JPH0774032A - High-voltage apparatus - Google Patents

Abstract

PURPOSE:To provide a high-voltage apparatus whose insulation reliability and operating efficiency are enhanced and whose mechanical strength is excellent. CONSTITUTION:A low-voltage winding which is formed by winding a conductor 24 on the circumference of an iron core 28 and a high-voltage winding which is formed at its outside via insulating barriers 2a are installed. L-shaped barriers 31 are arranged at the upper and lower end parts or the insulating barriers 2a. A foam material layer 1 is attached to, and mounted on, the whole outer circumferential face of the L-shaped barriers 31 in such a way that their surface including wedge-shaped gaps formed between the L-shaped barriers 31 and the insulating barriers 29 is covered completely. The foam material layer 1 is constituted of an epoxy-resin foamed substance, a polyurethane foamed substance or the like of open cell in which an insulating medium is permeated easily inside air babbles or of a silicon-based foamed substance or the like of independent air bubbles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to transformers and other high voltage equipment.

[0002]

2. Description of the Related Art Generally, a gas-insulated switchgear, a pipeline air transmission device, and a transformer are used as high-voltage equipment. In high voltage equipment, various insulators are used to support the high voltage conductor in an insulated state with respect to the grounded object. In gas-insulated switchgear and pipeline air transmission device, a large number of insulating spacers are used to insulate and support a high-voltage conductor in a grounded metal container. This insulating spacer is disclosed in, for example, Japanese Patent Publication No. 54-44106 and Japanese Patent Laid-Open No. 55-155512.
A high voltage conductor is supported by an insulating spacer body made of a thermosetting resin such as epoxy resin, and the flange portion of the insulating spacer is fastened and fixed to the flange portions of two adjacent metal containers. There is.

On the other hand, a transformer is constructed by enclosing an insulating medium, which is a gas or a liquid having an insulating property such as insulating gas or insulating oil, in a grounded metal container together with the contents of the transformer. In this case, as the contents of the transformer, a foil winding transformer that uses a metal sheet and an insulating sheet that are wound together and a foil winding, or a type that uses a winding formed by winding a conductor with an insulation coating is used. There are things like.

As an example of such a transformer, FIGS. 4 to 6 show a type using a wire winding formed by winding a conductor. In this case, FIG. 4 is a sectional view showing the structure of the winding,
FIG. 5 is an enlarged cross-sectional view showing in detail the structure of the winding of FIG. Further, FIG. 6 is a schematic cross-sectional view showing a state in which the winding wire of FIG. 4 is arranged around the iron core, and the spacer is omitted from the viewpoint of simplification of the drawing. First, as shown in FIG. 4, a rail 22 for a duct is fixed along the axial direction on the outer peripheral side of a basic insulating cylinder 21 arranged around an iron core (not shown). As shown in FIG.
As shown in, a conductor 24 covered with a covering insulator 23 such as an insulating paper, an insulating film, or an insulating film is wound by a strong tightening force to form a winding 25. The winding 25 is composed of a plurality of winding layers,
A spacer 26 having a constant thickness is inserted between each winding layer, and an inner peripheral side end portion (left side end portion in the drawing) of the spacer 26 is engaged with a groove of the rail 22. That is, the conductors 24 forming the winding 25 are divided by the spacers 26 to form the sections 27 for each winding layer, and the intervals between the respective sections 27 are kept constant by the thickness of the spacers 26. .

The winding 25 having such a structure
However, as shown in FIG. 6, the low voltage winding 25a and the high voltage winding 2
Used as 5b, it is housed in a container (not shown), and an insulating gas such as SF ₆ gas or an insulating medium such as insulating oil is enclosed. That is, the low-voltage winding 25a is arranged around the iron core 28, and the high-voltage winding 25b is arranged around the outer periphery of the low-voltage winding 25a via the insulating barrier 29. In addition, in such a winding structure, when a high voltage is applied to the high voltage winding 25b, an electric field concentrates on the upper and lower ends of the winding facing the iron core yoke 28a, so that electrostatic relaxation for electric field is applied to that portion. The shield 30 is attached, and one or more L-shaped barriers 31 made of press boats are arranged so as to cover a part from the inner peripheral surface of the high voltage winding 25b to the upper and lower end surfaces of the electrostatic shield 30, It is attached to the upper and lower ends of the insulation barrier 29. In this case, the high voltage winding 25b is clamped and fixed from above and below by the supporting insulator (not shown) via the L-shaped barrier 31. Furthermore, in order to prevent discharge from the corners of the conductor 24 in each section 27 of the high-voltage winding 25b, the conductor 2 in each section 27 of the high-voltage winding 25b is blocked.
In some cases, an insulator 32 formed by stacking a pressboard molded product or an insulator on the four corners and processing them is attached in a close contact state.

[0006]

However, in the transformer shown in FIGS. 4 to 5 as described above, a minute gap is generated between the conductor portion and the insulator, and the electric field is concentrated in this gap portion. Then, there is a problem that becomes a weak point in insulation.

Further, in the above-mentioned transformer, as shown in the enlarged view of FIG. 5, between the rail 22 and the covering insulator 23 and the spacer 26 of the conductor 24, or between the covering insulator 23 and the spacer 26. In addition, a wedge-shaped gap 33 is formed so that the gap length continuously changes. Therefore, in particular, when the insulating medium is an insulating gas, the electric field is concentrated in the gap 33 due to the difference in the dielectric constants of the insulating gas and the solid insulator and exceeds the breakdown electric field of the gas, and It becomes a weak point.

Further, in the above-mentioned transformer, it is necessary to increase the insulation distance S between the windings 25a and 25b as the voltage becomes higher. Will be done. for that reason,
An electric field is concentrated on the L-shaped barrier 31 due to the voltage applied between the windings 25a and 25b, and excessive stress is applied. In particular, the L-shaped barrier 31 covers the end portion of the high-voltage winding 25b and is formed in an arcuate cross section having a large curvature for the purpose of suppressing its own electric field as much as possible. A wedge-shaped gap 34 is formed over the entire outer peripheral surface of the L-shaped barrier 31 so that the gap length is continuously changed. Therefore, as in the case of the gap 33 portion described above, when the insulating medium is an insulating gas, the electric field is concentrated in the gap 34 portion due to the difference in the dielectric constants of the insulating gas and the solid insulator, and the insulating gas is isolated. It exceeds the breakdown electric field and becomes a weak point in insulation.

As described above, in the transformers of FIGS. 4 to 6, wedge-shaped gaps 33 and 34 are formed in the windings 25a and 25b and the respective supporting portions thereof, and electric fields are concentrated in the gaps 33 and 34 to cause insulation. It becomes a weak point above. Therefore, it is necessary to increase the insulation distance between the windings such as the distance between the sections 27, which leads to an increase in the size of the device.

Further, as shown in FIG.
Even if it is attempted to attach the insulator 32, which is formed by stacking a pressboard molding or an insulator on the conductor 24 corners in each section 27 of b, in a close contact state, in reality, the insulator 32 is sufficiently attached to the conductor 24 corners. There is a case where they do not come into close contact with each other. In such a case, there is a possibility that backlash may occur in the high-voltage winding 25b or a gap may be formed to impair the insulating effect. Moreover,
Insulators formed by such a molding process have a large number of manufacturing steps and are expensive, which is one of the factors that increase the manufacturing cost of the entire device.

The above problems are not limited to the gas-insulated transformer using the insulating gas as the insulating medium, and are similarly present in the oil-filled transformer using the insulating oil as the insulating medium. . That is, in the oil-filled transformer,
After all, similar wedge-shaped gaps and minute gaps are formed in each part of the winding, so that electric field concentration similarly occurs and insulation reliability deteriorates. In this case, in the oil-filled transformer, since the insulating medium is oil, the difference between the dielectric constant of the oil-filled transformer and that of the solid insulator is smaller than that of the gas-insulated transformer. Although less prominent than gas-insulated transformers, the problem of reduced insulation reliability due to electric field concentration still exists.

The above problems are not limited to transformers such as gas-insulated transformers and oil-filled transformers, but are also applicable to the gas-insulated switchgear and the pipeline air-transmitting device as described above. Similarly, a wedge-shaped gap or a minute gap is formed in the supporting portion of the high-voltage conductor, and similarly, insulation reliability is deteriorated due to electric field concentration.
That is, in general high voltage equipment including these equipments, a supporting insulator is generally used to insulate and support a high voltage conductor, which causes the same problem.

Further, since the supporting insulator and the conductor covering insulator shrink due to drying and dying with long-term operation of the high-voltage equipment, the conductor supporting portion is displaced or loosened during operation or transportation, There is also a problem that this causes a decrease in mechanical strength and causes vibration and noise.

The present invention has been proposed in order to solve the problems of the prior art as described above, and an object thereof is to provide a high voltage device having improved insulation reliability and working efficiency and excellent mechanical strength. Is to provide.

[0015]

In order to achieve the above object, the high-voltage equipment according to claim 1 is a high-voltage equipment in which a gas or liquid insulating medium is enclosed in the equipment body. A foam material layer made of a solid insulating material having permeability of the insulating medium is provided in a predetermined portion therein.

According to the invention described in claim 2,
A conductor and a solid insulator are provided in the device body described above, and the foam material layer is provided at a part or all of the conductor and the solid insulator or between the solid insulators.

The invention according to claim 3 is characterized in that the foam material layer according to claim 1 is composed of a foamed body composed of closed cells or open cells.

The invention according to claim 4 is characterized in that the foam material layer according to claim 1 is provided by being molded in advance.

The invention according to claim 5 is characterized in that the foam material layer according to claim 1 is provided by foaming a solid insulating material by coating or filling.

[0020]

In the high voltage device of the present invention configured as described above, the wedge-shaped or minute gap generated between the conductor and the solid insulator in the device body or between the solid insulators can be filled with the foam material layer. it can. Therefore, the electric field concentration in each part can be almost eliminated, and the insulation reliability is improved.

Further, due to the compressive force and elasticity of the foam material layer, the gap between the conductor and the solid insulator can be absorbed, and the conductor can be firmly fixed. This is when driving or transporting
No deviation or loosening occurs, sufficient mechanical strength can be maintained, and vibration and noise problems do not occur.

Further, the foam material layer has a communication property between cells and a permeability of the insulating medium, so that an insulating gas or liquid insulating medium penetrates into the foam material layer and is easily filled inside the bubbles. . As a result, the foam material layer does not dry or die due to long-term operation, the dielectric strength is improved, and mechanical deformation is prevented. Furthermore, since the air in the bubbles is completely replaced by the insulating medium, there is no difference in the dielectric constant, the electric field is not concentrated, and the insulation reliability is greatly improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a high voltage device according to the present invention will be described below with reference to the drawings. It should be noted that members having the same functions as those of the conventional art are designated by the same reference numerals and the description thereof will be omitted.

(1) First Embodiment FIG. 1 In this embodiment, the present invention is applied to the transformer shown in FIGS. 4 to 6 as an example of high voltage equipment.

In this embodiment, as shown in FIG.
The foam material layer 1 is molded on the entire outer peripheral surface of the L-shaped barrier 31 so as to completely cover the surface thereof including the wedge-shaped gap 34 formed between the L-shaped barrier 31 and the insulating barrier 29, and mounted. Has been done. The foam material forming the foam material layer 1 is, for example, a continuous cell in which cells are connected to each other, and a foam such as an epoxy resin foam or a polyurethane foam in which the insulating medium easily penetrates into the cell, or It is composed of a foam such as a silicone-based foam that is independent bubbles and has excellent communication between the bubbles, has permeability to the material itself, and facilitates permeation of the insulating medium into the bubbles.

The operation and effect of the present embodiment configured as described above are as follows. That is, the insulation barrier 29 and L
Since the foam material layer 1 is mounted between the barrier 31 and the letter-shaped barrier 31, a wedge-shaped gap is not formed between the barriers 29 and 31. Therefore, it is possible to eliminate the electric field concentration portion, which has been a problem in the same type of transformer of the related art (FIG. 6), and it is possible to improve the insulation reliability of the winding supporting portion. Further, when the foam material layer 1 is provided between the insulating barrier 29 and the L-shaped barrier 31 as in the present embodiment, the corner portion that blocks the partial discharge generated from the conductor corner portion of the high voltage winding 25b. Since the insulation thickness of the portion can be made thickest, the discharge blocking effect can be maximized, and also in this respect, the insulation reliability can be improved. Furthermore, L-shaped barrier 31 associated with long-term operation
Even when shrinkage occurs, the shrinkage can be absorbed by the compressive force and elasticity of the foam material layer 1, so that there is no slippage or loosening during operation or transportation, and sufficient mechanical strength is maintained. It is possible and does not cause the problem of vibration and noise.

Further, in the foam material layer 1 of this embodiment,
Since the insulating medium penetrates, the insulating medium is easily filled inside the bubbles of the foam material layer. The foam material layer 1 itself does not dry or die. Therefore, the foam material layer 1 itself does not shrink, the dielectric strength is improved, and the mechanical strength is high.

Moreover, since the air in the bubbles is completely replaced with the insulating medium, there is no difference in the dielectric constant between the insulating medium and the inside of the bubbles in the foam material layer. Also, the foam material layer 1
The insulating medium penetrates to the respective contact surfaces of the insulating barrier 29 and the L-shaped barrier 31. As a result, the electric field does not concentrate on the bubble portion of the foam material layer 1 and the respective contact surfaces of the foam material layer 1 with the insulating barrier 29 and the L-shaped barrier 31, so that there is no weak point in insulation. . Therefore, in this embodiment, the insulation reliability can be greatly improved. Moreover, since the insulating medium penetrates into the foam material layer 1, there is no fear of mechanical deformation when the insulating medium is sealed in the container, and the workability is improved.

In this embodiment, instead of pre-molding the foam material layer 1, the foam material is foamed on the surface of the L-shaped barrier 31 including the wedge-shaped gap between the foam material layer 1 and the insulating barrier 29. It is also possible to form layer 1. In this case, no special molding die or the like for the foam material layer 1 is required, and the working efficiency can be improved.

(2) Second Embodiment FIG. 2 In this embodiment, as in the first embodiment, the present invention is applied to the transformer winding shown in FIGS. 4 to 6 as an example of high voltage equipment. Is applied.

In this embodiment, as shown in FIG.
A foam material layer 2, which is a molded insulator having a U-shaped cross section, is attached to each section 27 along an inner peripheral side corner (a left side corner in the drawing) of the conductor 24. This foam material layer 2 is, for example, a foam such as an epoxy resin foam or a polyurethane foam that allows continuous penetration of the insulating medium into the bubbles, or closed cells that are permeable to the material itself. And a foam such as a silicone-based foam that facilitates the permeation of the insulating medium into the bubbles. Therefore, the rail 22 and the spacer 26 are not connected to the conductor 2
4 and the foam material layer 2 are in contact with each other.

In this embodiment having the above structure, the conductor 2
A foam material layer 2 having a compressive force and elasticity is attached and protected along its corners. Therefore, the discharge from the corners of the conductor 24 in each section 27 is reliably prevented by the foam material layer 2, and the insulation reliability is improved. Particularly, in the foam material layer 2, since the insulating medium easily penetrates into the bubbles, the air inside the bubbles is replaced with an insulating medium such as insulating gas or insulating oil enclosed in the container, and the conductor is 24 and foam material layer 2
The insulating medium penetrates to the contact surface with. As a result, there is no difference in the dielectric constant at the bubble portion or the contact surface. Moreover, since the insulating medium penetrates into the air bubbles of the foam material layer 2, the foam material layer itself does not dry or die and does not shrink even during the winding process or long-term operation of the winding. It is possible to remarkably improve the physical strength.

Further, the conductor 24 is formed by the winding force (tightening force) in the radial direction, the axial tightening force for vertically tightening the winding wire, and the compressive force and elasticity of the foam material layer 2 to form the foam material. Through the layer 2, the rail 22 and the spacer 26 can be completely adhered. Therefore, a wedge-shaped gap or a minute gap which is a weak point in insulation does not occur around the conductor 24,
The electric field is not concentrated, and the insulation reliability is significantly improved. Further, in the conductor 24, since the conductor 24, the rail 22 and the spacer 26 are pressure-bonded to each other via the foam material layer 2, winding backlash and displacement do not occur, and each section 27 can be firmly fixed. At the same time, the compressive force and elasticity of the foam material layer 2 can absorb vibrations during operation and transportation, so that an effect of reducing vibrations and noises can be obtained.

In this embodiment, the foam material layer 2 is attached to the corners of the conductor 24, and as shown in FIG.
It is also possible to mount the solid insulator 3 on the outer peripheral surface of the foam material layer 2. Thereby, the insulation reliability can be significantly improved.

Further, by arranging the solid insulator 3 so as to have a gap between the solid insulator 3 and the conductor 24, filling the gap with a foam material and foaming it to form the foam material layer 2 or the like. It is also possible to arrange the foam material layer 2 in close contact with the corner portions of the conductor 24. When the foam material is filled in the gap and foamed to form the foam material layer 2 in this manner, a special molding die or the like for the foam material layer 2 is not required, and the work efficiency can be improved. .

Further, in this embodiment, the foam material layer 2 is arranged and attached in a U-shaped cross section along the inner peripheral side corner portion (left side corner portion in the drawing) of the conductor 24 of each section 27. This can also be attached so as to cover the entire surface of each section 27, that is, the outer peripheral side corner (right side corner in the figure) of the conductor 24. Further, the foam material layer 2 is not limited to the U-shape, but may be configured to be attached to a part of each section in accordance with the shape of the conductor 24 corner portion by the L-shape or the like. The same effect can be obtained. Further, the foam material layer 2 may be attached to not only all the sections but also some of the sections.

(3) Third Embodiment FIG. 3 In this embodiment, as in the first and second embodiments, the transformer winding shown in FIGS. 4 to 6 is used as an example of a high voltage device. The present invention is applied.

In this embodiment, as shown in FIG.
The foam material layer 4 is mounted on the outer peripheral surface of the rail 22, and the conductor 24 is wound on the foam material layer 4 to form each section 27 of the winding. The foam material layer 5 is mounted on the surface of the spacer 26 provided between the respective sections 27. In this case, the inner peripheral end (the left end in the figure) of the spacer 26 is engaged with the groove of the rail 22 together with the foam material layer 5. The spacers 26 are partially arranged in the circumferential direction and clamped from above and below via the foam material layer 5 so as to prevent looseness and displacement of the windings. The foam material layers 4 and 5 used in this embodiment are continuous foams, such as an epoxy resin foam or a polyurethane foam that facilitates the permeation of the insulating medium into the foams, or an independent foam. It is composed of a foam such as a silicon-based foam that allows the material itself to have excellent permeability in the cells and facilitates the penetration of the insulating medium into the cells.

In the present embodiment thus constructed,
Since the conductor 24 is fastened to the rail 22 and adheres to the foam material layer 4 having elasticity, a wedge-shaped gap or a minute gap between the rail 22 and the conductor 24 does not occur unlike the prior art. Further, since the foam material layer 5 having elasticity is also disposed between the spacer 26 partially arranged in the circumferential direction of the winding and the conductor 24 of the winding, the winding is tightened from the vertical direction. By conductor 2
4 and the spacer 26 are completely adhered to the foam material layer 5 interposed therebetween, and no wedge-shaped gap or a minute gap is generated. As described above, in the present embodiment, the conductor 24 can be completely adhered to the rail 22 portion and the spacer 26 portion via the foam material layers 4 and 5 without forming a wedge-shaped gap or a minute gap. it can.

Moreover, when the insulating medium is enclosed in a container (not shown), the insulating medium penetrates into the bubbles of the foam material layers 4 and 5, and the air in the bubbles is replaced with the insulating medium. A gap, which is a weak point in insulation, is not formed, and a difference in dielectric constant does not occur. Therefore, insulation reliability can be significantly improved. Moreover, since the insulating medium penetrates into the air bubbles of the foam material layers 4 and 5, the foam material layers 4 and 5 themselves do not dry or die and shrink even during the winding process or long-term operation of the winding. The mechanical strength can be significantly improved as compared with the technology.

The conductor 24 is applied to the rail 22 and the spacer 26 via the foam material layers 4 and 5 by a winding force (tightening force) in the radial direction or an axial tightening force that vertically tightens the winding. It is crimped. As a result, the windings do not rattle or shift, and the sections 27 can be firmly fixed to each other. Moreover, since the insulating medium penetrates into the air bubbles of the foam material layers 4 and 5, the foam material layers 4 and 5 themselves do not dry or die and shrink even during the winding process or long-term operation of the winding. The mechanical strength can be significantly improved as compared with the technology. At the same time, due to the compressive force and elasticity of the foam material layers 4 and 5,
Since vibrations during operation and transportation can be absorbed, vibration and noise can be reduced. As a modified example of this embodiment, for example, a configuration in which the foam material layer is provided only on one of the rail 22 and the spacer 26 is also possible.

In this embodiment as described above, the foam material layer is not limited to being preformed and used.
It is also possible to provide the foam material on the second surface or the surface of the spacers 26 by foaming by applying or filling.

The present invention is not limited to the above-mentioned embodiments, but can be widely applied to all high-voltage equipment in which a high-voltage conductor is provided in an insulating medium such as gas or insulating oil.

[0044]

As described above, according to the present invention, by mounting the foam material layer having the permeability of the insulating medium in close contact with the high voltage conductor or the solid insulator, the difference in the dielectric constant does not occur. It is possible to obtain a high voltage device with excellent insulation reliability.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a first embodiment of a high-voltage device of the present invention and showing a state in which windings are arranged around an iron core of a transformer of a type using windings.

FIG. 2 is a cross-sectional view of the essential parts showing the configuration of the windings of the transformer according to the second embodiment of the present invention.

FIG. 3 is a cross-sectional view of the essential parts showing the configuration of the windings of the transformer according to the third embodiment of the present invention.

FIG. 4 is a cross-sectional view of a main part showing the configuration of a winding of a transformer of a type that uses a winding as an example of a conventional technique.

5 is an enlarged cross-sectional view of an essential part showing details of the winding wire in FIG.

FIG. 6 is a schematic cross-sectional view showing a state in which the winding wire of FIG. 4 is arranged around an iron core.

[Explanation of symbols]

 1, 2, 4, 5 ... Foam material layer 3 ... Solid insulator 21 ... Basic insulating cylinder 22 ... Rail 23 ... Coated insulator 24 ... Conductor 25 ... Winding 26 ... Spacer 27 ... Section 28 ... Iron core 29 ... Insulation barrier 30 ... Electrostatic shield for electric field relaxation 31 ... L-shaped barrier made of press boat 32 ... Insulator 33, 34 ... Wedge-shaped gap

Claims (5)

[Claims] 1. In a high-voltage device in which a gas or liquid insulating medium is enclosed in a device body, a foam material layer made of a solid insulating material having permeability of the insulating medium is provided at a predetermined portion in the device body. High-voltage equipment characterized by being provided with. 2. The high-voltage device is provided with a conductor and a solid insulator in a device body, and the foam material layer is provided in a part or all of the conductor and the solid insulator or between the solid insulators. The high-voltage device according to claim 1, wherein 3. The high-voltage device according to claim 1, wherein the foam material layer is formed of a foamed body composed of closed cells or open cells. 4. The high voltage device according to claim 1, wherein the foam material layer is provided by being molded in advance. 5. The high voltage device according to claim 1, wherein the foam material layer is provided by foaming a solid insulating material by coating or filling.