CN113611494A

CN113611494A - Structure of high-impedance transformer

Info

Publication number: CN113611494A
Application number: CN202110920820.2A
Authority: CN
Inventors: 张亚杰; 侯义明; 刘新颜; 庞建丽; 刘洪文; 张庆波
Original assignee: Baoding Tianwei Group Tebian Electric Co Ltd
Current assignee: Baoding Tianwei Group Tebian Electric Co Ltd
Priority date: 2021-08-11
Filing date: 2021-08-11
Publication date: 2021-11-05

Abstract

The invention provides a structure of a high-impedance transformer, which comprises an iron core, a winding assembly and a magnetic gathering ring. The winding assembly comprises a first winding and a second winding, and the first winding and the second winding are respectively sleeved on the core post of the iron core; the magnetic gathering ring is arranged in the hollow channel between the first winding and the second winding and used for increasing the magnetic permeability in the hollow channel so as to increase the short-circuit impedance. The structure of the high-impedance transformer provided by the invention improves the short-circuit impedance of the transformer under the condition of not increasing the volume of the transformer, does not increase the consumption of materials, and avoids the problem of local overheating of the high-impedance transformer.

Description

Structure of high-impedance transformer

Technical Field

The invention belongs to the technical field of transformers, and particularly relates to a structure of a high-impedance transformer.

Background

Short-circuit impedance is an important technical index of a transformer, a high-impedance power transformer and a special transformer are often used for limiting short-circuit current or reducing harmonic current in a frequency conversion system, and at present, the short-circuit impedance is increased mainly by increasing the number of turns of a winding and increasing the leakage area.

For a conventional transformer, to obtain a larger short-circuit impedance, the number of turns of the winding is mainly increased, and the distance between the two windings is increased, which increases the weight of the lead and the volume of the transformer, correspondingly increases the manufacturing cost of the transformer, has the disadvantages of increased material consumption and easily causes local overheating due to high magnetic leakage generated by the large air channel between the two windings.

Disclosure of Invention

The embodiment of the invention provides a structure of a high-impedance transformer, aiming at solving the problems of increased material consumption and local overheating caused by improving the short-circuit impedance of the transformer.

In order to solve the problems, the invention adopts the technical scheme that: provided is a structure of a high impedance transformer, including:

an iron core;

the winding assembly comprises a first winding and a second winding, the first winding and the second winding are respectively sleeved on the core post of the iron core, and the second winding is positioned on the outer side of the first winding; and

and the magnetic gathering ring is arranged in a hollow channel between the first winding and the second winding.

As another embodiment of the present application, the magnetic gathering ring comprises a plurality of magnetic gathering arcs arranged at intervals.

As another embodiment of the application, the magnetic focusing arc comprises a plurality of layers of laminated arc-shaped silicon steel sheets and insulating paper boards coated on the inner side and the outer side.

As another embodiment of the application, the arc-shaped silicon steel sheets of adjacent layers are bonded by epoxy resin.

As another embodiment of the application, the lower end parts among a plurality of arc-shaped silicon steel sheets of the magnetic arc focusing are welded in an equipotential mode, and a lead is used for leading out the ground.

As another embodiment of the application, the magnetic gathering ring comprises a plurality of layers of laminated annular silicon steel sheets with openings and insulating paper boards coated on the inner side and the outer side.

As another embodiment of the application, the annular silicon steel sheets with openings in adjacent layers are bonded by epoxy resin.

As another embodiment of the present application, lower end portions of the magnetic gathering rings between the plurality of annular silicon steel sheets provided with the openings are welded in an equipotential manner, and are led out to be grounded by using a conducting wire.

As another embodiment of the present application, a minimum distance between the magnetic gathering ring and the first winding is 5mm, and a minimum distance between the magnetic gathering ring and the second winding is 10 mm.

Compared with the prior art, the structure of the high-impedance transformer provided by the embodiment of the invention has the advantages that the magnetic gathering ring is additionally arranged in the empty channel between the first winding and the second winding, the magnetic gathering ring can obviously increase the average magnetic permeability in the empty channel so as to increase the short-circuit impedance, the design size of the empty channel between the first winding and the second winding can be correspondingly reduced, the size miniaturization design of the transformer is further realized, the short-circuit impedance of the transformer is improved, the consumption of materials is not increased, and the problem of local overheating is avoided.

Drawings

Fig. 1 is a schematic diagram of a high impedance transformer according to an embodiment of the present invention, which is configured in a three-winding form;

fig. 2 is a schematic diagram of a high impedance transformer according to an embodiment of the present invention in a dual winding form;

FIG. 3 is a cross-sectional view of the split-structure magnetic polymer ring of FIG. 2;

FIG. 4 is a schematic view of the magnetic poly arc of FIG. 3;

fig. 5 is a schematic cross-sectional view of the magnetic poly ring of the overall structure of fig. 2.

In the figure: 100. an iron core; 200. a low voltage winding; 300. a magnetic gathering ring; 400. a medium voltage winding; 500. a high voltage winding; 600. a voltage regulating winding; 310. magnetic focusing arc; 320. a wire; 330. and a ground terminal.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It should be noted that the terms "length," "width," "height," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," "tail," and the like, indicate orientations or positional relationships that are based on the orientations or positional relationships illustrated in the drawings, are used for convenience in describing the invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore should not be construed as limiting the invention.

It is also noted that, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," "disposed," and the like are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Further, "plurality" or "a plurality" means two or more unless specifically limited otherwise.

Referring to fig. 1 to 5, an embodiment of the structure of the high impedance transformer provided by the present invention will now be described. The structure of the high-impedance transformer is used in a power transmission system to limit short-circuit current as a prominent function, and comprises a core 100, a winding assembly and a magnetic gathering ring 300.

The winding assembly comprises a first winding and a second winding, the first winding and the second winding are respectively sleeved on the core column of the iron core 100, the second winding is located on the outer side of the first winding, and a hollow channel is formed between the first winding and the second winding. Referring to fig. 1, when the structure of the high-impedance transformer provided by the embodiment of the present invention is a three-winding type, a low-voltage winding 200, a medium-voltage winding 400, and a high-voltage winding 500 are sequentially sleeved on a core leg of an iron core 100 from inside to outside (of course, a voltage-regulating winding 600 may be disposed on an outer side of the high-voltage winding 500), in this case, a first winding may be the low-voltage winding 200, and a second winding may be the medium-voltage winding 400, or the first winding may be the medium-voltage winding 400 and the second winding may be the high-voltage winding 500. Referring to fig. 2, when the structure of the high-impedance transformer provided by the embodiment of the present invention is a dual-winding type, the low-voltage winding 200 and the high-voltage winding 500 are sequentially sleeved on the core leg of the iron core 100 from inside to outside (of course, a voltage regulating winding 600 may be further disposed on the outer side of the high-voltage winding 500), the first winding is the low-voltage winding 200, and the second winding is the high-voltage winding 500.

The magnetic gathering ring 300 is arranged in a hollow channel formed by the first winding and the second winding and used for increasing magnetic permeability in the hollow channel to increase magnetic field energy storage, and according to the principle that the short-circuit impedance of the transformer is in direct proportion to the magnetic field energy storage in the hollow channel and the magnetic field energy storage is in direct proportion to the magnetic permeability in the hollow channel, the magnetic permeability of the magnetic gathering ring 300 is thousands of times to ten thousand times of the magnetic permeability of insulating oil or air of the transformer, so that the magnetic gathering ring 300 is placed in the hollow channel to remarkably increase the magnetic permeability in the hollow channel and further improve the short-circuit impedance of the transformer.

Compared with the prior art, the structure of the high-impedance transformer provided by the embodiment of the invention has the advantages that the magnetic gathering ring is additionally arranged in the empty channel between the first winding and the second winding, the magnetic gathering ring can obviously increase the magnetic permeability in the empty channel so as to increase the short-circuit impedance, the design size of the empty channel between the first winding and the second winding can be correspondingly reduced, the size miniaturization design of the transformer is further realized, the short-circuit impedance of the transformer is improved, the consumption of materials is not increased, and the problem of local overheating is avoided.

In some embodiments, referring to fig. 3, the magnetic gathering ring 300 includes a plurality of magnetic gathering arcs 310 disposed at intervals in the hollow track. When the magnetic gathering ring 300 has a plurality of magnetic gathering arcs 310, the magnetic gathering ring 300 is a split structure formed by the plurality of magnetic gathering arcs 310 uniformly distributed around the circumference of the first winding.

In some embodiments, referring to fig. 4, the magnetic focusing arc 310 includes a plurality of stacked arc-shaped silicon steel sheets and an insulating paper sheet wrapped on the inner side and the outer side, the insulating paper sheet may be integrally connected with the magnetic focusing arc 310 through an insulating bolt, and the insulating paper sheet is used for insulating the magnetic focusing arc 310 and has a fixing and supporting function on the magnetic focusing arc 310.

In some embodiments, referring to fig. 4, the arc-shaped silicon steel sheets of adjacent layers are bonded by epoxy resin, so that the plurality of arc-shaped silicon steel sheets are laminated by epoxy resin to form the magnetic focusing arc 310.

In some embodiments, referring to fig. 4, the arc-shaped silicon steel sheets are connected with a conducting wire 320 for grounding, when a split structure is adopted, spot welding of multiple layers of silicon steel sheets is firstly performed at the end of each magnetic convergence arc 310 to achieve equipotential of each silicon steel sheet, that is, solder or molten silicon steel is used at the end to achieve connection of each silicon steel sheet to achieve equipotential of each silicon steel sheet. And then, the magnetic focusing arcs 310 are connected pairwise at the inner sides of the magnetic focusing arcs 310 by using copper strips, a pair of adjacent magnetic focusing arcs 310 are left unconnected, a lead 320 is used for leading out the ground, one end of the lead 320 is connected with a ground terminal 330, and the ground terminal 330 is used for a ground wire, so that the ground wire has good grounding conditions.

In some embodiments, referring to fig. 5, the magnetic gathering ring 300 includes a plurality of layers of laminated annular silicon steel sheets with openings and insulating paper sheets wrapped on the inner side and the outer side of the magnetic gathering ring 300, and the magnetic gathering ring 300 is an integral structure with openings and integrally arranged around the first winding in the circumferential direction. The insulating paper board can be connected with the magnetic polymer ring 300 into a whole through an insulating bolt, is used for insulating the magnetic polymer ring 300 and has a fixing and supporting effect on the magnetic polymer ring 300.

In some embodiments, the annular silicon steel sheets with openings of adjacent layers are bonded with epoxy resin, so that the plurality of annular silicon steel sheets with openings are laminated into the magnetic gathering ring 300 by the epoxy resin.

In some embodiments, the end of the magnetic gathering ring 300 is spot-welded to connect multiple layers of silicon steel sheets to achieve equipotential of each silicon steel sheet, that is, the end is welded or melted to connect the silicon steel sheets to achieve equipotential of each silicon steel sheet. And lead out the ground by the wire 320, one end of the wire 320 is connected with a ground terminal 330, the ground terminal 330 is used for the ground wire, make the ground wire have good ground condition.

In some embodiments, referring to fig. 3 and 5, the magnetic poly ring 300 has a minimum distance of 5mm from the first winding and a minimum distance of 10mm from the second winding. The magnetic poly ring 300 does not exceed the first winding and the second winding in the height direction.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A structure of a high impedance transformer, comprising:

an iron core;

2. The structure of a high impedance transformer of claim 1 wherein said magnetically focusing ring comprises a plurality of magnetically focusing arcs spaced apart.

3. The structure of the high impedance transformer of claim 2, wherein the magnetic focusing arc comprises a plurality of laminated arc-shaped silicon steel sheets and insulating paper sheets coated on the inner side and the outer side.

4. The structure of high impedance transformer of claim 3, wherein the arc-shaped silicon steel sheets of adjacent layers are bonded with epoxy resin.

5. The structure of the high impedance transformer of claim 3, wherein the lower end portions between the plurality of arc-shaped silicon steel sheets of the magnetic focusing arc are welded in an equipotential manner and are grounded by a lead wire.

6. The structure of a high impedance transformer as claimed in claim 1, wherein the magnetic gathering ring comprises a plurality of laminated annular silicon steel sheets with openings and insulating paper sheets coated on the inner and outer sides.

7. The structure of high impedance transformer according to claim 6, wherein the annular silicon steel sheets having openings in adjacent layers are bonded with epoxy resin.

8. The structure of the high impedance transformer according to claim 6, wherein the lower end portions between the annular silicon steel sheets provided with the openings of the magnetic gathering ring are welded equipotentially and are led out to the ground by a lead wire.

9. The structure of a high impedance transformer of any one of claims 1 to 8 wherein the minimum distance between the said magnetic poly ring and the said first winding is 5mm and the minimum distance between the said magnetic poly ring and the said second winding is 10 mm.