JP6246484B2 - Static induction machine - Google Patents

Description

  Embodiments of the present invention relate to a static induction electric device having an improved insulation configuration at a portion to which a DC voltage is applied.

  In recent years, direct current power transmission having many merits in system operation, such as large capacity, long distance power transmission, and different frequency linkage, has been used in various fields. For example, in some areas in Japan, ± 250 kV DC transmission that links AC systems is implemented, and ± 800 kV DC transmission is implemented overseas.

  In direct current power transmission, an AC / DC converter station is installed to convert alternating current into direct current or direct current into alternating current. The AC / DC converter station converts an AC voltage into a DC voltage through a transformer for transformer and a thyristor valve, and transmits the DC voltage to a DC line through a DC reactor.

  As an insulation method for such a transformer for transformer and a DC reactor, an oil insulation method is mainly used. Some oil insulation systems employ a composite insulation structure composed of insulating oil and a press board made of a solid insulator. The insulating oil forms part of the insulating structure and flows so as to circulate in the static induction appliance, and also serves as a cooling medium for cooling the windings.

  Since the press board has a higher volume resistivity than the insulating oil, most of the DC voltage is shared. Therefore, since the electric field is not applied to the insulating oil having a small volume resistivity, the insulation can be strengthened. Since the dielectric strength of the press board is several times higher than that of the insulating oil, there is no problem even if an electric field is applied if the press board can be properly arranged.

JP-A-9-009623

  However, in the conventional static induction appliance, an opening for circulating insulating oil is provided in the press board. In this opening, the DC equipotential distribution shared by the press board and the insulating oil is disturbed, and the DC electric field of the insulating oil tends to be locally increased. The direct current withstand voltage of the insulating oil is about an order of magnitude smaller than that of the press board. In the vicinity of the opening, the insulating oil itself or the interface between the insulating oil and the press board tends to cause dielectric breakdown, which is a weak point in insulation.

  Therefore, a plurality of angle press boards that cover the corners of the windings with a space are arranged to face each other, an opening is formed between the angle press boards, and an insulating board is provided in the vicinity of the opening to provide insulating oil. It has been proposed to form a flow path. However, even if the insulation is strengthened in this way, there is a portion where the electric field of the insulating oil is locally increased, and it has not been possible to solve the weak point in insulation. Therefore, in the conventional static induction appliance, it is necessary to increase the insulation dimension in order to ensure the insulation performance, and there is a problem that the static induction appliance is enlarged.

  The embodiment of the present invention has been proposed in order to solve the above-described problems of the prior art. The purpose is to provide a small and highly reliable static induction electric device that improves the insulation in the vicinity of the opening even when the press board has an opening.

In a static induction electric machine according to an embodiment for achieving the above object, a winding is housed in a container filled with insulating oil, and between the container and the axial end of the winding. In the static induction appliance in which an electrostatic shield is provided, a plurality of press boards are arranged through a space so as to surround the winding and the electrostatic shield, and an opening is formed in the press board. The opening is provided so as to be shifted in the circumferential direction of the winding so as not to overlap with the opening of the adjacent press board, and the flow path of the insulating oil is formed in a Z shape .

The wiring diagram which shows an example of a general AC / DC conversion station. It is sectional drawing which shows an example of the insulation structure of the static induction appliance of 1st Embodiment. It is an expanded sectional view showing an example of insulating composition of an opening of a 1st embodiment. It is A-A 'sectional drawing of the expanded sectional view of FIG. It is an expanded sectional view which shows an example of the insulation structure of the opening part in the conventional static induction appliance. It is a distribution map of the DC equipotential line in the conventional static induction appliance. It is a distribution map of a DC equipotential line in the vicinity of the opening of the static induction appliance of the first embodiment. It is a distribution map of the DC equipotential lines in parts other than the vicinity of the opening in the static induction appliance of the first embodiment. It is explanatory drawing which shows the relationship between the distance between opening parts, and a DC electric field. It is sectional drawing which shows an example of the insulation structure of the static induction appliance of 2nd Embodiment.

[1. First Embodiment]
[1.1 Arrangement Example]
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a layout diagram illustrating an example of an AC / DC converter station in which a static induction electrical appliance according to the present embodiment is disposed. As shown in FIG. 1, the AC / DC converter station converts an AC voltage input from the AC line 1 into a DC voltage through converter transformers 2 a and 2 b and thyristor valve groups 3 a and 3 b. It is configured to transmit power to the line 5.

  In this case, the thyristor valves 6a and 6b forming the thyristor valve groups 3a and 3b are main elements that convert an AC voltage into a DC voltage or a DC voltage into an AC voltage. As such thyristor valves 6a and 6b, air-insulated valves are often used from the viewpoint of operation performance, maintenance and inspection. The air-insulated thyristor valves 6 a and 6 b are usually housed in a building called a valve hole 7. In the figure, 8a and 8b are lightning arresters for a transformer, 9 is a lightning arrester for a DC reactor, and 10 is an anode-cathode lightning arrester of the thyristor valve groups 3a and 3b.

[1.2 Configuration of Embodiment]
(1) Schematic Configuration of Static Induction Appliance FIG. 2 shows a cross-sectional view of a static induction appliance arranged in this way. In this embodiment, a transformer for a converter will be described as an example of a static induction device. In the static induction electric machine of the present embodiment, transformer windings wound around the iron core I are arranged around the iron core I and concentrically. This transformer winding is housed in a container T filled with insulating oil 11, and an inner winding is an AC winding 12 and an outer winding is a DC winding 13.

  Among these, the AC winding 12 is coupled to the AC line 1, and the DC winding 13 is connected to the thyristor valve group 3a or 3b. Between the container T and the axial end of the winding direction of each of the windings 12 and 13, an electrostatic shield 14 whose periphery is covered with an insulating material for electric field relaxation is disposed. One electrostatic shield 14 may be provided at each end of each of the windings 12 and 13, or may be divided into a plurality of parts in order to enhance insulation.

  A plurality of press boards 15 made of a solid insulating material such as paper are provided around each of the windings 12 and 13 and the electrostatic shield 14 through a space, and surround the windings 12 and 13 in layers. Yes. Hereinafter, in each of the windings 12 and 13, the side on which the electrostatic shield 14 is disposed is expressed as “up”.

(2) Outline of Insulation Configuration Each of the plurality of press boards 15 is arranged through a space, and a plurality of stages are arranged around the windings 12 and 13. This is because the insulating strength of the press board 15 is greater than that of the insulating oil 11 alone. This is also because the volume of the insulating oil 11 is divided by the press board 15. The volume resistivity of the insulating oil 11 is very small compared to the press board 15. Therefore, the breakdown electric field of the insulating oil 11 has a negative dependency on the volume of the insulating oil 11. Therefore, by providing a plurality of preboards 15, the pressure resistance of the insulating oil 11 is increased by subdividing the volume of the insulating oil 11.

  The press board 15 is concentric with the windings 12 and 13, a plurality of press board panels 15 a arranged at approximately equal intervals, and the cross-section L-shaped surrounding the windings 12, 13 and the electrostatic shield 14. A plurality of angle press boards 15b and press board rings 15c and 15d surrounding the end of the electrostatic shield 14. The plurality of press board panels 15a are arranged on the inner and outer circumferences of the windings 12 and 13, respectively.

  The plurality of angle press boards 15b are L-shaped members that cover the inner peripheral side and outer peripheral side corners of the windings 12 and 13 through a space, and are connected to the inner and outer peripheral press board panels 15a. Has been. The inner side angle press board 15 b has a surface arranged in parallel to the inner side surface of each of the windings 12 and 13 and a surface arranged in parallel to the upper surface of the electrostatic shield 14. The outer peripheral angle press board 15 b has a surface disposed parallel to the outer peripheral surface of each of the windings 12 and 13 and a surface disposed parallel to the upper surface of the electrostatic shield 14. Since the angle press board 15b covers the electrostatic shield 14 in multiple layers, the insulation of the windings 12 and 13 is reinforced.

  The press board 15 subdivides the insulating oil 11 as described above, and forms a flow path that circulates around the windings 12 and 13 using the insulating oil 11 as a cooling medium. The arrows in the figure indicate the direction in which the insulating oil 11 flows. Hereinafter, the insulation configuration around the windings 12 and 13 will be described in detail.

(2.1) Insulation structure around AC winding One end of the AC winding 12 is provided with one electrostatic shield 14. A plurality of stages of angle press boards 15b on the inner peripheral side and the outer peripheral side are alternately arranged via a space so as to surround the AC winding 12 and the electrostatic shield 14. Accordingly, a space is formed between the electrostatic shield 14, the angle press board 15b adjacent to the electrostatic shield 14, and the plurality of adjacent angle press boards 15b.

  In this space, spacers 16 made of a solid insulator such as paper are arranged. The spacers 16 are arranged so as to keep the distance between the electrostatic shield 14 and the angle press board 15b adjacent to the electrostatic shield 14 and the distance between the adjacent angle press boards 15b constant. As the spacer 16, the same insulator as the press board 15 can be used.

  In the AC winding 12, the insulating oil 11 introduced from the lower part of the AC winding 12 flows upward while cooling the AC winding 12. Since the inner and outer angle press boards 15b are alternately arranged one by one, an opening is formed by the end of the surface arranged parallel to the electrostatic shield 14 and the adjacent angleless board 15b. Accordingly, the insulating oil 11 that has reached the upper side of the AC winding 12 passes the flow path formed by the angle press boards 15b arranged alternately one by one in the winding radial direction, as indicated by arrows in FIG. It flows in a Z shape and flows out from above the winding 12.

(2.2) Insulation structure around the DC winding As shown in FIG. 3, the electrostatic shield 14 of the DC winding 13 is divided into an inner peripheral electrostatic shield 14a and an outer peripheral electrostatic shield 14b. Yes. A spacer 17 made of a solid insulator such as paper is provided between the inner peripheral side electrostatic shield 14a and the outer peripheral side electrostatic shield 14b, and maintains a gap between the electrostatic shields 14a and 14b. An insulating structure having an inverted U-shaped cross section is formed in a plurality of stages through a space so as to surround the periphery of the DC winding 13 and the electrostatic shield 14.

  Specifically, the inner peripheral angle press board 15b is provided in a plurality of stages so as to surround the DC winding 13 and the inner peripheral electrostatic shield 14a. A plurality of outer peripheral angle press boards 15b are provided so as to surround the DC winding 13 and the outer peripheral electrostatic shield 14b. The inner and outer angle press boards 15b are arranged such that the ends of the surfaces arranged in parallel with the electrostatic shield 14 face each other with a space in between.

  The plurality of press board rings 15c are provided so as to connect a space portion formed between the end portions of the inner peripheral side and the outer peripheral side angle press board 15b. One end of the press board ring 15c is connected to the angle press board 15b on the inner peripheral side, and the other end is connected to the angle press board 15b on the outer peripheral side.

  A press board ring 15 d is further provided through the space in a space formed by arranging the connected press boards 15 in a plurality of stages. Therefore, the insulating structure on the upper side of the DC winding 13 is such that the connected press boards 15 and press board rings 15d are alternately provided via the spaces. The length of the pressboard ring 15d in the winding radial direction (hereinafter referred to as the width) is a surface parallel to the end of the DC winding 13 in the pressboard 15 adjacent to the winding side of the pressboard ring 15d. It is almost the same as the width. Therefore, the width of the plurality of press board rings 15d becomes wider as the distance from the DC winding 13 increases. The press board ring 15d is also provided above the uppermost connected press board 15.

  In the space between the electrostatic shield 14 and the adjacent press board ring 15c, and the space between the connected press board 15 and the press board ring 15d, spacers 18 made of a solid insulator such as paper are respectively disposed. Yes. One spacer 18 is arranged on the inner peripheral side and the outer peripheral side of the winding so as to face each other through openings O of press board rings 15c and 15d described later. Therefore, in the space between the spacers 18 provided facing each other, the length in the winding radial direction becomes the width of the flow path of the insulating oil 11 formed by the press board 15.

  The spacer 18 is disposed so as to keep constant the distance between the electrostatic shield 14 and the press board ring 15c adjacent to the electrostatic shield 14 and the distance between the adjacent press board ring 15 and press board ring 15d. . As the spacer 18, the same insulator as the press board 15 can be used.

  The flow path of the DC winding 13 is divided into a plurality in the winding circumferential direction. FIG. 4 is a cross-sectional view taken along the line A-A ′ of FIG. FIG. 4 shows one of the flow paths of the insulating oil 11 separated by the spacer 19. In a section forming one flow path sandwiched between the spacers 19, openings O are formed in the plurality of pressboard rings 15c and 15d, respectively. The opening O is arranged so as to be shifted in the circumferential direction of the winding so that the position of the opening O of the adjacent press board ring 15c and the opening O of the press board ring 15d do not overlap.

  The distance between the openings is preferably at least 30 mm in the winding circumferential direction. The distance between the openings means the distance from the end of the opening O of the press board ring to the end of the opening O of the adjacent press board ring in the winding circumferential direction. The positions of the openings O of the press board rings 15c are arranged so as to overlap each other. The position of the opening O of each press board ring 15d is also arranged so as to overlap. Since the press board rings 15c and 15d are alternately arranged, the openings O are also alternately arranged in the winding circumferential direction.

  The spacer 19 is provided in the opening O of the press board ring 15c in the vicinity of the side opposite to the opening side of the press board ring 15d. Further, the spacer 19 is also provided in the vicinity of the opening O of the press board ring 15d on the side opposite to the opening side of the press board ring 15c. Therefore, in the section in the winding circumferential direction sandwiched between the spacers 19, the press board ring rings 15 c and 15 d and their opening O form a Z-shaped flow path.

  The spacer 19 holds a space between the press board rings 15 c and 15 d and also serves as an oil stopper for the insulating oil 11. As the spacer 19, the same insulator as the press board 15 can be used.

  A plurality of Z-shaped flow paths are formed in the winding circumferential direction. That is, Z-shaped flow paths are adjacent to each other through the spacer 19. For example, when one end of the spacer 19 coincides with the end of the opening O of the pressboard ring 15c of a certain Z-shaped flow path, the other end is adjacent to the Z-shaped flow path. It coincides with the end of the opening O of the press board ring 15d of the flow path. Therefore, the opening O of one Z-shaped flow path and the opening O of the other Z-shaped flow path are adjacent to each other through the spacer 19.

  The spacer 17 provided between the electrostatic shields 14a and 14b can be provided so as to cover the opening O below the opening. In FIG. 4, the spacer 17 is provided below the openings O so as to overlap with the positions of the adjacent openings O through the spacer 19. The length of the spacer 17 in the winding circumferential direction is preferably longer than the length of the opening O adjacent through the spacer 19. A spacer 19 corresponding to the opening O of the press board ring 15c and a spacer corresponding to the opening of the press board ring 15d may be separately installed. In that case, the length of the spacer 17 in the circumferential direction may be longer than the length of each opening O.

  In the DC winding 13 as described above, the insulating oil 11 flowing in from the lower portion of the DC winding 13 flows upward while cooling the DC winding 12. The press board rings 15c and 15d having the openings O at the shifted positions are alternately arranged. Therefore, the insulating oil 11 that has reached the upper side of the DC winding 13 flows through the space between the electrostatic shields 14a and 14b, as shown in FIG. 4, and then the openings provided in the press board rings 15c and 15d The flow path formed by O and the spacer 19 flows in a Z shape in the circumferential direction of the winding and flows out from above the winding 13.

[1.2 Action]
The operation of the present embodiment having the above-described configuration will be described below in comparison with a static induction device in which the opening is shifted in the winding radial direction as shown in FIG. The static induction electric machine of FIG. 5 has an opening formed in a space between the press board ring 15d and the opposite end portions of the inner and outer angle press boards 15b. These openings are arranged so as to be shifted in the winding radial direction. The spacer 18 is disposed together with the end of the opening in the winding radial direction, and determines the width of the flow path of the insulating oil 11. The present embodiment is also different from the present embodiment in that the spacer 17 is not provided between the electrostatic shields 14a and 14b.

  When analyzing the DC potential distribution of the static induction electric machine of FIG. 5, as shown in FIG. It turns out that it has not changed in each inside but has changed to an adjacent member through an oil gap. In particular, in the vicinity of the opening, the DC equipotential line E is transferred, and the electric field applied to the insulating oil 11 is increased. The portion where the high electric field is generated in this way is a weak point in insulation.

  On the other hand, in the static induction appliance of the present embodiment, the opening O in the DC winding 13 is shifted in the winding circumferential direction. A spacer 17 is provided in the space between the electrostatic shields 14a and 14b. FIG. 7 shows the result of analyzing the DC potential distribution of the B-B ′ cross-sectional view (cross-sectional view near the opening) in FIG. 4. FIG. 8 shows the result of analyzing the DC potential distribution of the C-C ′ sectional view of FIG. 4 (the sectional view of the press board rings 15 c and 15 d).

  As is apparent from FIGS. 7 and 8, the DC equipotential lines E are shifted inside the electrostatic shields 14a and 14b, the spacers 17 and 18, and the press board rings 15c and 15d, respectively. In the present embodiment, the DC equipotential line E hardly shifts through the oil gap. In addition, although a DC equipotential line E that partially moves through the oil gap is also seen, the electric field applied to the insulating oil 11 is small because the interval between the equipotential lines is very rough.

(1) Action by Arrangement of Opening Part The part provided with the opening part O may cause a transfer of the DC equipotential line E at the end part of the press board 15 forming the end part of the opening part O . For example, in the vicinity of the opening of the press board ring 15c, the DC equipotential line E may be transferred to the adjacent press board ring 15d from the end of the press board ring 15c, and a DC electric field may be applied to the insulating oil 11. .

  In the present embodiment, the opening portions O of the adjacent press board rings 15c and 15d are provided so as to be displaced in the winding circumferential direction. By shifting the position of the opening O in the winding circumferential direction, the distance at which the press board ring 15c and the press board ring 15d are arranged to overlap can be extended. Since the DC equipotential line E can be transferred even at the overlapping portion of the press board rings 15c and 15d, it is possible to avoid intensive transfer of the DC equipotential line E in the vicinity of the opening.

  Further, in the case where the opening is displaced in the winding radial direction as shown in FIG. 5, the winding-side angle press board 15b and the press board ring 15c have a narrow width in the winding radial direction. The opening needs to have a low flow rate in order to suppress the flow charge of the insulating oil 11. Therefore, the width of the opening cannot be made smaller than a certain value. As described above, in the configuration in which the opening is shifted in the winding radial direction, it is difficult to secure the distance between the openings, and thus the electric field in the vicinity of the opening is high.

  On the other hand, in the present embodiment, the opening O is configured to be shifted in the winding circumferential direction, so that a sufficient distance between the openings can be secured. FIG. 9 is a graph showing the relationship between the distance between the openings of adjacent press board rings 15c and 15d and the electric field. FIG. 9A shows a portion where the maximum electric field is generated in the vicinity of the opening by a dotted circle. As shown in FIG. 9B, the electric field generated in the maximum electric field portion is the highest when the distance between the openings is a negative value, that is, when the openings O are arranged so as to overlap. On the other hand, it can be seen that the electric field generated in the maximum electric field portion decreases as the distance between the openings increases.

  Since the standard deviation of the breakdown electric field of the insulating oil 11 is around 10%, in order to positively reduce the maximum electric field by increasing the distance between the openings, the maximum electric field value is reduced by 20% or more, corresponding to the −2σ value. It is preferable to do so. Therefore, as in this embodiment, when the distance between the openings is shifted by 30 mm or more, the maximum electric field value can be reduced by 20% or more, thereby avoiding intensive transfer of the DC equipotential lines E in the vicinity of the openings. it can.

(2) Action of the spacer 17 Since the opening O is provided in the press board ring 15c in the BB 'cross-section part of FIG. 4, an insulating structure is formed only by the press board ring 15d. Therefore, the number of press board rings installed is half of the CC ′ cross section. Although the DC breakdown voltage of the press board 15 is several times higher than the DC breakdown voltage of the insulating oil 11, if an excessive DC electric field is applied to the press board ring 15d, there is a possibility of dielectric breakdown.

  However, in the present embodiment, the spacer 17 is provided so as to cover the opening O below. The DC equipotential line E can move between the electrostatic shields 14 a and 14 b via the spacer 17. Therefore, the spacer 17 shares the DC voltage, and the voltage sharing of the press board ring whose number is reduced by the opening O can be reduced.

[1.3 Effect]
The effects of the present embodiment as described above are as follows.
(1) By shifting the opening O in the circumferential direction of the winding, the DC equipotential line E can be prevented from moving through the oil gap in the vicinity of the opening, and the electric field applied to the insulating oil 11 can be reduced. . Even when the DC equipotential line E moves through the insulating oil 11, the electric field applied to the insulating oil 11 can be reduced because the interval between the equipotential lines is very rough. Therefore, there is no insulation weak point in the vicinity of the opening, and the insulation can be improved.

(2) When the distance between the openings is 30 mm or more, the electric field value can be further reduced, and intensive transfer of the DC equipotential lines E in the vicinity of the openings can be avoided. Therefore, there is no insulation weak point in the vicinity of the opening, and the insulation can be improved.

(3) When the electrostatic shield 14 is divided into a plurality of parts, by providing a spacer between the divided electrostatic shields 14, it is possible to reduce the voltage sharing of the press board ring having the opening O. it can. Therefore, there is no insulation weak point in the vicinity of the opening, and the insulation can be improved.

(4) Furthermore, since the insulation dimension can be reduced by improving the insulation as described above, it is possible to provide a highly reliable and small static induction appliance.

[2. Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the opening O is shifted in the winding circumferential direction only in the press-board ring on the winding side, and is basically the same as the first embodiment. Accordingly, the same parts as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, in the insulating configuration of the press board 15 on the winding side, the opening O is arranged shifted in the winding circumferential direction. As shown in FIG. 10, two stages of the angle press board 15b and the press board ring 15e are arranged on the winding side. Each of the angle press board 15b and the press board ring 15e has an opening O, and the opening is displaced in the circumferential direction of the winding as in the first embodiment. Therefore, in the two-stage insulation structure on the winding side, a Z-shaped insulating oil 11 flow path is formed in the circumferential direction of the winding.

  In the insulating configuration of the press board 15 away from the windings 12 and 13, the opening O is arranged so as to be shifted in the winding radial direction. On the outside of the two-stage insulation structure formed on the winding side, two stages of angle press boards 15b are arranged. Each angle press board 15b has an opening O, and is offset from the opening O of the adjacent angle press board 15b in the winding radial direction. Therefore, in a two-stage insulation configuration separated from the winding, a Z-shaped insulating oil 11 flow path is formed in the winding radial direction.

  In the insulation configuration on the winding side, as described above, the width of the press board 15 in the winding radial direction is narrowed. Therefore, the insulation in the vicinity of the opening can be improved by adopting the same configuration as that of the first embodiment. In the press board 15 apart from the windings 12 and 13, the width in the radial direction of the winding is widened, so that it is possible to shift the opening O in the radial direction while ensuring a sufficient distance between the openings. Therefore, in the insulating structure of the press board separated from the winding, the number of members of the insulating structure can be reduced and the insulating property in the vicinity of the opening can be improved. That is, even when the configuration of the present embodiment is adopted, the same operational effects as those of the first embodiment can be obtained.

[3. Other Embodiments]
(1) In the above embodiment, the configuration example of the DC winding has been described. However, the insulation configuration of the DC winding can be applied to the insulation configuration of the AC winding. It can also be provided on both the DC side and the AC side.

  (2) In the above embodiment, the insulating configuration around the winding is configured by the press board, the angle press board, and the press board ring. However, these members may be combined in any way. The shape of each member can be changed as appropriate in view of the insulation configuration of the winding. Moreover, the opening part should just be provided in either of the press boards, and what is necessary is just to select a specific member suitably.

  (3) In the above embodiment, the configuration on the side from which the insulating oil flows is the upper part of the winding, and the surrounding insulating configuration has been described. This insulating configuration around the winding is applicable to the side where the insulating oil flows, that is, the lower part of the winding.

  (4) 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 embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

I ... Iron core T ... Container 11 ... Insulating oil 12 ... AC winding 13 ... DC windings 14, 14a, 14b ... Electrostatic shield 15 ... Press board 15a ... Press board panel 15b ... Angle press boards 15c, 15d, 15e ... Press Board ring 16, 17, 18, 19 ... spacer

Claims (4)

The winding is housed in a container filled with insulating oil, and an electrostatic shield is provided between the container and the axial end of the winding so as to surround the winding and the electrostatic shield. A plurality of press boards are arranged in a plurality of stages through a space, and in the static induction appliance in which an opening is formed in the press board,
The opening is provided so as to be shifted in the circumferential direction of the winding so as not to overlap with an opening of an adjacent press board, and a flow path for insulating oil is formed in a Z shape. Electricity. The electrostatic shield is divided into a plurality, and a spacer is provided between the plurality of electrostatic shields;
The spacer is disposed at a position overlapping the opening,
The stationary induction device according to claim 1, wherein the circumferential length of the winding of the spacer is longer than the circumferential length of the winding of the opening.   3. The stationary induction device according to claim 1, wherein the opening is provided so as to be shifted from an opening of an adjacent press board by 30 mm or more. 4. Of the press boards arranged in a plurality of stages, an opening of the winding-side press board is provided so as to be displaced in the circumferential direction of the winding,
The static induction machine according to any one of claims 1 to 3, wherein an opening of the container-side press board is provided so as to be displaced in a radial direction of the winding.

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