JP2001223125A - Electrostatic shielding body and electrostatic shielding device of induction equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic shielding device of an induction equipment, which is capable of restraining overheat caused by an eddy current loss by lessening an eddy current attendant on interlinkage of a leakage flux, and equalizing an electric field so as to be improved in dielectric strength, easily worked, and simple in structure so as to be enhanced in mechanical strength. SOLUTION: A winding 12 is wound on the periphery of an iron core 11 through the intermediary of electrostatic shielding electrodes 13 formed of an insulating covered conductive wire 14. The electrostatic shielding electrodes 13 are woven lie a net of plain weave using a plurality of the insulating covered conductive wires 14, the insulating covered conductive wires 14 are electrically insulated from each other with an insulating film 16 at points at which they intersect each other, and the edges 14a are electrically connected together at a point. Furthermore, a point at which the edges 14a are electrically connected is connected to the iron core 11 or the winding 12 with a lead wire (not shown in Figure), and the potential of an electrically connected point is kept equal to that of the iron core 11 or the winding 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic shield and an electrostatic shield device for an induction machine.

[0002]

2. Description of the Related Art In general, an induction device such as a transformer, a reactor, or a rotating machine includes an iron core and windings wound around the iron core. An electric field exists. In order to reduce the size and efficiency of these induction devices, it is necessary to make the electric field as even as possible to improve the dielectric strength. However, due to functional requirements, the core often uses a silicon steel plate, and the windings use a rectangular wire made of copper or aluminum, and the electric field is more concentrated than a smooth surface (hereinafter referred to as a local electric field). To mitigate this local electric field, the core or winding end, etc., on the side facing the core facing the winding to which high voltage is applied, or on the side facing the winding facing the winding to which high voltage is applied, By providing an electrostatic shielding electrode having the same potential as the potential, the local electric field is reduced to improve the dielectric strength.

[0003] Further, in the above-mentioned induction equipment, there may be leakage magnetic flux. When this magnetic flux links with an electrostatic shielding electrode or the like, an eddy current is generated, and there is a disadvantage that heat is generated due to eddy current loss.

FIG. 12 shows, for example, Japanese Patent Application Laid-Open No. 50-22221.
FIG. 1 is a cross-sectional view showing a conventional electrostatic shielding device for an induction device disclosed in Japanese Patent Application Laid-Open Publication No. HEI 10-115,036. In FIG. 12, the winding 2 is wound around the outer periphery of the iron core 1 via the electrode 3 for electrostatic shielding. The electrostatic shielding electrode 3 is made of metal and formed in a net shape and is grounded. Since the local electric field around the iron core 1 is reduced by the electrostatic shielding electrode 3, the electric field between the iron core 1 and the winding 2 is made closer to a uniform electric field, and the dielectric strength is improved.

Furthermore, since the electrostatic shielding electrode 3 is formed in a metal mesh, the number of meshes is selected, or a material having an appropriate specific resistance is used to increase the electric resistance, so that the electrostatic shielding electrode 3 is formed. The eddy current loss when the leakage magnetic flux is linked is reduced as compared with the case where the electrode for use 3 is formed of a metal plate or a metal foil. As a result, the calorific value is reduced, and overheating is suppressed.

[0006]

In a conventional electrostatic shielding electrode for equalizing an electric field, in order to suppress overheating due to eddy current loss, selection of a material of a wire mesh forming the electrostatic shielding electrode is required. It is necessary to reduce the thickness of the metal wire or to reduce the number of meshes. However, in practice, there are many types of combinations of the leakage flux density and the upper limit of the heat generation density linked to the area and the electrode for electrostatic shielding due to differences in capacity and specifications, so prepare many types of wire mesh or It is necessary to make the electrode into a strip shape for the electrostatic shielding electrode with a large interlinking area and a large amount of heat generation, or to divide it into multiple parts and take measures to insulate each other except for the electrical connection points However, there is a problem that the work is complicated.

In addition, since the mechanical strength of the wire mesh is reduced due to the thinning of the metal wires constituting the electrostatic shielding electrode and the reduction in the number of meshes, it is necessary to reinforce the wire mesh with an insulating material. There was a problem that the number of processes increased.

Further, the conductive metal wire is exposed in the metal mesh forming the electrostatic shielding electrode, and the leakage magnetic flux which forms a circulating current path by making electrical contact with other conductive exposed portions is chained. If they do, overheating will occur. In order to suppress this overheating, it is necessary to protect the surface of the wire mesh with an insulating material. Although the protective insulating material that covers the surface of the wire mesh and the insulating member for reinforcing the mechanical strength can also be used, there is a problem that the number of parts increases and the number of working steps increases.

Further, in order to alleviate the electric field at the end of the wire netting constituting the electrostatic shielding electrode, an end treatment for increasing the curvature of the end is performed, and the metal wire is made thinner. In such a case, there is a problem that a precise work is required for the edge treatment.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and reduces eddy current loss associated with leakage flux linkage, thereby suppressing overheating due to eddy current loss and improving electric field. It is an object of the present invention to obtain an electrostatic shielding device for an induction device, which has a simple structure for ensuring a mechanical strength by improving the dielectric strength by making the distances closer to each other.

[0011]

In an electrostatic shielding device for an induction machine according to the present invention, a first conductive portion having a first potential and a second conductive portion having a second potential different from the first potential are provided.
An electrostatic shielding device for an induction device comprising a conductive portion of
The electrostatic shielding device is composed of a plurality of lines intersecting in a net-like manner, and among the plurality of lines intersecting in a net-like manner, at least one of the lines constituting the intersection has conductivity, and a portion intersecting in a net-like manner is insulated. Is what it is.

[0012] The electrostatic shielding device may be configured such that a conductive line is electrically connected at one location, and the potential of the electrically connected location and the potential of the first conductive portion or the second conductive portion. Is maintained at the same potential.

[0013] Further, the present invention is an electrostatic shielding device for an induction machine having an iron core and a winding, wherein the electrostatic shielding device is composed of a plurality of lines intersecting in a mesh, and at least one of the plurality of lines intersecting in a mesh. The line forming one of the intersections has conductivity,
The portions that cross in a net shape are insulated.

Further, in the electrostatic shielding device, the conductive wire is electrically connected at one place, and the potential of the electrically connected place and the potential of the iron core or the winding are maintained at the same potential. Is what it is.

[0015] The electrostatic shielding device is formed of an insulated conductor.

Further, one of the electrostatic shielding devices is made of an insulated wire and the other is made of an insulated wire.

Further, one of the electrostatic shielding devices is formed of an insulated conductor, and the other is formed of a bare conductor.

Further, one of the electrostatic shielding devices is made of a bare conductor, and the other is made of an insulated wire.

The electrostatic shielding device is provided between conductive portions having different potentials with an insulating member interposed therebetween.

The insulated wire is an oil-resistant enameled wire.

The insulated conductor is a Teflon-coated electric wire.

Further, the electrostatic shielding device comprises a first electrostatic shielding electrode and a second electrostatic shielding electrode, wherein the first electrostatic shielding electrode is electrically connected to a coil conductor forming a winding. Are electrically connected and wound around a coil conductor, and a second electrostatic shielding electrode is wound around an insulating layer provided around the first electrostatic shielding electrode to electrically connect with the iron core. Is connected to

Still further, the present invention is an electrostatic shield that shields only an electric field without shielding a magnetic field, wherein the electrostatic shield comprises a plurality of lines intersecting in a mesh pattern.
At least one of the crossing lines has conductivity, the portions crossing in a net shape are insulated, and the conductive lines are electrically connected at one location.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an embodiment of the present invention, the first
As the first conductive portion having a potential of, a winding made of a rectangular wire such as copper or aluminum to which a high voltage is applied, a bushing terminal portion, a tap changer for switching the potential, and the like, and a second potential different from the first potential As the second conductive portion having a potential, for example, an iron core made of a silicon steel plate, a shield iron core provided on the inner wall of the container, and the like are used. Both conductive portions have a projection on, for example, a flat wire or a silicon steel plate, and at a portion where the projection faces a conductive portion having a different potential, the electric field is concentrated compared to a smooth surface, and the other portion has There is a high local electric field. In order to alleviate this local electric field, the first conductive portion, the second conductive portion, or both conductive portions are electrically opposed to the second conductive portion provided facing the first conductive portion. By providing an electrostatic shielding device which is connected to and has the same potential, the local electric field is alleviated and the dielectric strength is improved. In addition, the electrostatic shielding device is composed of a plurality of lines intersecting in a mesh, and among the plurality of lines intersecting in a mesh, at least one line forming the intersection has conductivity, and a portion intersecting in a mesh is used. Insulation prevents formation of a circulating current and suppresses overheating due to eddy current loss. Hereinafter, the embodiment will be described.

Embodiment 1 FIG. 1 is a diagram for explaining an electrostatic shielding device for an induction device according to a first embodiment of the present invention, and more specifically, an electrostatic shielding device used for a core-type oil-immersed transformer as an induction device. It is sectional drawing which looked at the apparatus from the upper part. FIG. 2 is an explanatory diagram showing the configuration of the electrostatic shielding device of the guidance device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view of the insulated conductor constituting the electrostatic shielding electrode. In FIG. 1 to FIG. 3, a winding 12 is provided on an outer periphery of an
It is wound via an electrostatic shielding electrode 13 made of.
The insulated conductor 14 includes a conductor 15 and an insulated covering 16. The conductor 15 is made of an electric conductor such as copper or aluminum, and the insulating coating 16 is made of formal (PVF). Specifically, a formal-coated enamel electric wire is used as the insulated conductor 14.

The electrostatic shielding electrode 13 is made of an insulated wire 14
Are formed in a net-like shape by plain weaving using a plurality of insulating coatings.
At the end 14a, and is electrically connected at one point. Further, the electrically connected portion is connected to the iron core 11 or the winding 12 with a lead wire (not shown), and the potential of the electrically connected portion and the potential of the iron core 11 or the winding 12 are connected. It is kept at the same potential. For this reason, the electrostatic shielding electrode 13 can reduce the local electric field around the protrusion of the iron core 11 or the winding 12, make it closer to a uniform electric field, and improve the dielectric strength.

Also, unlike the conventional metal-made electrostatic shielding electrode 3 formed in a net shape, the electrostatic shielding electrode 13 has an insulating coating 16 where the insulating coating conductors 14 cross each other.
Therefore, the formation of a circulating current path extending over the plurality of conductors 15 can be prevented. Therefore, the eddy current loss generated by the magnetic flux interlinking with the electrostatic shielding electrode 13 can be reduced, and the overheating due to the eddy current loss can be suppressed. Actually, magnetic flux interlinks even in the conductor 15 alone, causing eddy current loss. However, with a practical wire diameter of several mm or less, the calorific value is small as compared with the winding, and there is no problem of overheating.

As a result, in order to suppress overheating due to eddy current loss as in the prior art, the area of the electrostatic shielding electrode is limited,
Or, it was divided and insulated from each other except for electrical connection points, and furthermore, the selection of the material of the wire mesh constituting the electrostatic shielding electrode, the thinning of the metal wire, or the reduction in the number of meshes were performed according to the capacity and specifications. However, these can be made unnecessary. In this way, the conductor 15
Since the material and the shape can be appropriately selected, the mechanical strength can be easily secured, the reinforcement with an insulating material can be omitted, the number of parts can be reduced, and the number of work steps can be reduced.

Further, since overheating due to eddy current loss can be suppressed, it is possible to prevent the conductor 15 from being thinned, so that a fine work is not required for the end treatment for increasing the curvature of the end of the electrostatic shielding electrode 13. It becomes possible.

Inductive devices often require long-term reliability of several decades. For example, in an oil-filled transformer, the insulating coating 16 may be exposed to high temperatures of around 100 ° C. in oil for long periods of time. If the insulating coating 16 is thermally degraded and its mechanical strength is reduced, the insulating coating 16 is mechanically damaged by vibrations generated at the time of starting the equipment, and the conductors 15 intersecting each other are short-circuited. A circulating current path is formed over the insulated conductor 14. If the magnetic flux interlinks, a circulating current may flow and cause overheating due to eddy current loss. Therefore, by using a formal wire having both oil resistance and heat resistance as the insulating coating 14, the deterioration of the insulating coating in high-temperature oil can be suppressed, and the short-circuiting of the conductors 15 that intersect each other can be prevented. Overheating due to eddy current loss of the shielding electrode 13 can be suppressed.

The insulated conductor 14 is electrically connected at one end at the end 14a, and the potential of the electrically connected location and the potential of the iron core 11 or the winding 12 are set to the same potential. In this case, the configuration is such that the lead wire (not shown) is connected to the iron core 11 or the winding 12 in order to maintain the above-mentioned condition. Further, the above-mentioned method can make the electric field equal by ensuring the same potential, but even if each of the insulated conductors 14 is not electrically connected to the other, the iron core 11 and the electrostatic shielding The potential becomes a voltage divided by the capacitance between the electrode 13 and the winding 12, and the electric field can be made closer to a uniform electric field to improve the dielectric strength.

Although the electrostatic shielding electrode 13 is shown as a plain woven mesh using a plurality of insulated conductors 14, a part or all of the electrostatic shielding electrode 13 may be replaced by one.
It is also possible to use a net formed by knitting the continuous insulating coated conductors 14. In this case, it is necessary to prevent one insulated conductor 14 from being electrically connected at a plurality of locations. Furthermore, the weaving method is not limited to plain weaving, and twill weave or knitting may be used, and the same operation and effect as described above can be obtained.

Also, the enameled electric wire coated with formal (PVF) has been described as the insulated conductor 14.
Other insulated wires having oil resistance and heat resistance, such as Teflon-coated wires, may be used, and the same operation and effects as described above can be obtained.

Further, even in an induction device having an air-core winding without an iron core, and even when it is necessary to alleviate an electric field in an electric field concentration portion such as a protrusion of the winding, the above-mentioned electrostatic shielding electrode is used. It goes without saying that you can do it. In short, the above-mentioned electrostatic shielding electrode is applicable to an area where a magnetic field and an electric field are present, not a magnetic field but only an electric field, and an eddy current loss is a problem. Further, in order to suppress overheating of the equipment container, this electrostatic shielding device may be provided between a shield core (not shown) provided on the inner wall of the container and the high-voltage part, and the same operation and effect as described above can be obtained. Have.

Embodiment 2 FIG. 4 shows Embodiment 2 of the present invention.
It is an explanatory view showing the composition of the electrostatic shielding device of the guidance equipment which is. In FIG. 4, the electrostatic shielding electrode 23 is composed of an insulated wire 14 and an insulated wire 24 made of a natural fiber, a synthetic fiber or an inorganic fiber and having oil resistance and heat resistance, and is formed in a plain-woven net shape. . Where the insulated conductor 14 and the insulated wire 24 intersect each other, the two wires 14,
24, and are electrically insulated at one end at the end 14a. Further, the electrically connected portion is connected to the iron core 11 or the winding 12 by a lead wire (not shown), and the electric potential of the electrically connected portion and the iron core 11 or the winding 12
Is maintained at the same potential. For this reason, the electrostatic shielding electrode 23 can reduce the local electric field around the protrusion of the iron core 11 or the winding 12, make it closer to a uniform electric field, and improve the dielectric strength.

Since there is no intersection between the insulated conductors 14 as in the first embodiment, no short circuit occurs between the conductors 15 due to mechanical damage to the insulative coating 16. Can be prevented from being formed. For this reason, eddy current loss generated by magnetic flux interlinking with the electrostatic shielding electrode 23 can be reduced, and overheating due to eddy current loss can be suppressed.

As described above, since overheating due to eddy current loss can be suppressed, it is possible to appropriately select the material and shape of the conductor 15 used for the electrostatic shielding electrode 23, and it is easy to secure mechanical strength. Therefore, it is not necessary to reinforce with an insulating material, and it is possible to reduce the number of parts and the number of working steps. In addition, since overheating due to eddy current loss can be suppressed, thinning of the conductor 15 can be prevented, and therefore, fine work is not required for end treatment for increasing the curvature of the end of the electrostatic shielding electrode 23. Becomes possible.

Embodiment 3 FIG. 5 shows Embodiment 3 of the present invention.
It is an explanatory view showing the composition of the electrostatic shielding device of the guidance equipment which is. In FIG. 5, the electrostatic shielding electrode 33 is composed of the insulating covered conductor 14 and a bare conductor 34 made of copper, aluminum, or the like, and is formed in a plain weave net shape. Where the insulated conductor 14 and the bare conductor 34 intersect each other, they are electrically insulated by the
a and 34a are electrically connected at one point. Further, the electrically connected portion is connected to the iron core 11 or the winding 12 by a lead wire (not shown), and the electric potential of the electrically connected portion and the iron core 11 or the winding 12
Is maintained at the same potential. For this reason, the electrostatic shielding electrode 33 can reduce the local electric field around the protrusion of the iron core 11 or the winding 12, make it closer to a uniform electric field, and improve the dielectric strength.

Further, formation of a circulating current path extending between the plurality of conductors 15 and the bare conductor 34 can be prevented. For this reason, eddy current loss generated by magnetic flux interlinking with the electrostatic shielding electrode 33 can be reduced, overheating due to eddy current loss can be suppressed, and the material of the conductor 15 and the bare conductor 34 can be reduced. Since the shape and shape can be appropriately selected, it is easy to secure the mechanical strength, the reinforcement with an insulating material can be omitted, the number of parts can be reduced, and the number of work steps can be reduced. In addition, since overheating due to eddy current loss can be suppressed, thinning of the conductor 15 and the bare conductor 34 can be prevented, and therefore, precise work is required for the end treatment for increasing the curvature of the end of the electrostatic shielding electrode 33. It becomes possible to make it unnecessary.

Embodiment 4 FIG. FIG. 6 shows Embodiment 4 of the present invention.
It is an explanatory view showing the composition of the electrostatic shielding device of the guidance equipment which is. In FIG. 6, the electrostatic shielding electrode 43 is composed of the insulating wire 24 and the bare conductor 34, and is formed in a plain-woven net shape. Where the insulated wire 24 and the bare conductor 34 intersect each other, they are electrically insulated by the insulated wire 24, and are electrically connected at one end 34a. Further, the electrically connected portion is connected to the iron core 11 or the winding 12 by a lead wire (not shown), and the electric potential of the electrically connected portion and the iron core 11 or the winding 12
Is maintained at the same potential. For this reason, the electrostatic shielding electrode 43 can reduce the local electric field around the protrusion of the iron core 11 or the winding 12, make it close to a uniform electric field, and improve the dielectric strength.

Further, formation of a circulating current path extending over the plurality of bare conductors 34 can be prevented. For this reason, eddy current loss generated by magnetic flux interlinking with the electrostatic shielding electrode 43 can be reduced, overheating due to eddy current loss can be suppressed, and the material and shape of the bare conductor 34 can be reduced. Since it can be appropriately selected, it is easy to secure the mechanical strength, the reinforcement with an insulating material can be omitted, the number of parts can be reduced, and the number of work steps can be reduced. In addition, since overheating due to eddy current loss can be suppressed, it is possible to prevent the bare conductor 34 from being thinned, and therefore, it is not necessary to perform a precise operation for the end treatment for increasing the curvature of the end of the electrostatic shielding electrode 43. It becomes possible.

Embodiment 5 FIG. FIG. 7 is a view for explaining an electrostatic shielding device for an induction device according to a fifth embodiment of the present invention, and more specifically, an electrostatic shielding device used for a core-type oil-immersed transformer as an induction device. It is sectional drawing which looked at the apparatus from the upper part. In FIG. 7, the windings 12 are formed on the outer periphery of the iron core 11 via an insulator 18 made of a press board.
Any one of the electrostatic shielding electrodes 13, 23, 33, 43 indicated by the symbol is wound.

The insulator 18 prevents the electrostatic shielding electrode from coming into contact with the iron core 11.
In the electrostatic shielding electrodes 33 and 43 as shown in FIG. 4, the bare conductor 34 forming the electrostatic shielding electrodes 33 and 43 is
1 can be prevented from forming a circulating current path.
Further, in the electrostatic shielding electrodes 13 and 23 as described in the first and second embodiments, for example, the insulating coating 16 is damaged by vibration while being in contact with the iron core 11 or the like, and the conductor 15 and the iron core 1 are damaged.
1 can be prevented from electrically contacting and forming a circulating current path. Since the formation of the circulating current path can be prevented in this manner, overheating due to eddy current loss can be suppressed.

The electrostatic shield electrode is provided between conductive portions having different potentials with an insulator interposed therebetween, and any insulator may prevent the contact between the electrostatic shield electrode and the conductive portion. The same operation and effect as described above can be obtained. Further, if the electrostatic shielding electrode is sandwiched in close contact with the insulator 18, even if there is a conductive component between the winding 12 and the conductive component, the conductive component and the electrostatic shielding electrode Can be prevented from coming into contact with the damaged portion of the insulated conductor 14 or the bare conductor 34, and the formation of a circulating current path can be prevented.

Embodiment 6 FIG. FIG. 8 is a view for explaining an electrostatic shielding device for an induction device according to a sixth embodiment of the present invention, and more specifically, an electrostatic shielding device used for a shell-type oil-immersed transformer as an induction device. It is sectional drawing which shows arrangement | positioning of an apparatus.
FIG. 9 is a cross-sectional view as viewed from the side of FIG. 8, and FIG. 10 is an explanatory view showing an electrostatic plate which is a kind of an electrostatic shielding electrode provided in FIG. 8 to 10, the winding 52 is a core 51.
Is wound around the outer periphery of the coil 52 via an electrostatic shielding electrode 53, and an iron core 51 is wound around the outer periphery of the winding 52 by an iron core 51.
Surrounded by three.

The electrostatic shielding electrode 53 is the same as the electrostatic shielding electrode 13 shown in FIGS. 2 and 3, and is formed in a net-like shape by plain weaving using a plurality of insulated conductors 14. At the places where the conductors 14 cross each other, the conductors 14 are electrically insulated by the insulating coating 16, and at the end 14 a,
It is electrically connected at one place. Further, the electrically connected portion is connected to the iron core 51 or the winding 52 by a lead wire (not shown), and the potential of the electrically connected portion and the potential of the iron core 51 or the winding 52 are connected. It is kept at the same potential. For this reason, the electrostatic shielding electrode 53 can reduce the local electric field around the protrusion of the iron core 51 or the winding 52, make it closer to a uniform electric field, and improve the dielectric strength.

Further, since the electrostatic shielding electrode 53 is electrically insulated by the insulating coating 16 at the places where the insulating coating wires 14 cross each other, a circulating current path extending over the plurality of conductors 15 is formed. Can be prevented. For this reason,
The eddy current loss generated by the magnetic flux interlinking with the electrostatic shielding electrode 53 can be reduced, and overheating due to the eddy current loss can be suppressed. The reason why the electrostatic shielding electrode 53 is divided into a plurality of parts as shown in FIG. 8 is to prevent a circulating current path from being formed.

As described above, since overheating due to eddy current loss can be suppressed, the material and shape of the conductor 15 used for the electrostatic shielding electrode 53 can be appropriately selected, and mechanical strength can be easily secured. Therefore, it is not necessary to reinforce with an insulating material, and it is possible to reduce the number of parts and the number of working steps. In addition, since overheating due to eddy current loss can be suppressed, thinning of the conductor 15 can be prevented, and therefore, precise work is not required for end treatment for increasing the curvature of the end of the electrostatic shielding electrode 53. Becomes possible.

An electrostatic plate 54 which is a kind of an electrostatic shielding electrode
10 has the same cross-sectional shape as the windings 52 as shown in FIG.
1 and the winding 52 and is connected to the winding 52.
As shown in FIG. 10, the electrostatic shielding electrode 54 may be formed on an insulator whose corners are formed with a large curvature by using any of the electrostatic shielding electrodes 13, 23, 33, and 43 shown in the first to fourth embodiments. Is formed by sticking the electrostatic shielding electrode. This electrostatic shielding electrode 54 reduces the local electric field at the corners formed at the ends of the windings 52, and between the different windings 52, the windings 52 and the iron core 5.
1. The electric field between the winding 52 and the other electrostatic shielding electrode 53 can be made closer to a uniform electric field, and the dielectric strength can be improved.

Further, since the conductor 15 or the bare conductor 34 is insulated except at one electrical connection point, it is possible to prevent the formation of a circulating current path even if the leakage magnetic flux is linked. Thus, eddy current loss is reduced and overheating can be suppressed. Incidentally, the conventional electrostatic shielding electrode has been configured by winding a metal foil tape or attaching a plurality of wire nettings to an insulator having a corner with a large curvature as shown in FIG.

In addition, the electrostatic shielding electrode 54 is formed on an insulator having a large curvature at the corner, and the electrostatic shielding electrodes 13, 23,
Although any one of the electrodes 33 and 43 is formed by attaching the electrostatic shielding electrode, the electrostatic shielding electrode may be wound in a tape shape, and the same operation and effect as described above can be obtained. Further, after the electrostatic shielding electrode is brought into close contact with the press board, the electrode is pressed and pressed by applying pressure to a mold so as to have the same shape as the outer shape of the electrostatic shielding electrode 54, or Instead of using a press board, the electrostatic shielding electrode 54 may be press-formed alone by applying pressure to a mold and exerting the same effect as described above.

Embodiment 7 FIG. FIG. 11 is a view for explaining an electrostatic shielding device for an induction device according to a seventh embodiment of the present invention, and more specifically, used for a rotating electric machine such as an induction motor or a synchronous generator as the induction device. It is a perspective view which shows the cross-sectional arrangement of an electrostatic shielding device. Referring to FIG.
Is provided with a slot 62, and a winding 63 is accommodated in the slot 62 and fixed by a wedge 67. Winding 63
A coil conductor 64 composed of a plurality of strands, an electrostatic shielding electrode 65a wound around the coil conductor 64, an insulating layer 66 provided around the electrostatic shielding electrode 65a, Electrostatic shielding electrode 65b wound around layer 66
And is accommodated in a slot 62 in the iron core 61.

The electrostatic shielding electrode 65a wound around the coil conductor 64 is electrically connected to the coil conductor 64,
The curvature of the irregularities and corners of the coil conductor 64 on the surface is increased. Further, the electrostatic shielding electrode 65b on the outer periphery of the insulating layer 66 is electrically connected to the iron core 61 on the outer side thereof, and the curvature of the unevenness on the surface of the iron core 61 is increased. The electrostatic shielding electrodes 65a and 65b are formed by cutting any one of the electrostatic shielding electrodes 13, 23, 33, and 43 shown in the first to fourth embodiments into a tape shape and winding it. It is formed.

Thus, the electric field between the coil conductor 64 and the iron core 61 can be equalized, and the dielectric strength can be improved. Further, since the conductor 15 and the bare conductor 34 in the electrostatic shielding electrodes 13, 23, 33 and 43 are insulated except at the electrical connection points at the ends 14a and 34a, the leakage flux is linked. Even in this case, the formation of a circulating current path can be prevented, and therefore, eddy current loss is reduced and overheating can be suppressed.

Further, the effect of suppressing overheating does not practically depend on the wire diameter or material of the components of the electrostatic shielding electrode. Therefore, if the mechanical strength is selected, the temperature during operation and during shutdown can be reduced. Even if a shear stress acts between the coil conductor 64 and the insulating layer 66 due to the difference, the distortion can be suppressed to a small value so that no crack occurs in the insulating layer.

Incidentally, since the conventional electrostatic shielding electrodes use semiconductive tapes or paints, these tapes or paints are used to prevent overheating due to eddy current loss when leakage magnetic flux is linked. 100Ω ~ 1kΩ for paint
Is used. In such a rotating electric machine, there is a difference in the coefficient of thermal expansion between the coil conductor 64 constituting the winding 63 and the insulating layers 66 and 4 due to a temperature difference between the operation and the stop, and a shear stress is applied to the interface between the two. Occurs.
There is a problem that the stress may be repeatedly applied to cause cracks in the insulating layer having low mechanical strength, which may cause an abnormality. However, according to the seventh embodiment of the present invention, as described above, This problem can be solved.

In this embodiment, the net 4 composed of a conductor and an insulator is cut into a tape shape and wound. However, the net 4 may be wound in a sheet shape, and may be wound in the form of a sheet. It has a function and effect.

[0058]

Since the present invention is configured as described above, it has the following effects.

An electrostatic shielding device for an induction device according to the present invention includes a first conductive portion having a first potential and a second conductive portion having a second potential different from the first potential. An electrostatic shielding device for an induction device, wherein the electrostatic shielding device is composed of a plurality of net-shaped intersecting lines, and among the plurality of intersecting lines, at least one of the intersecting lines has conductivity. Since the portions that intersect in a mesh shape are insulated, it is possible to prevent the formation of a circulating current path extending over a plurality of conductive lines. For this reason, the eddy current loss generated by the magnetic flux linked to the electrostatic shielding device can be reduced,
It is possible to suppress overheating due to eddy current loss.

Further, the electrostatic shielding device may be configured such that a conductive line is electrically connected at one location, and the potential of the electrically connected location is equal to the potential of the first conductive portion or the second conductive portion. Is maintained at the same potential as that of the first conductive portion or the second conductive portion, thereby reducing the local electric field around the first conductive portion or the second conductive portion.
It is possible to improve the dielectric strength.

Also, the present invention is an electrostatic shielding device for a conductive device provided with an iron core and a winding, wherein the electrostatic shielding device is composed of a plurality of lines intersecting in a mesh, and at least one of the plurality of lines intersecting in a mesh. Since the line forming one of the intersections has conductivity and the crossed portions are insulated, it is possible to prevent the formation of a circulating current path over a plurality of conductive lines. For this reason, eddy current loss generated by linkage of magnetic flux leaking into the electrostatic shielding device can be reduced, and overheating due to eddy current loss can be suppressed. In addition, since overheating due to eddy current loss can be suppressed, it is possible to appropriately select the material and shape of the wire constituting the electrostatic shielding device, it is easy to secure mechanical strength, and the wire is made of an insulating material. The reinforcement can be omitted, and the number of parts can be reduced to reduce the number of working steps. Furthermore, since overheating due to eddy current loss can be suppressed, it is possible to prevent the lines constituting the electrostatic shielding device from being thinned, and therefore, it is necessary to perform a precise treatment for the end portion which increases the curvature of the end portion of the electrostatic shielding device. Work becomes unnecessary.

Further, in the electrostatic shielding device, a conductive wire is electrically connected at one location, and the potential of the electrically connected location and the potential of the iron core or the winding are maintained at the same potential. By doing so, it is possible to reduce the local electric field around the iron core or the winding and improve the dielectric strength.

Further, since the electrostatic shielding device is made of the insulated conductor, it is possible to prevent the formation of the circulating current path extending over the insulated conductor.

In addition, since one of the electrostatic shielding devices is made of an insulated wire and the other is made of an insulated wire, it is possible to prevent the formation of a circulating current path over the insulated wire.

In addition, since one of the electrostatic shielding devices is formed of an insulated conductor and the other is a bare conductor, a circulating current path extending between the insulated conductor and the bare conductor can be prevented.

Further, since one of the electrostatic shielding devices is made of a bare conductor and the other is made of an insulated wire, it is possible to prevent the formation of a circulating current path over the bare conductor.

Further, since the electrostatic shielding device is provided between the conductive portions having different potentials with the insulating member interposed therebetween, the insulating member prevents the contact between the electrostatic shielding device and the conductive portion. Can be prevented from being formed.

Further, since the insulation-covered conductor is an oil-resistant enameled wire, deterioration of the insulation covering in high-temperature oil is suppressed, and short-circuiting between the insulation-covered conductors crossing each other is prevented. Can be prevented from being formed.

Further, since the insulation-coated conductor is a Teflon-coated electric wire, deterioration of the insulation coating in high-temperature oil is suppressed, and short-circuiting between the insulation-coated conductors crossing each other is prevented, so that a circulating current path is formed. Can be prevented.

Further, the electrostatic shield device comprises a first electrostatic shield electrode and a second electrostatic shield electrode, wherein the first electrostatic shield electrode comprises a coil conductor forming a winding. It is electrically connected and wound around the coil conductor, and the second electrostatic shielding electrode is wound around an insulating layer provided around the first electrostatic shielding electrode, and is electrically connected to the iron core. Eddy current loss caused by the magnetic flux interlinking the two electrostatic shielding electrodes can be reduced, and the electric field between the coil conductor and the iron core should be close to the equivalent electric field. Becomes possible.

An electrostatic shield which does not shield a magnetic field but shields only an electric field, wherein the electrostatic shield comprises a plurality of net-crossed lines, and at least one of the crosses among the plurality of net-crossed lines. Are electrically conductive, the portions crossing in a mesh form are insulated, and the conductive lines are electrically connected at one place, so that a plurality of conductive lines Circulating current path can be prevented. For this reason, the eddy current loss generated by linkage of the magnetic flux leaking into the electrostatic shield can be reduced, and overheating due to the eddy current loss can be suppressed. In addition, since the conductive line is electrically connected at one place, when suppressing the local electric field, the potential of the electrically connected part and the potential of the part to be suppressed are controlled. Are easily maintained at the same potential.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an electrostatic shielding device for an induction device according to a first embodiment;

FIG. 2 is an explanatory diagram illustrating a configuration of an electrostatic shielding device of the guidance device according to the first embodiment;

FIG. 3 is a cross-sectional view of an insulating film conductor constituting an electrostatic shielding electrode.

FIG. 4 is an explanatory diagram illustrating a configuration of an electrostatic shielding device of an induction device according to a second embodiment.

FIG. 5 is an explanatory diagram showing a configuration of an electrostatic shielding device of an induction device according to a third embodiment.

FIG. 6 is an explanatory diagram illustrating a configuration of an electrostatic shielding device of an induction device according to a fourth embodiment.

FIG. 7 is a diagram illustrating an electrostatic shielding device for an induction device according to a fifth embodiment.

FIG. 8 is a view for explaining an electrostatic shielding device of an induction device according to a sixth embodiment.

FIG. 9 is a cross-sectional view as viewed from the side of FIG.

FIG. 10 is an explanatory view showing an electrostatic plate which is a kind of the electrostatic shielding electrode provided in FIG.

FIG. 11 is a view for explaining an electrostatic shielding device for an induction device according to a seventh embodiment.

FIG. 12 is a view for explaining a conventional electrostatic shielding device for an induction device.

[Explanation of symbols]

 11, 51, 61 Iron core 12, 52, 63 Winding 13, 23, 33, 43 Electrostatic shielding electrode 14 Insulated covering conductor 18 Insulating member 24 Insulating conductor 34 Bare conductor 64 Coil conductor 65a First electrostatic shielding electrode 65b second electrostatic shielding electrode 66 insulating layer

Claims (13)

[Claims] 1. An electrostatic shielding device for an induction machine, comprising: a first conductive portion having a first potential; and a second conductive portion having a second potential different from the first potential. The electrostatic shielding device comprises a plurality of lines intersecting in a mesh, and among the plurality of lines intersecting in a mesh, at least a line constituting one of the intersections has conductivity, and the intersecting in a mesh. An electrostatic shielding device for an induction device, characterized in that the isolated portion is insulated. 2. The electrostatic shielding device according to claim 1, wherein the conductive wire has one wire.
The potential is electrically connected at a location, and the potential of the electrically connected location and the potential of the first conductive portion or the potential of the second conductive portion are maintained at the same potential. Item 2. An electrostatic shielding device for an induction device according to Item 1. 3. An electrostatic shielding device for a conductive device provided with an iron core and a winding, wherein the electrostatic shielding device is composed of a plurality of lines intersecting in a mesh, and among the plurality of lines intersecting in a mesh. An electrostatic shielding device for an induction device, characterized in that at least a line forming one of the intersections has conductivity, and a portion where the intersection is formed in a mesh shape is insulated. 4. The electrostatic shielding device according to claim 1, wherein the conductive wire has one wire.
The electric potential of the electrically connected part and the electric potential of the iron core or the winding are maintained at the same electric potential at the point, and the electrostatic potential of the induction device according to claim 3, wherein Shielding device. 5. The static electricity shielding device for an induction device according to claim 1, wherein the static electricity shielding device is made of an insulated wire. 6. The electrostatic shielding device according to claim 1, wherein one of the electrostatic shielding devices is formed of an insulated conductor and the other is formed of an insulated wire. apparatus. 7. The electrostatic shield of an induction device according to claim 1, wherein one of the electrostatic shields is made of an insulated conductor and the other is made of a bare wire. apparatus. 8. The electrostatic shielding device according to claim 1, wherein one of the electrostatic shielding devices comprises a bare conductor and the other comprises an insulated wire.
The electrostatic shielding device for an induction device according to any one of claims 1 to 4. 9. The electrostatic induction device according to claim 1, wherein the electrostatic shielding device is provided between conductive portions having different potentials with an insulator interposed therebetween. Shielding device. 10. The electrostatic shielding device for an induction device according to claim 5, wherein the insulation-covered conductor is an oil-resistant enameled wire. 11. The electrostatic shielding device for an induction device according to claim 5, wherein the insulated wire is a Teflon-coated wire. 12. An electrostatic shielding device comprising: a first electrostatic shielding electrode and a second electrostatic shielding electrode, wherein the first electrostatic shielding electrode forms a coil; Electrically connected and wound around the coil conductor, wherein the second electrostatic shielding electrode is wound around an insulating layer provided around the first electrostatic shielding electrode The electrostatic shielding device for an induction device according to any one of claims 5 to 8, wherein the electrostatic shielding device is electrically connected to an iron core. 13. An electrostatic shield that shields only an electric field without shielding a magnetic field, wherein the electrostatic shield comprises a plurality of lines intersecting in a mesh, and among the plurality of lines intersecting in a mesh, At least one of the lines forming the intersection has conductivity, the portion crossing in a mesh shape is insulated, and the line having conductivity is electrically connected at one position. Electrostatic shield.