Three-phase star-shaped three-dimensional transformer iron core and wiring structure thereof

Abstract

The utility model discloses a three-phase star-shaped three-dimensional transformer iron core and a wiring structure thereof. The iron core comprises iron core columns and iron yokes, a triangular block is arranged in a through hole in the center of the iron yoke and is formed by overlapping a plurality of iron sheets matched with the through hole in shape from top to bottom; the triangular block is provided with three short circuit rings, the short circuit rings are rectangular closed metal rings, the long edges of the short circuit rings extend in the overlapping direction of the iron sheets, and the short edges of the three short circuit rings extend from the three corners of the triangular block to the center respectively. Due to the adoption of the technical scheme, compared with the prior art, the strength of eddy current is greatly reduced, so that the conditions of heating and harmonic generation of the transformer iron core are weakened. And secondly, the problem that the magnetic conductance coefficient is reduced due to the fact that the sectional area of the triangular block is inconsistent with the sectional area of the iron core column is solved, the vertical space occupied by the three-phase three-dimensional transformer iron core is reduced, and the length of a connecting line between adjacent high-voltage coils is reduced.

Description

Technical Field

[0001] The utility model relates to the field of transformers, and particularly relates to a three-phase star-shaped three-dimensional transformer core and its wiring structure. Background Art

[0002] The three-phase transformer evolved from three single-phase transformers. The main magnetic flux of each phase must pass through the magnetic circuits of the other two phases to be closed, so the three-phase magnetic circuits are related to each other. Generally, the iron core of a three-phase transformer is in a planar structure form. The magnetic circuit lengths of the three phases are not equal. The magnetic circuit of the middle phase is short, and the magnetic circuits of the other two phases are long, resulting in slightly different magnetic reluctances of the three phases. When a three-phase symmetrical voltage is applied externally, the no-load currents of the three phases will be unequal. The magnetic circuit lengths are different, and the magnetic circuit directions are also different. The current of the middle phase is small, and the currents of the other two phases are large, which affects the load operation of the transformer and causes some losses.

[0003] In order to overcome the above defects, the Chinese utility model patent with the publication number of CN111223648A discloses a folding three-phase transformer and its manufacturing method, which transforms the transformer core into a star-shaped structure. Each side of the star-shaped structure is composed of a plurality of bent yoke iron sheets stacked side by side, thus solving the problem of asymmetric magnetic circuits.

[0004] However, the inventors of the present application found that the above technology has at least the following technical problems: After the three-phase neutral copper bus is connected and passes through the center of the yoke, if the sum of the three-phase currents is zero, no eddy current will be generated in the three-phase yoke. However, if the sum of the three-phase currents is not zero, eddy currents will be generated, which will cause the transformer core to heat up and generate harmonics. Secondly, as Figure 1 shown, the connecting copper bus of the low-voltage coil of the existing transformer is too long. Summary of the Invention

[0005] One of the utility model purposes of the present application is to provide a three-phase star-shaped three-dimensional transformer core to solve the problem that when the sum of the three-phase currents of the existing three-phase star-shaped three-dimensional transformer core is not zero, eddy currents will be generated, which will cause the transformer core to heat up and generate harmonics.

[0006] To achieve the above object, the present application adopts the following technical solution: A three-phase star-shaped three-dimensional transformer core includes a core column and a yoke; a triangular block is provided in the through hole at the center of the yoke. The triangular block is composed of a plurality of iron sheets whose shapes match the through hole and are stacked from top to bottom; three short-circuit rings are provided on the triangular block. The short-circuit rings are rectangular closed metal rings. The long sides of the short-circuit rings extend along the stacking direction of the iron sheets, and the short sides of the three short-circuit rings extend from the three corners of the triangular block to the center.

[0007] Thus, when eddy currents are generated due to the sum of the three-phase currents not being zero, the three short-circuit rings will generate a magnetic field in the opposite direction, greatly reducing the intensity of the eddy currents, thereby weakening the heating of the transformer core and the generation of harmonics. On the other hand, since the triangular block is formed by stacking a plurality of iron sheets whose shapes match the through holes from top to bottom, the problem of reduced magnetic permeability coefficient caused by the inconsistent cross-sectional areas of the triangular block and the core column is solved.

[0008] In some embodiments, a first through hole is provided at the center of the triangular block, and three second through holes are respectively provided at three corners. The two long sides of the short-circuit ring respectively pass through the first through hole and the second through hole.

[0009] Another utility model object of the present application is to provide a wiring structure for a three-phase star-shaped three-dimensional transformer core to solve the problem of the excessively long connecting copper bars of the low-voltage coils of existing transformers. To achieve the above object, in some embodiments, there are three core columns, a low-voltage coil is provided outside each core column, and a high-voltage coil is provided outside each low-voltage coil;

[0010] A first low-voltage copper bar and a second low-voltage copper bar are provided at the top of each low-voltage coil, and both ends of the low-voltage coil are electrically connected to the first low-voltage copper bar and the second low-voltage copper bar on the low-voltage coil; the three first low-voltage copper bars on the three low-voltage coils converge towards the center of the three low-voltage coils and are electrically connected; the three low-voltage coils are located directly below the triangular block;

[0011] A first high-voltage copper bar and a second high-voltage copper bar are oppositely provided on the side wall of each high-voltage coil, and both ends of the high-voltage coil are electrically connected to the first high-voltage copper bar and the second high-voltage copper bar on the high-voltage coil, and the first high-voltage copper bar is electrically connected to the second high-voltage copper bar on the adjacent high-voltage coil.

[0012] Thus, the position of the first low-voltage copper bar is changed from above the upper yoke to below the upper yoke, reducing the vertical space occupied by the three-phase three-dimensional transformer core. Secondly, since the two copper bars on the high-voltage coil of the existing three-phase three-dimensional transformer core are located on the same side, the connecting wire on the high-voltage coil needs to wind around the high-voltage coil for half a turn to be connected to the adjacent high-voltage coil; in the present application, by arranging the two copper bars on the high-voltage coil oppositely, the connecting wire on the high-voltage coil does not need to wind around the high-voltage coil for half a turn to be connected to the adjacent high-voltage coil, thereby reducing the length of the connecting wire.

[0013] In some embodiments, when viewed from top to bottom, the first high-voltage copper bar and the second high-voltage copper bar are respectively located on both sides of the first low-voltage copper bar and are both perpendicular to the first low-voltage copper bar.

[0014] In some embodiments, the second low-voltage copper bar is aligned with the first high-voltage copper bar or the second high-voltage copper bar.

[0015] In some embodiments, the three first low-voltage copper bars on the three low-voltage coils are fixed together by a connecting plate; a metal connecting rod is provided at the center of the connecting plate, one end of the metal connecting rod is electrically connected to the three first low-voltage copper bars, and the other end penetrates through the first through hole and extends outside the triangular block.

[0016] In some embodiments, the connecting plate includes an upper connecting plate and a lower connecting plate. A plurality of corresponding connecting holes are respectively formed on the upper connecting plate, the lower connecting plate, and the three first low-voltage copper bars. The upper connecting plate and the lower connecting plate sandwich the three first low-voltage copper bars in the middle and are connected by bolts.

[0017] In some embodiments, one end where the three first low-voltage copper bars are electrically gathered is arrow-shaped, the included angle of the arrow is 120°, and a one-third circular hole is formed at the tip of the arrow, so that a complete circular hole is formed after the three first low-voltage copper bars are gathered.

[0018] In some embodiments, corresponding mounting holes are provided at the centers of the upper connecting plate and the lower connecting plate. A nut is provided at the mounting hole on the lower surface of the lower connecting plate. One end of the metal connecting rod sequentially passes through the mounting hole on the upper connecting plate and the circular hole formed after the three first low-voltage copper bars are gathered, and is threadedly connected to the nut.

[0019] In some embodiments, insulating sleeves are provided on the middle part of the metal connecting rod, the low-voltage coil, and the high-voltage coil.

[0020] The present application has at least the following technical effects or advantages:

[0021] 1. When eddy currents are generated because the sum of the three-phase currents is not zero, the three short-circuit rings will generate a magnetic field opposite to it, greatly reducing the intensity of the eddy currents, thereby weakening the heating of the transformer iron core and the generation of harmonics.

[0022] 2. Solve the problem of the reduction of the magnetic permeability coefficient caused by the inconsistent cross-sectional areas of the triangular block and the iron core column.

[0023] 3. The position of the first low-voltage copper bar is changed from above the upper yoke to below the upper yoke, reducing the vertical space occupied by the iron core of the three-phase three-dimensional transformer.

[0024] 4. The connection line on the high-voltage coil can be connected to the adjacent high-voltage coil without winding half a turn around the high-voltage coil, thereby reducing the length of the connection line between adjacent high-voltage coils. Description of the Drawings

[0025] Figure 1 It is a schematic wiring structure diagram of an existing three-phase star-shaped three-dimensional transformer iron core;

[0026] Figure 2Schematic diagram of the structure of the three-phase star-shaped three-dimensional transformer core in an embodiment of the present application;

[0027] Figure 3 Schematic diagram of the structure of the triangular block (without short-circuit ring installed) in an embodiment of the present application;

[0028] Figure 4 Schematic diagram of the structure of the triangular block (with short-circuit ring installed) in an embodiment of the present application;

[0029] Figure 5 Schematic diagram of the structure of the short-circuit ring in an embodiment of the present application;

[0030] Figure 6 Schematic diagram of the wiring structure of the three-phase star-shaped three-dimensional transformer core (without metal connecting rod installed) in an embodiment of the present application;

[0031] Figure 7 Schematic diagram of the wiring structure of the three-phase star-shaped three-dimensional transformer core (with metal connecting rod installed) in an embodiment of the present application;

[0032] Figure 8 Schematic diagram of the structure of the low-voltage coil in an embodiment of the present application;

[0033] Figure 9 Schematic diagram of the structure of the high-voltage coil in an embodiment of the present application;

[0034] Figure 10 Schematic diagram of the structure of the upper connecting plate in an embodiment of the present application;

[0035] Figure 11 Schematic diagram of the structure of the lower connecting plate in an embodiment of the present application;

[0036] Figure 12 Schematic diagram of the wiring structure of the three-phase star-shaped three-dimensional transformer core (with core columns installed) in an embodiment of the present application;

[0037] Figure 13 Schematic diagram of the wiring structure of the three-phase star-shaped three-dimensional transformer core (with core columns and yokes installed) in an embodiment of the present application;

[0038] Figure 14 Schematic diagram of the structure of the metal connecting rod in an embodiment of the present application. Detailed implementation manners

[0039] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0040] Embodiment 1

[0041] See Figures 2 - 5, A three-phase star-shaped three-dimensional transformer core, including a core column 1 and a yoke. The yoke includes an upper yoke 21 and a lower yoke 22. Triangular blocks 3 are provided in the through holes at the centers of the upper yoke 21 and the lower yoke 22. The triangular blocks 3 are formed by stacking a plurality of iron sheets whose shapes match the through holes from top to bottom. A first through hole 31 is provided at the center of the triangular block 3, and three second through holes 32 are provided at three corners respectively. As Figure 3 and Figure 5 shown, three short-circuit rings 4 are provided on the triangular block 3. The short-circuit rings 4 are rectangular closed metal rings. The two long sides of the short-circuit rings 4 extend along the stacking direction of the iron sheets and respectively pass through the first through hole 31 and the second through hole 32. The short sides of the three short-circuit rings 4 extend from the three corners of the triangular block 3 towards the center.

[0042] Embodiment 2

[0043] As Figures 6 - 13 shown, a wiring structure of the above three-phase star-shaped three-dimensional transformer core. In the above three-phase star-shaped three-dimensional transformer core, there are three core columns 1. A low-voltage coil 5 is provided outside each core column 1, and a high-voltage coil 6 is provided outside each low-voltage coil 5. Insulating sleeves (the low-voltage coil 5 and the high-voltage coil 6 with insulating sleeves shown in the figure) are sleeved on the low-voltage coil 5 and the high-voltage coil 6.

[0044] As Figures 6 - 9 、 Figure 12 and Figure 13 shown, a first low-voltage copper bar 51 and a second low-voltage copper bar 52 are provided at the top of each low-voltage coil 5. The two ends of the low-voltage coil 5 are respectively electrically connected to the first low-voltage copper bar 51 and the second low-voltage copper bar 52 on the low-voltage coil 5. The three first low-voltage copper bars 51 on the three low-voltage coils 5 converge towards the center of the three low-voltage coils 5 and are electrically connected. The three low-voltage coils 5 are located directly below the triangular block 3.

[0045] A first high-voltage copper bar 61 and a second high-voltage copper bar 62 are oppositely provided on the side wall of each high-voltage coil 6. The two ends of the high-voltage coil 6 are respectively electrically connected to the first high-voltage copper bar 61 and the second high-voltage copper bar 62 on the high-voltage coil 6. The first high-voltage copper bar 61 is electrically connected to the second high-voltage copper bar 62 on the adjacent high-voltage coil 6.

[0046] As Figure 6 shown, when looking down from top to bottom, the first high-voltage copper bar 61 and the second high-voltage copper bar 62 are respectively located on both sides of the first low-voltage copper bar 51 and are both perpendicular to the first low-voltage copper bar 51. The second low-voltage copper bar 52 is aligned with the first high-voltage copper bar 61 or the second high-voltage copper bar 62.

[0047] As Figure 7 、 Figure 10 and Figure 11As shown, the three first low-voltage copper bars 51 on the three low-voltage coils 5 are fixed together by a connecting plate. Specifically, the connecting plate includes an upper connecting plate 71 and a lower connecting plate 72. A number of corresponding connecting holes are respectively provided on the upper connecting plate 71, the lower connecting plate 72, and the three first low-voltage copper bars 51. The upper connecting plate 71 and the lower connecting plate 72 sandwich the three first low-voltage copper bars 51 in the middle and are connected by bolts.

[0048] As Figure 6 shown, the converging end of the three first low-voltage copper bars 51 is arrow-shaped, the included angle of the arrow is 120°, and one-third of a circular hole is provided at the tip of the arrow, so that a complete circular hole is formed after the three first low-voltage copper bars 51 converge. As Figure 7 shown, corresponding mounting holes are provided at the centers of the upper connecting plate 71 and the lower connecting plate 72. A nut 73 is provided at the mounting hole on the lower surface of the lower connecting plate 72. One end of the metal connecting rod 8 sequentially passes through the mounting hole on the upper connecting plate 71 and the circular hole formed after the three first low-voltage copper bars 51 converge, and is threadedly connected to the nut 73 on the lower connecting plate 72. One end of the metal connecting rod 8 is electrically connected to the three first low-voltage copper bars 51, and the other end passes through the first through hole 31 and extends outside the triangular block 3, serving as the low-voltage neutral end point of the three-phase transformer. The three second low-voltage copper bars 52 extend upward, serving as the three-phase low-voltage live wire end points of the three-phase transformer. An insulating sleeve 81 is provided in the middle of the metal connecting rod 8, as Figure 14 shown.

[0049] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0050] Similarly, it should be understood that in order to streamline this disclosure and assist in understanding one or more of the various aspects of the utility model, in the above description of the exemplary embodiments of the utility model, the various features of the utility model are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting the intention that the claimed utility model requires more features than are expressly recited in each claim. Rather, as reflected by the claims, the aspects of the utility model lie in less than all the features of the single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim stands on its own as a separate embodiment of the present invention.

[0051] Those skilled in the art should understand that the modules or units or groups of the devices in the examples disclosed herein can be arranged in the devices as described in this embodiment, or alternatively can be located in one or more devices different from the devices in this example. The modules in the foregoing examples can be combined into one module or can be further divided into multiple sub-modules.

[0052] Those skilled in the art can understand that the modules in the devices in the embodiments can be adaptively changed and arranged in one or more devices different from this embodiment. The modules or units or groups in the embodiments can be combined into one module or unit or group, and in addition, they can be divided into multiple sub-modules or sub-units or sub-groups. Except that at least some of such features and / or processes or units are mutually exclusive, any combination can be adopted to combine all the features disclosed in this specification (including the accompanying claims, abstract and drawings) and all the processes or units of any method or device so disclosed. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract and drawings) can be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0053] In addition, those skilled in the art can understand that although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of the present utility model and forms different embodiments. For example, in the following claims, any one of the claimed embodiments can be used in any combination.

[0054] As used herein, unless otherwise specified, the use of ordinal numbers "first", "second", "third", etc. to describe ordinary objects only indicates different instances of similar objects and does not intend to imply that the objects so described must have a given order in terms of time, space, sorting, or in any other way.

[0055] Although the present utility model is described in terms of a limited number of embodiments, those skilled in the art in this technical field will understand, based on the above description, that other embodiments can be conceived within the scope of the present utility model thus described. In addition, it should be noted that the language used in this specification is mainly selected for readability and teaching purposes, rather than for the purpose of explaining or limiting the subject matter of the present utility model. Therefore, many modifications and changes will be obvious to those of ordinary skill in the art in this technical field without departing from the scope and spirit of the appended claims. For the scope of the present utility model, the disclosure of the present utility model is illustrative rather than restrictive, and the scope of the present utility model is defined by the appended claims.

[0056] Finally, it should be noted that the commonly recognized knowledge in this field is not elaborated in detail in this utility model. The above description is only a specific embodiment of this utility model and is not intended to limit this utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this utility model shall be included within the protection scope of this utility model.

Claims

1. A three-phase star-shaped transformer core, comprising a core column and an iron yoke; characterized in that: A triangular block is provided in the through hole at the center of the iron yoke, and the triangular block is formed by stacking a plurality of iron sheets whose shapes match the through hole from top to bottom; three short-circuit rings are provided on the triangular block, and the short-circuit rings are rectangular closed metal rings, and the long sides of the short-circuit rings extend along the stacking direction of the iron sheets, and the short sides of the three short-circuit rings extend from the three corners of the triangular block to the center respectively.

2. The three-phase star-shaped transformer core according to claim 1, characterized in that: A first through hole is provided at the center of the triangular block, and three second through holes are respectively provided at the three corners. The two long sides of the short-circuit ring pass through the first through hole and the second through hole respectively.

3. A connection structure of a three-phase star-shaped transformer core as claimed in claim 2, characterized in that: There are three core columns, each of which is provided with a low-voltage coil on the outside, and each of which is provided with a high-voltage coil on the outside; a first low-voltage copper bar and a second low-voltage copper bar are provided on the top of each low-voltage coil, and the two ends of the low-voltage coil are electrically connected to the first low-voltage copper bar and the second low-voltage copper bar on the low-voltage coil respectively; the three first low-voltage copper bars on the three low-voltage coils are gathered at the center of the three low-voltage coils and electrically connected; Three low-voltage coils are located directly below the triangular block; A first high-voltage copper bar and a second high-voltage copper bar are arranged opposite to each other on the side walls of each high-voltage coil. The two ends of the high-voltage coil are electrically connected to the first high-voltage copper bar and the second high-voltage copper bar on the high-voltage coil respectively. The first high-voltage copper bar is electrically connected to the second high-voltage copper bar on the adjacent high-voltage coil.

4. The connection structure of the three-phase star-shaped transformer core according to claim 3 is characterized in that: When viewed from top to bottom, the first high-voltage copper bar and the second high-voltage copper bar are respectively located on both sides of the first low-voltage copper bar and are both perpendicular to the first low-voltage copper bar.

5. The connection structure of the three-phase star-shaped transformer core according to claim 4 is characterized in that: The second low-voltage copper bar is aligned with the first high-voltage copper bar or the second high-voltage copper bar.

6. The connection structure of the three-phase star-shaped transformer core according to claim 3 is characterized in that: The three first low-voltage copper bars on the three low-voltage coils are fixed together by a connecting plate; a metal connecting rod is provided at the center of the connecting plate, one end of the metal connecting rod is electrically connected to the three first low-voltage copper bars, and the other end passes through the first through hole and extends outside the triangular block.

7. The connection structure of the three-phase star-shaped transformer core according to claim 6 is characterized in that: The connecting plate includes an upper connecting plate and a lower connecting plate. The upper connecting plate, the lower connecting plate and the three first low-voltage copper bars are respectively provided with a plurality of corresponding connecting holes. The upper connecting plate and the lower connecting plate sandwich the three first low-voltage copper bars and connect them by bolts.

8. The connection structure of the three-phase star-shaped transformer core according to claim 7 is characterized in that: One end where the three first low-voltage copper busbars are electrically connected is in the shape of an arrow, the angle of the arrow is 120°, and a third of a circular hole is opened at the tip of the arrow, so that the three first low-voltage copper busbars form a complete circular hole after being connected.

9. The connection structure of the three-phase star-shaped transformer core according to claim 8, characterized in that: Corresponding mounting holes are provided at the centers of the upper connecting plate and the lower connecting plate, and a nut is provided at the mounting hole on the lower surface of the lower connecting plate. One end of the metal connecting rod passes through the mounting hole on the upper connecting plate and the circular hole formed by the three first low-voltage copper bars in sequence, and is then threadedly connected to the nut.

10. The connection structure of the three-phase star-shaped transformer core according to claim 9, characterized in that: Insulating sleeves are arranged on the middle part of the metal connecting rod, the low-voltage coil and the high-voltage coil.

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