JP2000260627A - Tank structure of transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low-noise transformer in which an iron core, windings, an insulating material, etc., as contents of the transformer are placed in a tank and the tank is filled with insulating material. SOLUTION: Of four junction parts of a tank 5 of a transformer joined by a lower face plate 1 of the tank and side plate 2 thereof, at least one junction part is integrally mounted with a prismatic member 4 of the same material as the tank 5. Or the prismatic member 4 of the same material as a cover 3 is integrally mounted on the cover 3 of the transformer between a junction part 6 of the cover 3 and tank 5 and tightening studs 22 for the transformer contents. Vibrations generated within the transformer including windings and an iron core can be attenuated by the action of a variation in the cross section area of the tank structure. As a result, there can be obtained a tank structure which can reduce generated noise while minimizing increase in the size of the transformer or in its cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer, and more particularly to a tank structure thereof.

[0002]

2. Description of the Related Art A conventional transformer tank structure will be described with reference to FIG. A transformer in which a winding 11 formed by winding an electric wire is arranged around an iron core 10 on which magnetic steel sheets are laminated, the contents of the core 1
It is formed by tightening the winding 11 using the clamp 20 and the tightening stud 22 which sandwich the yoke portion of No. 0.

On the other hand, a transformer tank 5 for storing the contents of the transformer is composed of a tank lower plate 1 disposed on the bottom of the transformer tank 5 and a tank side plate 2 disposed on a side surface thereof. It is joined by such means. Further, the cover 3 of the transformer is arranged on the upper part of the transformer tank 5 and the joint 6
At the transformer tank 5.

[0004] The contents of the transformer are the tank 5 of the transformer.
And a lower steady rest 21 having one end of the fastening stud 22 fixed to the cover 3 and the other end fixed to the tank lower plate 1.
Is fixed to the tank and the cover by engaging with a bolt. The space surrounded by the tank 5 and the cover 3 is filled with an insulating material 12 such as insulating oil.

It is known that, in principle, the winding of a transformer generates vibration having a frequency twice as high as that of the AC power to be transformed. It is also known to generate vibrations of an integer multiple of frequency.

[0006] By the vibration generated in the winding and the iron core,
Noise is emitted outside the transformer. The route will be described with reference to FIG. In FIG. 4, vibrations generated in the iron core 10 and the windings 11 propagate to the tank side plate 2 mainly through three paths. The first path propagates from the clamp 20 to the tank side plate 2 via the lower steady rest 21 and the tank lower plate 1 in this order. The second path propagates from the clamp 20 to the tank side plate 2 via the fastening stud 22, the cover 3, and the joint 6 in this order. The third path propagates through the insulating material 12 from the winding 11 and the iron core 10 to the tank side plate 2.

[0007] The vibration of the tank side plate 2 vibrates the air present in the surroundings, and particularly causes noise.

When installing a transformer near a residential area,
As described above, the noise generated from the transformer may be a problem. When noise reduction is necessary, cover the outer surface of the tank with soundproofing material or block the shock absorber between the transformer contents and the tank to block the propagation of vibration from the transformer contents to the tank. We are dealing with that.

[0009]

Covering the outer surface of the tank with the above-mentioned soundproofing material or sandwiching the cushioning material between the contents of the transformer and the tank involves problems such as an increase in size and cost of the transformer. You are shunned. Moreover, from the viewpoint of environmental protection, transformers are required to have lower noise than ever.

Therefore, an object of the present invention is to increase the size of the transformer by attenuating the vibration in the vibration propagation path passing through the tank bottom plate and the cover among the three main vibration propagation paths. Another object of the present invention is to provide a transformer tank structure capable of reducing generated noise while minimizing cost increase.

[0011]

Means for Solving the Problems To solve the above-mentioned problems, the present invention relates to a document (for example, “Acoustic Engineering Course 4 Noise Edited by the Acoustical Society of Japan” published by Corona Co., Ltd. on July 10, 1996).・ Vibration (above) ”6.4.3. See the section on attenuation during propagation of solid-state sound).
Hereinafter, this principle will be described in detail with reference to FIG.

In FIG. 2, a structural member 71 having a certain cross-sectional area S1 and a structural member 72 having a certain cross-sectional area S2 are joined at a joint 73. When the input vibration 51 is incident from the side of the structural material 71, it propagates through the structural material 71 and reaches the joint 73.

If the propagating vibration is a longitudinal wave, the characteristic impedance Z ₇₁ of the structural material 71 is equal to the product of the mass m ₇₁ per unit length of the propagation medium and the propagation speed c ₇₁ , and Z ₇₁ =
represented by m _{7 1} c _71. Similarly, the characteristic impedance of the structural member 72 is represented by _{Z 72 = m 7 2 c 72} . When the structural material 71 and the structural material 72 are made of the same material and only the cross-sectional area is changed, the masses m ₇₁ and m ₇₂ per unit length are obtained.
Are different, the characteristic impedances Z ₇₁ , Z ₇₂
Also changes in proportion to the cross-sectional area.

On the other hand, when the characteristic impedance is Z₇₁To Z
₇₂The damping rate R (dB) of the vibration at the part where
= 10 log₁₀｛1 / (1- | r |²)｝
You. Here, r is the amplitude response when the vibration propagates through the medium.
The emissivity, r = (Z₇₁-Z ₇₂) / (Z₇₁+ Z
₇₂).

In FIG. 2, the sectional area S1 of the structural material 71 is shown.
When the ratio of the sectional area S2 of the structural material 72 is 1:10, the characteristic impedance ratio Z ₇₁ : Z ₇₂ is 1:10.
And the amplitude reflectance is r = −9 / 11.
The damping rate of the vibration propagating from 1 to the structural material 72 is R = 4.8.
dB.

With respect to propagation of a transverse wave, various conditions such as a propagation speed and an angular velocity overlap, but the area ratio is 100 times and about 23 times.
dB attenuation is described in the literature.

As described above, it is possible to attenuate the vibration by applying the principle that the vibration is attenuated by changing the cross-sectional area in the middle of the structural material to the tank structure of the transformer.

According to a first aspect of the present invention, in order to solve the above-mentioned problems, a prismatic member is disposed at a joint between a tank lower plate and a tank side plate of a transformer, and the tank side plate and the corner are connected to each other. The joint portion between the columnar member and the joint portion between the tank lower surface plate and the prismatic member is entirely joined by means such as welding. Due to the change in the cross-sectional area of the prismatic member, the effect of damping the vibration based on the principle described above is exerted on the vibration transmitted from the tank lower plate to the tank side plate via the clamp and the lower steady rest.

According to a second aspect of the present invention, in order to solve the above-mentioned problem, at least one of a front surface and a rear surface of a cover of a transformer, wherein the contents of the transformer are engaged with the cover. Around the studs, between the joint between the tank side plate of the transformer and the cover, a prismatic member is arranged, and the joint between the prismatic member and the cover is formed by means such as welding. And the entire surface is joined. Due to the change in the cross-sectional area of the prismatic member, the vibration is attenuated according to the above-described principle with respect to the vibration propagating from the fastening stud to the tank side plate via the cover.

The invention described in claim 3 is characterized in that the structure described in the preceding paragraph and the structure described in the preceding paragraph are applied to one tank.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention described in claim 1 will be described with reference to FIG. Transformer tank 5
A prismatic member 4 is disposed at at least one of the four sides of the joint between the lower portion of the tank side plate 2 and the periphery of the tank lower surface plate 1, and the prismatic member 4 is provided at the joint between the tank lower plate 1 and the tank side plate 2. The joint with the member 4 has a structure joined over the entire surface by means such as welding. With the above-described tank structure, the vibration generated in the transformer contents composed of the windings and the iron core passes from the tank lower surface plate of the transformer to the tank side plate through the transformer contents clamps and lower steady rests. At the joint between the tank bottom plate and the prismatic member disposed at the joint between the tank side plate.

An embodiment of the present invention described in claim 2 will be described with reference to FIG. Between the periphery of the engagement between the cover 3 of the transformer and the fastening studs 22 and the joint 6 between the cover 3 and the tank 5, a rectangular column made of the same material as the cover 3 is formed on the front and back surfaces of the cover 3. The member 4 is arranged, and the joint between the cover 3 and the prismatic member 4 is joined over the entire surface by means such as welding. With the above-described tank structure, the vibration generated in the transformer contents constituted by the windings and the iron core passes through the transformer contents clamps and tightening studs, and the transformer cover and the tightening are performed. When propagating from the engagement portion with the stud to the tank side plate, it attenuates at the position of the prismatic member on the cover.

The embodiment of the present invention described in claim 3 will not be described with reference to the drawings and the like. However, as shown in the paragraphs before and after the preceding paragraph, the clamp of the transformer contents and the lower steady rest are provided. Vibration reaching the tank side plate via the tank, and vibration arriving at the tank side plate via the clamps and fastening studs and the cover of the transformer, is a prismatic member arranged at the joint between the tank bottom plate and the tank side plate. At the position of the prism-shaped member disposed on the cover.

[0024]

As described above, according to the present invention, it is possible to attenuate the vibration generated in the contents of the transformer composed of the windings and the iron core by the action of the cross-sectional area change of the tank structure. As a result, it is possible to provide a transformer tank structure in which generated noise is reduced while minimizing the size and cost of the transformer.

[Brief description of the drawings]

FIG. 1 is a transformer tank structural diagram showing one embodiment of the invention according to claim 1;

FIG. 2 is a diagram illustrating the principle of the present invention.

FIG. 3 is a transformer tank structural diagram showing one embodiment of the invention according to claim 2;

FIG. 4 is a diagram illustrating a structure of a conventional transformer tank and propagation of vibration.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tank bottom plate 2 tank side plate 3 cover 4 prismatic member 5 tank 6 joint 10 iron core 11 winding 12 insulating material 20 clamp 21 lower steady rest 22 fastening stud 51 input vibration 71, 72 structural material 73 joint

Claims (3)

[Claims] 1. A transformer comprising a winding and an iron core,
A transformer which is placed in a tank filled with an insulating material, an upper part of the transformer is engaged with a cover of the tank, and a lower part of the transformer is engaged with the tank lower plate. A transformer characterized in that a prismatic member of the same material as the tank is attached to at least one side of a joint portion between the tank and the tank side plate, and an attachment surface of the prismatic member is joined over the entire surface by means such as welding. Tank structure. 2. A transformer comprising a winding and an iron core,
A transformer which is placed in a tank filled with an insulating material, an upper portion of the transformer is engaged with a cover of the tank, and a lower portion of the transformer is engaged with a lower surface plate of the tank. At least one of the front surface and the back surface of the cover between the upper portion of the cover and the cover engaging portion, and the joint portion between the cover and the tank side plate, is attached with a prism-shaped member made of the same material as the cover, Wherein the mounting surfaces of the members are joined over the entire surface by means such as welding. 3. A transformer comprising a winding and an iron core,
2. The transformer according to claim 1, wherein said transformer is placed in a tank filled with an insulating material, said upper part of said transformer is engaged with a cover of said tank, and said lower part of said transformer is engaged with said tank bottom plate. A tank structure for a transformer, having both the features of (1) and (2).