JP2000331844A - Stationary electromagnetic induction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve miniaturization as a whole by improving insulating property of a stationary electromagnetic induction apparatus. SOLUTION: In this stationary electromagnetic induction apparatus, both ends of a fourth winding L4 in a low-voltage side winding 14, and both ends of a first through a ninth winding layers H1 through H9 and a tapped winding T in a high voltage side winding 16, are provided so as to be covered with insulating members 19 each having a substantially U-shaped cross-section. In this case, assuming that dielectric constant of the surrounding insulating member is 1.0, dielectric component of the insulating member 19 is set to 0.3 or more and 1.0 or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stationary electromagnetic induction device having improved insulation performance.

[0002]

2. Description of the Related Art Various types of transformers, which are stationary electromagnetic induction devices, are provided according to the type of a cooling medium. Among them, for example, a gas insulated transformer using SF6 gas as a cooling medium is incombustible. It is widely used because it features high reliability and high reliability. However, in such a gas-insulated transformer, the Vt characteristic (time vs. voltage characteristic) of the dielectric breakdown of SF6 gas becomes substantially flat at 1 μs or more, so that the application of lightning surge and switching surge is weak in terms of insulation. Becomes

FIG. 17 shows a winding configuration of a conventional gas-insulated transformer using SF6 gas as a cooling medium. That is, the conventional gas-insulated transformer includes, for example, a low-voltage-side winding 4 composed of four winding layers and a nine-position winding on the outside of the leg 1 of the iron core 3 composed of the leg 1 and the yoke 2. Winding layer and 1
A multi-cylindrical winding structure is formed by winding a high-tension winding 5 composed of two tap winding layers. An end shield 6 is provided on the end side of the first winding layer as the innermost winding layer of the high voltage side winding 5 and on the end side of the tap winding layer as the outermost winding layer.

[0004]

The conventional gas insulated transformer using SF6 gas as a cooling medium has the following problems. (1) Since a high electric field is applied to the end of the high-voltage side winding 5, it is necessary to provide an end shield 6. Also, when a lightning surge is applied to the winding, especially the high-voltage side winding 5. Since a large shared voltage is applied to each of the winding layers, it is necessary to provide a large insulating distance between the winding layers, and there has been a problem that the size of the entire winding is increased due to the insulating performance of SF6 gas as an insulating medium.

(2) A lead wire for lead-out is connected to the winding start end of the high-voltage side winding 5, but it is necessary to increase the insulation distance between the lead wire and the grounding portion (iron core 3). There was a problem that it became large.

(3) A lead wire drawn from the low-voltage side winding 4 or the high-voltage side winding 5 may cross the vicinity of the high-voltage side winding 5 which is a high electric field side. It is necessary to increase the insulation distance between the wire and the high-voltage side winding 5, and there is a problem in that the overall size is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stationary electromagnetic induction device capable of improving insulation performance and achieving downsizing.

[0008]

According to a first aspect of the present invention, there is provided a stationary electromagnetic induction device, wherein a dielectric constant of a surrounding insulating member at a high electric field side portion or an end portion is 0.3 or more and 1 or less. It has a winding provided with an insulating member having a dielectric constant. According to such a configuration, the insulation performance is improved and the overall size can be reduced as compared with the case where the winding is formed only of the element wires.

According to a third aspect of the present invention, there is provided a stationary electromagnetic induction device having an insulation having a dielectric constant of 0.3 or more and 1 or less when the dielectric constant of the surrounding insulating member is 1 at the end of the wire constituting the winding layer. It is characterized by having a winding provided with a member. According to such a configuration, the insulation performance between the winding layers can be improved, and the size can be further reduced.

According to a fourth aspect of the present invention, in the stationary electromagnetic induction device, the dielectric constant of the peripheral insulating member around the winding start end side and the winding end end side is 1 or more and 0.3 or less and 1 or less. A winding provided with an insulating member having the following characteristics. According to such a configuration, the number of insulating members to be applied to the windings can be reduced, and the productivity is improved.

According to a still further aspect of the present invention, there is provided a stationary electromagnetic induction apparatus characterized in that an insulating member is applied thicker to a portion having a high electric field. According to such a configuration, the insulation performance can be further improved.

According to a still further aspect of the present invention, there is provided a stationary electromagnetic induction device having an insulation having a dielectric constant of 0.3 or more and 1 or less when the dielectric constant of the surrounding insulating member is 1 at the end of the wire constituting the winding. The feature is that the member is applied and drawn out as a lead wire. According to such a configuration, since the element wire of the winding can be used as a lead, connection between the winding and the lead is not required, thereby improving manufacturability and improving the insulation performance of the lead. Therefore, the size can be reduced as a whole.

According to a seventh aspect of the present invention, there is provided the stationary electromagnetic induction apparatus wherein the dielectric constant of the surrounding insulating member is set at about 1 around the portion corresponding to the high electric field portion side of the lead wire drawn from the winding.
It is characterized in that an insulating member having a dielectric constant of 3 or more and 1 or less is provided. According to such a configuration, the insulation performance for the lead wire, the high electric field portion, and the ground portion can be improved, and the smoke saving distance between them can be reduced, so that the overall size can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to a gas-insulated transformer will be described below with reference to FIGS. First, FIG. 1 shows a configuration of a multiple cylindrical winding of a gas insulated transformer using SF6 gas as a cooling medium. That is, for example, a low-voltage side winding 14 in which first to fourth four winding layers L1 to L4 are concentrically arranged is wound around the leg 11 of the iron core 13 including the leg 11 and the yoke portion 12. I have. Each of the winding layers L1 to L4 is formed by winding up and down a plurality of wires 15 each of which is provided with an insulating coating around a conductor. The lower end of the wires 15 constituting the first winding layer L1 and the second winding Between the lower end of the strand 15 forming the layer L2 and the second
The upper end of the wire 15 constituting the winding layer L2 and the third winding layer L3
, And between the lower end of the wire 15 forming the third winding layer L3 and the lower end of the wire 15 forming the fourth winding layer L4 are lead wires. The winding layers L1 to L4 are connected in series.

Here, the upper end of the wire 15 forming the first winding layer L1 and the wire 1 forming the second winding layer L2 are used here.
5, the upper end of the wire 15 forming the third winding layer L3 and the lower end of the wire 15 forming the fourth winding layer L4 each have a winding start end 151. Winding end 15n for each one turn at each end
And

Further, outside the low-voltage side winding 4, the first to ninth nine winding layers H 1 to H 9 and the tap winding layer T
Are wound concentrically.
Each of the winding layers H1 to H9 is formed by winding up and down a plurality of strands 17 (see FIG. 2) formed by applying an insulating coating 17b around a conductor 17a.
7, between the lower end of the wire 17 forming the second winding layer H2 and the upper end of the wire 17 forming the second winding layer H2.
Between the lower end of the wire 17 forming the third winding H3 and the lower end of the wire 17 forming the fourth winding H4, Of the wire 17 constituting the fourth winding layer H4 and the wire 17 forming the fifth winding layer H5
Between the lower end of the wire 17 forming the fifth winding layer H5 and the lower end of the wire 17 forming the sixth winding layer H6,
Between the upper end of the wire 17 forming the sixth winding layer H6 and the upper end of the wire 17 forming the seventh winding layer H7, the seventh winding layer H7
And between the lower end of the wire 17 constituting the eighth winding H8 and the lower end of the wire 17 forming the eighth winding H8, and the upper end of the wire 17 forming the eighth winding H8 and the ninth winding H9. Each of the windings H1 to H9 is connected in series with a lead wire between the upper ends of the strands 17 to be formed.

In this case, the upper end of the wire 17 forming the first winding layer H1, the wire 1 forming the second winding layer H2 is used here.
7, the upper end of the strand 17 constituting the third winding layer H3,
The lower end of the wire 17 forming the 47th winding H4, the upper end of the wire 17 forming the fifth winding H5, the lower end of the wire 17 forming the sixth winding H6, the seventh winding One end of each of the upper ends of the wires 17 forming the H7, the lower ends of the wires 17 forming the eighth winding layer H8, and the upper ends of the wires 17 forming the ninth winding layer H9 starts to be wound. 171 and the winding end at each of the opposite ends is equal to the winding end 17.
n.

The tap winding layer T is formed by winding up and down a plurality of strands 18 each of which is provided with an insulating coating around a conductor.
It has multiple taps. The plurality of taps of the tap winding layer T are connected to a tap changer via lead wires. Incidentally, the winding end 17n of the element wire 17 constituting the ninth winding layer H9 of the high-voltage side winding 16 is also connected to the tap changer via a lead wire.

The insulating member 19 is formed in an annular shape having a substantially U-shaped cross section, and as shown in FIG. 3, as shown in FIG. It is manufactured from the insulator 21 in which one or several objects are combined. Specifically, as shown in FIG. 4, an insulating material 21 is set in a receiving mold (female mold) 101 in a heating furnace 100 and pressed by a press mold (male mold) 102 to thereby form a long insulating material. Heat molding of the member,
This long insulating member is formed of both ends of the fourth winding layer L4 of the low-voltage winding 14 and the winding layers H1 to H of the high-voltage winding 16.
9 and both ends of the tapped layer T, and are fixed by bonding, thereby forming an annular insulating member 19 having a substantially U-shaped cross section. In this case, each insulating member 19 is provided at both ends of the fourth winding layer L4 of the corresponding low-voltage winding 14, at both ends of the winding layers H1 to H9 of the high-voltage winding 16, and at both ends of the tap winding T. It is formed in a diameter suitable for the diameter. Note that the length of the insulating member 19 is
The height is set to about twice the height dimension of 5, 17.

The insulating member 20 is provided at the winding start end 171 of the wire 17 constituting the first winding layer H1 of the high-voltage side winding 16.
The second winding part 173 and the winding part 17n-2 two turns before the winding end end 17n are provided. Specifically, as shown in FIG. 5, the insulator 21 shown in FIG. Is wound in advance.

The insulating members 19 and 20 are spacer members interposed between the winding layers L1 to L4 of the low voltage side winding 14 and between the winding layers H1 to H9 and T of the step-down side winding 16. And the low voltage side winding 14 and the low voltage side winding 16
Is set to have a dielectric constant of 0.3 or more and 1 or less when a dielectric constant of a peripheral insulating member (not shown) formed of a supporting structure supporting the above is set to 1.

FIG. 6 shows an experimental apparatus for explaining the grounds for setting the permittivity of the insulating members 19 and 20 to 0.3 or more and 1 or less when the permittivity of the surrounding insulating members is set to 1. is there. In FIG. 6, a wire body 200 simulates a first winding layer H1 of the high-voltage side winding 16 and has a wire 201
Simulates a first winding part (winding start end) 171 and a second winding part 172 in a wire 17 constituting the winding layer H1, and a wire 202 is a wire 17 forming the winding layer H1. Simulates the third winding part 173 in FIG.
03 simulates the insulating member 19, the insulating member 204 simulates the insulating member 20, and the surrounding insulating member 205 includes the winding layers L1 to L4 of the low-voltage side winding 14.
The winding layers H1 to H9, T between each other and the high-voltage side winding 16
This simulates a peripheral insulating member (not shown) including a spacer member interposed therebetween and a support structure that supports the low-voltage side winding 14 and the step-down side winding 16. The fourth winding layer L4 of the low-voltage side winding 14 is simulated, the cavity 207 simulates the space between the winding layer L4 and the winding layer H1, and the tank (earth electrode) 208 Simulates a tank (not shown) for storing the iron core 13, the low-voltage side winding 14, and the high-voltage side winding 16, and the experimental apparatus 209 is configured as described above.

The experimental apparatus 209 shown in FIG.
FIG. 7 shows an experimental result of a dielectric breakdown voltage when a surge voltage is applied to the wire body 200 by using insulators having various dielectric constants as the insulating members 203 and 204 in the six gases. In FIG. 7, the horizontal axis shows the ratio of the dielectric constant of the insulating members 203 and 204 when the dielectric constant of the peripheral insulating member 205 is 1, and the vertical axis shows the ratio of the dielectric breakdown voltage. From this experimental result, it is clear that the dielectric breakdown voltage decreases as the dielectric constant ratio increases. It is considered that this is because the electrolysis on the surface of the insulating member 203 increases as the ratio of the dielectric constant increases.

FIG. 8 shows the result of analysis of the dielectric breakdown voltage at the insulating members 203 and 204 by conducting an experiment in the same manner as in FIG. Since the analysis result of the insulating member 203 substantially coincides with the experimental result shown in FIG. 7, in the following description, the analysis result of FIG. 8 will be referred to. From this analysis result, as the dielectric constant ratio decreases, the strand 201 (1
It has been found that the breakdown voltage of (71, 172) is improved.
It can be seen that the dielectric breakdown ratio rises remarkably with a decrease in the dielectric constant ratio from around 1. Further, as the dielectric constant ratio decreases, the dielectric breakdown voltage of the wire 202 (173) decreases, and when the dielectric constant ratio becomes less than 0.3,
It can be seen that the breakdown voltage of the strand 202 is lower than the breakdown voltage of the strand 201.

From the analysis results of FIG. 8, when the dielectric constant of the peripheral insulating member is set to 1, the dielectric constant of the insulators 19 and 20 is set to 0.3 or more and 1 or less (preferably 0.35 or more and 1 or less). It turned out to be necessary.

Therefore, according to this embodiment, when the dielectric constant of the surrounding insulating member is 1, the insulating member 19 having a dielectric constant of 0.3 or more and 1 or less (preferably 0.35 or more and 1 or less) is used. An insulating member 20 having the same dielectric constant is applied to both ends of the fourth winding L4 of the low-voltage winding 14, both ends of the windings H1 to H9 of the high-voltage winding 16 and both ends of the tap winding T. The winding part 171 of the strand 17 constituting the winding layer H1
, 17n-2, the main insulating portion between the low voltage side winding 14 and the high voltage winding 16, the high voltage side winding 16 and the yoke 1
2 (ground portion), and the insulation performance between the winding layers H1 to H9 (interlayer) can be improved, and the insulation distance between them can be significantly reduced as compared with the related art. And miniaturization can be achieved as a whole.

Since the insulating members 19 and 20 are made of one or a plurality of crepe-shaped insulators 21 made of a paper-like insulator or a film-like insulator, a normal paper-like insulator or a film-like insulator is used. The density is extremely low as compared with the case where the insulating member is made of an insulating material. Therefore, when the dielectric constant of the surrounding insulating member is 1, the dielectric constant is 0.3 or more and 1 or less (preferably 0.35 or more and 1 or less) Insulating member 1 having
9 and 20 can be easily obtained.

FIGS. 9 to 11 show a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and different parts will be described below. This second
In this embodiment, unlike the first embodiment, the insulating members 19 are not provided at both ends of the high-voltage side winding 16 from the third winding layer H3 to the eighth winding layer H8. In other words, the insulating member 19 is formed by the first winding layer H of the high-voltage side winding 16.
1, the second winding layer H2, the ninth winding layer H9, and the tap winding layer T are provided at both ends. That is, when viewed from the high voltage side winding 16 as a whole, the insulating member 19 is provided on the winding start end side and the winding end end side. The insulating member 20 is the same as in the first embodiment.

In the gas-insulated transformer having such a configuration, when a high impact voltage is applied to the high-voltage side winding 16, a high electric field is generated at the end thereof. Here, the potential distribution inside the high-voltage side winding 16 with respect to the shock voltage is shown in FIG.
0, and can be calculated by placing the circuit in an equivalent circuit as shown in FIG.
Is usually expressed by equation (1). Here, V is the peak value of the applied voltage E, N is the total number of windings, C is the total ground capacitance, K
Is the total series capacitance.

[0030]

(Equation 1)

Applying this equation at the voltage entry end,
When n >> N, the expression (2) is established.

(Equation 2)

FIG. 11 shows the ratio between the voltage vn at the voltage entry end and the applied voltage peak value V calculated from the equation (2). As described above, when the impact voltage enters the high-voltage side winding 16, a large potential distribution is provided between the layers on the end side where the impact voltage has entered. Therefore, by applying the insulating member 19 (20 if necessary) to the winding start end side and the winding end end side of the high voltage side winding 16, effective insulation reinforcement can be performed, and the overall size can be reduced. Can be achieved. Then, the third winding layer H of the high-voltage side winding 16
Insulating members 19 are provided at both ends from the third to eighth winding layers H8.
Is not provided, the number of insulating members to be applied is reduced by that much, which is effective in terms of improvement in manufacturability.

FIGS. 12 and 13 show a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and different parts will be described below. In the third embodiment, in addition to the insulating member 19, an annular insulating member 22 having a substantially L-shaped cross section is used.
The insulating member 22 is made of an insulator 21 (see FIG. 3), and its length is set to be the same as that of the insulating member 19. The relative permittivity of the insulating member 22 is the same as that of the insulating member 1.
Of course, it is set the same as that of No. 9. Then, the insulating member 22 is applied by bonding to the outside of the insulating member 19 located at the portion where the electric field at the end of the strand is high. That is, the portion where the electric field at the end of the strand is high is defined as the upper end and the lower end of the winding layer L4 on the side opposite to the upper end and the lower end of the winding layer H1, and the lower end of the winding layer L4 in the winding layer H1. The lower end of the winding layer H2, the upper end of the winding layer H1 facing the upper end of the winding layer H1, the lower end of the winding layers H2 and H3 on the side facing each other, and the upper end of the winding layers H3 and H4 on the side facing each other. , The lower ends of the winding layers H4 and H5 on the opposite sides, the upper ends of the winding layers H5 and H6 on the opposite sides, the lower ends of the winding layers H6 and H7 on the opposite sides, and the winding layers H7 and H8. Upper ends of the sides facing each other,
A lower end portion of the winding layers H8 and H9 facing each other, and an upper end portion of the winding layer H9 facing the upper end portion of the tapped winding layer T.

According to the third embodiment, in addition to the insulating member 19, the insulating member 22
Is applied to thicken the insulating member in a portion where the electric field is high as a whole, so that the insulating performance can be further improved. Note that the insulating member 22 is provided outside the insulating member 19.
In performing the bonding, in addition to bonding, binding or winding with an insulating thread or an insulating tape may be performed.

FIGS. 14 and 15 show a fourth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the reference numerals, and different parts will be described below. This fourth
In the embodiment, the first winding layer H1 of the high-voltage winding 16 is used.
An insulating member 20 is applied to the winding start end 171 of the wire, and the winding start end 171 is formed to be long beforehand.
3.

According to the fourth embodiment, the winding layer H
It is not necessary to separately connect a lead wire to the winding start end 171, and the lead wire 23 can be handled as a part of the element wire 17, thereby improving workability. Moreover, since the insulation performance of the lead wire 23 can be improved by the insulating member 20, the insulation distance between the lead wire 23 and the yoke portion 12 (see FIG. 1) serving as the ground portion can be reduced, so that the entire length is reduced accordingly. As a result, miniaturization can be achieved. The low-voltage winding 14 and the high-voltage winding 16 are provided with the insulating member 1 in the same manner as in the first embodiment or the second embodiment.
9, the same effect as in the first embodiment or the second embodiment can be obtained.

FIG. 16 shows a fifth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and different parts will be described below. In the gas-insulated transformer, various lead wires are arranged, for example, corresponding to the high-voltage side winding 16 which is drawn from the low-voltage side winding 14 (see FIG. 1) and is a high electric field side. Lead wire 24,2
There are also four. In such a case, it is necessary to increase the insulation distance between the lead wires 24, 24 and the high-voltage side winding 16,
There is a problem that the size becomes large as a whole.

For this reason, in the fifth embodiment,
An insulating member 25 made of an insulator 21 (see FIG. 3) is provided around a portion of the lead wires 24, 24 corresponding to the high-voltage side winding 16,
25, and insulating members 25, 25
Is set to 0.3 or more and 1 or less (preferably 0.35 or more and 1 or less) when the dielectric constant of the surrounding insulating member is set to 1.

Thus, the insulation performance between the lead wires 24, 24 and the high-voltage side winding 16 can be improved, and the overall size can be reduced. Since the low-voltage winding 14 and the high-voltage winding 16 are also provided with the insulating member 19 as in the first embodiment or the second embodiment, the first embodiment or the second embodiment is used. The same effect as the example can be obtained together.

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications and extensions are possible. The insulating member 19 may be configured by being wound around a wire in advance similarly to the insulating member 20.

The present invention can be applied not only to a gas insulating transformer using SF6 gas as a cooling medium but also to a gas insulating transformer using another insulating gas as a cooling medium. It can be applied to a gas-insulated reactor.

[0042]

As is apparent from the above description, the stationary electromagnetic induction device of the present invention is provided between the winding and the ground, between the windings, between the winding layers constituting the winding, and the lead wire. It is possible to improve the insulation performance between the lead wire and the ground portion or between the lead wire and the high electric field portion, and to achieve a reduction in size as a whole.

[Brief description of the drawings]

FIG. 1 is a diagram showing a winding configuration according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a configuration of one winding layer.

FIG. 3 is a diagram illustrating a configuration of an insulator.

FIG. 4 is a configuration diagram of a heating furnace for forming an insulating member.

FIG. 5 is a side view of a first winding layer of the high-voltage side winding.

FIG. 6 is a schematic configuration diagram of an experimental apparatus.

FIG. 7 is a diagram showing experimental results.

FIG. 8 is a view showing an analysis result.

FIG. 9 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 10 is an equivalent circuit diagram.

FIG. 11 is a diagram showing potential sharing;

FIG. 12 is a view corresponding to FIG. 1, showing a third embodiment of the present invention;

FIG. 13 is a diagram corresponding to FIG. 2;

FIG. 14 is a side view of a lead wire lead-out portion showing a fourth embodiment of the present invention.

FIG. 15 is an enlarged sectional view taken along the line AA in FIG. 14;

FIG. 16 is a plan view showing a positional relationship between a lead wire and a high-voltage winding according to a fifth embodiment of the present invention.

FIG. 17 is a diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

In the drawing, 11 is a leg portion, 12 is a yoke portion, 13 is an iron core (earth portion), 14 is a low-voltage side winding, 15 is a strand, 151 is a winding start end, 15n is a winding end end, and 16 is a high pressure side. Winding, 17
Is a strand, 171 is a winding start end, 17n is a winding end end, 1
8 is a strand, 19 is an insulating member, 20 is an insulating member, 21 is an insulator, 22 is an insulating member, 23 is a lead wire, 24 is a lead wire, 25 is an insulating member, and L1 to L4 are first to fourth.
, H1 to H9 indicate first to ninth winding layers, and T indicates a tap winding layer.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsushi Okamoto 2121, Nao, Asahi-machi, Mie-gun, Mie Prefecture Inside Mie Plant, Toshiba Corporation (72) Inventor, Masahiro Hamaguchi 2121, Oaza, Asahi-cho, Mie-gun, Mie Prefecture Inside the Toshiba Mie Plant (72) Inventor Hiroshi Shioda 2121 Nagoya, Asahi-cho, Mie-gun, Mie Prefecture F-term in the Toshiba Mie Plant (reference) 5E044 AB01 CA05 CB03 5E050 HA06 5G309 LA06 MA01

Claims (7)

[Claims] 1. A stationary electromagnetic device comprising: a winding provided with an insulating member having a dielectric constant of 0.3 or more and 1 or less when a dielectric constant of a peripheral insulating member is set to 1 on a high electric field side portion. Induction equipment. 2. A stationary electromagnetic induction device having a winding provided at an end with an insulating member having a dielectric constant of 0.3 or more and 1 or less when the dielectric constant of a peripheral insulating member is set to 1. . 3. A winding in which an insulating member having a dielectric constant of 0.3 or more and 1 or less when the dielectric constant of a peripheral insulating member is 1 is provided at an end of a wire constituting a winding layer. Characteristic stationary electromagnetic induction equipment. 4. A winding provided with an insulating member having a dielectric constant of 0.3 or more and 1 or less when the dielectric constant of the surrounding insulating member is 1 around the winding start end side and the winding end end side. A stationary electromagnetic induction device characterized by having: 5. The stationary electromagnetic induction device according to claim 1, wherein the insulating member is thickened by a portion having a high electric field. 6. An insulating member having a dielectric constant of 0.3 or more and 1 or less when the dielectric constant of a peripheral insulating member is set to 1 at an end of a wire constituting a winding so as to be drawn out as a lead wire. A stationary electromagnetic induction device characterized by the following. 7. The dielectric constant of the surrounding insulating member is set to 1 around the portion corresponding to the high electric field portion side of the lead wire drawn out of the winding.
A stationary electromagnetic induction apparatus characterized in that an insulating member having a dielectric constant of 0.3 or more and 1 or less is provided when the above conditions are satisfied.