Example embodiments disclosed herein generally relate to a transformer, more specifically, to an open wound dry-type transformer with air guiding plates.
Like all of the electrical distribution equipment serving critical systems, transformers are key components widely used, with various types and specifications. For example, large dry-type distribution transformers are typically fed by medium-voltage power systems (tens of kilovolts) and feature a secondary voltage rating of 480V, 3-phase. Some of the larger common sizes of dry-type transformers available today have a capability up to tens of MVA (million VA). In these transformers, large current generates dramatic heat. Therefore, heat dissipation is vital when designing a distribution transformer.
An open wound dry-type transformer normally has a number of coils which are in the form of stacks of wire disks. Normally, the wire disks are stacked vertically. Currently, heat dissipation can be achieved by a fan disposed at the bottom of the stacks, but the fan is not able to effectively reduce the temperature deep inside the stacks.
Example embodiments disclosed herein propose a structure of a transformer in which heat can be dissipated more effectively.
In one aspect, example embodiments disclosed herein provide a transformer. The transformer includes: a first coil including a first stack of wire disks stacked in a first direction; an exterior barrier arranged to form a first air gap between outer sides of the wire disks of the first stack of wire disks and the exterior barrier; an interior barrier arranged to form a second air gap between inner sides of the wire disks of the first stack of wire disks and the interior barrier; a wind generator arranged to generate an air flow in the first direction; a core in the form of a cylinder that is surrounded by the first coil; and an air guiding plate fixed to one of the exterior barrier and the interior barrier, to guide the air flow in a second direction along first stack gaps between the wire disks of the first stack of wire disks.
Through the following description, it would be appreciated that the transformer according to the present disclosure provides an effective structure by which the air flow can be directly thoroughly among the wire disks in the transformer, which in turn improve the efficiency of active dissipation. In this way, the dimension of the transformer can be reduced, because even a smaller gap between the wire disks can result in an improved performance of heat dissipation by the structure according to the present disclosure. In addition, material costs can be lowered because less material is required for passive heat sinks.
Through the following detailed descriptions with reference to the accompanying drawings, the above and other objectives, features and advantages of the example embodiments disclosed herein will become more comprehensible. In the drawings, several example embodiments disclosed herein will be illustrated in an example and in a non-limiting manner, wherein:
Throughout the drawings, the same or corresponding reference symbols refer to the same or corresponding parts.
The subject matter described herein will now be discussed with reference to several example embodiments. These embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the subject matter described herein, rather than suggesting any limitations on the scope of the subject matter.
The term “comprises” or “includes” and its variants are to be read as open terms that mean “includes, but is not limited to.” The term “or” is to be read as “and/or” unless the context clearly indicates otherwise. The term “based on” is to be read as “based at least in part on.” The term “being operable to” is to mean a function, an action, a motion or a state can be achieved by an operation induced by a user or an external mechanism. The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment.” The term “another embodiment” is to be read as “at least one other embodiment.” Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass direct and indirect mountings, connections, supports, and couplings. Furthermore, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. In the description below, like reference numerals and labels are used to describe the same, similar or corresponding pans in the several views of
As shown in
A core 170 can be an iron core commonly used for various transformers. The core 170 shown in
An exterior barrier 130 is provided to form a first air gap 131 between outer sides of the wire disks 111 and the exterior barrier 130. The exterior barrier 130 is used for guiding the air flow along the first air gap 131 so as to bring away the generated heat from the wire disks 111. When the wire disks 111 are arranged in a way shown in
An interior barrier 140 is provided to form a second air gap 141 between inner sides (named with respect to the outer sides) of the wire disks 111 and the interior barrier 140. The interior barrier 140 is used for guiding the air flow along the second air gap 141 so as to bring away the generated heat from the wire disks 111. When the wire disks 111 are arranged in a way shown in
It is to be understood that, although
As shown in
One or more air guiding plates are fixed to at least one of the exterior barrier 130 and the interior barrier 140. In one example, the air guiding plate is shaped to match the exterior barrier 130 or the interior barrier 140, so that the existence of the air guiding plate blocks most of the air flow along the first air gap 131 or the second air gap 141, respectively. As shown in
The air flow generated by the wind generator 150 may travel in the following way. First of all, the generated air flow moves upward along the first air gap 131 until impinging on one of the first air guiding plate 161. Due to the blockage of the first air gap 131 by the first air guiding plate 161 fixed to the exterior barrier 130, the air flow will be redirected to move toward the interior barrier 140 via a number of first stack gaps 114 until impinging on die interior barrier 140. Then, the air flow is forced to move upward along the second air gap 141 until impinging on one of the second air guiding plate 162 fixed to the interior barrier 140. Due to the blockage of the second air gap 141 by the second air guiding plate 162, the air flow will be redirected to move toward the exterior barrier 130.
In this example, there are multiple first air guiding plates 161 provided on the exterior barrier 130, and multiple second air guiding plates 162 provided on the interior barrier 140. Each of the first and second air guiding plates 161, 162 are placed at different altitudes, so that the route of the air flow meanders throughout the first stock of wire disks 111.
In this way, the heat dissipation can be greatly improved, because the air flow passes almost each and every piece of the wire disks 111. In particular, the middle portions of the wire disks generate a lot of heat that are otherwise unreachable by the air flow if no air guiding plate is provided. In other words, if no air guiding plate is provided, even if the heat near the outer sides and the inner sides can be brought away by the air flow easily, the heat generated by the middle portions of the wire disks 111 can only be conducted to the outer and inner sides in a passive way, which is inefficient. Therefore, the existence of the air guiding plate forces the air flow in substantially horizontal directions, which cools down the overall temperature within the transformer 100 dramatically.
In some cases, even one air guiding plate is effective enough to lower the temperature in the middle portions of the wire disks 111. As such, the present disclosure does not intend to limit the quantity of the air guiding plate. In one example, the air guiding plate can protrude into the first stack of wire disks 111 to an extent that most of the air flow along either the first air gap 131 or the second air gap 141 is forced to change its travelling direction. As mentioned above, the air guiding plate may not protrude into the wire disks 111 as well, as long as a portion of the air flow is redirected into the first stack gap 114.
In one example, the first air guiding plate 161 (if existing) is fixed to the exterior barrier 130 in an air tight manner, and the second air guiding plate 162 (if existing) is fixed to the interior barrier 140 in an air tight manner. In this way, almost all the air flow will be redirected by die air guiding plate(s), forming a complete meander route passing through the wire disks. However, in another example, some holes or openings can be provided on the air guiding plate(s) as well. The area of the openings on the air guiding plate can be controlled so that the route of the air flow can be controlled accordingly.
Additionally or alternatively, the transformer 100 may include a second coil 120. In the example shown in
In the example shown in
A third air guiding plate 163 may be fixed to the interior burner 140 and a fourth air guiding plate 164 may be fixed to the core 170. Both of the third air guiding plate 163 and the fourth air guiding plate 164 may protrude between adjacent wire disks of the second stack of wire disks 121 to guide the air flow in the second direction D2 along second stack gaps 124 between the wire disks of the second stack of wire disks 121.
In another example, the second coil 120 may surround the core 170 and be arranged to be coaxial with the core 170, the exterior barrier 130 and the interior barrier 140. The third air guiding plate 163 may be in the form of a closed ring to be circumferentially fixed to the interior barrier 140, and the fourth air guiding plate 164 may be in the form of a closed ring to which the core 170 is circumferentially fixed. The third air guiding plate 163 may be fixed to the interior barrier 140 in an air tight manner, and the fourth air guiding plate 164 may be fixed to the core 170 in an air tight manner.
The arrangements of the components associated with the second coil 120 and the third and fourth air guiding plates 163, 164 may be in similar ways to those associated with the first coil 110 and corresponding air plate(s). The advantages brought by the third and fourth air guiding plates 163, 164 to the second stack of wire disks 121 are also related to the heat dissipation between the wire disks 121, and thus detailed descriptions will be omitted.
It should be understood that, although
There can be more or less coil(s) in the transformer 100. For example, the interior barrier 140 can be regarded as the exterior surface of the core 170 in some cases where the second coil 120 or 220 does not exist, and thus the first coil 110 is located between the core 170 and the exterior barrier 130. In other scenarios, additional coil(s) may be stacked atop the existing coil(s) as well.
From simulation results, by arranging a meander route with five first air guiding plates and five second air guiding plates for a stack of wire disks having a height of 123 cm and having air gaps of 2.2 cm, the temperature at the coil can be significantly reduced. Compared with a model without any air guiding plate, for the model having five first air guiding plates and five second air guiding plates, the average temperature at the coil can be lowered by about 30 degrees Celsius from 80° C., and the highest temperature during the simulation period at the coil can be lowered by about 20 degrees Celsius from about 100° C.
While operations are depicted in a particular order in the above descriptions, it should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several details are contained in the above discussions, these should not be construed as limitations on the scope of the subject matter described herein, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. On the other hand, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
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Number | Date | Country | |
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20190326050 A1 | Oct 2019 | US |
Number | Date | Country | |
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Parent | PCT/CN2017/078154 | Mar 2017 | US |
Child | 16502258 | US |