WO2017033554A1

WO2017033554A1 - Mold coil

Info

Publication number: WO2017033554A1
Application number: PCT/JP2016/068674
Authority: WO
Inventors: 裕介陦; 正治久保田
Original assignee: 東芝産業機器システム株式会社; 株式会社東芝
Priority date: 2015-08-21
Filing date: 2016-06-23
Publication date: 2017-03-02
Also published as: JP6833696B2; CN108292560A; JPWO2017033554A1; CN108292560B

Abstract

A mold coil comprises a plurality of tubular section coils which include winding conductor layers and of which the peripheries are covered with resin mold, the tubular section coils being disposed in a concentrically overlapping manner, with ducts provided between the section coils via a support material. The position of an end of the support material is present at a position withdrawn from an end face of the resin mold and the end of the winding conductor layer.

Description

Molded coil

Embodiment of this invention is related with the mold coil used for a static mold apparatus.

For molded coils used in electric power and industrial static mold equipment, such as mold transformers and mold reactors, each section of the mold coil is divided into section coils so that cooling air passes inside the mold coil. A duct is provided between them to cool the mold coil and insulate the section coils. This duct is configured, for example, by placing a corrugated support between each section coil. The end face of the support is usually arranged so as to align with the end face of the section coil.

JP-A-8-8121

When a conventional molded coil is used in, for example, a molded transformer having a high received voltage (primary voltage), the creeping insulation performance at the coil end face is reduced, or the shared voltage of the air layer between the coil sections is increased. Problems such as a decrease in insulation performance or a decrease in cooling performance between section coils have become apparent.

Therefore, an object of the embodiment of the present invention is to provide a molded coil excellent in creeping insulation performance, air layer insulation performance, and cooling performance.

The molded coil according to the present embodiment has a winding conductor layer, a plurality of cylindrical section coils whose surroundings are covered with a resin mold are provided concentrically, and a support is interposed between the section coils. With a duct configured. The position of the end portion of the support is present at a position retreated from the end surface of the resin mold and the end portion of the winding conductor layer.

Partially perspective sectional view showing a schematic configuration example of a molded coil according to the first embodiment Partially perspective sectional view showing a schematic configuration example of a molded coil according to the second embodiment Partially perspective sectional view showing a schematic configuration example of a molded coil according to a third embodiment A longitudinal sectional view showing a schematic configuration of the molded transformer according to the fourth embodiment

Hereinafter, embodiments will be described with reference to the drawings. In the description of the embodiment, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)
FIG. 1 is a partial perspective sectional view showing a schematic configuration example of a molded coil 10 according to the first embodiment. The molded coil 10 is formed such that a plurality of cylindrical section coils 10a are stacked concentrically. In the following description, a direction orthogonal to the radial direction of the molded coil 10 is referred to as an axial direction, and the axial direction is expressed as a vertical direction.

The winding conductor 12 has a configuration in which a winding conductor layer 12d and a crossover 12c are formed from the winding conductor inlet 12a of the molded coil 10 and connected to the winding conductor outlet 12b. These winding conductor layers 12d are U-connected by a jumper 12c. The winding conductor layer 12 d is covered with an insulating material, and constitutes a resin mold 18.

The resin mold 18 including the winding conductor layer 12d is formed as follows. The winding conductor layer 12d is covered with a nonwoven fabric or the like, and the support 16 is disposed so as to provide a predetermined space between the winding conductor layers 12d. In this state, for example, an epoxy resin is impregnated and then cured. In this manner, the resin mold 18 having the winding conductor layer 12d therein is formed. That is, the section coil 10a is configured such that the winding conductor 12 (winding conductor layer 12d) wound in a cylindrical shape is covered with an insulator (for example, epoxy resin).

The support 16 is, for example, a corrugated resin structure. A duct 14 having a passage extending in the axial direction of the molded coil 10 is formed between the section coils 10a by interposing the support 16 between the adjacent section coils 10a. The support 16 is made of, for example, an epoxy resin, and therefore the support 16 has a high dielectric constant.

The passage through which air flows is formed by the duct 14, and the mold coil 10 can be cooled by the air flowing through the passage. The distance between the section coils 10 a is defined by the support 16. The distance between the section coils 10a is manufactured in consideration of creeping insulation performance, cooling performance, and air layer insulation performance between the section coils 10a. In addition, the edge part of the support body 16 is called the support body end surface 16a.

A crossover wire 12c is provided between the winding conductor layers 12d of the section coil 10a, and these have a U connection, that is, a shape in which U shapes are joined in a staggered manner in the cross section, and the periphery thereof is covered with the resin mold 18. It is configured as follows. Here, the end of the winding conductor layer 12d on the opposite side as viewed from the side to which the connecting wire 12c is connected is referred to as a winding conductor layer end 12e. These winding conductor layers 12d, the crossover wires 12c, and the resin mold 18 are integrated to form the molded coil 10.

On the side of the U-connected mold coil 10 opposite to the side to which the crossover 12c is connected, the position of the support end surface 16a of the support 16 is the internal direction of the mold coil 10 structure (section) from the resin mold end surface 18a. The coil 10a exists in a position retracted by the retracting length L1 in the axial direction. The position of the support end surface 16a exists at a position retracted inward from the winding conductor layer end 12e.

The end insulating portion 20 indicates from the resin mold end surface 18a to the winding conductor layer end portion 12e of the resin mold 18, and the end insulating portion length from the resin mold end surface 18a toward the inside of the molded coil 10 structure. The winding conductor layer end 12e exists at a distance L2. As described above, since the position of the support end surface 16a exists at a position retracted inward from the winding conductor layer end 12e, the receding length L1 and the end insulating portion length L2 are “L1>”. L2 "relationship.

End insulating portions 20 are provided on the upper and lower portions of the molded coil 10 so as to be connected to the winding conductor layer 12d. At the end surface of the end insulating portion 20, the mold coil 10 (section coil 10a) has a resin mold end surface 18a.

The resin mold 18 has a resin mold corner 18b at the corner of the resin mold end surface 18a. The resin mold corner 18b is a place where the electric field related to the mold coil 10 is concentrated. If an electrical path such as the support end surface 16a exists in the vicinity of the resin mold corner 18b, a discharge is generated through this. It becomes easy.

The winding conductor 12 has a winding conductor corner 12f at the winding conductor layer end 12e. The winding conductor corner portion 12f is a place where the electric field tends to concentrate. In the vicinity of the strong electric field portion 18c, which is the surface of the resin mold 18 closest to the winding conductor corner portion 12f, for example, an electrical surface such as the support end surface 16a. If there is a path, electric discharge tends to occur through the path.

The effects of the molded coil 10 according to the first embodiment are summarized as follows.
According to the mold coil 10 according to the first embodiment, the position of the support end surface 16a of the support 16 exists at a position retracted from the resin mold end surface 18a. That is, the support end surface 16a and the resin mold end surface 18a do not form the same plane. For this reason, since the resin mold corner 18b where the electric field concentration occurs and the support end surface 16a are not close to each other, bridging between the section coils 10a is suppressed, and deterioration of the creeping insulation performance of the end surface of the section coil 10a can be suppressed. it can. Thereby, in the lightning impulse test, it is possible to suppress the occurrence of distortion exceeding the standard of the lightning impulse waveform starting from creeping dielectric breakdown between the section coils 10a.

Further, the position of the support end surface 16a of the support 16 is configured to be present at a position retracted inward from the end surface of the section coil 10a (that is, the resin mold end surface 18a) and the winding conductor layer end portion 12e. Yes. That is, the support end surface 16a exists at a position retracted inward from the resin mold end surface 18a by a distance equal to or longer than the receding length L1. As a result, the support end surface 16a is not close to the resin mold corner 18b but also not to the strong electric field 18c on the surface of the resin mold 18 nearest to the winding conductor corner 12f where the electric field is concentrated. By adopting this configuration, bridging between the section coils 10a can be suppressed, and deterioration of the creeping insulation performance at the resin mold end surface 18a (resin mold corner 18b) can be suppressed. Thereby, in the lightning impulse test, it is possible to suppress the occurrence of distortion exceeding the standard of the lightning impulse waveform starting from creeping dielectric breakdown between the section coils 10a.

Conventionally, the voltage shared by the air layer of the duct 14 is increased due to the presence of the support 16 having a high dielectric constant. According to the first embodiment, the position of the support end surface 16a is positioned at the resin mold. It is comprised so that it may become a position retreated from the end surface 18a. Thereby, the partial discharge performance in the resin mold corner 18b can be improved.

Also, with this configuration, the area where the support 16 does not exist in the duct 14 increases, the cooling area of the mold coil 10 can be increased, and the pressure loss of the air passing through the duct 14 can be reduced. Thereby, the cooling performance of the mold coil 10 can be improved.

(Second Embodiment)
Next, a second embodiment will be described. FIG. 2 is a partial perspective sectional view showing a schematic configuration example of the molded coil 10 according to the second embodiment. In FIG. 2, one section coil 10a and the support 16 are extracted and shown. In FIG. 2, the tape-type nonwoven fabric 22, the end nonwoven fabric 24, and the clip 26 are shown so that the state before the molded coil 10 is impregnated with resin and integrated can be understood.

The molded coil 10 is arranged so that the end nonwoven fabric 24 is connected to the upper end portion of the winding conductor 12 wound in a cylindrical shape, that is, the winding conductor layer 12d, and these are wound together with the tape-type nonwoven fabric 22 and gathered together. It is fixed to. Furthermore, in order to prevent the wound tape-type nonwoven fabric 22 from unwinding and collapsing the assembled shape, the end nonwoven fabric 24 and the tape-type nonwoven fabric 22 are overlapped and fixed by clips 26. . In addition, the position of the support end surface 16a of the support 16 exists at a position that is recessed inward from the resin mold end surface 18a and the winding conductor layer end 12e.

In the second embodiment, the end non-woven fabric 24, the tape-type non-woven fabric 22 around which the end non-woven fabric 24 is wound, and the clip 26 constitute the end insulating portion 20. The support end surface 16a exists at a position retracted inward from the resin mold end surface 18a and the winding conductor layer end 12e, that is, a receding length L1 which is a distance from the resin mold end surface 18a to the support end surface 16a. Is larger than the end insulating portion length L2, as in the first embodiment.

In the second embodiment, as described above, the molded coil 10 is impregnated with the resin as the integral part of the winding conductor 12 and the end nonwoven fabric 24 that are wound around the tape-type nonwoven fabric 22 and sandwiched and fixed by the clip 26. Are integrally formed by curing.

Next, a method for manufacturing the molded coil 10 of the second embodiment will be described. The support 16 and the winding conductor layer 12d are alternately arranged in a concentric cylindrical shape in a mold (not shown), and the winding conductor layer 12d is wound around the tape-type nonwoven fabric 22. Next, the clip 26 is fitted to the upper and lower ends of the winding conductor layer 12d wound with the tape-type nonwoven fabric 22 to fix the tape-type nonwoven fabric 22 so as not to collapse. Next, the resin is impregnated and then cured. As a result, the molded coil 10 is formed, in which the winding conductor layer 12d, the tape-type nonwoven fabric 22, and the clip 26 are integrally cured with the resin.

In this way, the tape-type nonwoven fabric 22 wound around the winding conductor layer 12d is fixed with the clip 26, so that the resin is impregnated and cured. Therefore, the tape-type nonwoven fabric is usually provided without a spacer disposed on the support 16. The nonwoven fabric 22 does not break and collapse.

The effects of the molded coil 10 according to the second embodiment are summarized as follows.
According to the molded coil 10 which concerns on 2nd Embodiment, there exists an effect similar to 1st Embodiment. In addition, by adopting such a configuration, even when the support end surface 16a is disposed at a position retracted from the resin mold end surface 18a, it is possible to suppress the collapse of the assembled shape due to the unfolding of the tape-type nonwoven fabric 22. . As a result, it is possible to realize the mold coil 10 configured such that the position of the support end surface 16a exists at a position retracted from the resin mold end surface 18a.

(Third embodiment)
Next, a third embodiment will be described. FIG. 3 is a partial perspective sectional view showing a schematic configuration example of the molded coil according to the third embodiment. FIG. 3 shows one section coil 10a and support 16 extracted. In FIG. 3, as in FIG. 2, the sheet-type nonwoven fabric 32 and the end nonwoven fabric 24 are shown so that the state before the molded coil 10 is impregnated with resin and integrated can be understood.

In the third embodiment, a self-supporting sheet-type non-woven fabric 32 that is not necessarily unfastened without being fixed by the clip 26 is used.
The molded coil 10 is arranged so that the end nonwoven fabric 24 is placed on the upper end portion of the winding conductor 12 wound in a cylindrical shape, that is, the winding conductor layer 12d, and these are wound around the sheet type nonwoven fabric 32. It is fixed to cover. The sheet-type nonwoven fabric 32 has such a strength as to have a so-called waist so that the shape can be maintained by itself. Furthermore, you may clamp and fix the winding conductor layer edge part 12e, the edge part insulation part 20, and the sheet-type nonwoven fabric 32 using the clip 26 demonstrated in 2nd Embodiment.

In the second embodiment, the end nonwoven fabric 24 and the sheet type nonwoven fabric 32 around which the end nonwoven fabric 24 is wound constitute the end insulating portion 20. The position of the support end surface 16a exists at a position retracted inward from the resin mold end surface 18a and the winding conductor layer end portion 12e, that is, a receding that is a distance from the resin mold end surface 18a to the support end surface 16a. The length L1 is larger than the end insulating portion length L2, as in the first and second embodiments.

In the second embodiment, as described above, the molded coil 10 is integrally configured by impregnating a resin with the winding conductor 12 and the end nonwoven fabric 24 wound by the sheet-type nonwoven fabric 32 as a unit. ing.

The effects of the molded coil 10 according to the third embodiment are summarized as follows.
According to the molded coil 10 which concerns on 3rd Embodiment, there exists an effect similar to 1st Embodiment. Further, since the winding conductor 12 is wound using the sheet-type nonwoven fabric 32 that can be self-supporting and can retain its shape, the support end surface 16a is retracted from the resin mold end surface 18a toward the inside of the mold coil 10 structure. Even if they are arranged in the same shape, the assembled shape can be maintained, so that an effect of excellent productivity is achieved.

(Fourth embodiment)
Next, a fourth embodiment will be described. FIG. 4 shows a schematic configuration of a molded transformer 100 that is a molded static induction device. The mold transformer 100 includes a mold transformer content 32 constituting the content of the mold type static induction device, a sealed container 33 in which the mold transformer content 32 is stored, and an outer side surface of the sealed container 33 (left and right in the figure). The heat exchanger 34 provided in the.

Among these, the molded transformer contents 32 are configured by combining the mold coil 10 whose surface is covered with a resin or an insulating material containing a resin and an iron core 36. The molded coil 10 includes a section coil 10a mounted on the outer periphery of the iron core 36, and a section coil 10a disposed on the outer periphery of the section coil 10a. Here, the molded coil 10 is the molded coil 10 according to the first, second, or third embodiment. The mold coil 10 is configured such that the position of the support end surface 16a (not shown in FIG. 4) is a position retracted from the resin mold end surface 18a.

In the sealed container 33, air 37 having a pressure exceeding the atmospheric pressure is enclosed in a state where the contents 32 of the mold transformer are accommodated. The sealed container 33 and the left and right heat exchangers 34 are connected by an upper connection path 38 and a lower connection path 39, respectively. The upper connection path 38 is connected to the upper part of the sealed container 33, and the lower connection path 39 is connected to the lower part of the sealed container 33.

As shown in FIG. 4, a partition plate 40 is provided in the sealed container 33 so as to be positioned above the lower connection path 39 and below the upper connection path 38. The partition plate 40 is provided in a fixed state on the inner surface of the sealed container 33. In the partition plate 40, a circular flow hole 40 a along the outer periphery of the mold coil 10 is formed in a portion adjacent to the outer periphery of the mold coil 10.

In the above configuration, when the operation of the mold transformer 100 is started, the contents of the mold transformer 32 generate heat, and accordingly, the temperature of the air 37 in the sealed container 33 rises. As shown by arrows in FIG. 4, the air 37 whose temperature has risen rises in the sealed container 33, and then flows to the heat exchanger 34 side through the upper connection path 38 to be cooled.

The air 37 cooled by the heat exchanger 34 circulates so as to be returned into the sealed container 33 through the lower connection path 39. Thus, the air 37 in the sealed container 33 circulates through the heat exchanger 34, whereby the air 37 in the sealed container 33 is cooled, and the mold transformer contents 32 are cooled.

In this case, a part of the air 37 circulating in the sealed container 33 passes through a gap between the flow hole 40a of the partition plate 40 and the outer peripheral portion of the mold coil 10 to cool the mold coil 10 from the outer peripheral portion. At this time, since the air 37 that circulates around the outer periphery of the mold coil 10 circulates in a place close to the mold coil 10, the cooling effect can be enhanced. Further, since the duct 14 is formed by the support 16 between the adjacent section coils 10a, a part of the air 37 circulating in the sealed container 33 also enters the duct 14, and the molded coil 10 is also inserted from the inside. Cooling. Thereby, the cooling effect of the mold coil 10 can be further enhanced.

Here, since the dielectric strength of air is almost proportional to its absolute pressure, air with a gauge pressure of 1 atm (absolute pressure of 2 atm) has almost twice the yield with respect to atmospheric air. In addition, as the density of gas increases, the heat carrying capacity increases, and air with a gauge pressure of 1 atm (absolute pressure of 2 atm) has a cooling capacity about twice that of atmospheric air if the flow rate is kept constant. .

According to the mold transformer 100 of the above-described embodiment, the mold transformer contents 32 are accommodated in the sealed container 33 in which the air 37 having a pressure exceeding the atmospheric pressure is sealed, so that the section coil 10a of the mold coil 10 is It is possible to improve the withstand voltage of the air 37 involved in the insulation between the molded coil 10 and the member having a ground potential such as the iron core 36.

In this case, the insulation withstand voltage of the molded transformer contents 32 alone is set to the standard operating voltage (ordinary voltage) or more, and the overall withstand voltage when the air 37 having a pressure exceeding the atmospheric pressure is stored in the sealed container 33 is as follows. The test voltage (commercial frequency voltage, impulse voltage, etc.) specified by the standard or higher shall be used. By setting the withstand voltage in this way, even when air is discharged from the hermetic container 33, it can be operated relatively safely during normal times.

Further, in the above description, the withstand voltage of the molded transformer contents 32 alone is equal to or higher than the standard operating voltage. However, the withstand voltage when the atmospheric air 37 is stored in the sealed container 33 is equal to or higher than the standard operating voltage. The same effect can be obtained by setting as above.

Further, since the heat exchanger 34 for increasing the density of the air 37 in the sealed container 33 and cooling the air 37 is provided, the cooling performance can be improved. As a result of this configuration, there is provided a molded transformer 100 having a higher voltage and a larger capacity that exceeds the upper limit of the voltage and capacity of a conventional mold transformer that relies on air at atmospheric pressure for its insulating function and cooling function. It becomes possible.

Further, in the molded coil 10, the support end surface 16a of the support 16 is disposed at a position retracted inside the end surface of the section coil 10a (that is, the resin mold end surface 18a) and the winding conductor layer end 12e. For this reason, since the mold coil 10 is enclosed in the airtight container 33 in which the air 37 having a pressure exceeding the atmospheric pressure is sealed, the cooling effect can be further improved in the retracted portion. Further, since the air blowing resistance around the support 16 is lowered by the amount of the retraction, the cooling effect by the air 37 circulating between the section coils 10a can be improved.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

For example, although the section coils 10a are arranged in a plurality of layers and concentrically, the section coils 10a may be supported and overlapped by the support 16 so as to be spaced apart from each other by a concentric shape. Moreover, the cross section of the mold coil 10 may not be circular but may be rectangular or elliptical.

In addition, although the support 16 for forming the duct 14 that defines the interval between the section coils 10a has been described using the support 16 having a corrugated plate in the above embodiment, it is not intended to be limited to this shape. For example, a support 16 having a rectangular wave cross section may be used, or a support 16 that is a plurality of rod-shaped spacers may be used.

Claims

A molded coil comprising a duct having a winding conductor layer, a plurality of cylindrical section coils whose surroundings are covered with a resin mold, concentrically stacked, and a support interposed between the section coils In
The mold coil in which the position of the end portion of the support exists at a position that is recessed from the end surface of the resin mold and the end portion of the winding conductor layer.
A molded coil comprising a duct having a winding conductor layer, a plurality of cylindrical section coils whose surroundings are covered with a resin mold, concentrically stacked, and a support interposed between the section coils In
Furthermore, it has an end insulating portion arranged to connect to the winding conductor layer,
The mold coil in which the position of the end part of the support is present at a position retracted more than the end insulating part length from the end face of the resin mold.
An end insulating portion disposed at the upper end of the winding conductor layer, a tape-type nonwoven fabric that collectively winds the winding conductor layer and the end insulating portion, and the winding conductor layer and the end insulating portion And a clip for sandwiching a tape-type nonwoven fabric for winding them,
3. The mold according to claim 1, wherein the winding conductor layer, the end insulating portion, the tape-type nonwoven fabric, and the clip for sandwiching these are integrally formed by impregnating the resin in this state. coil.
An end insulating portion disposed at the upper end of the winding conductor layer, and a sheet-type nonwoven fabric wound around the winding conductor layer and the end insulating portion,
3. The molded coil according to claim 1, wherein the coiled conductor layer, the end insulating portion, and the sheet-type nonwoven fabric are integrally formed by impregnating a resin in this state.