JP2001093749A - Electric apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical apparatus which can realize reduction in size reducing the length between electrodes. SOLUTION: A voltage source 13 capable of applying a high voltage is connected to electrodes 1a, 1b, shield electrodes 2a, 2b are disposed between the electrodes 1a, 1b and connected to the electrodes 1a, 1b via potential wires 3a, 3b so that the potentials are equal to those of the electrodes 1a, 1b, a solid insulator 4 is disposed between the shield electrodes 2a, 2b in close contact therewith, the solid insulator uses, e.g. a press board, epoxy, FRP, polyethylene, etc., and the electrodes 1a, 1b, the shield electrodes 2a, 2b, and the solid insulator 4 are housed in a tank in which a fluid insulator 9 such as insulation oil, insulation gas, etc. is sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric device constructed in a container filled with a fluid insulator, and more particularly to an electric device whose dimensions are improved while maintaining insulation performance.

[0002]

2. Description of the Related Art An electric device constructed by storing the contents such as an iron core and a winding in a container filled with a fluid insulator such as an insulating oil or an insulating gas depends on the insulation of the fluid insulator. I have. And such electrical equipment is often
Cooling as well as insulation relies on fluid insulators. Furthermore, in order to improve the insulation performance, together with the fluid insulator,
Many electric appliances have a composite insulation structure by using a solid insulator such as paper or a press board.

[0003] As an example of such electric equipment, a conventional oil-filled single-phase transformer will be described below with reference to Figs. FIG. 11 is a perspective plan view of an oil-filled single-phase transformer, FIG. 12 is a perspective front view, and FIG. 13 is AA ′ in FIG.
It is a longitudinal cross-sectional view in the line shown by. Also, FIG.
It is explanatory drawing which shows the flow of the insulating oil of a winding upper part.

[0004] That is, as shown in FIGS. 11 and 12, a winding 6 wound around an iron core 5 is made of an insulating clamp disposed between the upper and lower portions of the winding 6 and the iron core 5. It is fastened and fixed by a plate 8. Such iron core 5 and winding 6
Are housed in a tank 15 in which a fluid insulator (insulating oil) 9 is sealed.

[0005] As shown in FIG. 13, a plurality of insulating cylinders 7 made of a solid insulating press board are arranged between the windings 6 to improve the insulating performance. And winding 6
An oil passage is provided between the oil passage and the insulating cylinder 7 adjacent thereto, and cooling is performed by circulating insulating oil through the oil passage. More specifically, FIG.
As shown in the figure, the fluid insulator 9 heated in the winding 6 is
It passes between the fastening plate 8 and the upper part of the winding 6 and is led to an external cooler.

[0006] The electric field strength of each part in an alternating equal electric field is determined by the dielectric constant of an insulator interposed between the electrodes. Since the dielectric constant of the fluid insulator is generally lower than the dielectric constant of the solid insulator, the electric field of the fluid insulator portion becomes higher in an electric device using both the fluid insulator and the solid insulator. For example, the fluid insulator (insulating oil) shown in FIG.
9 and the insulating cylinder 7 made of press board, the dielectric constant ratio is about 1: 2, and the electric field strength ratio is about 2: 1. On the other hand, since the dielectric strength generally increases in proportion to the density of the insulator, the dielectric strength of a fluid insulator having a relatively low density is lower than that of a solid insulator.

From the above, it can be said that the weak point of the insulation in the electrical equipment in the fluid insulator is the fluid insulator portion such as oil or gas. However, since the fluid insulator plays the role of cooling as well as the role of insulation, it is difficult to remove it from between the electrodes in terms of thermal characteristics. In order to cope with this, in the electric equipment as described above, the dimensions between the electrodes are increased so that the electric field strength in the fluid insulator becomes lower than the dielectric breakdown strength.

[0008]

However, in the above-described electrical equipment having a large interelectrode dimension, it is necessary to increase the insulation dimension in proportion to the interelectrode voltage.
For this reason, the size of the entire electric device becomes large, and in particular, in the case of a high-voltage device, miniaturization becomes difficult.

The present invention has been proposed to solve the problems of the prior art as described above.
An object of the present invention is to provide an electric device that can be reduced in size by reducing the dimension between electrodes.

[0010]

In order to achieve the above object, the electric device according to the first aspect of the present invention has an interval between the opposing electrodes, in the vicinity of each of the electrodes, in which the fluid insulator flows. A shield electrode is disposed, the shield electrode and an electrode in the vicinity thereof are connected to each other by a potential line, and a space between the opposed shield electrodes is filled with a solid insulator. According to the first aspect of the present invention, since all the high electric field strength portions are confined in the solid insulator having a high dielectric breakdown strength, the insulation dimension between the electrodes can be reduced. Further, since the electrode connected to the potential line and the shield electrode have the same potential, the electric field between these electrodes is almost zero. Therefore, a fluid insulator having a low dielectric strength can flow between these electrodes without considering the electric field strength.

According to a second aspect of the present invention, in the electric device, a shield electrode is disposed in the vicinity of one of the electrodes between the opposing electrodes and at an interval through which a fluid insulator flows. The electrodes are connected to each other by a potential line, and a space between the shield electrode and the electrode on which the shield electrode is not disposed is filled with a solid insulator. According to the second aspect of the present invention,
Of the opposing electrodes, the electrode that does not require a fluid insulator to flow over the surface can omit the shield electrode and be filled with a solid insulator from the electrode surface, thereby reducing the extra width between the electrodes. it can.

According to a third aspect of the present invention, in the electric device according to the first or second aspect, an end of the shield electrode is rounded. According to the third aspect of the present invention, since the end of the shield electrode where the electric field is high is rounded, the electric field can be reduced.

According to a fourth aspect of the present invention, in the electric equipment according to any one of the first to third aspects, an end of the shield electrode is embedded in the solid insulator. I do. According to the fourth aspect of the present invention,
Since the end of the shield electrode is embedded in the solid insulator, the dielectric strength is improved and the surface creeping electric field strength can be reduced.

According to a fifth aspect of the present invention, in the electric device according to any one of the first to third aspects, the entirety of the shield electrode is embedded in the solid insulator. . According to the fifth aspect of the present invention,
The dielectric strength can be increased, the surface creeping electric field strength can be reduced, and the fabrication becomes easier.

According to a sixth aspect of the present invention, in the electric device according to any one of the first to fifth aspects, a floating electrode is provided in the solid insulator. According to the sixth aspect of the present invention, the inside of the solid insulator is
By arranging a required number of floating electrodes having an appropriate shape, it is possible to alleviate the electric field concentration generated on the end surface of the solid insulator or a part of the inside thereof, thereby preventing dielectric breakdown.

According to a seventh aspect of the present invention, a winding is disposed in an iron core frame, and the core and the winding are accommodated in a container filled with a fluid insulator, thereby constituting a stationary inductor. In the electric device, a clamp plate made of an insulator is disposed between the top and bottom of the winding and the iron core frame, and a shield electrode is provided inside or on the surface of the clamp plate on the winding side and the core side. The core and the shield electrode in the vicinity thereof are connected by a potential line, and the core and the shield electrode in the vicinity thereof are connected by a potential line. In the invention according to claim 7 described above, the shield electrodes are arranged on the winding side and the iron core side of the fastening plate, respectively, the shield electrode on the winding side is set to the winding end potential, and the shield electrode on the iron core side is used. Since the core potential, that is, the ground potential, can be used, the insulation dimension between the iron core and the winding can be reduced.

According to the present invention, a plurality of cylindrical windings are arranged concentrically in an iron core frame, and the iron core and the windings are housed in a container filled with a fluid insulator, thereby providing a stationary type. In an electric device configured as an inductor, a cylinder made of a solid insulator is arranged between the cylindrical windings, and a basic shield or a shield electrode is arranged inside or on the inner or outer diameter side of the cylinder. The inner and outer diameter base shields or shield electrodes are connected to the inner and outer windings by potential lines, respectively. According to the above-described invention, since the shield electrode provided in the cylinder between the windings takes an electric potential from a nearby winding, the diameter of the entire winding can be reduced, and the size of the shield electrode can be reduced.・ Lightening is possible.
In the case of a transformer winding, by employing a basic shield, the potential of the shield can be gradually changed from the upper portion to the lower portion so that the upper and lower portions can correspond to different potentials.

According to a ninth aspect of the present invention, a plurality of cylindrical windings are concentrically arranged in an iron core frame, and the core and the windings are accommodated in a container filled with a fluid insulator, so that static induction is achieved. In an electric device configured as a vessel, a cylinder made of a solid insulator is arranged between an iron core leg and the cylindrical winding, and a shield electrode is arranged inside or on the inner diameter side of the cylinder, Is connected to the iron core leg by a potential wire, and a shield electrode or a base shield is arranged inside or on the outer diameter side of the surface of the cylinder, and the outer diameter base shield or the shield electrode is wound in the vicinity thereof. And a potential line. According to the ninth aspect of the present invention,
The shield electrode placed on the cylinder between the iron core leg and the winding, the inner diameter side takes the potential from the iron core leg, and the outer diameter side takes the potential from the nearby winding, reducing the diameter of the entire winding It is possible to reduce the size and weight. In the case of transformer winding, by adopting a basic shield,
By gradually changing the potential of the shield from the upper portion to the lower portion, it is possible to make the upper portion and the lower portion correspond to different potentials.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) First Embodiment (Configuration) An embodiment corresponding to the first aspect of the present invention will be described.
This will be described with reference to FIGS. That is, as shown in FIG. 1, a voltage source 13 capable of applying a high voltage is connected to the electrodes 1a and 1b. Between the electrodes 1a and 1b,
Shield electrodes 2a and 2b are arranged. The shield electrodes 2a and 2b are connected to the electrodes 1a and 1b via potential lines 3a and 3b so that the potentials of the shield electrodes 2a and 2b are equal to those of the electrodes 1a and 1b.

A solid insulator 4 is disposed between the shield electrodes 2a and 2b in close contact. As a material of the solid insulator, for example, a press board, epoxy, FRP, polyethylene, or the like can be used. The electrodes 1a and 1b, the shield electrodes 2a and 2b, and the solid insulator 4 are accommodated in a tank in which a fluid insulator 9 such as an insulating oil or an insulating gas is sealed.

(Operation) The operation of the present embodiment as described above will be described below. That is, when a high voltage is applied between the electrodes 1a and 1b by the voltage source 13, the shield electrodes 2a and 2b have the same potential as the electrodes 1a and 1b, respectively, so that all voltages are applied to the solid insulator 4. Since the dielectric strength of the solid insulator 4 is higher than that of the fluid insulator, FIG.
As shown in FIG. 5B, the distance between the electrodes 1a and 1b can be reduced as compared with the case where all the space between the electrodes 1a and 1b is filled with a fluid insulator (shown in FIG. 5A).

No voltage is applied between the electrode 1a and the shield electrode 2a and between the electrode 1b and the shield electrode 2b. For this reason, even if a fluid insulator flows between the electrode 1a and the shield electrode 2a and between the electrode 1b and the shield electrode 2b in order to cool the electrodes 1a and 1b, dielectric breakdown in this portion is considered. No need.

Furthermore, even if the electrodes 1a and 1b have a special shape or have protrusions on the surface, or if foreign matter is mixed in the fluid insulator, a special insulating material is required. No consideration is needed.

(Effects) According to the above embodiment, the shield electrodes 2a and 2b and the solid insulator 4 are
a, 1b, the electrodes 1a, 1b
Since the space between them can be reduced, the entire electric device can be reduced in size and weight.

Further, since the insulation is entirely dependent on the opposing surfaces of the solid insulator 4 and the shield electrodes 2a and 2b, other parts need not be considered for the insulation of the opposing electrodes, and the structure becomes simpler. The reliability of insulation is improved.

(2) Second Embodiment (Configuration) An embodiment corresponding to the second aspect of the present invention is
This will be described with reference to FIG. That is, this embodiment has substantially the same configuration as the first embodiment, except that the electrode 1b and the solid insulator 4 are in close contact with each other, and the shield electrode 2b is not disposed therebetween. The difference is that a flow path for cooling the fluid insulator is provided behind the electrode 1b.

(Operation) In this embodiment as described above,
Since there is a cooling flow path made of a fluid insulator behind the electrode 1b, there is no need to flow the fluid insulator between the solid insulator 4 and the electrode 1b. For this reason, all the voltages are shared in the solid insulator 4 by filling the entire surface of the electrode 1b on the side where the fluid insulator does not need to flow with the solid insulator.

(Effect) According to the present embodiment as described above, the extra width between the electrodes 1a and 1b can be reduced, so that the size of the electric device can be further reduced as compared with the first embodiment. Can be smaller.

(3) Third Embodiment An embodiment corresponding to the invention described in claim 3 will be described with reference to FIG. That is, in the present embodiment, the ends of the shield electrodes 2a and 2b in the above-described embodiment have a smooth and rounded surface shape. With such a configuration, the electric field concentration at the ends of the shield electrodes 2a and 2b is reduced, and the electric field intensity is reduced. Therefore, the dimension between the shield electrodes 2a and 2b can be made smaller, and the size of the electric device can be reduced.

(4) Fourth Embodiment An embodiment corresponding to the invention described in claim 4 will be described with reference to FIG. That is, in the present embodiment,
The ends of the shield electrodes 2a and 2b having a smooth surface shape as in the third embodiment are molded and surrounded by the solid insulator 4. In general, the property that the dielectric breakdown strength is higher when the surface is covered with a solid insulator than when the electrode is bare and disposed in a fluid insulator is used. Therefore, with the configuration as in the present embodiment, the dielectric strength can be further increased as compared with the third embodiment.

According to the present embodiment, FIG.
As shown in FIG. 9, since the end surface creepage distance 1 of the solid insulator is longer than in the case of the third embodiment (shown in FIG. 9B), the electric field intensity on the end surface is further reduced. Therefore,
The dimension between the shield electrodes 2a and 2b can be made smaller.

When the shield electrodes 2a and 2b are molded with a solid insulator, cracks may occur at the ends due to stress concentration. However, by forming the electrode ends into a rounded surface shape. Stress concentration can be reduced.

(5) Fifth Embodiment An embodiment corresponding to the invention described in claim 5 will be described with reference to FIG. That is, in the present embodiment, the entirety of the shield electrodes 2a and 2b having smooth end portions as in the third embodiment is molded and wrapped with the solid insulator 4. Thus, the same effect as that of the fourth embodiment can be obtained, and the manufacturing is further simplified.

(6) Sixth Embodiment (Configuration) An embodiment corresponding to the invention described in claim 6 is
This will be described with reference to FIG. That is, in the present embodiment,
A plurality of floating electrodes 10 are arranged between the opposing shield electrodes 2a and 2b. Then, the shield electrodes 2a, 2
b and the floating electrode 10 are entirely molded with the solid insulator 4. The floating electrode 10 has a shield electrode 2a,
2b is opposed to a wide surface and the distance is close,
The potential of each floating electrode 10 is determined by coupling with the shield electrodes 2a and 2b by capacitance. Further, the distances between the respective electrodes are all d and are at equal intervals, and the width of the floating electrode 10 increases toward the center in the thickness direction of the solid insulator 4.

According to the present embodiment as described above, since the distance between the electrodes is all equal, the potential of the shield electrode 2a is set to V and the potential of the shield electrode 2b is set to 0. Then, the potential of each floating electrode becomes 3V / 4, V
/ 2, V / 4.

Since the width of the floating electrode 10 increases toward the center of the solid insulator 4 in the thickness direction, the creepage distance at the end of the solid insulator 4 is increased, and the creepage electric field strength is uniform. And the maximum electric field intensity on the surface of the insulator end can be reduced.

Accordingly, the dimension between the shield electrodes 2a and 2b can be made smaller, and the size of the electric equipment can be reduced. In addition, by changing the width and the number of the floating electrodes 10 as necessary, it is possible to freely set the end surface creeping electric field strength of the solid insulator 4.

(7) Seventh Embodiment (Configuration) An embodiment corresponding to the seventh aspect of the present invention is
This will be described with reference to FIG. FIG. 9 is a cross-sectional view of the air-core reactor. That is, in the present embodiment, the windings 6 are disposed in a square-shaped iron core frame 5 and are fixed from above and below by an upper fastening plate 8a and a lower fastening plate 8b made of an insulating material. . A shield electrode 2a is embedded in the upper core frame 5b side of the upper tightening plate 8a and a lower core frame 5d side of the lower tightening plate 8b, and a shield electrode 2b is embedded in the winding 6 side.

The potentials of the shield electrodes 2a and 2b are fixed to the ground potential and the winding end potential by the potential lines 3a and 3b, respectively. The outer diameter of the shield electrode 2a is formed larger than the outer diameter of the shield electrode 2b. The iron core frame 5 and other members are housed in a tank filled with insulating oil as a whole.

(Operation) In the present embodiment having the above configuration, the voltage between the upper part of the winding 6 and the upper core frame 5b and the voltage between the lower part of the winding 6 and the lower core frame 5d are all In order to share the inside of the solid insulating clamp plates 8a and 8b having a high dielectric breakdown strength, the clamp plate 8 is disposed between the winding 6 and the clamp plates 8a and 8b.
An electric field is hardly applied to a fluid insulator (insulating oil) having a low dielectric breakdown strength between the upper and lower core frames 5b and 5d.

Since the outer diameter of the shield electrode 2b is smaller than that of the shield electrode 2a, the equipotential lines are diffused at the ends of the clamping plates 8a and 8b, and the electric field is weakened. Therefore, it is possible to prevent dielectric breakdown on the end surfaces of the fastening plates 8a and 8b and in the insulating oil.

(Effects) According to the present embodiment as described above, the electric fields at the upper and lower ends of the winding 6 are all concentrated in the solid insulating clamping plates 8a and 8b having high dielectric breakdown strength.
Compared with the conventional structure, the winding 6 and the upper and lower core frames 5b, 5d
Can be reduced, and the entire air-core reactor can be reduced in size.

Furthermore, since the electric field at the end of the winding 6 is reduced, the amount of insulating material for reinforcing the end of the winding 6 which is conventionally required can be reduced, and the manufacturing cost can be reduced.

(8) Eighth Embodiment (Configuration) An embodiment corresponding to the eighth and ninth aspects of the present invention will be described with reference to FIG. Note that FIG.
FIG. 3 is a sectional view of the right half of the single-phase transformer. That is, the low-voltage winding 6a and the high-voltage winding 6b of the single-phase transformer in the present embodiment are arranged concentrically around iron core main leg 5a. Each of the windings 6a, 6b is provided with a fastening plate 8a, 8 made of an insulating material from above and below.
b, the shield electrodes 2a are embedded in the surfaces of the tightening plates 8a, 8b facing the upper core frame 5b and the lower core frame 5d, and the shield electrodes 2a are mounted on the surfaces facing the windings 6a, 6b. 2b and 2c are embedded.

Each electrode is set to a potential by the potential line 3, and the shield electrode 2a is connected to the ground potential.
The shield electrode 2b is fixed at the end potential of the low voltage winding 6a, and the shield electrode 2c is fixed at the end potential of the high voltage winding 6b.
Further, a cylinder 12a made of solid insulator is provided between the high-voltage winding 6b and the low-voltage winding 6a.
The cylinder 12b is disposed between the cylinder 12b and the cylinder 12a.

Electrodes called basic shields 11a and 11b are embedded on the inner and outer diameter sides of the cylinder 12a. A basic shield 11c is provided on the outer diameter side of the cylinder 12b.
Is embedded, and a shield electrode 2d is embedded on the inner diameter side. The basic shields 11a, 11b, 11c are composed of electrodes with fixed potentials arranged at the upper and lower ends, and a plurality of floating electrodes densely arranged therebetween. The structure between the electrodes is such that the capacitance is large,
The values are configured to be equal.

The upper and lower ends of each of the basic shields 11a, 11b, 11c are connected to the ends of the windings 6a, 6b at the corresponding positions by the potential line 3, and the shield electrode 2d is connected to the iron core main leg 5a and the potential line 3 Are joined by And the whole of the above-mentioned members is stored in a tank filled with insulating oil.

(Operation) In the present embodiment having the above-described configuration, the capacitance between the electrodes in the basic shields 11a, 11b, and 11c is large, and the values are equal. When the upper and lower potentials are fixed,
The intermediate floating electrode potential is a continuous potential connecting the upper and lower potentials. Therefore, the base shields 11a, 11b, 1 whose end potentials are fixed by the upper and lower potentials of the windings 6a, 6b.
The potential of each part of 1c is substantially the same as the potential of the corresponding part of the adjacent windings 6a and 6b.

For this reason, the winding 6a and the base shield 11
a, 11c, and the electric field between the winding 6b and the base shield 11b are significantly reduced as compared with the case where the base shields 11a to 11c are not used. Further, since the base shields 11a to 11c are arranged in the cylinders 12a and 12b made of a solid insulator having a high dielectric strength, the dimensions between the high-voltage winding 6b and the low-voltage winding 6a and the low-voltage winding 6
a and the dimension between the iron core main leg 5a can be made smaller than before.

(Effect) According to the present embodiment as described above, the dimension between the windings 6a and 6b and between the winding 6a and the iron core main leg 5a can be reduced, and the seventh embodiment is shown. By the same operation as the above, the distance between the ends of the windings 6a and 6b and the upper core frame 5b and the lower core frame 5d can be reduced. For this reason, a transformer of the same rating can be made smaller and lighter.

Since the end electric field is small, the winding 6
It is possible to reduce the amount of insulating material for reinforcing the end insulation of the a and 6b, thereby saving the manufacturing cost. In addition, since most of the strong electric field portion is concentrated in the solid insulator 4, insulation breakdown starting from the windings 6a and 6b and the insulating oil hardly occurs, and a transformer having high insulation reliability can be configured.

Further, the basic shields 11a to 11c
Originally, it has a function of improving the potential distribution in the windings 6a and 6b when shock waves such as lightning enter the windings 6a and 6b. Therefore, according to the present embodiment employing the basic shields 11a to 11c, such an effect can be obtained.

(9) Other Embodiments The present invention is not limited to the above embodiments. For example, in the first to sixth embodiments, the description has been given of the case of two opposed flat plate electrodes. However, the present invention is also applicable to coaxial cylindrical electrodes and electrodes of various other shapes. It is possible. The counter electrode is 2
The number of electrodes is not limited to three, and the invention can be applied to three or more electrodes.

In the seventh embodiment shown in FIG. 9, between the winding 6 and the iron core frame 5, the eighth embodiment shown in FIG.
In the embodiment, the high voltage winding 6b and the iron core side leg 5c
By using the cylinder in which the base shield and the shield electrode are arranged between the above and the above, the size between them can be reduced.

In the eighth embodiment, the floating electrodes are not arranged in the tightening plates 8a and 8b. In such a case, the electric field can be improved by arranging the floating electrodes as described in the sixth embodiment.

Although the seventh embodiment is applied to an air-core reactor, it can be applied to a reactor with a gap. The eighth embodiment is applicable not only to a single-phase transformer but also to other stationary inductors such as a three-phase transformer. Further, the seventh and eighth embodiments are:
Examples of oil-filled reactors and transformers are also applicable to equipment using other fluid insulators such as SF6 gas.

[0057]

As described above, according to the present invention,
By reducing the dimension between the electrodes, an electric device that can be reduced in size can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure between electrodes in a first embodiment of an electric device of the present invention.

FIG. 2 is an explanatory view showing the operation of the embodiment of FIG. 1,
(A) shows the prior art, and (B) shows the present embodiment.

FIG. 3 is a cross-sectional view illustrating a structure between electrodes in an electric device according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a structure between shield electrodes in a third embodiment of the electric apparatus of the present invention.

FIG. 5 is a cross-sectional view showing a structure between shield electrodes in a fourth embodiment of the electric device of the present invention.

FIGS. 6A and 6B are explanatory views showing the operation in the embodiment shown in FIG. 5, wherein FIG. 6A shows the present embodiment, and FIG. 6B shows the third embodiment.

FIG. 7 is a cross-sectional view showing a structure between shield electrodes in a fifth embodiment of the electric device of the present invention.

FIG. 8 is a cross-sectional view illustrating a structure between shield electrodes in an electric device according to a sixth embodiment of the present invention.

FIG. 9 is a sectional view showing a structure of an air-core reactor according to a seventh embodiment of the present invention.

FIG. 10 is a right half sectional view showing a structure of a transformer according to an eighth embodiment of the present invention.

FIG. 11 is a perspective plan view showing an example of a conventional single-phase three-legged oil-filled transformer.

FIG. 12 is a perspective front view of FIG. 11;

FIG. 13 is a longitudinal sectional view taken along the line AA ′ in FIG. 11;

FIG. 14 is an explanatory diagram of an upper cooling oil circulation structure in a conventional oil-immersed transformer.

[Explanation of symbols]

 1a, 1b: Electrode 2a, 2b, 2c: Shield electrode 3: Potential wire 4: Solid insulator 5: Iron core 5a: Iron main leg 5b: Upper core frame 5c: Iron side leg 5d: Lower iron frame 6: Winding 6a ... Low-voltage winding 6b High-voltage winding 3, 3a, 3b Potential line 7 Insulating cylinder 8 Clamping plate 8a Upper clamp plate 8b Lower clamp plate 11a to 11c Basic shield 12a, 12b Cylinder 13 ... voltage source 15 ... tank

Claims (9)

[Claims] 1. A shield electrode is disposed in the vicinity of each electrode between opposing electrodes, at an interval through which a fluid insulator flows, and the shield electrode and the electrodes in the vicinity thereof are connected to each other by a potential line, An electric device, wherein a space between the opposed shield electrodes is filled with a solid insulator. 2. A shield electrode is disposed in the vicinity of one of the electrodes between the opposing electrodes, at an interval through which a fluid insulator flows, and the shield electrode and an electrode in the vicinity thereof are connected to each other by a potential line, An electrical device, wherein a space between the shield electrode and an electrode on which the shield electrode is not disposed is filled with a solid insulator. 3. The electric device according to claim 1, wherein an end of the shield electrode is rounded. 4. An end of the shield electrode is buried in the solid insulator.
4. The electric device according to any one of 3. 5. The shield electrode according to claim 1, wherein the entirety of the shield electrode is embedded in the solid insulator.
4. The electric device according to any one of 3. 6. The electric device according to claim 1, wherein a floating electrode is provided in the solid insulator. 7. An electric device comprising a winding in a core frame and a stationary inductor by accommodating the core and the winding in a container filled with a fluid insulator. A clamping plate made of an insulator is disposed between the upper and lower sides of the wire and the core frame, and on the winding side and the core side inside or on the surface of the clamping plate,
An electric device, wherein a shield electrode is arranged, the winding and a shield electrode in the vicinity thereof are connected by a potential line, and the iron core and a shield electrode in the vicinity thereof are connected by a potential line. 8. A stationary inductor in which a plurality of cylindrical windings are arranged concentrically in an iron core frame, and the iron core and the windings are housed in a container filled with a fluid insulator. In the electric device, a cylinder made of a solid insulator is disposed between the cylindrical windings, and a base shield or a shield electrode is disposed inside or on the inside or outside of the surface of the cylinder. An electric device, wherein a radial-side basic shield or a shield electrode is connected to an inner winding and an outer winding, respectively, by a potential line. 9. An electric machine comprising a plurality of cylindrical windings arranged concentrically in an iron core frame, wherein the core and the windings are accommodated in a container filled with a fluid insulator, thereby forming an electric stationary inductor. In the device, a cylinder made of a solid insulator is disposed between the iron core leg and the cylindrical winding, a shield electrode is disposed inside or on the inner diameter side of the cylinder, and the inner diameter side shield electrode is A shield electrode or a base shield is arranged inside or on the outer diameter side of the surface of the cylinder, and the outer base shield or the shield electrode is connected to a winding nearby by a potential line. Electrical equipment characterized by being done.