KR20170089062A - Core and transformer using the same - Google Patents

Abstract

The present invention relates to a core which can effectively remove heat generated from the core while driving a transformer, and a transformer having the same. According to an embodiment of the present invention, the core comprises: an upper yoke and a lower yoke arranged in parallel with the upper yoke in a lower side of the upper yoke; and a plurality of legs connecting the upper and lower yokes. A passage can be formed in the center of at least one among the upper yoke, the lower yoke, and the plurality of legs.

Description

TECHNICAL FIELD [0001] The present invention relates to an iron core and a transformer having the iron core.

The present invention relates to an iron core capable of efficiently removing heat generated in an iron core during operation of a transformer and a transformer having the iron core.

A transformer is a transformer that changes the magnitude of AC voltage and current using electromagnetic induction.

Transformers are widely used from small electronic devices to large substation or transmission facilities. Particularly, in a large-sized power transmission facility or a transmission facility, an ultra-high-voltage large-capacity transformer is mainly used.

Generally, a transformer is formed by a structure in which a plurality of windings are wound around a common iron core, in which power is input to one winding and then power is output to the other winding.

Also, in the case of a power transformer, components such as a clamp and a tap changer may be included to fix and support the winding or the iron core. In addition, insulating oil is used as insulation medium to ensure the insulation between the parts, and it is placed in the enclosure and protected from external environment.

FIG. 1 is a perspective view schematically showing an iron core of a transformer according to the related art, and FIG. 2 is a cross-sectional view schematically showing a cross section taken along line A-A of FIG.

1 and 2, an iron core 20 of a transformer according to the prior art is disposed in an enclosure 11 and includes an upper yoke 50, a lower yoke 51, and legs 52 and 53 , And each component is formed by stacking a plurality of steel plates.

However, in the conventional case, since the flat steel plate is laminated to form the upper yoke 50, the lower yoke 51, and the legs 52 and 53, the insulating oil can not flow into the iron core, There is a problem that it is difficult to effectively remove heat.

If the heat generated during the operation of the transformer can not be efficiently removed, it may cause various problems such as deterioration in electrical characteristics and safety due to a rise in the internal temperature.

An object of the present invention is to provide an iron core capable of effectively removing heat generated in an iron core and a transformer having the iron core.

The iron core for a transformer according to an embodiment of the present invention includes an upper yoke, a lower yoke disposed in parallel with the upper yoke at a lower side of the upper yoke, and a plurality of legs connecting the upper yoke and the lower yoke, At least one of the upper yoke, the lower yoke, and the legs may have a passage formed at the center thereof.

In the present embodiment, at least one of the upper yoke, the lower yoke, and the legs includes a bending steel plate having a body bent, and a plurality of the bending steel plates may be laminated.

In the present embodiment, the bending steel sheet may be formed by bending the center at a right angle.

In the present embodiment, the bended steel plate includes four reference steel plates and a plurality of laminated steel plates laminated on the inner side surfaces of the reference steel plates, and the four reference steel plates are the outer steel plates of the other reference steel plates The four reference steel plates and the plurality of laminated steel plates are integrally formed so as to be in contact with the side surfaces of the four reference steel plates and the plurality of laminated steel plates as a whole A cylindrical structure can be constituted.

In the present embodiment, the flow path may be formed at the center of the cross beam shape formed by the four reference steel plates.

In the present embodiment, the reference steel plates may be formed in a curved corner portion.

Further, the transformer according to the embodiment of the present invention may include the iron core, the winding wire wound around the iron core, and the enclosure housing the iron core wound with the winding wire and filled with the insulating oil.

According to the embodiment of the present invention having such a configuration, the insulating oil filled in the transformer can flow into the flow path formed inside the iron core. Accordingly, since the cooling of the iron core is more efficiently performed during the operation of the transformer, the temperature rise inside the transformer can be suppressed and the safety of the transformer can be ensured.

1 is a perspective view schematically showing an iron core of a transformer according to the prior art;
FIG. 2 is a cross-sectional view schematically showing a cross section taken along the line AA of FIG. 1; FIG.
3 is a schematic diagram showing the construction of a transformer according to an embodiment of the present invention.
4 is a partially exploded perspective view showing a structure of an iron core according to BB of FIG.
5 is a plan view of the iron core shown in Fig.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. In addition, the shape and size of elements in the figures may be exaggerated for clarity.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a cross-sectional view schematically showing a transformer according to an embodiment of the present invention, and FIG. 4 is a partially exploded perspective view showing a structure of an iron core according to B-B of FIG. 5 is a plan view of the iron core shown in Fig.

3, a transformer 100 according to an embodiment of the present invention may include an enclosure 110, a coil 130, and an iron core 120. As shown in FIG.

The iron core 120 and the windings 130 may be disposed inside the enclosure 110. That is, the enclosure 110 is a member that isolates the iron core 120 and the coil 130 from the outside, and protects the iron core 120 and the coil 130 from the external environment.

Various fluids may be stored in the enclosure 110 according to the type of the transformer 100. For example, in the case of the inflow type transformer, the insulating oil 170 may be filled in the inside of the enclosure 110, and air may be filled inside the enclosure 110 in the case of the dry type transformer.

The winding 130 may be a wire type or a foil type wire wound on an iron core 120 to be described later, and may include a primary winding and a secondary winding. In this embodiment, the primary winding and the secondary winding are stacked and wound on the main leg 153 of the iron core 120 as an example. However, the configuration of the present invention is not limited thereto, and it is also possible to wind the side legs 152 as necessary.

The iron core 120 is a member that serves as a passage for magnetic force lines. Generally, the iron core 120 is formed in a laminated structure of thin steel sheets to reduce iron loss. In this embodiment, the iron core 120 is a laminated structure of the electric steel plates, and the electric steel plate may be a thin steel plate containing silicon. However, the present invention is not limited thereto.

The iron core 120 includes the yokes 150 and 151 and the legs 152 and 153.

The yokes 150 and 151 include an upper yoke 150 and a lower yoke 151.

The upper yoke 150 is a member for forming the upper part of the iron core 120, and may be formed in a rod shape and arranged long.

The lower yoke 151 is a member that forms a lower portion of the iron core 120. The lower yoke 151 may be disposed below the upper yoke 150 and parallel to the upper yoke 150. For example, the lower yoke 151 and the upper yoke 150 may be arranged in parallel along the horizontal direction.

The legs 152 and 153 are members vertically disposed between the upper yoke 150 and the lower yoke 151. The legs 152 and 153 may be spaced apart from each other by a predetermined distance between the upper yoke 150 and the lower yoke 151 along a vertical direction.

Specifically, the legs 152 and 153 according to the present embodiment include a main leg 153 disposed at the center and two side legs 152 disposed on both sides of the main leg 153, respectively.

However, the present invention is not limited thereto and various modifications are possible. For example, in the above-described embodiment, the main legs 153 are formed as one unit. However, when the transformers are configured as three-phase or parallel structures, the number of the main legs 153 may be plural.

In addition, the iron core 120 according to the present embodiment includes a plurality of bending steel plates 125. More specifically, at least one of the legs 152 and 153 and the yokes 150 and 151 may be formed through the bending steel plates 125.

The bending steel plate 125 refers to a steel plate whose body is bent through press working or bending.

The bending steel plate 125 has a higher natural frequency than the plate-shaped steel plate.

As a result of simulation, the natural frequency of a silicon steel sheet having a modulus of elasticity of 200 GPa, a Poisson's ratio of 0.33, a density of 7,850 kg / m ³ , a length of 0.2 m and a width of 0.5 m was measured, Was measured at 6.7 Hz when one end was fixed and 43 Hz when both ends were fixed.

On the other hand, the natural frequency of the bent silicon steel sheet bent at right angles to the center was measured as 34.4 Hz when one end is fixed and 80.1 Hz when both ends are fixed.

As described above, it can be seen that the natural frequency of the bent steel sheet is significantly higher than that of the flat steel plate due to the structural characteristics thereof.

Meanwhile, the iron core 120 according to the embodiment of the present invention may be constructed by stacking a plurality of bending steel plates 125 as shown in FIG.

The bended steel plate 125 may be formed by bending a plate-form steel plate at right angles. For example, it can be formed by bending a steel plate with a center line dividing the flat plate-like steel plate in the longitudinal direction into a fold line.

In addition, the plurality of bending steel plates 125 constituting the iron core 120 according to the embodiment of the present invention may include four reference steel plates 121 and a plurality of laminated steel plates 122.

The reference steel plate 121 may be a bended steel plate 125 disposed on the innermost side of the iron core 120 so as to be in contact with the outer surface of another reference steel plate 121 disposed adjacent to the outer side. Here, the outer surface of the reference steel plate 121 means the surface opposite to the direction in which the reference steel plate 121 is bent.

The four reference steel plates 121 are joined to each other with the above-described structure to form a cross beam shape.

A plurality of laminated steel plates 122 may be laminated on the inner surface of the reference steel plate 121.

However, the plurality of laminated steel plates 122 may be formed in such a shape that their widths gradually become shorter as they are disposed on the outside. Here, the outer side in the direction in which the laminated steel plates 122 are laminated means the radially outer side of the iron core 120 according to the embodiment of the present invention.

As described above, the four reference steel plates 121 and the plurality of laminated steel plates 122 stacked on the respective reference steel plates 121 can constitute a cylindrical structure as a whole as shown in FIG.

Since the natural frequencies of the bending steel plates 125 stacked in the iron core 120 according to this embodiment are larger than the natural frequency of the conventional steel plate, The natural frequency of the entire iron core 120 becomes remarkably larger than the natural frequency of the iron core 120 constituted of the conventional flat plate type steel plate.

For reference, an external frequency of about 120 Hz is generally generated in a transformer to which the iron core 120 according to an embodiment of the present invention can be applied.

At this time, the larger the difference between the magnitude of the external frequency and the magnitude of the natural frequency of the iron core 120, the less resonance occurs and the noise is reduced.

Therefore, the iron core 120 according to the embodiment of the present invention significantly increases the natural frequency of the iron core 120 itself through the bending steel plate 125, so that the difference from the external frequency becomes large, Noise can be reduced.

Also, the iron core 120 according to the present embodiment has a passage 180 through which the insulating oil 170 flows.

The flow path 180 is formed at the corner where the four reference steel plates 121 are gathered, that is, the center of the cross beam shape formed by the four reference steel plates 121.

More specifically, when the reference steel plates 121 according to the present embodiment are bent through the press working, the corner portions are not formed angularly but are formed as a round arc.

Accordingly, when the four reference steel plates 121 are coupled, a flow path 180 is formed in the central portion as shown in FIG.

Therefore, the flow path 180 can be formed in the iron core 120 without a separate process for forming the flow path 180.

The size of the passage 180 according to the present embodiment may be changed according to the size of the arc formed at the corner of the reference steel plate 121. That is, the cross-sectional area of the flow path 180 increases as the radius of the arc increases, and as the radius of the arc decreases, the cross-sectional area of the flow path 180 decreases.

On the other hand, in this embodiment, the four corners of the reference steel plates 121 are all formed into arc shapes. However, the present invention is not limited to this. Only one of the four reference steel plates 121 may be formed into an arc shape, and the remainder may be angled.

In this case, a channel having a very small cross-sectional area can be formed as compared with the embodiment shown in Fig. In this way, the iron core according to the present embodiment can selectively form the reference steel plate 121 in an arcuate shape in order to form a suitable size of the channel 180.

Further, by forming the reference steel plate 121 in an arc shape, the laminated steel plates 122 stacked on the reference steel plate 121 can also be formed into arc shapes at the corner portions. For example, the laminated steel plates 122 may be formed such that the corners of the laminated steel plates 122 correspond to the shapes of the reference steel plates 121, and the corners of the laminated steel plates 122 become angled toward the outside. However, the present invention is not limited thereto.

In the thus constructed flow path, the insulating oil filled in the transformer flows and flows. Accordingly, since the cooling of the iron core is more efficiently performed during the operation of the transformer, the temperature rise inside the transformer can be suppressed and the safety of the transformer can be ensured.

The insulating oil 170 flows into the oil passage 121 through the connecting portion 124 connecting the yokes 150 and 151 and the legs 152 and 153. In this embodiment, For this purpose, when coupling the yokes 150 and 151 with the legs 152 and 153 in the manufacturing process of the iron core 120, a gap (not shown) in which the insulating oil 170 can flow into the oil passage 180 Can be formed in the connection portion (124).

However, the present invention is not limited thereto, and it is also possible to form a separate hole connected to the flow path so that the insulating oil flows into the flow path through the hole. At this time, the hole may be formed to extend the flow path. In this case, the flow path formed in the leg is connected to the outside of the iron core through a hole penetrating the upper yoke and the lower yoke, and the flow path formed in the yoke can be connected to the outside through a hole penetrating the leg. However, the present invention is not limited thereto.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be obvious to those of ordinary skill in the art.

For example, in the above-described embodiment, a case where a flow path is formed in the upper yoke, the lower yoke, and the legs is taken as an example. However, the configuration of the present invention is not limited thereto, and it is also possible to form a flow path only in at least one of the upper yoke, the lower yoke, and the legs. For example, it is possible to form a flow path only in the reds, or to form a flow path only in the yokes.

100: Transformer
110: enclosure
120: iron core
130: Winding
150: upper yoke
151: Lower yoke
152: side leg
153: Main leg
170: insulating oil
180: Euro

Claims (7)

A lower yoke disposed on the lower side of the upper yoke and aligned with the upper yoke; And
A plurality of legs connecting the upper yoke and the lower yoke;
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Wherein at least one of the upper yoke, the lower yoke, and the legs has a channel formed at the center thereof.
2. The apparatus of claim 1, wherein at least one of the upper yoke, the lower yoke,
A bending steel plate whose body is bent,
And a plurality of the bended steel plates are laminated to form an iron core of the transformer.
3. The method of claim 2,
Wherein the bending steel plate is bent at a right angle at the center thereof.
The method of claim 3,
Wherein the bended steel plate includes four reference steel plates and a plurality of laminated steel plates laminated on the inner side surfaces of the reference steel plates,
The four reference steel plates are laminated so as to be in contact with the outer surfaces of the other reference steel plates which are arranged adjacent to each other,
Wherein the plurality of laminated steel plates are formed in such a shape that their width gradually decreases as they are disposed on the outside, and the four reference steel plates and the plurality of laminated steel plates constitute a cylindrical structure as a whole.
5. The apparatus according to claim 4,
And an iron core of a transformer formed at the center of a cross beam shape formed by the four reference steel plates.
[6] The method of claim 4,
An iron core of a transformer in which a bent corner portion is formed in an arc shape.
An iron core according to claim 1;
A winding wound around the iron core; And
An enclosure housing the iron core with the windings wound thereon and filled with insulating oil therein;
And a transformer.

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