JPH09312222A - Static induction electric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a static induction electric device capable of suppressing the vibration and noise at energizing by providing an electrostatic shields having a high dielectric strength which are mounted on winding ends and ensuring a sufficient winding tightening force. SOLUTION: Electrostatic shields 4a, 4b have curved surface parts 41 protruding in the radial direction of the shields more than a winding 3. The width e of a flat part 40 of each shield 4a, 4b agrees with the build size g of the winding 3. Support spacers 5a, 5b contact the entire flat parts 40 of the shields 4a, 4b and hence the width e of the flat part 40 of the shields agrees with the width f of the contact part of the support spacer 5a, 5b with the shield 4a, 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage static induction machine, and more particularly to an improved electrostatic shield of a static induction machine.

[0002]

2. Description of the Related Art Generally, a high-voltage static induction generator such as a transformer or a reactor is provided with an electrostatic shield for electrostatic shielding for the purpose of relaxing electric field concentration at the winding end. For example, a static induction electric device described in Japanese Examined Patent Publication No. 3-34644). Here, a conventional example of a static induction machine having an electrostatic shield will be specifically described with reference to FIG.

As shown in the figure, a tank 1 is filled with an insulating / cooling medium such as insulating oil or insulating gas, and an iron core 2 is housed in the tank 1. A winding 3 is wound around the iron core 2. Corners are formed at the upper and lower ends of the winding 3, and the ring-shaped electrostatic shield 4 is formed here.
a and 4b are attached.

The electrostatic shields 4a and 4b are ring-shaped core materials that do not form one turn, conductive layers 7a and 7b wound around the core materials, and an insulating layer 8a that covers the conductive layers 7a and 7b. , 8b, and are electrically connected to the winding 3 so as to have the same potential as the end of the winding 3.
Further, in the electrostatic shields 4a, 4b, a horizontal flat portion 40 is formed on an end surface portion on a side in contact with support spacers 5a, 5b described later, and a curved surface portion 41 is formed around the flat portion 40. The curved surface portion 41 is configured to have a curvature larger than that of the corner portion of the winding 3.

The winding 3 vibrates due to an electromagnetic mechanical force which is internally applied by the energizing current when energized. This vibration is one of the causes of vibration and noise when the static induction electric device is energized. Therefore, in order to suppress the influence of the electromagnetic mechanical force due to the current flowing through the winding 3, it is necessary to tighten the winding 3 in the vertical direction.
In the conventional example of FIG. 3, as the tightening member for tightening the winding 3 in the vertical direction, support spacers 5a and 5b are provided above the electrostatic shield 4a on the upper side and below the electrostatic shield 4b on the lower side.
And structural materials 6a and 6b are provided. The support spacers 5a and 5b are insulating members that transmit the tightening force from the structural members 6a and 6b to the winding 3, and the electrostatic shields 4a and 4b.
It contacts the flat part 40 of b.

In the electrostatic shields 4a, 4b of the static induction electric device having the above-mentioned structure, the support spacers 5a,
Since the curved surface portion 41 is formed on the end surface portion on the side that contacts with 5b, a minute gap surrounded by the insulating / cooling medium, a so-called wedge gap W, is formed between the curved surface portion 41 and the support spacers 5a and 5b. X, Y, Z will be formed. An electric field is likely to be concentrated in these wedge gaps W, X, Y, Z, and there is a risk of reducing the overall dielectric strength of the static induction machine.

Therefore, the wedge gaps W, X, Y, Z
Although it is required to avoid the deterioration of the dielectric strength due to the above, as a conventional example satisfying this requirement, a static induction electric machine as described in Japanese Utility Model Publication No. 7-1772 has been proposed. In this static induction machine, as shown in FIG.
A cutout portion 9 having a depth d of about several mm is formed in a portion of a that contacts the electrostatic shield 4a. Although not shown, the electrostatic shield 4 is provided on the support spacer 5b.
The notch 9 is also formed in the portion in contact with b. By forming the notch 9 as described above, the wedge gaps W, X, Y, and Z themselves can be eliminated. As a result, it is possible to prevent a decrease in dielectric strength due to electric field concentration.

[0008]

By the way, in order to suppress the vibration and noise of the winding wire 3 during energization, the support spacer 5 is used.
a, 5b and the structural members 6a, 6b clamp the winding 3 in the vertical direction. The factor that determines the strength of the tightening force at this time is the build dimension g of the winding 3 (shown in FIG. 4).
And the size of the area where the support spacers 5a and 5b can transmit the tightening force in the vertical direction. That is, not only the strength of the tightening force is adjusted according to the build dimension g of the winding 3, but the winding 3 is actually tightened through the supporting spacers 5a and 5b. We must also consider the tightening force (contact pressure). This is because the supporting spacers 5a and 5b may be broken if a tightening force exceeding the limit of the surface pressure that differs depending on the material of the supporting spacers 5a and 5b is applied.
The area where the support spacers 5a and 5b can transmit the tightening force is more specifically the contact area of the support spacers 5a and 5b with respect to the flat portion 40 of the electrostatic shields 4a and 4b. That is, in order to transmit a sufficient tightening force (contact pressure) from the support spacers 5a and 5b to the winding 3, the support spacers 5a and 5b and the flat portions 4 of the electrostatic shields 4a and 4b are provided.
It is desirable that 0 is in contact with a large area.

However, in the conventional example shown in FIG. 4, since the notch 9 is formed in the supporting spacers 5a and 5b, the width dimension f of the portion of the supporting spacers 5a and 5b which is in contact with the electrostatic shields 4a and 4b is flat. It became considerably narrower than the width e of the portion 40. As a result, the support spacers 5a and 5b for the flat portion 40 of the electrostatic shields 4a and 4b are formed.
The contact area of b was small, and the tightening force for the winding 3 was likely to be insufficient. When the tightening force on the winding wire 3 is insufficient, there arises a problem that vibration and noise when the winding wire 3 is energized increase.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art, and an object thereof is that the electrostatic shield attached to the winding end has a high dielectric strength. The object of the present invention is to provide a stationary induction machine capable of sufficiently securing the tightening force to the winding and suppressing vibration and noise during energization.

[0011]

In order to achieve the above object, the present invention provides a tank filled with an insulating / cooling medium, an iron core is housed in the tank, and the iron core is provided around the iron core. Is wound with a winding having a corner at its end, and a ring-shaped electrostatic shield is connected to at least one end of the winding so as to have the same potential as the end of the winding, A tightening member for tightening the winding is attached to the electrostatic shield, and the end face of the electrostatic shield that is in contact with the tightening member has a horizontal flat portion and a curvature larger than the curvature of the corner of the winding. And a curved surface portion having a curved surface portion of the electrostatic shield, the curved surface portion of the electrostatic shield is formed so as to project in the radial direction of the electrostatic shield more than the winding, and the entire surface of the flat portion of the electrostatic shield is formed. Against the tightening Wherein the member is configured to abut.

In the present invention having the above structure, since the curved surface portion of the electrostatic shield projects in the radial direction of the electrostatic shield rather than the winding, no wedge gap is formed around the electrostatic shield. In addition, it is possible to prevent a decrease in dielectric strength due to electric field concentration. Moreover, by projecting the curved surface portion of the electrostatic shield from the winding, it is possible to widen the width dimension of the flat portion of the electrostatic shield to the extent that it matches the build dimension of the winding. Since the tightening member contacts the entire surface of such a wide flat portion, the tightening member and the flat portion of the electrostatic shield can be in contact with each other over a wide area. Therefore, the tightening force from the tightening member is transmitted to the winding through a large area, and a strong tightening force can be secured.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Configuration Hereinafter, an example of an embodiment of the present invention will be specifically described with reference to FIGS. 1 and 2. 1 is a vertical sectional view of the present embodiment, and FIG. 2 is an enlarged sectional view of the upper end portion of the winding shown in FIG. The same members as those in the conventional example shown in FIGS. 3 and 4 are designated by the same reference numerals, and the description thereof will be omitted.

That is, the curved surface portions 41 of the electrostatic shields 4a and 4b are formed so as to project in the radial direction of the electrostatic shields 4a and 4b rather than the winding 3. At this time, the electrostatic shields 4 a and 4 b are set such that the inner diameter thereof is smaller than the inner diameter of the winding 3 and the outer diameter thereof is larger than the outer diameter of the winding 3. Further, since only the curved surface portion 41 protrudes from the winding 3, the width dimension e of the flat portion 40 of the electrostatic shields 4a and 4b matches the build dimension g of the winding 3.

Further, the supporting spacers 5a and 5b are shown in FIG.
There is no notch 9 as shown in, and the electrostatic shield 4
The support spacer 5 is provided on the entire surface of the flat portion 40 of a and 4b.
A and 5b are in contact with each other. Therefore, the width dimension e of the flat portion 40 of the electrostatic shields 4a and 4b also matches the width dimension f of the portions of the support spacers 5a and 5b that are in contact with the electrostatic shields 4a and 4b. That is, the width dimension e of the flat portion 40 of the electrostatic shields 4a and 4b, the width dimension f of the portions of the support spacers 5a and 5b that contact the electrostatic shields 4a and 4b, and the build dimension g of the winding 3 are three dimensions e. , F, g all have the same dimensions. In this embodiment, the insulating layers 8a and 8b of the electrostatic shields 4a and 4b are made of a low dielectric constant material, and the dielectric strength is further improved.

(2) Operation and Effect In the present embodiment having the above-described structure, the curved surface portions 41 of the electrostatic shields 4a and 4b project in the radial direction of the electrostatic shields 4a and 4b rather than the winding 3. Therefore, no wedge gap is formed around the electrostatic shields 4a and 4b. Therefore, the portion where the electric field is concentrated disappears, the overall dielectric strength of the static induction electric machine can be improved, and the device can be made compact by reducing the insulation distance for the same voltage class.

The above three widths e, f and g are the same, and the support spacers 5a and 5b and the electrostatic shield 4 are provided.
It will come into contact with a and 4b over a wide area. for that reason,
The tightening force from the support spacers 5a and 5b is surely transmitted to the winding 3. Therefore, it is possible to secure a strong tightening force for the winding 3, and it is possible to reliably suppress vibration and noise when the winding 3 is energized.

[0018]

According to the static induction device of the present invention as described above, the curved surface portion of the electrostatic shield is formed so as to protrude from the winding in the radial direction of the electrostatic shield, and the flat portion of the electrostatic shield is formed. With a simple structure in which the tightening member is brought into contact with the entire surface, there is no wedge gap around the electrostatic shield, so the dielectric strength can be increased, and in addition, the tightening member and the electrostatic shield come into contact with each other over a wide area. Therefore, a sufficient tightening force for the winding wire can be secured, and thus vibration and noise during energization can be reliably suppressed.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the upper end portion of the winding shown in FIG.

FIG. 3 is a vertical cross-sectional view of a conventional static induction generator.

FIG. 4 is an enlarged cross-sectional view of the upper end portion of the winding shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tank 2 ... Iron core 3 ... Winding 4a, 4b ... Electrostatic shield 40 ... Flat part 41 ... Curved part 5a, 5b ... Support spacer 6a, 6b ... Structural material 7a, 7b ... Conductive layer 8a, 8b ... Insulating layer 9 ... Notch portion W, X, Y, Z ... Wedge gap d ... Depth dimension of notch portion e ... Width dimension of flat portion of electrostatic shield f ... Width dimension of portion of supporting spacer in contact with electrostatic shield g ... Winding build dimensions

Claims (1)

[Claims] 1. A tank filled with an insulating / cooling medium is provided, an iron core is housed in the tank, and a winding having a corner at an end is wound around the iron core. A ring-shaped electrostatic shield is connected to at least one end of the wire so as to have the same potential as the end of the winding, and a tightening member for tightening the winding is attached to the electrostatic shield. Further, in the static induction electric device, further, a horizontal flat portion and a curved surface portion having a curvature larger than a curvature of a corner portion of the winding are formed on an end surface portion of the electrostatic shield which is in contact with the tightening member. The curved surface portion of the shield is formed so as to project in the radial direction of the electrostatic shield rather than the winding, and the clamping member is in contact with the entire surface of the flat portion of the electrostatic shield. Stationary invitation Electric Appliances.