Stationary induction apparatus

Abstract

To obtain a stationary induction apparatus capable of reducing oil hammer propagating to a tank while restraining deformation of a coil.SOLUTION: A stationary induction apparatus 1 includes a transformer section 2 having an iron core 21 and a coil 22, a box-shaped tank 3 that accommodates the transformer section 2 and insulating oil 7, an upper fastener 4 arranged above the transformer section 2, a lower fastener 5 arranged below the transformer section 2, and two connecting members 6 that are arranged so as to face each other through the transformer section 2 and connect the upper fastener 4 and the lower fastener 5. The tank 3 has a bottom wall 31, a side wall 32 that rises from the peripheral edge of the bottom wall 31 and is provided with a heat dissipation fin 37, and a welded portion 36 where the side wall 32 and the heat dissipation fin 37 are welded together. The connecting member 6 is arranged between the coil 22 and the side wall 32 in a first direction in which the two connecting members 6 face each other. An opening portion 61 penetrating through the connecting member 6 in the first direction is formed in a portion of the connecting member 6 that faces the welded portion 36 in the first direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a stationary inductor with a tank. [Background technology]

[0002] Conventionally, static inductors such as transformers and shunt reactors are known. The static inductor includes a transforming section and a box-shaped tank that houses the transforming section. The transforming section includes an iron core and a coil wound around the iron core. The tank contains insulating oil. The insulating oil insulates and cools the iron core and the coil.

[0003] The tank has a bottom wall and a side wall rising from the periphery of the bottom wall. The side wall is provided with a heat dissipation fin. The heat dissipation fin dissipates heat generated inside the tank due to heat generation in the transformer section to the outside of the tank. A part of the heat dissipation fin is fixed to the side wall by welding. Hereinafter, the part where the side wall and the heat dissipation fin are welded together will be referred to as the welded part.

[0004] When a stationary inductor is short-circuited, the electromagnetic mechanical force generated in the coil causes the coil to deform and bulge toward the side wall. Therefore, as in Patent Document 1, it is common to provide fasteners above and below the transformer, and provide a pair of connecting members between the coil and the side wall to connect both sides of the upper and lower fasteners, thereby suppressing the deformation of the coil.

[0005] The impact caused by the deformation of the coil is transmitted to the connecting member, and then transmitted to the side wall through the space between the connecting member and the side wall as oil impact via the insulating oil. In the following description, oil impact via the insulating oil is simply referred to as "oil impact." [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2011-138931 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, as disclosed in Patent Document 1, when the connecting member is a flat plate, there is no escape route for the insulating oil in the space between the connecting member and the side wall, and all of the oil hammer is likely to propagate to the side wall. As a result, the oil hammer propagated to the side wall causes abnormal vibrations in the heat dissipation fins of the side wall. This can damage the welded parts, which are vulnerable to vibrations, and cause oil leakage to the outside of the tank from the damaged parts.

[0008] The present disclosure has been made in consideration of the above, and aims to obtain a stationary inductor that can reduce oil hammer propagating to the tank while suppressing deformation of the coil. [Means for solving the problem]

[0009] In order to solve the above problems and achieve the object, the stationary inductor according to the present disclosure includes a transformer having an iron core forming a magnetic circuit and a coil wound around the iron core, and a box-shaped tank that contains the transformer and insulating oil. The stationary inductor according to the present disclosure also includes an upper fastener disposed above the transformer inside the tank, a lower fastener disposed below the transformer inside the tank, and two connecting members disposed facing each other through the transformer inside the tank and connecting the upper fastener and the lower fastener. The tank has a bottom wall, a side wall rising from the periphery of the bottom wall and provided with a heat dissipation fin, and a welded portion where the side wall and the heat dissipation fin are welded. The connecting member is disposed between the coil and the side wall in a first direction in which the two connecting members face each other. An opening penetrating the connecting member in the first direction is formed in a portion of the connecting member facing the welded portion in the first direction. Effect of the Invention

[0010] The stationary inductor according to the present disclosure has the advantage that it is possible to reduce oil hammer propagation to the tank while suppressing deformation of the coil. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a partially cutaway perspective view showing a static inductor according to a first embodiment; [Diagram 2] FIG. 1 is a vertical cross-sectional view showing a stationary inductor according to a first embodiment; [Diagram 3] FIG. 3 is a partially enlarged cross-sectional view of FIG. 2 showing an opening and a welded portion; [Figure 4] FIG. 1 is a horizontal cross-sectional view showing a static inductor according to a first embodiment. [Diagram 5] FIG. 5 is a partially enlarged cross-sectional view of FIG. 4, showing a flat portion and a bent portion; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a static inductor according to an embodiment will be described in detail with reference to the drawings.

[0013] Embodiment 1 FIG. 1 is a partially cutaway perspective view showing a stationary inductor 1 according to the first embodiment. FIG. 2 is a vertical cross-sectional view showing the stationary inductor 1 according to the first embodiment. FIG. 2 shows an XZ cross-section in FIG. 1, but is drawn without hatching. FIG. 3 is a partially enlarged cross-sectional view of FIG. 2, showing an opening 61 and a welded portion 36. FIG. 4 is a horizontal cross-sectional view showing the stationary inductor 1 according to the first embodiment. FIG. 4 shows an XY cross-section in FIG. 1. FIG. 5 is a partially enlarged cross-sectional view of FIG. 4, showing a flat portion 62 and a bent portion 63. As shown in FIG. 1, the stationary inductor 1 includes a transformer portion 2, a tank 3, an upper fastener 4, a lower fastener 5, and two connecting members 6.

[0014] In the following description, the width direction of the stationary inductor 1 is the X-axis direction, the depth direction of the stationary inductor 1 is the Y-axis direction, and the height direction of the stationary inductor 1 is the Z-axis direction. In the following description, the direction parallel to the Z-axis direction may be referred to as the up-down direction, and the direction perpendicular to the up-down direction may be referred to as the horizontal direction. In the following description, the direction toward the center of the stationary inductor 1 in the X-axis direction is referred to as the inside, and the opposite side to the inside is referred to as the outside. In this embodiment, the X-axis direction is the first direction, and the Y-axis direction is the second direction. In this embodiment, the Z-axis direction is the connecting direction of the connecting member 6. The connecting direction is the direction in which the upper fastener 4 and the lower fastener 5 are connected by the connecting member 6.

[0015] The transformer unit 2 has an iron core 21 that forms a magnetic circuit, and a plurality of coils 22 wound around the iron core 21. As shown in FIG. 2, the iron core 21 includes two iron core yokes 21a and three iron core legs 21b. The iron core yoke 21a extends in the X-axis direction. The two iron core yokes 21a are arranged apart from each other in the Z-axis direction. The iron core legs 21b extend in the Z-axis direction and connect the two iron core yokes 21a. The three iron core legs 21b are arranged apart from each other in the X-axis direction. The upper end of the iron core leg 21b is connected to one of the iron core yokes 21a. The lower end of the iron core leg 21b is connected to the other iron core yoke 21a. This magnetically connects the three iron core legs 21b and the two iron core yokes 21a.

[0016] The coils 22 are wound around each of the core legs 21b. In this embodiment, the number of coils 22 is three. The three coils 22 are arranged side by side in the X-axis direction. That is, the arrangement direction in which the three coils 22 are arranged is the X-axis direction. As shown in FIG. 4, the shape of the coil 22 is a rectangular tube that opens in the Z-axis direction. More specifically, the shape of the coil 22 is a rectangular tube having two long sides 22a and two short sides 22b. The normal line of the long sides 22a faces the X-axis direction. The normal line of the short sides 22b faces the Y-axis direction. A curved corner 22c is formed between the long sides 22a and the short sides 22b.

[0017] As shown in Fig. 2, the tank 3 is a box-shaped member that contains the transformer unit 2 and insulating oil 7. The tank 3 also contains an upper fastener 4, a lower fastener 5, and two connecting members 6. The insulating oil 7 serves to insulate and cool the iron core 21 and the coil 22. The shape of the tank 3 is a rectangular parallelepiped in this embodiment, but it may be a cube or the like. The material of the tank 3 is metal or the like.

[0018] As shown in Fig. 1, the tank 3 has a bottom wall 31, an upper frame member 33, a lower frame member 34, a plurality of side plates 35, and welded portions 36. The bottom wall 31 is a flat wall. The bottom wall 31 has a rectangular shape in a plan view. Two legs 38 are provided on the lower surface of the bottom wall 31 for fixing the stationary inductor 1 to an installation location. The two legs 38 are disposed apart from each other in the X-axis direction.

[0019] The shape of the upper frame material 33 is a square cylinder that opens in the Z-axis direction. The upper frame material 33 has four walls. The opening of the upper frame material 33 is covered by a cover plate (not shown). The cover plate is fixed to the upper frame material 33 with bolts or the like.

[0020] The lower frame member 34 is shaped like a square cylinder that opens in the Z-axis direction. The lower frame member 34 has four walls. The opening of the lower frame member 34 is covered by the bottom wall 31. The lower frame member 34 is fixed to the periphery of the bottom wall 31 by welding. The lower frame member 34 is disposed below the upper frame member 33 and spaced apart from the upper frame member 33.

[0021] The side plate 35 has a rectangular shape in a side view. The side plates 35 connect the upper frame member 33 and the lower frame member 34. Although FIG. 1 illustrates the side plates 35 with some of them cut away, in reality, the side plates 35 are arranged side by side around the entire circumference of the tank 3. Adjacent side plates 35 are fixed to each other by welding. The side plates 35 are corrugated plates formed by bending a single steel plate into a wave shape.

[0022] A plurality of heat dissipation fins 37 are provided on the side plate 35. The heat dissipation fins 37 are formed integrally with the side plate 35. The heat dissipation fins 37 serve to dissipate heat generated inside the tank 3 due to heat generation from the transformer unit 2 to the outside of the tank 3. That is, the heat dissipation fins 37 serve to dissipate heat of the insulating oil 7 warmed by heat generation from the transformer unit 2 to the outside of the tank 3. The heat dissipation fins 37 protrude horizontally toward the outside of the tank 3 beyond other parts of the side plate 35. The heat dissipation fins 37 extend in the vertical direction. The plurality of heat dissipation fins 37 are arranged at intervals from each other in the horizontal direction. The heat dissipation fins 37 are formed in a flat plate shape.

[0023] The upper frame member 33, the lower frame member 34, and the multiple side plates 35 constitute a side wall 32 rising from the periphery of the bottom wall 31 in the Z-axis direction. The side wall 32 has a rectangular frame shape in plan view. As shown in FIG. 4, the side wall 32 is composed of four walls 32a, 32b, 32c, and 32d. The walls 32a and 32b are spaced apart from each other in the X-axis direction. The walls 32c and 32d are spaced apart from each other in the Y-axis direction. A curved corner 32e is formed between the wall 32a and the walls 32c and 32d. A curved corner 32e is formed between the wall 32b and the walls 32c and 32d.

[0024] As shown in FIG. 3, the welded portion 36 is a portion where the side wall 32 and the heat dissipation fin 37 are welded. More specifically, the welded portion 36 welds the lower frame member 34 to the lower end portion of the heat dissipation fin 37. Although not shown in the figure, a plurality of welded portions 36 are arranged in the Y-axis direction to weld the side wall 32 to each of the plurality of heat dissipation fins 37. The lower end portion of the heat dissipation fin 37 is in contact with the outer surface of the lower frame member 34. The welded portion 36 is arranged in a position facing the connecting member 6. The welded portion 36 is arranged away from the connecting member 6 in the X-axis direction. The welded portion 36 is arranged outside the connecting member 6.

[0025] As shown in Fig. 2, the upper fastener 4 is disposed above the transformer unit 2 inside the tank 3. The upper fastener 4 covers the transformer unit 2 from above. The upper fastener 4 has a concave shape that opens toward the transformer unit 2. In other words, the upper fastener 4 has a box shape that is open on the bottom. The material of the upper fastener 4 is metal.

[0026] The lower fastener 5 is disposed below the transformer unit 2 inside the tank 3. The lower fastener 5 covers the transformer unit 2 from below. The lower fastener 5 supports the transformer unit 2 from below. The lower fastener 5 is shaped concavely and opens toward the transformer unit 2. In other words, the lower fastener 5 is shaped like a box with an open top. The lower fastener 5 is made of metal. The lower fastener 5 is disposed below the upper fastener 4 and spaced apart from the upper fastener 4.

[0027] The two connecting members 6 are plate-like members arranged opposite each other via the transformer unit 2 inside the tank 3 to connect the upper fastener 4 and the lower fastener 5. The two connecting members 6 are arranged apart from each other in the X-axis direction. One connecting member 6 connects one end of the upper fastener 4 and the lower fastener 5 in the X-axis direction. The other connecting member 6 connects the other end of the upper fastener 4 and the lower fastener 5 in the X-axis direction. The connecting members 6 are fixed to the upper fastener 4 and the lower fastener 5 by fixing bolts 8. The connecting members 6 are made of metal.

[0028] The connecting members 6 are disposed between the coil 22 and the side wall 32 in the X-axis direction. One connecting member 6 is disposed between the long side portion 22a of the coil 22 located furthest in the X-axis direction among the multiple coils 22 and the wall portion 32a of the side wall 32. The other connecting member 6 is disposed between the long side portion 22a of the coil 22 located furthest in the X-axis direction among the multiple coils 22 and the wall portion 32b of the side wall 32. The connecting members 6 are disposed only at positions facing the long side portion 22a of the coil 22. The connecting members 6 are disposed with a gap between them and the coil 22, or in contact with them.

[0029] As shown in FIG. 3, a space 10 is interposed between the connecting member 6 and the side wall 32. Insulating oil 7 is present in the space 10. An opening 61 is formed in a portion of the connecting member 6 facing the welded portion 36 in the X-axis direction, penetrating the connecting member 6 in the X-axis direction. The opening 61 communicates with a space 9 located on the coil 22 side and a space 10 located on the side wall 32 side, with the connecting member 6 as a boundary, inside the tank 3. As shown in FIG. 1, the shape of the opening 61 is a rectangle that is longer in the Y-axis direction than in the Z-axis direction in this embodiment, but may be changed as appropriate. The opening 61 is provided so as to face each of the multiple welded portions 36 arranged in the Y-axis direction. The opening 61 is formed in a flat portion 62, which will be described later.

[0030] 4, the connecting member 6 has a flat portion 62 and a bent portion 63. The flat portion 62 is a planar portion extending in the Y-axis direction and parallel to the side wall 32. The flat portion 62 is parallel to the wall portions 32a and 32b of the side wall 32.

[0031] The bent portion 63 is a portion that bends from both ends of the flat portion 62 in the Y-axis direction toward the coil 22. The bent portion 63 is bent so as to be positioned inward as it moves away from both ends of the flat portion 62 in the Y-axis direction. As shown in FIG. 5, the bent portion 63 is disposed between the corner 22c of the coil 22 and the corner 32e of the side wall 32. The bent portion 63 is bent so as to follow the outer peripheral shape of the coil 22.

[0032] Next, the effects of the stationary inductor 1 according to this embodiment will be described.

[0033] In this embodiment, as shown in FIG. 3, the connecting member 6 is disposed between the coil 22 and the side wall 32 in the X-axis direction, and an opening 61 penetrating the connecting member 6 in the X-axis direction is formed in a portion of the connecting member 6 facing the welded portion 36 in the X-axis direction. With this configuration, the opening 61 becomes an escape route for the oil hammer 11, and a part of the oil hammer 11 escapes from the space 10 between the connecting member 6 and the side wall 32 to the space 9 located on the coil 22 side. In other words, a part of the impact caused by the deformation of the coil 22 generated when the stationary inductor 1 is short-circuited is not propagated to the side wall 32 of the tank 3 as the oil hammer 11 via the insulating oil 7. For this reason, the oil hammer 11 propagated to the tank 3 can be reduced, and the abnormal vibration generated in the heat dissipation fin 37 can be reduced. As a result, the welded portion 36, which is vulnerable to vibration, is less likely to be damaged, and the occurrence of oil leakage to the outside of the tank 3 can be suppressed.

[0034] 3, in this embodiment, the opening 61 is formed in a portion of the connecting member 6 that faces the welded portion 36 in the X-axis direction, so that the insulating oil 7 itself, which causes oil hammer 11, is not pushed toward the welded portion 36. In other words, the oil hammer 11 does not directly strike the welded portion 36. This makes it possible to prevent damage to the welded portion 36, which is vulnerable to vibration, and to prevent oil leakage to the outside of the tank 3.

[0035] In this embodiment, as shown in FIG. 2, the stationary induction device 1 includes an upper fastener 4 arranged above the transformer unit 2 inside the tank 3, a lower fastener 5 arranged below the transformer unit 2 inside the tank 3, and two connecting members 6 arranged opposite to each other through the transformer unit 2 inside the tank 3 to connect the upper fastener 4 and the lower fastener 5. With this configuration, the outer periphery of the coil 22 along the X-axis direction and the Z-axis direction is surrounded, so that deformation of the coil 22 can be suppressed. Therefore, in this embodiment, the oil hammer 11 propagating to the tank 3 can be reduced while suppressing deformation of the coil 22. Note that, as shown in FIG. 4, if the coil 22 is shaped like a square tube having a long side portion 22a and a short side portion 22b, the long side portion 22a of the coil 22 is deformed so as to bulge outward. In this regard, in this embodiment, the connecting member 6 is arranged between the long side portion 22a of the coil 22 and the side wall 32 of the tank 3 in the X-axis direction, so that deformation of the coil 22 can be appropriately suppressed.

[0036] In this embodiment, as shown in FIG. 4, the connecting member 6 is disposed between the coil 22 and the side wall 32 in the X-axis direction. In this embodiment, the connecting member 6 has a flat portion 62 extending in the Y-axis direction and parallel to the wall portions 32a and 32b, which are portions of the side wall 32 located in the X-axis direction, and a bent portion 63 that bends from both ends of the flat portion 62 in the Y-axis direction toward the coil 22. With these configurations, as shown in FIG. 5, the area of ​​the connecting member 6 that is parallel to the side wall 32 of the tank 3 can be reduced, and the propagation of the oil hammer 11 between the parallel portions of the side wall 32 of the tank 3 and the connecting member 6 can be suppressed. Therefore, the oil hammer 11 propagating to the side wall 32 of the tank 3 can be reduced throughout the tank 3, and the abnormal vibrations occurring in the heat dissipation fins 37 can be reduced. As a result, the welded portion 36, which is vulnerable to vibration, is less likely to break, and the occurrence of oil leakage to the outside of the tank 3 can be suppressed.

[0037] As a method for reducing the oil hammer 11 propagating to the side wall 32 of the tank 3 shown in FIG. 3, a method of providing a buffer space by lengthening the distance in the X-axis direction between the side wall 32 of the tank 3 and the connecting member 6 is considered. However, this method entails an increase in size of the tank 3 by the amount of the buffer space, and there is a problem in that the product dimensions of the tank 3, the total mass of the tank 3, and the amount of insulating oil 7 inside the tank 3 increase. In this regard, in the present embodiment, an opening 61 is formed in a portion of the connecting member 6 facing the welded portion 36 in the X-axis direction, so that the oil hammer 11 propagating to the tank 3 can be reduced, and therefore it is not necessary to provide a buffer space by lengthening the distance in the X-axis direction between the side wall 32 of the tank 3 and the connecting member 6. As a result, the oil hammer 11 propagating to the tank 3 can be reduced without increasing the product dimensions of the tank 3, the total mass of the tank 3, and the amount of insulating oil 7 inside the tank 3.

[0038] Next, a modification of the first embodiment will be described.

[0039] The arrangement of the heat dissipation fins 37 shown in Fig. 1 is not limited to the illustrated arrangement. For example, the heat dissipation fins 37 may extend in the horizontal direction or in a direction inclined with respect to the vertical direction.

[0040] As shown in FIG. 4, the shape of coil 22 in this embodiment is a rectangular tube having long sides 22a and short sides 22b, but may be modified as appropriate.

[0041] 4, in the present embodiment, the connecting member 6 has a structure including a flat portion 62 and a bent portion 63, but may not include the bent portion 63. In other words, the entire connecting member 6 may be parallel to the wall portions 32a and 32b of the side wall 32.

[0042] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0043] 1 static inductor, 2 transformer section, 3 tank, 4 upper fastener, 5 lower fastener, 6 connecting member, 7 insulating oil, 8 fixing bolt, 9,10 space, 11 oil hammer, 21 iron core, 21a iron core yoke, 21b iron core leg, 22 coil, 22a long side portion, 22b short side portion, 22c, 32e corner portion, 31 bottom wall, 32 side wall, 32a, 32b, 32c, 32d wall portion, 33 upper frame material, 34 lower frame material, 35 side plate, 36 welded portion, 37 heat dissipation fin, 38 leg portion, 61 opening, 62 flat portion, 63 bent portion.

Claims

1. a transformer unit having an iron core that forms a magnetic circuit and a coil wound around the iron core; a box-shaped tank that contains the transformer unit and insulating oil; an upper fastener disposed inside the tank and above the transformer; a lower fastener disposed inside the tank below the transformer; Two connecting members are disposed inside the tank facing each other across the transformer unit and connecting the upper fastener and the lower fastener; Equipped with The tank is The bottom wall and a side wall rising from a periphery of the bottom wall and provided with heat dissipation fins; a welded portion at which the side wall and the heat dissipation fin are welded; having The connecting members are disposed between the coil and the side wall in a first direction in which the two connecting members face each other, A stationary inductor, characterized in that an opening penetrating the connecting member in the first direction is formed in a portion of the connecting member facing the welded portion in the first direction.

2. The connecting member is a flat surface portion extending in a second direction perpendicular to the first direction and the connecting direction of the connecting member and parallel to a portion of the side wall located in the first direction; a bent portion bent from both ends of the planar portion in the second direction toward the coil; 2. The stationary inductor according to claim 1, further comprising:

3. The coil has a rectangular tubular shape having long sides and short sides, 3. The stationary inductor according to claim 1, wherein the connecting member is disposed between the long side portion of the coil and the side wall in the first direction.

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