CN117095915A - Iron core, iron core structure and transformer - Google Patents

Abstract

The invention discloses an iron core, an iron core structure and a transformer, wherein the iron core comprises: the heart column comprises a plurality of heart column sheets which are arranged along a first direction and are stacked; the final-stage core column sheet is formed by combining a plurality of strip-shaped laminations, and N is more than or equal to 1, wherein the final-stage core column sheet is an N-stage core column sheet positioned at the outermost side of the core column; the arrangement direction of the plurality of strip-shaped laminates is a second direction, and two adjacent strip-shaped laminates are insulated; the iron yoke comprises a plurality of iron yoke sheets which are arranged along a third direction and are stacked, and any two directions of the first direction, the second direction and the third direction are perpendicular to each other. The iron core provided by the invention reduces eddy current loss.

Description

Iron core, iron core structure and transformer

Technical Field

The invention relates to the technical field of transformer equipment, in particular to an iron core, an iron core structure and a transformer.

Background

In a power transformer, a core is an important magnetic path medium, and loss is generated in the core by alternating magnetic flux.

As the working frequency of the transformer increases, the unit iron loss in the laminated material of the iron core sheet of the transformer, namely the silicon steel sheet, can be obviously increased, so that the overall loss of the iron core sheet is greatly increased, and further the iron core temperature rise is over-limited; meanwhile, with the improvement of the working frequency, on the iron core column sleeved with the coil, the eddy current loss generated by the body leakage magnetic flux in the iron core final stage silicon steel sheet is greatly increased, so that the iron core final stage loss and the temperature rise are over-limited, and in the conventional power frequency power transformer design, the mode of arranging the magnetism isolating groove in the iron core final stage silicon steel sheet cannot meet the requirement of reducing the eddy current loss under the high-frequency working condition.

Therefore, how to reduce the eddy current loss is a problem to be solved by the person skilled in the art.

Disclosure of Invention

In view of this, the present invention provides a core to reduce eddy current loss. The invention also provides an iron core structure with the iron core and a transformer.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a core, comprising:

the heart column comprises a plurality of heart column sheets which are arranged along a first direction and are stacked; the final-stage core column sheet is formed by combining a plurality of strip-shaped laminations, and N is more than or equal to 1, wherein the final-stage core column sheet is an N-stage core column sheet positioned at the outermost side of the core column; the arrangement direction of the plurality of strip-shaped laminates is a second direction, and two adjacent strip-shaped laminates are insulated;

the iron yoke comprises a plurality of iron yoke sheets which are arranged along a third direction and are stacked, and any two directions of the first direction, the second direction and the third direction are perpendicular to each other.

Optionally, the core includes:

a plurality of core laminations including the leg pieces and the yoke pieces;

and a plurality of oil channels, wherein a space is reserved between two adjacent oil channels, and fluid in the oil channels can exchange heat with the stem plates and the iron yoke plates.

Optionally, in the iron core, an oil inlet and an oil outlet of the oil duct are respectively positioned at the lower end of the iron yoke and the upper end of the iron yoke;

the oil duct is a zigzag oil duct and is provided with a plurality of horizontal flow paths along the horizontal direction and a vertical flow path connecting two adjacent horizontal flow paths;

one end of the horizontal flow path is an inlet end, and the other end of the horizontal flow path is an outlet end;

and one end of the vertical flow path is communicated with the outlet end of one horizontal flow path, and the other end of the vertical flow path is communicated with the inlet end of the other horizontal flow path.

Optionally, in the above-mentioned core, the oil passage is surrounded by an insulating support bar and an insulating baffle plate positioned on a stacking surface of the core lamination;

the two side surfaces of the insulating support bar are oil duct walls of the oil duct, and one side surface of the insulating baffle is the oil duct wall of the oil duct.

Optionally, in the core, the distance between two adjacent oil channels along the first direction is 80mm-150mm;

and/or the thickness of the oil duct ranges from 3mm to 5mm, and the thickness of the oil duct is the dimension of the oil duct along the first direction.

Optionally, in the above-mentioned core, the final core leg piece is formed by stacking a plurality of the strip-shaped laminations and curing with epoxy resin.

The invention also provides an iron core structure, which comprises an iron core, wherein the iron core is any one of the iron cores.

Optionally, in the above-mentioned core structure, further includes:

the clamping piece comprises an upper clamping piece and a lower clamping piece which extend along the first direction, the upper clamping piece is arranged corresponding to an upper iron yoke of the iron core, and the lower clamping piece is arranged corresponding to a lower iron yoke of the iron core;

and the pull plates are arranged along the arrangement direction of the upper clamping piece and the lower clamping piece, and the first direction is perpendicular to the surface of the pull plates.

Optionally, in the above-mentioned iron core structure, an oil flow hole is formed in a web of the clip, and the oil flow hole is communicated with an oil inlet of an oil duct of the iron core;

the iron core structure is also provided with a plurality of trapezoid cushion blocks which are symmetrically arranged on the periphery of the oil flow hole;

the opposite surfaces of the trapezoid cushion blocks and the surfaces of the clamping pieces enclose a diversion structure for guiding fluid to flow into the oil flow holes.

The invention also provides a transformer, which comprises an iron core structure, wherein the iron core structure is any one of the iron core structures.

According to the technical scheme, the last-stage core column sheet of the core column is formed by combining the plurality of strip-shaped lamination sheets, the arrangement direction of the plurality of strip-shaped lamination sheets is the second direction, the plurality of core column sheets are arranged and stacked along the first direction, the first direction Z is perpendicular to the second direction, and the adjacent two strip-shaped lamination sheets are insulated, so that after leakage magnetic flux vertically enters the surface of the core column, the cross section area of the last-stage core column sheet is small, and eddy current loss is effectively reduced. Namely, the final core column sheet is arranged to form a magnetic flux path with high magnetic conductivity and low loss by arranging strip laminations, and an axial low-reluctance loop can be provided for leakage magnetic flux, so that eddy current loss is reduced, eddy current reaction is weakened, and distribution uniformity of magnetic density (magnetic induction intensity) is improved.

The iron core structure and the transformer provided by the invention comprise any iron core. Since the core has the above technical effects, the core structure and the transformer having the core have the same technical effects, and will not be described in detail herein.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of an iron core structure according to an embodiment of the present invention;

fig. 2 is a schematic partial structure of an iron core structure according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a mandrel provided in an embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of an iron yoke according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a final core column sheet of a first transformer according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an oil gallery of a first transformer according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a final core column sheet of a second transformer according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of an oil gallery of a second transformer according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a final core column sheet of a third transformer according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of an oil gallery of a third transformer according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a final core column sheet of a fourth transformer according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of an oil gallery of a fourth transformer according to an embodiment of the present invention;

fig. 13 is a schematic structural diagram of a final core column sheet of a fifth transformer according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of an oil gallery of a fifth transformer according to an embodiment of the present invention;

fig. 15 is a schematic front view of a final stem according to an embodiment of the present invention;

FIG. 16 is a schematic side view of a final stem plate according to an embodiment of the present invention;

wherein,

the oil duct 1, the oil outlet 101, the oil inlet 102, the stem piece 2, the final stem piece 2-1, the iron yoke piece 3, the pull plate 4, the clamping piece 5, the clamping piece oil guiding box 6, the coil 7, the coil supporting plate 8, the box wall 9, the oil duct 10 and the leakage magnetic flux 11.

Detailed Description

The invention discloses an iron core for reducing eddy current loss. The invention also provides an iron core structure with the iron core and a transformer.

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in fig. 1 to 6, an embodiment of the present invention provides an iron core, including a core leg and an iron yoke, where the core leg includes a plurality of core leg pieces 2 arranged along a first direction Z; the final-stage core column sheet 2-1 is formed by combining a plurality of strip-shaped laminations, the final-stage core column sheet 2-1 is an N-stage core column sheet 2 positioned at the outermost side of the core column, and N is more than or equal to 1; the arrangement direction of the plurality of strip-shaped laminations is a second direction Y, and two adjacent strip-shaped laminations are insulated; the yoke comprises a plurality of yoke pieces 3 arranged along a third direction X, and any two directions of the first direction Z, the second direction Y and the third direction X are mutually perpendicular.

According to the iron core provided by the embodiment of the invention, the last-stage core column sheet 2-1 of the core column is formed by combining a plurality of strip-shaped laminated sheets, the arrangement direction of the plurality of strip-shaped laminated sheets is the second direction Y, wherein the plurality of core column sheets 2 are arranged and stacked along the first direction Z, and the first direction Z is perpendicular to the second direction Y, and two adjacent strip-shaped laminated sheets are insulated, so that after leakage magnetic flux 11 vertically enters the surface of the iron core, the eddy current loss is effectively reduced due to the small sectional area of the last-stage core column sheet 2-1. Namely, the final core plate 2-1 is arranged to form a magnetic flux path with high magnetic permeability and low loss by arranging the strip laminations, and an axial low-reluctance loop can be provided for the leakage magnetic flux 11, so that the eddy current loss is reduced, the eddy current reaction is weakened, and the distribution uniformity of magnetic density (magnetic induction intensity) is improved.

In the stem processing process, the stacking direction of the plurality of stem pieces 2 is a vertical upward direction, and after the stem is formed by stacking, the direction of the stem is adjusted so that the stacking direction of the plurality of stem pieces 2 is a first direction Z (horizontal direction); in the yoke processing process, the stacking direction of the plurality of yoke pieces 3 is a vertical upward direction, and after the yokes are stacked and formed, the positions of the yokes are moved and form an iron core together with the core column, so that the stacking direction of the plurality of yoke pieces 3 is a third direction X (vertical direction). That is, the plurality of leg pieces 2 are stacked in the first direction Z and the plurality of yoke pieces 3 are stacked in the third direction X to form a specific stacking direction after the core is formed, and the stacking direction during the assembly of the leg pieces and the yoke is not performed alone.

In this embodiment, n=2. That is, the final stem web 2-1 includes two-stage stem webs 2 located at the outermost sides of the stem. N may also be other integers such as n=1 or n=3, etc.

As shown in fig. 13 and 14, the final stem plate 2-1 is stacked with a number of bar-shaped laminations and cured with epoxy. Wherein, the thickness of the strip lamination is t, the width is H, the length is L, the lamination direction is the width direction (the second direction Y) of the mandrel, and the main orientation direction is the length direction (the third direction X) of the pulling plate. Wherein, the value range of H is between 20mm and 25mm, and the body leakage magnetic flux at the last stage of the iron core is obtained according to the magnetic field calculation for further verification, and the finally determined H is satisfied:

Φ/(W·H)≥B _c ；

in the above formula:

Φ: body leakage flux at the last stage of the core;

w: the width of the final stem plate 2-1;

h: the thickness of the final core column sheet 2-1;

B _c : controlling magnetic density. Wherein, for electrical silicon steel sheet material, B _c Take a value of 0.25T.

As shown in fig. 1, the leakage flux 11 of the transformer body forms a closed loop through the metal structural members such as the iron core, the clamping member 5, the pull plate 4, the clamping member oil guiding box 6 and the like.

The iron core provided by the embodiment of the invention is suitable for a non-power frequency high-leakage transformer iron core structure, can absorb the radial leakage magnetic flux at the last-stage silicon steel sheet (the last-stage column sheet 2-1) of the iron core and enable the last-stage silicon steel sheet to be closed along the height direction of the transformer body, forms a shielding effect on the last-stage silicon steel sheet (the last-stage column sheet 2-1) of the iron core, and effectively reduces the eddy current loss of the iron core.

The iron core provided by the embodiment of the invention can also comprise a side column. The iron yoke comprises an upper iron yoke and a lower iron yoke. Preferably, the oil inlet is the lower end of the lower iron yoke, and the oil outlet is the upper end of the upper iron yoke; 2. the oil inlet is the upper end of the upper iron yoke, and the oil outlet is the lower end of the lower iron yoke

The final core column sheet 2-1 is processed by electrical steel, and the electrical steel is cut into thin strip-shaped lamination strips due to the insulating paint film coated on the surface of the electrical steel, and then the cut lamination strips are vertically arranged. That is, the opposite surfaces of the adjacent two bar-shaped laminations are surfaces of electrical steel, and thus insulation between the adjacent two bar-shaped laminations can be achieved.

Of course, it is also possible to process the strip-shaped laminations directly and then to apply an insulating layer to the opposite faces of the two adjacent strip-shaped laminations.

The last-stage core column sheet 2-1 adopts the mode of vertical arrangement, the last-stage iron yoke sheet (the N-stage iron yoke sheet 3 positioned at the outermost side of the iron yoke) of the iron yoke is laid through in a horizontal lamination mode (the arrangement mode is the same as that of other iron yoke sheets 3), and the other stages are laminated normally. After the cut pieces (the core column piece 2 and the iron yoke piece 3) are cut, the burrs are needed to be removed, the surface resistance is measured after lamination is finished, the measurement is performed at intervals of 10mm along the lamination direction, and the resistance value is larger than 500 omega. When the silicon steel sheet lamination is adopted, the silicon steel sheet orientation measurement is required to be carried out, the main orientation direction of the silicon steel sheet is ensured to be correct, and the final-stage core column sheet 2-1 is poured by epoxy resin after confirming that the silicon steel sheet is error-free.

Specifically, when the working frequency of the transformer is less than 200Hz, the final-stage core sheet 2-1 is formed by stacking silicon steel sheets, wherein the stacking direction is the width direction (second direction Y) of the core sheet 2, that is, the silicon steel sheets are arranged perpendicular to the surface of the pull plate 4 of the iron core structure, and the main orientation direction of the silicon steel sheets is the length direction of the pull plate 4.

The structure of the adjusting core column (the last-stage core column sheet 2-1 is formed by combining a plurality of strip-shaped laminations) can reduce electromagnetic heating, and further avoid the overrun of the temperature rise of the iron core.

On the other hand, the heat dissipation can be enhanced, and the overrun of the temperature rise of the iron core can be avoided. Specifically, the core includes a plurality of core laminations and a plurality of oil passages 1. Wherein, the core lamination comprises a core column sheet 2 and an iron yoke sheet 3; a space is reserved between two adjacent oil channels 1, and fluid in the oil channels 1 can exchange heat with the stem plates 2 and the iron yoke plates 3.

The heat in the iron core is taken away by the flow of the fluid in the oil duct 1.

In order to improve the heat dissipation effect, the modes of forced oil circulation oil supply, increased number of oil channels and prolonged length of the oil channels can be adopted.

The way of prolonging the length of the oil path is that an oil inlet 102 and an oil outlet 101 of the oil path 1 are respectively positioned at the lower end of the iron yoke and the upper end of the iron yoke; the oil passage 1 is a zigzag-shaped oil passage having a plurality of horizontal flow passages in the horizontal direction and a vertical flow passage connecting adjacent two of the horizontal flow passages; one end of the horizontal flow path is an inlet end, and the other end of the horizontal flow path is an outlet end; and a vertical flow path between two adjacent horizontal flow paths, one end of which is communicated with the outlet end of one horizontal flow path, and the other end of which is communicated with the inlet end of the other horizontal flow path. Through the arrangement, the oil flow path is increased, and the iron core lamination is further enabled to fully dissipate heat.

Preferably, the oil inlet 102 is located at the lower end of the lower yoke and the oil outlet 101 is located at the upper end of the upper yoke. Of course, the oil inlet 102 may be located at the upper end of the upper yoke, and the oil outlet 101 may be located at the lower end of the lower yoke.

Further, the oil duct 1 is surrounded by an insulating support bar and an insulating baffle plate positioned on the stacking surface of the iron core lamination; the two side surfaces of the insulating support bar are oil duct walls of the oil duct 1, and one side surface of the insulating baffle is the oil duct wall of the oil duct 1.

By the above arrangement, the oil passage 1 is made an insulated oil passage.

The number of the oil channels is increased, specifically, the distance between two adjacent oil channels 1 along the first direction Z is 80-150 mm. Preferably, the interval between the adjacent two oil passages 1 is 100mm.

The range of the thickness of the oil duct 1 is 3mm-5mm, and the thickness of the oil duct 1 is the size of the oil duct 1 along the first direction Z. Specifically, the thickness of the oil passage 1 is preferably 3.9mm.

Further, in order to improve structural stability, the final stem plate 2-1 is formed by stacking a plurality of bar-shaped laminations and curing with epoxy resin.

The forced oil circulation oil supply mode is to adopt forced guiding oil circulation (OD, forced-directed oil circulation and forced air circulation) in the transformer, and the circulation multiplying power of the fluid is increased by adding an oil pump. The oil circulation oil supply is forced, so that the oil flow in unit time is effectively increased.

The embodiment of the invention also provides an iron core structure, which comprises any iron core.

Since the core has the above technical effects, the core structure having the core has the same technical effects, and will not be described in detail herein.

It will be appreciated that the core structure includes a core, clamping members, insulation members, grounding tabs, and the like.

Specifically, the iron core structure further comprises a clamping piece 5 and a pulling plate 4, and the clamping piece 5 and the pulling plate 4 are clamping pieces. The clamping piece 5 comprises an upper clamping piece and a lower clamping piece, wherein the upper clamping piece and the lower clamping piece extend along the first direction Z, the upper clamping piece is correspondingly arranged with an upper iron yoke of the iron core, and the lower clamping piece is correspondingly arranged with a lower iron yoke of the iron core; the pull plate 4 is arranged along the arrangement direction of the upper clamping piece and the lower clamping piece, and the first direction Z is perpendicular to the surface of the pull plate 4.

Further, the core structure further comprises a clamping piece oil guiding box 6, a coil 7, a coil supporting plate 8 and the like, which are all positioned in a box wall 9 of the transformer.

Further, the web plate of the clamping piece 5 is provided with an oil flow hole, and the oil flow hole is communicated with the oil inlet 102 of the oil duct 1 of the iron core; the iron core structure is also provided with a plurality of trapezoid cushion blocks which are symmetrically arranged at the periphery of the oil flow hole; the opposite surface of the trapezoidal cushion block and the surface of the clamping piece 5 enclose a diversion structure for guiding fluid to flow into the oil flow hole.

Wherein the oil flow holes and the plurality of oil passages 1 form an oil passage 10. The trapezoidal pad plays a role in guiding oil flow in addition to supporting the iron core.

Specifically, the oil flow holes are located in the web of the lower clip member so that the fluid in the oil passage 10 flows from bottom to top.

The invention also provides a transformer comprising any one of the iron core structures. Since the core structure has the above technical effects, the transformer having the core structure has the same technical effects and will not be described in detail herein.

The iron core structure is particularly suitable for non-power frequency high-leakage transformers. The power transformer is particularly used for oil immersed power transformers with frequencies of 50Hz and 60Hz and upper limit of 500 Hz. For higher frequency oil immersed power transformers, the loss per unit weight of the core needs to be controlled to be not more than 3W/kg.

As shown in fig. 5 and 6, the transformer provided by the present invention is a single-phase three-pole transformer, which has a transformer a phase. And, the oil inlet 102 of the oil duct 1 is located below the oil outlet 101 thereof, so that the fluid in the oil duct 1 flows from bottom to top. Specifically, each layer of heat dissipation oil duct is internally provided with oil baffle plates (insulating support bars) which are horizontally staggered. Preferably, the distance between two adjacent oil baffles is 50-100 mm, and the specific distance size is determined according to actual requirements.

Specifically, the insulating baffle is adhered to one half of the length direction of the iron yoke in the iron yoke oil duct, so that each column of oil duct 1 is mutually independent, and each column of oil duct 1 is provided with an independent oil inlet 102 and an independent oil outlet 101, so that fluid cannot flow in a plurality of flow directions in the iron core, can only flow at intervals along a single direction, and heat in the iron core is fully taken away.

As shown in fig. 7 and 8, the transformer provided by the present invention is a single-phase four-pole transformer having a transformer a phase. And, the oil inlet 102 of the oil duct 1 is located below the oil outlet 101 thereof, so that the fluid in the oil duct 1 flows from bottom to top.

As shown in fig. 9 and 10, the transformer provided by the present invention is a single-phase five-pole transformer, which has a transformer a phase. And, the oil inlet 102 of the oil duct 1 is located below the oil outlet 101 thereof, so that the fluid in the oil duct 1 flows from bottom to top.

As shown in fig. 11 and 12, the transformer provided by the present invention is a three-phase three-pole transformer, which has a transformer a phase, a transformer B phase, and a transformer C phase. And, the oil inlet 102 of the oil duct 1 is located below the oil outlet 101 thereof, so that the fluid in the oil duct 1 flows from bottom to top.

As shown in fig. 13 and 14, the transformer provided by the present invention is a three-phase five-pole transformer, which has a transformer a phase, a transformer B phase, and a transformer C phase. And, the oil inlet 102 of the oil duct 1 is located below the oil outlet 101 thereof, so that the fluid in the oil duct 1 flows from bottom to top. In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A core, comprising:

the heart column comprises a plurality of heart column sheets which are arranged along a first direction and are stacked; the final-stage core column sheet is formed by combining a plurality of strip-shaped laminations, and N is more than or equal to 1, wherein the final-stage core column sheet is an N-stage core column sheet positioned at the outermost side of the core column; the arrangement direction of the plurality of strip-shaped laminates is a second direction, and two adjacent strip-shaped laminates are insulated;

the iron yoke comprises a plurality of iron yoke sheets which are arranged along a third direction and are stacked, and any two directions of the first direction, the second direction and the third direction are perpendicular to each other.

2. The core according to claim 1, comprising:

a plurality of core laminations including the leg pieces and the yoke pieces;

and a plurality of oil channels, wherein a space is reserved between two adjacent oil channels, and fluid in the oil channels can exchange heat with the stem plates and the iron yoke plates.

3. The core according to claim 2, wherein an oil inlet of the oil passage and an oil outlet thereof are located at a lower end of the yoke and an upper end of the yoke, respectively;

the oil duct is a zigzag oil duct and is provided with a plurality of horizontal flow paths along the horizontal direction and a vertical flow path connecting two adjacent horizontal flow paths;

one end of the horizontal flow path is an inlet end, and the other end of the horizontal flow path is an outlet end;

and one end of the vertical flow path is communicated with the outlet end of one horizontal flow path, and the other end of the vertical flow path is communicated with the inlet end of the other horizontal flow path.

4. A core according to claim 3, wherein the oil passage is defined by insulating support bars and insulating baffles positioned on the stacking surface of the core laminations;

the two side surfaces of the insulating support bar are oil duct walls of the oil duct, and one side surface of the insulating baffle is the oil duct wall of the oil duct.

5. A core according to claim 2, wherein the distance between two adjacent oil passages in the first direction is in the range of 80mm to 150mm;

and/or the thickness of the oil duct ranges from 3mm to 5mm, and the thickness of the oil duct is the dimension of the oil duct along the first direction.

6. A core according to any of claims 1-5, wherein said final leg pieces are stacked from a plurality of said bar-shaped laminations and cured with epoxy.

7. A core structure comprising a core, characterized in that the core is as claimed in any one of claims 1-6.

8. The core structure of claim 7, further comprising:

the clamping piece comprises an upper clamping piece and a lower clamping piece which extend along the first direction, the upper clamping piece is arranged corresponding to an upper iron yoke of the iron core, and the lower clamping piece is arranged corresponding to a lower iron yoke of the iron core;

and the pull plates are arranged along the arrangement direction of the upper clamping piece and the lower clamping piece, and the first direction is perpendicular to the surface of the pull plates.

9. The core structure of claim 8, wherein the webs of the clips are provided with oil holes, and the oil holes are communicated with oil inlets of oil channels of the core;

the iron core structure is also provided with a plurality of trapezoid cushion blocks which are symmetrically arranged on the periphery of the oil flow hole;

the opposite surfaces of the trapezoid cushion blocks and the surfaces of the clamping pieces enclose a diversion structure for guiding fluid to flow into the oil flow holes.

10. A transformer comprising a core structure, characterized in that the core structure is as claimed in any one of claims 7-9.