JPH0950920A - Stationary induction electric apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make charge decoupling hard to occur when insulating liquid is circulated at high speed and enable the reduction of charged static electricity, by forming a drifting charging suppressing part, composed of a material with a low degree of electrification, in part of a cooling circulation path for supplying the winding in a tank with the non-combustible insulating liquid. SOLUTION: A cooler 8 and a circulating pump 9 are placed between an upper pipe 10 and a lower pipe 11 led out of a transformer body tank 4 on its side. A circulation path for cooling is thereby formed, through which non-combustible insulating liquid is to be circulated from the circulating pump 9 to the upper pipe 11 to a common cooling path 12 to winding 2 to the vicinity of an upper fastener 13 to the lower pipe 10 to the cooler 8. Insulating paper 211 is wound around conductors 210, and a fluororesin film made of a flutcroresin with a low degree of electrification is wound around the surface of its outermost layer to form a drifting charging suppressing part 212. The drifting charging suppressing part 212 is placed in part of the circulation path for cooling. This makes charge decoupling hard to occur when the insulating liquid is circulated at high speed and thus enables the reduction of charged static electricity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stationary induction device,
In particular, the present invention relates to a static induction generator such as a high-voltage large-capacity transformer that circulates and cools an insulating liquid in a heat generating part in a tank.

[0002]

2. Description of the Related Art Generally, in a static induction electric machine such as an oil-filled iron type transformer, a low voltage winding is arranged around an iron core leg housed in a tank of a transformer main body, and a high voltage winding is provided around the low voltage winding. When wires are arranged concentrically and both windings are composed of disk coils, a spacer between coils is interposed between both windings to maintain insulation and ensure a horizontal cooling passage for transformer oil circulation. An insulating cylinder barrier and a linear spacer are arranged along the windings between the windings to maintain insulation and form a vertical cooling passage for circulating the transformer oil. On the other hand, on the outer circumference of the transformer body tank, a cooler and a pump connected to the inside of the tank by piping are placed, and cooling is performed by forcibly circulating and cooling the transformer oil through each winding that is the heat generating part. A circulation circuit is formed.

In this cooling circuit, for example, in the cooling path passing through the winding, charge separation occurs at the interface between the transformer oil and the insulator, the transformer oil is positively charged, and the insulator is negatively charged. That is, so-called electrostatic charging occurs. The magnitude of the charge changes depending on the properties of the oil, the flow velocity, and the surface condition of the insulator, but when the accumulated charge density becomes high, the electric field at that part becomes high, causing electrostatic discharge, and during the operation of the transformer at AC voltage. There is a danger of progressing to a dielectric breakdown accident. These are generally known as the flow electrification phenomenon of transformers, and are described in "Flux electrification phenomenon in large capacity transformers" described in "Journal of the Institute of Electrical Engineers of Japan", Vol. 99, p. There is. Further, Japanese Patent Application Laid-Open No. 52-156335 discloses a structure in which an edge portion and a bent portion of an insulating material that serves as an oil passage to a transformer winding are provided with a roundness of 5 to 50 mm to prevent electrostatic charging. Has been done. Furthermore, Japanese Unexamined Patent Publication No.
In Japanese Patent Laid-Open No. 3-15518, an ether bond or a thioether is added to an electrically insulating paper as an insulator, or methyl cellulose, ethyl cellulose, polyethylene sulfide, polysulfide, a mixture of ethyl cellulose and polyether, or the like is applied, or the electrically insulating paper is formated. Then, the specific resistance of the electrically insulating paper is set to an appropriate value to suppress the accumulation of generated static electricity.

Further, from the viewpoint of increasing power demand and disaster prevention, a transformer installed in an underground substation in an urban area is required to have a large capacity and non-combustible at ultrahigh voltage, and to be compact from the viewpoint of space saving. In response to these needs, a transformer using a perfluorocarbon liquid as an insulating liquid and a gas insulated transformer filled with SF ₆ gas have been developed and are already in practical use. Perfluorocarbon liquid is an excellent cooling medium. For example, C ₈ F ₁₆ O having a chemical structural formula has a kinematic viscosity coefficient of about 0.8 centimeter stroke at room temperature of 25 ° C., which is much higher than that of transformer oil. Is characterized by low viscosity. Further, the dielectric breakdown strength of perfluorocarbon liquid is similar to that of transformer oil, and it is known that it is also excellent as an insulating liquid for high-voltage equipment.

[0005]

However, when the perfluorocarbon liquid is circulated for cooling in a static induction electric device using the perfluorocarbon liquid as the insulating liquid, the flow rate in the winding increases due to the small viscosity coefficient. However, it was found that electrostatic charging occurs in the cooling circuit due to high speed circulation. Even if the curved portion of the cooling circulation passage is rounded to smooth the flow and suppress turbulence as described in JP-A-52-156335, an increase in the flow rate and a high flow velocity are achieved. Insufficient to suppress the corresponding electrostatic charging.
Further, the surface treatment of the electrically insulating paper as described in JP-A-53-15518 has no effect on the perfluorocarbon liquid. That is, even if it is possible to prevent electric charges from remaining on the surface of the insulating material that serves as the cooling circulation path, since perfluorocarbon liquid has a very large specific resistance, for example, in transformer oil, 10 ¹³ to 10 ¹⁵ Ω / cm at room temperature is used. While,
Since the perfluorocarbon liquid is as large as 10 ¹⁵ to 10 ¹⁷⁵ Ω / cm, the electric charge does not escape and the perfluorocarbon liquid itself flows with an excessive charge, and the charge relaxation occurs in the slow flowing portion, and the electric charge is accumulated. Electrostatic charge will occur.

It is an object of the present invention to provide a static induction electric device which makes it difficult to separate charges when an insulating liquid circulates at a high speed, reduces electrostatic charging, and prevents dielectric breakdown due to flow charging.

[0007]

In order to achieve the above object, the present invention has a winding arranged in a tank, and a cooling circuit for supplying a non-combustible insulating liquid to the winding. In the static induction electric device, at least a part of the cooling circuit is provided with a flow electrification suppressing unit made of a material having a low degree of electrification.

[0008]

In the static induction electric device according to the present invention, as described above, the flow electrification suppressing portion is formed of a material having a low electrification degree in at least a part of the cooling circulation passage made of the insulating liquid.
The charge separation due to the circulation of the insulating liquid can be suppressed to reduce the electrostatic charging, and the dielectric breakdown due to the flow charging can be prevented, which enables the high-speed circulation of the insulating liquid.
The cooling efficiency can be further enhanced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 14 shows the results of examining the amount of electrified charge using a pipe model using a perfluorocarbon liquid as an insulating liquid as a static induction electric device according to an embodiment of the present invention.

FIG. 1 shows the current density per unit area of the inner wall surface of the pipe when the perfluorocarbon liquid is flown through the pipe. The current density shown on the vertical axis depends on the material of the pipe shown on the horizontal axis. Is changing. Among these, polytetrafluoroethylene (hereinafter referred to as PTFE) pipe had the smallest current density, which was about 1/6 to 1/35 of the metal pipe, and generally the insulation of the transformer. It is 1/16 to 1/25 with respect to aramid paper, kraft paper and press board used as materials,
It is 1/300 for a glass fiber reinforced resin (hereinafter referred to as GFRP) pipe. It is considered that the reason why the flow current of the PTFE pipe is small as described above is that the liquid and the solid are the same fluorine-based substance, so that the charge separation at the interface hardly occurs.

Therefore, when a cooling circuit is constructed by connecting a cooler to a static induction electric machine and circulating a non-flammable insulating liquid with a circulation pump, the surface of the cooling circulation path in contact with the insulating liquid is subjected to flow charging. If the suppressing member is made of, for example, a fluororesin, charge separation hardly occurs and electrostatic charging can be suppressed.

FIG. 1 is a cross-sectional view showing a transformer as a static induction generator according to an embodiment of the present invention.

Perfluorocarbon liquid 7 which is an insulating liquid
An iron core 1 clamped and fixed by a lower metal fitting 19 and an upper tightening metal fitting 13 is placed in a transformer main body tank 4 filled with, and a winding wire 2 is concentrically wound around the iron core 1 and an insulating cylinder 3 is provided outside thereof. Is provided, and the lower end of the insulating cylinder 3 is fixed to and supported by the flow rate adjusting plate 14. Further, a conservator 5 is provided on the upper part of the transformer main body tank 4 and communicates with the inside of the transformer main body tank 4 to fill the partition membrane 6 with the perfluorocarbon liquid 7. Gas is enclosed above the partition film 6 of the conservator 5, and the pressure is adjusted by the reaction of the partition film 6 due to expansion and contraction. Further, the upper pipe 10 and the lower pipe 11 led out from the side surface of the transformer body tank 4
A cooler 8 and a circulation pump 9 are connected between them, and as shown by the arrows, the circulation pump 9 ... Lower piping 11 ... Common cooling passage 1
2 ... Winding 2 ... In the vicinity of the upper clamp 13 ... Upper pipe 10 ... Forming a cooling circulation path through which the insulating liquid circulates to the cooler 8. Although the flow of the insulating liquid on the surface of the iron core 1 is not shown, passages are provided between the iron core 1 and the windings 2 and in the iron core 1 to form a cooling circuit for the insulating liquid.

FIG. 2 is an enlarged detailed cross-sectional view showing the lower portion of the winding 2 of FIG. 1. The winding 2 is constructed by stacking a disc coil 25 and a disc coil 26, and an inter-coil spacer (not shown) is provided. They are arranged to form a horizontal cooling passage between the coils, and the insulating cylinder 31 on the side of the iron core 1, the insulating cylinders 32 and 33 arranged between the disk coils 25 and 26, and the transformer main body tank 4 side are arranged. A vertical cooling passage is formed by the insulating cylinder 34 and a linear spacer (not shown) arranged between the disk coils 25 and 26. Insulation ring 1 supported on the lower bracket 19
Flow rate adjusting plates 132 and 134 for adjusting the flow rate between the insulating cylinders 31 and 34 are provided on the upper portions of the numbers 31 and 133. The perfluorocarbon liquid 7 enters the common cooling passage 12 from the lower pipe 11, flows upward in the vertical cooling passages between the insulating ring 131 and the insulating cylinder 32 and between the insulating ring 133 and the insulating cylinder 33, and then the winding 25 , 26. The perfluorocarbon liquid 7 supplied to the windings 25 and 26 is surrounded by the insulating cylinders 31 to 34, respectively, and meanderingly flows as indicated by the arrows by the rectifying rings 35 to 38 provided at appropriate positions to wind. The cooling in the lines 25 and 26 is made uniform. However, when the perfluorocarbon liquid 7 flows in the disk coils 25 and 26,
Since the viscosity of the perfluorocarbon liquid 7 is small and the flow is disturbed due to the unevenness of the surface, the flow velocity is locally increased on the surface of the disk coils 25, 26, etc. Separation is likely to occur. Therefore, the following measures are taken in order to locally increase the flow velocity of the perfluorocarbon liquid 7 and make it difficult for charge separation to occur in the portion where the flow velocity increases.

FIG. 3 is a perspective view showing the covered windings which form the disk coils 25 and 26.

As shown in the figure, the coated windings constituting the disk coils 25 and 26 are obtained by winding an insulating paper 211 around a conductor 210 and winding a fluorine resin film made of a fluorine resin on the outermost layer surface. The flow charge suppressing unit 212 is configured. As described with reference to FIG. 14, the fluorine-based resin is a material in which charge separation is unlikely to occur, and by utilizing this, the fluorine-based resin is arranged at a portion where the insulating liquid contacts and flows. That is, when the perfluorocarbon liquid 7 flows through the disk coils 25 and 26 shown in FIG. 2, the viscous coefficient of the perfluorocarbon liquid 7 is small and the flow is disturbed due to the unevenness of the surface. , 26, the flow velocity is locally increased, and the higher the flow velocity, the more easily charge separation occurs. However, the surface of the insulating material facing the flow of the insulating liquid is covered with a fluororesin film to cause flow charging. Since the suppression unit 212 is configured, charge separation does not easily occur at the boundary surface, and electrostatic charging can be suppressed. As the coated winding, even if the flow charge suppressing portion 212 is formed by winding all layers of the fluororesin film, the effect of suppressing electrostatic charge is the same, but voids remain between the film layers and the original immersion insulation strength is reduced. In order to improve this, a laminated paper obtained by laminating a polytetrafluoroethylene film with kraft paper or synthetic paper having a good liquid impregnating property is wound around all layers, and no voids remain.
Further, the fluidized charge suppressing portion 212 may be configured by using this laminated paper only for the outermost layer. Furthermore, the coating winding of the portion where the flow velocity of the insulating liquid is slow and charge separation does not occur has the same structure as the conventional one, and the portion where the flow turbulence is large or the portion where the flow velocity is high, for example, the lower portion of the winding that is the liquid inlet If only the coil is coated with the fluorine-based resin film or the like to form the flow charge suppressing portion 212, an inexpensive static induction electric device in which electrostatic charging is suppressed can be obtained.

FIG. 4 is an enlarged perspective view showing the insulating cylinder 32 shown in FIG. 2, and the perfluorocarbon of the insulating cylinder 32 is manufactured by molding a thick insulating paper board in order to prevent charge separation. A fluidized-charge suppressing unit 320 made of a fluororesin film is provided on the surface in contact with the liquid 7.
The flow electrification suppressing unit 320 is formed by laminating a thin polytetrafluoroethylene film or coating a thermosetting fluororesin. Static electricity generated at the interface between a solid and a liquid can be suppressed even if the film thickness of the fluororesin is reduced. Due to the difficulty, it is appropriate to apply a film of several microns to several tens of microns. Further, even if the insulating cylinder 32 is entirely made of thick fluorine-based resin, it is possible to suppress the generation of static electricity on the surface.

FIG. 5 is a detailed perspective view showing an enlarged view of the insulating ring 131 shown in FIG. 2, and a plurality of insulating plates 136.
Insulating pieces 135 are arranged at predetermined intervals in between to form the insulating ring 131. Further, the flow rate adjusting plate 132 arranged between the disk coil 25 and the insulating ring 131 adjusts the amount of the insulating liquid flowing through the disk coil 25 by adjusting the protruding size from the insulating ring 131. . The surfaces of the insulating ring 131 and the flow rate adjusting plate 132 are portions where the insulating liquid flows at a high speed, and in order to reduce the amount of static electricity generated, a polytetrafluoroethylene film is attached to the surface or a fluorine resin is used. The flow charge suppressing section is formed by thinly coating and covering with fluorine resin. If the fluidized charge suppressing portion is composed of a thin coating film of a fluorine-based resin, it is possible to effectively suppress electrostatic charging without impairing the liquid impregnation property.

FIG. 6 shows the transformer body tank 4 shown in FIG.
FIG. 3 is a perspective view showing a lower pipe 11 that connects the cooler 8 and the lower pipe 11. The inner surface of the lower pipe 11 is covered with a fluororesin film to form a flow charge suppressing unit 110. This flow charge suppressing unit 110
May be formed by applying a fluororesin paint,
It is more durable to use for a long period of time by heating powder coating and heat fixing, and electrostatic charging can be effectively suppressed even at a high flow rate.
The upper pipe 10 has the same structure.

FIG. 7 is a perspective view showing a leg portion of the iron core 1, in which the surface of the laminated silicon steel plates is coated with a fluororesin to form a flow charge suppressing portion 101. Since the iron core 1 of the transformer becomes a heating element due to iron loss and needs to be cooled, a cooling passage is provided on the surface or inside of the iron core 1 to circulate the insulating liquid. In this way, if the surface of the iron core 1 that serves as a cooling circulation path is coated with a fluororesin to form the flow charge suppressing portion 101, charge separation due to static electricity is less likely to occur, and the charge amount of the insulating liquid is reduced. Can be made smaller.

FIG. 8 shows the cooler 8 shown in FIG. 1. A large number of metal pipes 82 are arranged in a cooler tank 81, and an insulating liquid circulates on the outer surface side of each metal pipe 82. In addition, the water 70 circulates inside the metal pipe 82. FIG. 9 is a cross-sectional view of the metal pipe 82. For example, the outside of the copper pipe 820 is coated with a fluorine-based resin to form a flow charge suppressing portion 821. Therefore, since the surface of the copper pipe 820 in contact with the insulating liquid is covered with the flow charge suppressing portion 821 made of a fluororesin that hardly causes charge separation, even if the insulating liquid circulates at a high speed, a large amount of charge is generated. Never be. FIG.
Reference numeral 0 is a cross-sectional view showing another type of metal pipe 82. For example, the perfluorocarbon liquid 7 as an insulating liquid is passed inside the copper pipe 820 and the water 70 is passed outside. In the inside of the copper pipe 820 which is in contact with the perfluorocarbon liquid 7, a flow charge suppressing portion 822 made of a fluororesin coating is formed to prevent electrostatic charge due to charge separation.

FIG. 11 is a perspective view showing the pump 9 for circulating the insulating liquid shown in FIG. 1. The shaft of the motor 94 is sealed and directly connected to the rotary blade 93, and the outer peripheral portion of the rotary blade 93 is pumped. It is surrounded by a casing 91. The insulating liquid enters the inside of the pump casing 91 from the pipe 95 connected to the cooler (not shown), and is delivered to the transformer main body tank 4 by the rotary vanes 93 through the lower pipe 11 (not shown) as shown by the arrow. Here, the pump casing 9
On the inner surface of No. 1, the surface of the rotary blade 93, the inner surface of the pipe 95, etc., a fluorine-based resin processing is applied to form a flow charge suppressing portion 92, and this flow charge suppressing portion 92 prevents charge separation from occurring. . In particular, although the rotary blade 93 rotates at a high speed, the amount of generated charges can be reduced because it is covered with the flow charge suppressing portion 92 made of a fluororesin.

The flow velocity of the insulating liquid passing through the inner wall surface of the transformer main body tank 4 becomes slower than that at the above-mentioned portion, and not the charge separation but the charge relaxation occurs. If the charge relaxation is small, the liquid will have an excess charge, and a high electric field portion will be created by the adhesion of the charge to an insulator or the like, which will cause a discharge. Therefore, it is necessary to let the electric charge of the insulating liquid escape to the ground as soon as possible. Therefore, it is better that the insulation resistance of the coating film on the surface of the transformer main body tank 4 is small. Therefore, even on the tank wall surface of the transformer main body tank 4, when the flow velocity is high, charge separation occurs. Therefore, the flow-induced charge suppressing portion is formed by the fluororesin coating in the portion where the flow velocity is high, and the charge is reduced in the portion where the flow velocity is low. It is advisable to form a resin film for resistance.

FIG. 12 is a sectional view showing a schematic structure of a liquid immersion composite gas insulation type transformer as a static induction electric generator according to another embodiment of the present invention.

In the transformer body tank 4, an insulating container 21 made of GFRP, which is airtightly sealed at the lower part and sealed with a rubber film 60 at the upper part, is provided, and an iron core tightened and fixed by an upper tightening fitting 13 in the insulating container 21. 1, the winding 2 is concentrically wound around the iron core 1, and the insulating container 21 is filled with the perfluorocarbon liquid 7 which is an insulating liquid. On the other hand, an insulative gas is filled between the transformer body tank 4 and the insulating container 21 to form a liquid immersion composite gas insulation type transformer. Further, the upper pipe 10 and the lower pipe 11 are led out to the outside of the transformer main body tank 4 while maintaining airtightness from the upper and lower portions of the insulating container 21, and the cooler 8 and the circulation are circulated between the upper pipe 10 and the lower pipe 11. The pump 9 is connected to form a cooling circulation path through which the insulating liquid as shown by the arrow circulates.

As shown in the above-mentioned FIG. 14, which shows a comparison of flowing currents as a measure of the degree of charging, GFRP is a material having a large degree of charging, and the material of the insulating container 21 is from the viewpoint of suppressing fluid charge. It is inappropriate. Therefore, in order to reduce electrostatic charge, a flow charge suppressing section 22 is formed in which the inner surface of the insulating container 21 is covered with a fluororesin. More specifically, as shown in FIG. 13, which is a perspective view of a cross section of the insulating container 21, a polytetrafluoroethylene film is attached to the inner surface of the insulating container 21 made of GFRP, or a fluorine resin paint or spray coating is applied. Or the fluorine-based resin is heat-sealed to form the flow charge suppressing portion 22. Therefore, as in the previous embodiment, the charge separation due to the circulation of the perfluorocarbon liquid 7 can be suppressed and the electrostatic charge can be reduced.

FIG. 15 is a sectional view showing a schematic structure of a liquid flow-down type transformer as a static induction electric device according to still another embodiment of the present invention.

Transformer body tank 4 filled with SF ₆ gas
Inside, an iron core 1 around which a winding wire 2 is wound is arranged.
A liquid pool box 15 having a drain hole 16 is arranged on the upper part of the winding 2, and a bottom pool 17 is formed on the lower part of the transformer main body tank 4, and an upper part having an inner end reaching the liquid pool box 15 is formed. A pipe 10 and a lower pipe 11 having an inner end reaching the bottom pool 17 are led out to the outside of the transformer main body tank 4, and a cooler 8 and a circulation pump 9 are connected between these lead ends. A pressure regulator 18 is connected to another part of the transformer body tank 4. The insulating liquid such as the perfluorocarbon liquid 7 in the bottom pool 17 is pumped up to the liquid storage box 15 by the circulation pump 9, and the liquid is dropped from the liquid drain hole 16 to the iron core 1 and the winding 2 to be cooled. It forms the cooling circuit of the arrow. In such a cooling circuit,
Since there are many portions that come into contact with the perfluorocarbon liquid 7, and in particular, the vicinity of the drain hole 16 is a portion where the insulating insulating liquid flows at high speed, charge separation easily occurs. Therefore, the same effect as that of the previous embodiment can be obtained by coating the same portion or a contact portion with another insulating liquid with a fluororesin or the like to form the flow charge suppressing portion.

FIG. 16 is a cross-sectional view showing a schematic structure of a liquid flow down-winding cooling type transformer as a static induction generator according to still another embodiment of the present invention.

The basic structure is the same as that of FIG. 15, but the winding 2 is surrounded by an insulating tube 40, and the liquid storage box 15 is arranged on the upper part thereof to communicate with the inside of the insulating tube 40 through a pipe 16. , The lower pipe 116 is connected to the lower part of the insulating cylinder 40, and the liquid storage box 1
Insulating liquid such as perfluorocarbon liquid 7 in 5 is wound 2
A cooling circulation path is configured to be recovered by the circulation pump 9 from the lower pipe 116 and then returned to the liquid storage box 15 after cooling by falling down to and cooling. In the transformer having such a structure, charge separation easily occurs because the pipe 16 and the lower pipe 116 of the liquid storage box 15 are portions where the insulating liquid flows at high speed. Therefore, the same effect as that of the previous embodiment can be obtained by coating the same portion or a contact portion with another insulating liquid with a fluorine-based resin or the like to form the flow charge suppressing portion.

FIG. 17 is a sectional view showing a schematic structure of a winding immersion type transformer as a static induction electric device according to still another embodiment of the present invention.

In the transformer main body tank 4, the winding wire 2 wound around the iron core 1 is surrounded by an insulating cylinder 40, and the upper pipe 10 is connected to the upper portion of the insulating cylinder 40 via an insulating pipe 41 and a connecting fitting 43. On the other hand, the lower pipe 11 is connected to the lower part of the insulating tube 40 via the insulating pipe 42 and the connecting fitting 44, and the cooler is provided between the ends of both pipes 10 and 11 led out to the outside of the transformer main body tank 4. 8 and the circulation pump 9 are connected to form a cooling circulation path indicated by an arrow. A transformer having such a cooling circuit requires a small amount of liquid, but an insulating liquid such as perfluorocarbon liquid 7 must be circulated at a high speed, and the charge is separated on the wall surface of the cooling circuit accordingly. Is likely to occur. Therefore, the insulating cylinder 40, the insulating pipes 41 and 42, the connecting fittings 43 and 44, and the upper and lower pipes 10 and 11 that form the cooling circulation path are provided with a flow charge suppressing portion made of a fluororesin on the inner surfaces to cause charge separation. It makes it difficult and suppresses fluid flow.

In each of the above-mentioned embodiments, the perfluorocarbon liquid 7 is exemplified as the insulating liquid, but the insulating liquid is not limited to this, and may be a mixed liquid of the fluorocarbon liquid and another liquid, for example, perchlorethylene. In order to suppress the flow charge suppressing portion provided with a fluororesin, the flow charge suppressing portion may be formed of a material having a small charge degree other than the above.

[0035]

As described above, in the static induction electric device of the present invention, since the flow charge suppressing portion covered with the material having a low degree of charge is formed on at least a part of the cooling circuit of the insulating liquid, the insulating liquid is insulated. It is possible to suppress the charge separation due to the circulation of the liquid, to reduce the electrostatic charge, and to prevent the dielectric breakdown due to the flow charge, which enables the insulating liquid to circulate at high speed and further improve the cooling efficiency.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a transformer as a static induction generator according to an embodiment of the present invention.

2 is an enlarged cross-sectional view showing a winding portion of the transformer shown in FIG.

FIG. 3 is an enlarged perspective view showing windings of the transformer shown in FIG.

FIG. 4 is an enlarged perspective view showing an insulating cylinder of the transformer shown in FIG.

5 is an enlarged perspective view showing an insulating ring of the transformer shown in FIG. 1. FIG.

6 is an enlarged perspective view showing a lower pipe of the transformer shown in FIG.

7 is a perspective view showing an iron core of the transformer shown in FIG. 1. FIG.

8 is an enlarged cross-sectional view showing a cooler of the transformer shown in FIG.

9 is a cross-sectional view of the metal pipe shown in FIG.

10 is a sectional view showing another embodiment of the metal pipe shown in FIG.

11 is an enlarged perspective view showing a circulation pump of the transformer shown in FIG.

FIG. 12 is a cross-sectional view showing a schematic configuration of an immersion composite gas insulation type transformer as a static induction generator according to another embodiment of the present invention.

FIG. 13 is an enlarged perspective view showing an insulating cylinder of the liquid immersion composite gas insulation type transformer shown in FIG.

FIG. 14 is a table showing a comparison of electrified charge amounts of various materials.

FIG. 15 is a sectional view showing a schematic configuration of a liquid flow-down type transformer as a static induction generator according to still another embodiment of the present invention.

FIG. 16 is a cross-sectional view showing a schematic configuration of a down-flow coil cooling type transformer as a static induction generator according to still another embodiment of the present invention.

FIG. 17 is a cross-sectional view showing a schematic configuration of a winding immersion type transformer as a static induction generator according to still another embodiment of the present invention.

[Explanation of symbols]

 1 Iron core 2 Winding 3 Insulation cylinder 4 Transformer main body tank 7 Perfluorocarbon liquid 8 Cooler 9 Circulation pump 10 Upper pipe 11 Lower pipe 212,320 Flow static charge suppression unit

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Hiroshi Miyao 7-1, 1-1 Omika-cho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Tatsu Saito 7-1, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Ltd., Hitachi Research Laboratory (72) Inventor Kiyoto Hiraishi 1-1-1, Kokubun-cho, Hitachi City, Ibaraki Prefecture In-house Hitachi Ltd., Kokubun Plant (72) Inventor Hiroyuki Fujita Kokubun, Hitachi City, Ibaraki Prefecture 1-1-1 Machi Kokubun Plant, Hitachi, Ltd.

Claims (8)

[Claims] 1. A static induction machine having a winding circuit arranged in a tank, the cooling circuit supplying a non-combustible insulating liquid to the winding, and at least a part of the cooling circuit. A static induction electric device characterized by being provided with a flow electrification suppressing section made of a material having a low degree of electrostatic charge. 2. The static induction electric device according to claim 1, wherein at least a part of the cooling circuit is provided at a high flow velocity of the insulating liquid. 3. The static induction electric machine according to claim 1, wherein at least a part of the cooling circuit is provided at a place where the flow velocity of the insulating liquid is high and a place where turbulent flow occurs. 4. The static induction electric device according to claim 1, wherein at least a part of the cooling circuit is a surface of an insulating material which is in contact with the insulating liquid in the cooling circuit. . 5. The static induction electric device according to claim 1, wherein a fluorocarbon resin is used as the material having a low degree of electrostatic charge. 6. The static induction electric device according to claim 1, wherein a perfluorocarbon liquid is used as the insulating liquid. 7. The static induction electric device according to claim 1, wherein a mixed liquid of perfluorocarbon liquid and perchlorethylene is used as the insulating liquid. 8. The static induction electric device according to claim 1, wherein the insulating liquid is a perfluorocarbon liquid, and a fluorine resin is used as the material having a low degree of electrostatic charge.