Shell-type transformer

Abstract

The insulating plates (140) are positioned between adjacent planar windings (130) of the planar windings (130). The insulators include a plurality of first insulators and at least one second insulator that contacts at least one planar winding (130) at a position closer to the iron core (110) than the plurality of first insulators. The at least one second insulator is made of a material having a lower dielectric constant than the plurality of first insulators.

Description

Technical Field

[0001] The present disclosure relates to an external iron type transformer.

Background Art

[0002] As a prior art document that discloses the configuration of an oil-filled transformer, there is Japanese Utility Model Publication No. 3-12410 (Patent Document 1). The oil-filled transformer described in Patent Document 1 has an oil duct that circulates insulating oil around the winding for cooling. Low dielectric constant materials with a relative dielectric constant of 4.0 or less are used for the insulating materials of the duct pieces and vertical wedges that are arranged in the region with a high shared voltage and constitute the oil duct.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since low dielectric constant materials are relatively expensive, if the entire duct piece is made of a low dielectric constant material, the device cost will increase.

[0005] The present disclosure has been made in view of the above problems, and by using a low dielectric constant material only for the insulating member adjacent to the location where a high electric field is generated in the flat winding, an external iron type transformer is provided that improves insulation reliability while suppressing an increase in device cost.

Means for Solving the Problems

[0006] An external iron transformer according to this disclosure comprises an iron core, a plurality of plate windings, a plurality of insulating plates, and a plurality of insulators. The plurality of plate windings are arranged in the axial direction of the iron core and wound around the iron core. The plurality of insulating plates are arranged in the axial direction and are positioned between adjacent plate windings in the plurality of plate windings. The plurality of insulators are in contact with at least one of the plurality of plate windings. The plurality of insulators include a plurality of first insulators and at least one second insulator that is in contact with at least one plate winding at a position closer to the iron core than the plurality of first insulators. The at least one second insulator is made of a material with a lower dielectric constant than the plurality of first insulators. [Effects of the Invention]

[0007] According to this disclosure, by using a low dielectric constant material only in the insulating member adjacent to the area where a high electric field is generated within the flat winding, it is possible to improve insulation reliability while suppressing an increase in equipment costs. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the configuration of an external iron type transformer according to one embodiment. [Figure 2] This is an exploded perspective view showing the configuration of the winding group in an external iron type transformer according to one embodiment. [Figure 3] This is a longitudinal cross-sectional view of a part of an external iron type transformer according to one embodiment. [Modes for carrying out the invention]

[0009] The following description of an external iron type transformer according to one embodiment will be given with reference to the drawings. In the following description of the embodiment, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0010] Figure 1 is a perspective view showing the configuration of an external iron type transformer according to one embodiment. Figure 2 is an exploded perspective view showing the configuration of the winding group of the external iron type transformer according to one embodiment. Figure 3 is a longitudinal cross-sectional view of a part of the external iron type transformer according to one embodiment. Note that the tank is not shown in Figures 1 to 3 in order to facilitate understanding of the internal structure of the external iron type transformer.

[0011] An external iron transformer 100 according to one embodiment of the present disclosure is an on-board transformer. As shown in Figure 1, it comprises an iron core 110 and a winding group 120. The iron core 110 and the winding group 120 are housed in a tank (not shown) immersed in insulating oil. The iron core 110 includes a main leg portion 111 and a pair of side leg portions 112. The pair of side leg portions 112 are connected to the main leg portion 111. The axial direction of the iron core 110 is the Z-axis direction.

[0012] The winding group 120 includes a primary winding group 121 and a secondary winding group 122. The primary winding group 121 is positioned between the secondary winding groups 122. A higher voltage is applied to the primary winding group 121 than to the secondary winding group 122.

[0013] As shown in Figure 2, the winding group 120 comprises a plurality of flat windings 130 and a plurality of insulating plates 140. The plurality of flat windings 130 are arranged in the axial direction (Z-axis direction) of the iron core 110 and are wound around the main leg portion 111 while passing between the main leg portion 111 and the side leg portion 112. Each of the plurality of flat windings 130 has an oval shape. The short direction of the flat winding 130 is the X-axis direction, and the long direction of the flat winding 130 is the Y-axis direction. Each of the plurality of flat windings 130 includes an insulated conductor portion.

[0014] Multiple insulating plates 140 are arranged in a line along the axial direction (Z-axis direction) of the iron core 110, and are positioned between adjacent flat windings 130 in the multiple flat windings 130. In the axial direction (Z-axis direction) of the iron core 110, flat windings 130 and insulating plates 140 are arranged alternately, one at a time. Alternatively, one flat winding 130 may be arranged for every multiple insulating plates 140. The insulating plates 140 have a substantially oval shape, similar to the flat windings 130.

[0015] As shown in Figures 2 and 3, multiple insulators are arranged in contact with at least one of the multiple flat plate windings 130. In this embodiment, the multiple insulators include multiple insulating spacers 141, multiple first angles 160, 170, and multiple second angles 150.

[0016] The plurality of insulators include a plurality of first insulators and at least one second insulator that is in contact with at least one flat winding 130 at a position closer to the iron core 110 than the plurality of first insulators. The at least one second insulator is made of a material with a lower dielectric constant than the plurality of first insulators. In this embodiment, the plurality of first insulators are made of pressboard. The at least one second insulator is made of polyamide resin. Note that it is sufficient that the dielectric constant of the second insulator is lower than that of the first insulators, and the material of the first insulators is not limited to pressboard, and the material of the second insulator is not limited to polyamide resin.

[0017] Specifically, multiple insulating spacers 141 are arranged on the main surface 140s of each of the multiple insulating plates 140, spaced apart from each other. Each of the multiple insulating spacers 141 is joined and fixed to the main surface 140s of the insulating plate 140. Each of the multiple insulating spacers 141 is sandwiched between the flat winding 130 and the insulating plate 140, and the insulating spacers 141 form a channel through which insulating oil flows between the flat winding 130 and the insulating plate 140.

[0018] As shown in Figure 3, the multiple insulating spacers 141 include a plurality of first insulating spacers 141a positioned closer to the main leg portion 111 on the main surface 140s of each of the plurality insulating plates 140, a plurality of second insulating spacers 141b positioned closer to the side leg portion 112, and a plurality of third insulating spacers 141c other than the plurality of first insulating spacers 141a and the plurality of second insulating spacers 141b.

[0019] In this embodiment, each of the plurality of first insulating spacers 141a and plurality of second insulating spacers 141b is a second insulating material, and the plurality of third insulating spacers 141c is a first insulating material. That is, the dielectric constant of the material constituting each of the plurality of first insulating spacers 141a and plurality of second insulating spacers 141b is lower than the dielectric constant of the material constituting each of the plurality of insulating plates 140 and plurality of third insulating spacers 141c. At least one of the plurality of first insulating spacers 141a and plurality of second insulating spacers 141b may be a second insulating material, and the rest of the plurality of first insulating spacers 141a and plurality of second insulating spacers 141b and all of the plurality of third insulating spacers 141c may be first insulating materials. Alternatively, if at least one of the first angles 160, 170 and second angles 150 described later is a second insulating material, then all of the plurality of insulating spacers 141 may be first insulating materials.

[0020] As shown in FIGS. 2 and 3, the external iron type transformer 100 further includes a plurality of first angles 160, 170 and a plurality of second angles 150. In the present embodiment, among the plurality of first angles 160, 170 and the plurality of second angles 150, some of the angles arranged at the positions where high electric fields are generated are second insulators, and the remaining angles are first insulators. Specifically, among the winding groups 120, the second angles 150 that contact the outer surface of the flat winding 130 where the electric field generated at the end is relatively high or the first angles 160, 170 that contact the inner surface are second insulators, and the second angles 150 that contact the outer surface of the flat winding 130 where the electric field generated at the end is relatively low or the first angles 160, 170 that contact the inner surface are first insulators. In addition, when at least one of the plurality of insulating spacers 141 is a second insulator, all of the plurality of first angles 160, 170 and the plurality of second angles 150 may be first insulators.

[0021] The plurality of first angles 160, 170 are located between the inner surfaces 130a of the plurality of flat windings 130 and the main leg portions 111. The plurality of first angles 160, 170 are arranged so as to surround the main leg portions 111. Each of the plurality of first angles 160, 170 is in contact with the inner surface 130a of the flat winding 130.

[0022] Each of the plurality of first angles 160 extends in the first direction (Y-axis direction) along the inner surface 130a. Each of the plurality of first angles 170 includes a portion extending in the first direction (Y-axis direction) along the corner portion of the inner surface 130a and a portion extending in the second direction (X-axis direction) orthogonal to the first direction (Y-axis direction).

[0023] The plurality of second angles 150 are located between the outer surfaces 130b of the plurality of flat windings 130 and the side leg portions 112. Each of the plurality of second angles 150 extends in the first direction (Y-axis direction) along the side leg portions 112. Each of the plurality of second angles 150 is in contact with the outer surface 130b of the flat winding 130.

[0024] Here, the specific shapes of each of the multiple first angles 160, 170 and the multiple second angles 150 in this embodiment will be described. In this embodiment, each of the first angles 160, 170 and the second angles 150 is an angle with a bent portion at one end in the axial direction (Z-axis direction) of the main part, which will be described later. However, it may also be a channel with bent portions at both ends in the axial direction (Z-axis direction) of the main part.

[0025] Each of the multiple first angles 160 includes a main portion 161 that runs along the axial direction (Z-axis direction) of the iron core 110, and a bent portion 162 that bends from the axial end (Z-axis direction) of the main portion 161 and contacts the main surface 140s of the insulating plate 140. The main portion 161 extends in a first direction (Y-axis direction) along the inner surface 130a. The bent portion 162 is formed in a comb-like shape. The bent portion 162 extends in a second direction (X-axis direction) from the axial end (Z-axis direction) of the main portion 161.

[0026] Each of the multiple first angles 170 includes a main portion 171 that runs along the axial direction (Z-axis direction) of the iron core 110, and bent portions 172 and 173 that are bent from the axial end (Z-axis direction) of the main portion 171 and come into contact with the main surface 140s of the insulating plate 140. The main portion 171 includes a portion that extends in a first direction (Y-axis direction) and a portion that extends in a second direction (X-axis direction) along the corner of the inner surface 130a.

[0027] The bent portions 172 and 173 are formed in a comb-like shape. The bent portion 172 extends from the end in the axial direction (Z-axis direction) of the portion of the main portion 171 that extends in the first direction (Y-axis direction) in the second direction (X-axis direction). The bent portion 173 extends from the end in the axial direction (Z-axis direction) of the portion of the main portion 171 that extends in the second direction (X-axis direction) in the first direction (Y-axis direction).

[0028] Each of the multiple second angles 150 includes a main portion 151 that runs along the axial direction (Z-axis direction) of the iron core 110, and a bent portion 152 that bends from the axial end (Z-axis direction) of the main portion 151 and contacts the main surface 140s of the insulating plate 140. The main portion 151 extends in a first direction (Y-axis direction) along the outer surface 130b. The bent portion 152 is formed in a comb-like shape. The bent portion 152 extends in a second direction (X-axis direction) from the axial end (Z-axis direction) of the main portion 151.

[0029] As described above, in the external iron transformer 100 according to this embodiment, by using a second insulator made of a low dielectric constant material only in the insulating member adjacent to the end of the flat winding 130, where a high electric field is generated within the flat winding 130, it is possible to improve insulation reliability by mitigating the electric field in the oil while suppressing an increase in equipment costs. Specifically, by making only the first insulating spacer 141a, the second insulating spacer 141b, the first angles 160, 170, and the second angle 150 from a low dielectric constant material, and making the insulating plate 140 and the third insulating spacer 141c from pressboard, it is possible to improve insulation reliability while suppressing an increase in equipment costs. This configuration may be applied only to the primary winding group 121, or it may also be applied to the secondary winding group 122. As described above, it is sufficient that at least one second insulator is placed closer to the core than the first insulator. At least one second insulator is in contact with at least one flat winding 130 at the position closest to the iron core 110 among the multiple insulators.

[0030] In this embodiment, only the material of the insulating member adjacent to the end of the flat winding 130, where a high electric field is generated within the flat winding 130, is changed, making it easily applicable to existing external iron type transformers.

[0031] In the external iron type transformer 100 according to this embodiment, the material of the first insulator is pressboard, and the material of the second insulator is polyamide resin. By using insulating members made of inexpensive pressboard in areas where high electric fields do not act, and arranging insulating members made of polyamide resin, which has a lower dielectric constant than pressboard, only in areas where high electric fields act, it is possible to mitigate the electric field in the oil and improve insulation reliability while suppressing an increase in equipment costs.

[0032] In the external iron type transformer 100 according to this embodiment, the multiple first angles 160, 170 include a portion extending in a first direction (Y-axis direction) and a portion extending in a second direction (X-axis direction) so as to surround the main leg portion 111. This makes it possible to place an insulator with a low dielectric constant over the entire circumference of the inner part of the flat plate winding 130, where a high electric field is generated within the flat plate winding 130, thereby improving insulation reliability.

[0033] In the external iron type transformer 100 according to this embodiment, the bent portions 152, 162, 172, and 173 of the multiple first angles 160, 170 and the multiple second angles 150 are formed in a comb-like shape. As a result, insulating oil can flow into the spaces between adjacent bent portions 152, 162, 172, and 173, so that the ends of the flat windings 130 can be effectively cooled by the insulating oil.

[0034] Furthermore, the embodiments disclosed herein are illustrative in all respects and are not intended to be restrictive. Therefore, the technical scope of this disclosure is not construed solely by the embodiments described above, but is defined based on the claims. This includes all modifications within the meaning and scope of the equivalents of the claims. [Explanation of Symbols]

[0035] 100 Iron transformer, 110 Iron core, 111 Main legs, 112 Side legs, 120 Winding group, 121 Primary winding group, 122 Secondary winding group, 130 Flat winding, 130a Inner surface, 130b Outer surface, 140 Insulating plate, 140s Main surface, 141 Insulating spacer, 141a First insulating spacer, 141b Second insulating spacer, 141c Third insulating spacer, 150 Second angle, 151, 161, 171 Main section, 152, 162, 172, 173 Bent section, 160, 170 First angle.

Claims

1. Iron core and A plurality of flat windings arranged side by side in the axial direction of the iron core and wound around the iron core; a plurality of insulating plates arranged side by side in the axial direction and sandwiched between adjacent planar windings in the plurality of planar windings; a plurality of insulators in contact with at least one of the plurality of planar windings; The plurality of insulators are A plurality of first insulators; at least one second insulator in contact with the at least one flat winding at a position closer to the iron core than the plurality of first insulators; The at least one second insulator is made of a material having a lower dielectric constant than the plurality of first insulators.

2. 2. The shell-type transformer according to claim 1, wherein the at least one second insulator is in contact with the at least one planar winding at a position among the plurality of insulators that is closest to the iron core.

3. The plurality of first insulating materials are made of pressboard, 2. The shell type transformer according to claim 1, wherein the at least one second insulator is made of polyamide resin.

4. 4. The shell-type transformer according to claim 1, wherein the at least one second insulator is at least one channel or angle in contact with an outer surface or an inner surface of the at least one planar winding.

5. 4. The shell type transformer according to claim 1, wherein the at least one second insulator is at least one spacer provided on a main surface of each of the plurality of insulating plates.

6. one second insulator of the at least one second insulator extends in a first direction along the outer surface of the at least one planar winding; 5. The shell-type transformer according to claim 4, wherein another of the at least one second insulator includes a portion extending in the first direction and a portion extending in a second direction perpendicular to the first direction so as to surround the core.

7. The at least one second insulator is A main portion extending along the axial direction; a bent portion bent from an end portion in the axial direction of the main portion and in contact with a main surface of at least one of the plurality of insulating plates, The shell type transformer according to claim 4 , wherein the bent portion is formed in a comb-teeth shape.

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