This application claims priority under 35 U.S.C. §119 to European Patent Application No. 09164540.8 filed in Europe on Jul. 3, 2009, the entire content of which is hereby incorporated by reference in its entirety.
The present disclosure relates to a wound transformer core with at least one core loop made of a magnetic material. More particularly, the present disclosure relates to a wound transformer core which includes a plate-like support structure, and to a transformer including such a wound transformer core.
It is known that transformers with an amorphous core provide lower electrical losses than transformers with a conventional core. On the other hand, amorphous transformer cores are rather difficult to manufacture, since a suitable amorphous core material is generally only available in thin band-like sheets of a thickness of approximately a few 10 μm and a width of some 10 cm. Thus, a known amorphous core for a transformer with some few MW rated power requires some 1,000 or more layers of such concentrically stacked material. The characteristics of this material are sensitive to mechanical stress, such that a core without any stabilizing arrangement or support structure is not stable enough to bear the weight of some coils or not even its own weight.
Stabilizing arrangements are known, for example, from CN 201112062. In this publication, so-called called E-plates are suggested to be mounted and glued on both sides of major parts of the concentrically stacked transformer core. The upper yoke of the transformer core is not foreseen to be stabilized by an E-plate, since the core has to be re-opened for mounting the coils on the limbs of the transformer core.
However, on one side, the gluing process during manufacturing is rather complex. On the other side, the respective cut-off scrapes for manufacturing such an E-plate is rather high.
An exemplary embodiment of the present disclosure provides a wound transformer core which includes at least one core loop made of a magnetic material. In addition, the exemplary wound transformer core includes multiple thin amorphous band-like iron sheets which are concentrically stacked around at least one center axis to form a lower yoke section, an upper yoke section, and at least two limb sections. The lower yoke section, the upper yoke section and the at least two limb sections each have a first face side and a second face on opposite sides thereof, respectively. The exemplary wound transformer core also includes a modular plate-like support structure which is affixed upright to the center axis on both the first and second face sides of the lower yoke section and on both the first and second face sides of each limb section such that neighbored iron sheets are affixed together at their outer edge. The modular plate-like support structure includes, for each face side of the lower yoke, upper yoke and limb sections, at least two plate-like modules, which are connectable to each other by one of a first plug-in connection and a second plug-in connection.
An exemplary embodiment of the present disclosure also provides a transformer which includes the wound transformer core, at least one primary electrical winding, and at least one secondary electrical winding.
Additional refinements, advantages and features of the present disclosure are described in more detail below with reference to exemplary embodiments illustrated in the drawings, in which:
The reference symbols identified in the drawings are summarized in the list of reference symbols below.
Exemplary embodiments of the present disclosure provide an amorphous wound core with an improved support structure, which avoids the disadvantages of the known techniques mentioned above.
An exemplary embodiment of the present disclosure provides a wound transformer core with a modular plate-like support structure. The modular plate-like support structure includes, for each face side of the corresponding core sections, at least two plate-like modules, which are connected to each other by a first or second plug-in connection.
Accordingly, it is possible to mount a support structure in several steps by using separate modules. This arrangement simplifies the manufacturing process. The plug-in connections are shaped in such a way that one module is connectable with an adjacent module by a simple sliding or hooking movement, while the concentrically wound core is in a desirable (e.g., horizontal) position. Even the plug-in connection as such might be stiff enough to support the transformer core such that it could be useful to strengthen the connection with some amount of glue or some other connection medium, such as a screw, for example.
In accordance with an exemplary embodiment of the present disclosure, the plate-like support structure includes, for each face side of the corresponding core sections, a first plate-like module adapted to the size of the corresponding side of the lower yoke section, and further plate-like modules adapted to the size of the corresponding side of each limb section, which each are connected to the corresponding first plate-like module by a first or second plug-in connection.
In accordance with this modular arrangement, the plug-in connections have their maximum stability in vertical direction if the ready mounted transformer is in its upright (e.g., horizontal) working position. This is required for the lifting of the transformer since the transformer core itself has no own stiffness. Thus, such a transformer core can be lifted by using lifting lugs in the upper part of the upright standing transformer, whereas the major weight load is accumulated at its bottom. The upper yoke section is normally not glued together with a module of the support structure, since the transformer core has to be openable for mounting or de-mounting its coils. In addition, those I-shaped parts are producible without a major cut-off.
In accordance with an exemplary embodiment of the present disclosure, the plate-like support structure includes, for each face side, a second plate-like module adapted to the size of the corresponding side of the upper yoke section, which each are connected to the further plate-like modules on the corresponding sides by a first plug-in connection. To keep the upper yoke openable, it normally has not to be glued together with a module of the support structure. Furthermore, a second plate-like module—if provided—can be removable for the same purpose, thus those plug-in connections have to be openable.
According to an exemplary embodiment of the present disclosure, a first plug-in connection includes at least one barbed nozzle of at least one plate-like module which is adapted to fit into a corresponding hole in an adjacent plate-like module to be connected, so that a puzzle-piece like connection is realized. The hole might be developed as a through hole, although a milled non-through hole is also conceived. Such a connection enables an easy and robust merging together of the corresponding module parts, while the transformer core is in a horizontal manufacturing position. It only has to be ensured, that the connected parts are fixed within the same plane, for example, by gluing them on the transformer. If this kind of plug-in connection is not glued additionally with the transformer core, for example, in the case of the upper yoke, it is also easily openable.
In accordance with an exemplary embodiment of the present disclosure, at least one first or one second plate-like module includes two plates of a similar size, which are mounted together on top of each other, whereas only the plate contacting one of the face sides of the transformer core includes the respective holes into which the barbed nozzles which are fit for the connection to the adjacent modules. This is helpful to prevent a slipping of a barbed nozzle out of the corresponding hole, especially in the case of the upper yoke, where this plug-in connection has to be openable and no glue is foreseen. In addition, the second module part gets strengthened, which enables, for example, lifting lugs to be mounted thereon.
According to an exemplary embodiment of the present disclosure, a second plug-in connection includes a bent section of at least one of the plate-like modules which is hooked into a matching slit within another adjacent plate-like module to be connected. This is also a stable kind of connection, which on the other hand is not as suitable for re-opening. Thus, a second plug-in connection is conceived for the lower yoke area, since it is not required to be re-opened.
In accordance with another exemplary embodiment of the present disclosure, the plate-like support structure includes an upper U-shaped beam-like module which is adapted to the size of the upper side of the upper yoke section and which is arranged thereon, whereas those plate-like modules, which are covering both sides of the limb sections are elongated over the upper side of the upper yoke section so that the elongated parts are at least in part adjacent to the sides of the U-shaped module, such that a mechanical connection in between the adjacent parts can be achieved.
This arrangement enables a reduction of the weight of the support structure, since the U-shaped module can be built from a rather thin material. While the ready mounted transformer stands in its upright working position, no major forces are applied on the U-like module or the alternately used second plate-like modules. Only in case of a lifting of the transformer using some lifting lugs—which can be attached or part of the plate-like module related to the upper yoke—forces are applied on this module. According to this arrangement, the lifting lugs are attachable to the elongated further plate-like modules, which are adapted to the size of the sides of the limbs. Accordingly, the U-like module can be provided to fix the elongated further plate-like modules.
In accordance with an exemplary embodiment of the present disclosure, lifting lugs can be provided at both sides and both ends of the U-shaped module, whereas those lifting lugs are strengthened by congruent holes of corresponding once more elongated module parts. This enables an easy possibility to gain stable lifting lugs.
According to an exemplary embodiment, the wound transformer core can include three core loops, as well as a first, a second and a third toroidal rectangular amorphous iron sheet package. The basically round toroidal shape is developed more in a rectangular manner each including a rather rectangular shaped inner hole. The first and second iron sheet packages are arranged side by side within the inner hole of the third package. Hence, a three phase transformer core is realized, which can be implemented, for example, in distribution networks for electrical energy. Of course, other variants with more or less core loops are conceivable. For example, a five limb transformer core is realized.
In an accordance with an exemplary embodiment of the present disclosure, the corners of the toroidal rectangular developed amorphous iron packages are shaped as soft, such that two approximately triangular hollows are built inbetween the three sheet packages. At least one through bolt is arranged therethrough, which connects the opposing module parts of the support structure.
Even a connection in between the opposing modules of the support structure on both face sides of the transformer core has not to apply any pressure on the fragile core, an exemplary embodiment provides that the support structure can have a certain stiffness. This can be gained for example by the U-shaped module mentioned above, but also by through bolts with a screw thread. For example, these through bolts can be arranged near the core, whereupon the support structure is respectively enlarged to reduce the size of the coil. On the other hand, the use of the above-mentioned triangular hollow as a throughhole for through bolts enables the placing of a through bolt or such at exactly these points of the support structure, where it is most useful for stabilization purposes.
An exemplary embodiment of the present disclosure provides elongated through holes within the plate-like structure, which are arranged at least in part crosswise to the longitudinal extension of the stacked iron sheets.
An amorphous concentrically wound transformer core should not become glued with its total surface on a support structure. It is sufficient to foresee in certain distances some areas of the surface in between core and support structure with such a glue connection. Thus, exemplary embodiments of the present disclosure are based on the idea of applying the glue during the manufacturing process mainly through some elongated holes which are cut in the plate-like support structure in such a way that they are arranged at least in part crosswise to the longitudinal extension of the stacked iron sheets. Nearly all layers of the concentrically wound amorphous material are reachable at their outer edges by sections through the elongated holes. Therefore, the manufacturing process is simplified since the glue is easy to apply while the transformer core and the support structure are laid each on each other. A pre-applying of the glue is avoided or at least reduced, so that the relative position in-between the fragile core and the support structure can become optimized in an easier way before applying the glue into the elongated holes. Furthermore, a needless movement or flapping of the fragile transformer core during the gluing process is avoided. Another aspect is that the weight of the support structure is reduced by these holes.
An exemplary embodiment of the present disclosure also provides a transformer including a transformer core of the aforementioned kind and at least one primary electrical winding and at least one secondary electrical winding, as shown in
In the exemplary embodiment of
With reference to
The plate-like modules 46, 48, 50 which are adapted (e.g., designed) to the size of the corresponding limb sections 26, 28, 30, and the plate-like module 44, which is adapted to the size of the lower yoke 24, are provided to be affixed (e.g., glued) on a transformer core of the aforementioned kind. To simplify the affixation (e.g., gluing) process, horizontal elongated holes 54 are cut in the limb-related modules 46, 48, 50, and vertical elongated holes 52 are cut in the lower-yoke related module 44. Thus, the elongated holes are always across to the longitudinal extension of the stacked iron sheets, so that a plate-like module can be placed in the right position on a horizontal transformer core, whereas a major part of the required glue can be applied afterward through the elongated holes 52, 54. In accordance with an exemplary embodiment, the upper yoke related module is not provided with such elongated holes, since it has to be re-openable as mentioned before and a glue connection is not useful. However, it is conceivable for the upper yoke related module 42 to be provided with such elongated holes according to various design implementations.
With reference to
The symmetrical support structure parts 74, 76 mainly include two yoke-related and three limb-related plate-like module parts each, which are connected by first or second plug-in connections 62 in the lower yoke area, or only by first plug-in connections 64 in the upper yoke area. The plug-in connections 62, 64 are explained more in detail in
Thus, it will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.
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10009106 | Sep 2010 | EP | regional |
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Number | Date | Country |
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201112062 | Sep 2008 | CN |
Number | Date | Country | |
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20120056706 A1 | Mar 2012 | US |