JPH07183140A - Stationary induction - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a static induction electric device capable of improving insulation reliability between windings and maintaining mechanical strength of insulation between windings. [Structure] An insulating spacing member is provided between a plurality of windings that are wound around an insulating core that is concentrically arranged around an iron core. A cutout portion having a shape in which the opening area is gradually reduced in the direction of the end face having a predetermined area at a portion located in the shortest insulation distance direction between the high voltage outlet portion of the winding and the other winding of the insulating spacing material. To provide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static induction device such as a transformer, and more particularly to a static induction device having an insulating spacing member arranged in the radial direction between windings.

[0002]

2. Description of the Related Art In static induction generators, higher voltage
When applying to large capacity, the biggest technical problem is how to provide high dielectric strength to the equipment and improve the cooling capacity, and how to secure the strength against radial mechanical force at the time of short-circuit accident. ing.

An example of a conventional static induction device will be described below with reference to FIGS. 8 and 9, which is a radial cross-sectional view of FIG. As shown in FIG. 9, a conductor covered with an insulating paper, an insulating film, or an insulating material such as an insulating coating is wound on the outer peripheral side of the basic insulating cylinder arranged inside the winding arranged around the iron core 1. The inner winding 3 is wound by turning. Cooling ducts 4 are formed in the inner winding 3 at appropriate intervals as gaps extending in the stack direction. Insulating spacers 12 fixed along the axial direction of the winding to secure the cooling duct 4 are arranged at equal intervals in the circumferential direction.
Further, the cooling duct 4 is divided by a plurality of insulating cylinders 5, and an insulating spacing member 12 is arranged between them. A conductor covered with an insulating paper, an insulating film, or an insulating coating insulating material is attached to the insulating spacing member 12 arranged along the axial direction on the inner peripheral side of the insulating cylinder 5 arranged outside the winding. The outer winding 2 is formed by winding. These windings are housed in a tank together with a liquid or gas such as oil or SF ₆ gas, or a solid insulating medium. Outer winding 2
A line end lead 10 and a neutral point lead 11 are connected to the line end, and a voltage is applied from the line end lead 10 to the outer winding 2. Here, between the inner winding 3 and the outer winding 2, the central portion of the winding to which the line end lead 10 of the outer winding 2 is connected has a high voltage, and the insulation reliability is low. In order to solve this, the notch 13 is taken out from the insulating spacing member 12 near the connecting portion of the line end lead 10 to the outer winding 12, and this portion is used as an insulating medium, and the insulating spacing member 12 and the insulating tube 5 are used. For insulating media with a lower relative permittivity compared to. Outer winding 2 and inner winding 3
A method of increasing insulation reliability by increasing the voltage sharing between the two was used.

In the static induction winding thus constructed, the notch portion creeping straight line portion L interlinking with the equipotential line of the insulating medium of the notch portion 13 is produced. An insulating medium such as insulating gas or insulating oil exists in the cutout portion 13, but in general, the specific dielectric constant of the insulating medium is higher than that of the insulating spacer 12 or the solid insulating material of the insulating cylinder 5. Because it is small, this notch
The electric field concentrates on 13 and especially the straight line part L along the notch
Then, the electric field in the creeping direction becomes high, which causes dielectric breakdown.
Insulation reliability was poor, and it was necessary to increase the insulation distance between the windings, leading to an increase in the size of the device.

[0005]

The present invention has been made to solve the problems of the prior art, and its purpose is to improve the insulation reliability between windings and to improve the mechanical strength of the insulation between windings. It is to provide a stationary induction machine that can be maintained.

[0006]

SUMMARY OF THE INVENTION The present invention comprises an insulating spacing member arranged between a plurality of windings wound through an insulating cylinder arranged concentrically around an iron core. In a static induction device, the opening area is gradually reduced toward the end face having a predetermined area at a portion located in the shortest insulation distance direction between the high voltage outlet portion of the winding of the insulating spacing member and another winding. A notch having a shape is provided.

[0007]

With this structure, the creeping portion of the cutout portion becomes long, and the electric field in the creeping direction of the cutout portion decreases,
The insulation reliability between the windings is increased and the vibration of the windings is absorbed, and the mechanical strength is increased.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same parts as those in the above-described embodiment are designated by the same reference numerals. FIG. 1 is a sectional view showing an embodiment of a static induction generator according to the present invention. As shown in the figure, the end face in the axial direction of the notch 13 of the insulating spacing member 12 is inclined on the surface that was perpendicular to the cylindrical inner winding 3 and outer winding 2. FIG. 2 is a perspective view showing a cutout state of the insulating spacing member. That is, a notch having a shape in which the opening area is gradually reduced is provided in a portion located in the shortest insulation distance direction between the high voltage output portion of the winding and another winding.

The effect of the present invention will be described with reference to FIGS. FIG. 3 shows a creeping direction electric field at a cutout portion of a solid insulator in an electrode system in which gas and a solid insulator coexist,
It is a schematic diagram which calculates the relationship with the diagonal ratio of a notch part. A solid insulator 21 is provided between the high voltage electrode 23 and the ground electrode 22.
Is provided, and a part thereof is cut out. The creeping direction electric field E of the notched portion and the oblique proportion of the notched portion are defined as shown in the figure, and the proportion of the creeping electric field E and the creeping length of the notched portion to the thickness of the solid insulator (L / t ) Was calculated. FIG. 4 shows the relationship between the creeping electric field E in the cutout portion of the solid insulator 21 of FIG. 3 and the oblique ratio (L / t) of the cutout portion, where L / t = 0 (no oblique cutout). Was shown as 100%. It can be seen from FIG. 4 that the electric field value on the creeping surface of the notch becomes lower as the oblique ratio of the notch becomes larger.

However, in the structure shown in FIG. 1, a wedge-shaped gap G is formed between the obliquely cut-away creeping portion and the insulating cylinder 5 in contact with the insulating spacing member 12. In general, in the wedge-shaped gap G, the insulating medium has a lower relative permittivity than the solid insulator, resulting in a high electric field, which is an electrical weak point and poor in reliability.

FIG. 5 is a sectional view of an insulating spacing member showing a second embodiment of the present invention. As shown in the drawing, the cutout portion of the insulating spacing member is slanted, and the contact portion T of the cutout portion with the insulating spacing material is made perpendicular to the insulating spacing material, so that the insulating portion is insulated from the cutout portion. The wedge-shaped gap of high electric field generated at the contact portion with the spacer is eliminated, and the insulation reliability is improved. In addition, since the structure in which the surface of the insulating spacing material contacts the insulating cylinder increases, the insulating spacing material and the insulating cylinder are firmly joined when tightening the winding, and the entire winding is firmly fixed to the winding structural material. To be done. Therefore, the backlash of the winding does not occur even when the insulation shrinks or withers during the drying process of the winding or long-term operation. Therefore, the mechanical strength is improved without lowering the winding tightening strength. In addition, since it also absorbs vibrations during energization, it also has the effect of reducing vibrations and eventually noise.

FIG. 6 is a sectional view of an insulating spacer according to a fourth embodiment of the present invention, and FIG. 7 is a sectional view showing a state in which the insulating spacer shown in FIG. is there. Insulator having flexibility in the part where the insulating spacer contacts the insulating tube
With the structure in which 30 is attached, when the insulating spacing member is disposed between the insulating cylinders 5, the wedge-shaped gap formed by the cutout portion 13 which is the insulating medium and the insulating cylinder 5 is flexible. The insulating reliability 20 is further improved by being filled with the insulating material 20 having high properties and not having a high electric field portion. In addition, the insulating spacing member 12 is an insulator having flexibility in the insulating cylinder 5.
Since the structure is obtained by crushing 30, the insulating spacing member and the insulating cylinder are firmly and closely joined to each other when the winding is tightened, and the entire winding is firmly fixed to the winding structural material. Therefore, in the same manner, the backlash of the winding does not occur even when the insulation shrinks or withers due to the drying process of the winding or long-term operation. Therefore, the mechanical strength is improved without lowering the winding tightening strength. It also absorbs vibrations when energized, reducing vibrations.
As a result, it also has the effect of reducing noise.

Further, by using the flexible insulator 30 itself as a material having a dielectric constant lower than that of the insulating cylinder 5, a minute gap is provided between the insulating spacing member 12 and the flexible insulator 20. Even if formed, the electric field in the gap is reduced, and the insulation reliability is further improved.

[0014]

As described above, according to the present invention, the equipotential lines of the insulating medium in the cutout portion of the spacing member arranged to secure the radial insulation distance between the windings are interlinked. It is possible to provide a static induction generator in which the electric field along the surface of the cutout portion becomes low, the insulation reliability of the winding is increased, the mechanical strength is increased, and vibration and noise are reduced.

[Brief description of drawings]

FIG. 1 is a sectional configuration diagram according to a first embodiment of the present invention.

FIG. 2 is an exemplary solution diagram of a cutout shape of the insulating spacing member shown in FIG.

FIG. 3 is an example solution diagram for calculating a notch shape of an insulating spacer and a creeping electric field value.

FIG. 4 is a relationship diagram between the notch shape and the creeping electric field value shown in FIG.

FIG. 5 is a sectional view of an insulating spacing member according to a second embodiment of the present invention.

FIG. 6 is a sectional view of an insulating spacer according to a third embodiment of the present invention.

FIG. 7 is an illustrative view of an insulating spacing member according to a third embodiment of the present invention when it is pressed and fixed.

FIG. 8 is a perspective view of a main part of a conventional static induction machine.

9 is a radial cross-sectional view of FIG.

[Explanation of symbols]

 1 ... Iron core 2 ... Outer winding 3 ... Inner winding 4 ... Cooling duct 5 ... Insulating cylinder 10 ... Line end lead 11 ... Neutral point lead 12 ... Insulating spacer 13 ... Notch 20 ... Insulating medium 21 ... Solid Insulator 22 ... Ground electrode 23 ... High-voltage electrode 30 ... Flexible insulator G ... Wedge-shaped gap L ... Notch portion creeping linear portion T ... Contact portion with insulating spacer

Claims (4)

[Claims] 1. A static induction electric machine comprising an insulating spacing member arranged between a plurality of windings wound around an iron core and concentrically arranged around an insulating cylinder. A notch having a predetermined area is formed at a portion of the spacing member located in the direction of the shortest insulation distance between the high voltage output portion of the winding and another winding and having a shape in which the opening area is gradually reduced toward the end face. A static induction electric device characterized by that. 2. The static induction machine according to claim 1, wherein the opening of the notch holds the same opening shape for a predetermined distance in the end face direction. 3. A flexible insulating member is closely arranged between an end face of the insulating spacing member located on the opening side of the cutout portion and an end face of the insulating cylinder facing the end face. The static induction electric device described. 4. The flexible insulating member is disposed in close contact with a predetermined portion of the insulating spacer located in a direction in which the opening area is reduced from the opening and a predetermined portion of the insulating spacing member and the end face of the insulating cylinder. The stationary induction electric machine according to claim 3, wherein