded in a cured insulating Oberspannungsteilwicklungen and lower press plates for pressing the core sections, wherein a lowermost Oberspannungssteilwicklung is supported on the lower press plates.

Such a transformer, which is also referred to as Mehrstocktransforma- tor is known in the art to those skilled in the art. Previously known multi-level transformers are designed as so-called dry transformers. The windings of the transformer are therefore not in a liquid Iso ^¬ liermedium, such as a mineral oil, arranged, but wound in a cast resin transformer usually with curable insulating or cast in a casting resin. Each partial winding thus provides an indi vidual ^¬ block defining a circular cylindrical inner contour generally. The bottom and Oberspannungsteilwick- lungs are concentric to each other and arranged to form a sub-sub-winding ^¬ voltage by projecting core leg. To hold the upper part voltage windings these are clamped ver ^¬ clamping means between the lower and upper Pressbiechen. The press plates advantageously have two in each case. Sheets on, in the interstice of the core sections protrude. Thus, the press plates are firmly connected to the core. The object of the invention is to provide a transformer of the type mentioned, in which the production costs are further reduced. The invention solves this problem in that all Oberspan ^¬ tion partial windings lie directly against each other and are connected to each other without compression.

In the context of the invention, the Oberspannungssteilwicklun- conditions are no longer held by pressing together. In contrast to transformers according to the prior art, the transformer according to the invention is free of clamping means. Rather, the upper voltage sub-windings are directly adjacent to each other, wherein the lowest upper-voltage sub-winding is supported on the lower press plate and connected thereto. The remaining upper-voltage sub-windings are simply stacked on the lowest upper-voltage sub-winding, so that a second upper-voltage sub-winding rests directly on the lowermost subvoltage winding. Possibly. a third undervoltage sub-winding is applied to the second undervoltage sub-winding, and so on. The adjoining upper part voltage windings are firmly connected by a connecting means. According to the invention it was recognized that windings a sufficiently large mechanical strength of the upper ^¬ voltage windings is provided by a compound of Oberspannungsteil- each other by a convenient Verbindungsmit ^¬ tel.

According to the invention, the upper-voltage partial windings are hollow-cylindrical and define with their inner wall a circular-cylindrical cavity. It is advantageous that all upper part voltage windings have the same inner diameter. The same applies to the outer contour, but the outer contour can deviate from a kreiszylindri- see design.

Conveniently, all upper part voltage windings are identical. In this case, the one upper upper Voltage sub-winding aligned to a lower subvoltage subwinding, so that it terminates flush with the bottom most subvoltage winding part.

In the context of the invention, the connecting means, by which the upper voltage part windings are connected to each other are arbitrary. For example, the Oberspannungssteil ^¬ windings by brackets, screws or the like with each other be connected. It is essential in the context of the invention only that such a high connection force is provided that the upper voltage sub-windings over the specified life of the transformer away are kept safe. According to a preferred embodiment of the invention, the upper part voltage windings are connected to each other via an adhesive bond or a Velcro connection. An adhesive or Velcro connection is inexpensive and also provides the required mechanical strength for a sufficient connection force of the upper voltage sub-windings for undervoltage sub-winding ready.

According to an advantageous embodiment, the lowermost upper-voltage partial winding is screwed to the lower press plates. The screwing increases the mechanical Festig ^¬ speed, the screwing can inexpensively and quickly suc ^¬ conditions. For this purpose, for example, a thread is embedded in the cured insulating material of the lowest upper-voltage partial winding. As an insulating material is, for example cast resin, in particular epoxy resin into consideration. The embedding of the windings takes place by known casting with the insulating material in liquid form.

The lower press plates generally have two profiled supports, which lie opposite each other and define a gap into which the core sections protrude individually or together. By screwing the lower press plates are clamped against each other, wherein the said core sections together. menpressen. As a rule, upper pressing plates within the scope of the invention are provided adjacent the lower pressing plates, which also define a gap into which the Kernab ^¬ sections extend with its end facing away from the lower end of core sheet inside. The pressing of the core sections is carried out as described above, so that also at the upper end of the core sections a sufficiently large mechanical support is provided. In contrast to the prior art, the Oberspannungs- part windings are no longer connected to the upper press plate in any way, but all high-voltage windings are supported solely by their weight forces the lower press plates.

According to a preferred embodiment of the invention, the insulating material of the lowermost upper-voltage sub-winding out Abstützfüße, wherein the Abstützfüße are bolted to the lower press plates ^¬ . In other words, the supporting feet, which are integrally formed on the insulating material, are provided with an internal thread, so that the supporting feet can be firmly screwed to the lower pressing plates. Thus, a stable ^¬ le connection between the high-voltage part windings and the lower pressing plates is provided.

Advantageously, each low-voltage winding is held on the core portion which it encloses. In contrast to the upper-voltage sub-windings, the lower-voltage sub-windings are not deposited on the lower press plates. Rather, the undervoltage sub-windings are fixed to the

Core section mounted, they enclose. The type and Wei ^¬ se assembly is basically arbitrary within the scope of the invention. Advantageously, however, the low-voltage windings are jammed at the core portion. For wedging appropriate wedges are made of insulating material, which on both sides against ^¬ overlying sides of the core portion jamming of the enable respective undervoltage sub-winding. The jamming of the undervoltage sub-windings allows a further cost reduction over the previously known solutions. Conveniently, each upper voltage sub-winding is concentrated ^¬ risch arranged to each lower voltage sub-winding. The concentric arrangement produces the best results in the operation of the transformer according to the invention.

Further expedient refinements and advantages of the inven ^¬ tion are the subject of the following description of embodiments of the invention with reference to the figures of the drawing, wherein like reference numerals to like-acting component

Figure 1 shows an embodiment of the invention

 2 shows the transformer according to FIG. 1 in a perspective view from behind, FIG.

Figure 3 shows the transformer shown in Figures 1 or 2 in a sectional side view and

Figure 4 illustrate the transformer according to Figures 1 and 2 in a sectional plan view.

FIG. 1 shows an embodiment of the transformer 1 according to the invention in a perspective front view. The transformer 1 is designed as a double-decker transformer. On lower rails 2, which run for example on the floor of the installation site, two lower press plates 3 and 4 are screwed. On the lower press plates 3 and 4, a lower upper-voltage sub-winding 5 is supported, wherein a further upper-voltage sub-winding 6 is in direct contact with the lower upper-voltage sub-winding 5. In this case, the upper voltage sub-winding 6 is connected by a suitable connection. connecting means 7 firmly connected to the lower part of the winding. The lower upper voltage sub-winding 5 forms Abstützfüße 8, which have an internal thread. The Abstellfüße 8 are firmly bolted to the lower press plates 3 and 4. The upper voltage sub-windings 5 and 6 are arranged concentrically with respect to a lower voltage sub-winding, of which only the upper sub-voltage sub-winding 9 can be seen in the upper image area. The undervoltage sub-windings enclose a core leg 10 as a core portion so that each undervoltage sub-winding is concentric with a leg 10 of the core of the transformer 1. In addition, upper pressing plates 11 and 12 can be seen, which delimit a gap in which the core legs 10, which consist of core plates, extend into it. By the upper and unte- ren press plates the core sheets are firmly clamped together ^¬ ver, is so as to provide for a sufficiently high strength of the core 10. The winding terminals of the upper chip ^¬ tion partial windings 5, 6 are interconnected by the connecting conductor 13. In addition to the said interconnection, optional taps 18 of the high-voltage windings 5, 6 can be seen in FIG.

FIG. 2 shows the transformer 1 according to FIG. 1 from the rear. Here, instead of the taps and connecting conductors of the upper-voltage partial windings 5, 6, the winding terminals 14 of the lower-voltage partial winding are illustrated. Incidentally, the comments on Figure 1 apply here accordingly.

FIG. 3 shows a sectional side view of the transformer. In particular, it can be seen here that the lower upper ^¬ voltage subwinding 5 supporting feet 8 forms, which are firmly bolted to the lower press plates 3 and 4. In addition, it can be seen that the leg 10 of the core extends between the lower press plates 3 and 4, so that by clamping the press plates 3 and 4, the sheets of the core portion 10 are pressed firmly against each other and with the yoke. The lower upper-voltage sub-winding 5 stands on the lower pressing plates 3, 4. The upper upper-voltage sub-winding ment 6 is - as already stated - directly and thus immedi ^¬ immedi ately supported on the lower upper voltage sub-winding 5, wherein an adhesive connection 7 between the upper upper voltage sub-winding 6 and the lower upper voltage sub-winding 5 provides the necessary mechanical strength. ^{Instead of} the adhesive connection 7 used here, within the scope of the invention it is also possible to guarantee any other joint connection or a connection deviating therefrom. In contrast, a lower undervoltage sub-winding 15 can be seen. This lower undervoltage sub-winding 15 is arranged concentrically to the core leg 10 and concentric to the lower upper-voltage sub-winding 5. In this case, both partial ^¬ windings limit a circular cylindrical interior, through which the core leg 10 extends.

However, the lower undervoltage sub-winding 15 is held firmly on the core section 10 via a clamping connection 17. However, the jamming of an undervoltage sub-winding on the core section is known to the person skilled in the art, so that it is not necessary to go into detail here.

FIG. 4 shows the transformer 1 according to FIGS. 1 or 2 in a plan view, in which the concentric arrangement of the lower upper-voltage partial winding 5 and the lower lower-voltage partial winding 15 can be seen. In addition, it can be seen that the lower undervoltage sub-winding 15 is connected via clamping means 17 fixed to the core portion 10. The clamping means 17 comprise, for example, made of an insulating material ^¬ wedges.

Claims

claims 1. Transformer (1) for a distribution network or for operation with power converters with a core having a plurality of core sections (10), Under ^¬ having a enclosing a core portion (10) of low-voltage winding comprising a plurality of superposed and each ^¬ weils embedded in a cured insulating voltage part windings (9,15), - - A high-voltage winding having a plurality of superposed and each in a cured insulating a ^¬ bedded upper part voltage windings (6,7) and - Lower press plates (3,4) for pressing the core sections (10), wherein a lowermost subvoltage winding is supported on the lower pressing plates (3,4), d a d u r c h e c e n c i n e s that all upper part voltage windings (4,5) abut each other directly and are connected to each other without compression. 2. Transformer (1) according to claim 1, d a d u r c h e c e n c i n e s that the upper part voltage windings (5, 6) are connected to each other via an adhesive connection (7) or a Velcro connection. 3. Transformer (1) according to claim 1 or 2, d a d u r c h e c e n c i n e s that the lowest upper-voltage sub-winding is screwed to the lower pressing plates. 4. Transformer (1) according to claim 3, d a d u r c h e c e n c i n e s that the insulating material of the lowermost upper-voltage partial winding (5) forms support feet (8), wherein the support feet (8) are screwed to the lower press plates (3, 4). 5. Transformer (1) according to one of the preceding claims, characterized in that each low-voltage winding (9, 15) is held on the core section (10) which it encloses. 6. Transformer (1) according to claim 5, d a d u r c h e c e n c i n e s that each undervoltage winding (9, 15) is clamped to the core section (10). 7. The transformer according to claim 1, wherein: each upper-voltage sub-winding (5, 6) is arranged concentrically with respect to an undervoltage sub-winding (9, 15).