JP3274241B2 - Cooling structure for static induction equipment windings - Google Patents

Abstract

PURPOSE:To miniaturize configuration and to reduce weight by enabling heat to be transferred easily to the heat-collecting part of a cooling pipe from a coil winding and then improving the cooling property of the coil. CONSTITUTION:With the cooling structure of coils of an induction machine, a coil 13 is constituted by a non-loop type capillary heat pipe where actuation liquid is sealed into a capillary container 12 in hollow pipe shape and at the same time a heat-collecting part 16 which is brought into close contact with a specific cooling part of the non-loop type capillary heat pipe and a cooling pipe 15 which is constituted so that a refrigerant is circulated inside having an external heat exchanger and a refrigerant circulation pump are provided. Then, the heat-collecting part 16 is constituted in a shape, for example a plate shape, with a sufficient contact area with the coil 13 by metal and at the same time a part connected to a refrigerant channel of at least the heat-collecting part 16 out of the cooling pipe 15 is constituted of an insulation material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a winding of a static induction device suitable for reducing the size and weight of the configuration of the static induction device.

[0002]

2. Description of the Related Art In recent years, power equipment has been increasingly installed in urban areas in response to an increase in power demand in urban areas. Among these types of power equipment, for example, transformers, which are large stationary induction equipment installed in buildings and underground malls, are required to have flame retardancy. For this reason, the insulating medium used in transformers is also being replaced by nonflammable gas and flame-retardant epoxy resin from conventional flammable mineral oils.
Further, application studies of solid-liquid intermediate materials such as silicone gels are also being conducted.

However, when the above-described non-combustible or non-flammable insulating medium is employed, the liquid insulating / cooling medium convectively circulates and cools the main body of the apparatus as in an oil-immersed transformer. In any case, since the cooling performance is lowered, it is necessary to take measures such as lowering the current density of the winding, and this tends to increase the size and weight of the entire configuration.

On the other hand, in urban areas, downsizing and weight reduction of transformers are top priorities because of the nature of installing transformers in places where land prices are high and entry restrictions are strict. There is a strong demand for improved wire cooling.

In order to solve such a problem, the present inventor has proposed a configuration in which the winding is formed by a non-loop type thin tube heat pipe to improve the cooling property of the winding, that is, a cooling structure of the transformer winding. And invented it earlier (Japanese Patent Application No.
-7389). One embodiment of the above configuration is shown in FIGS.

[0008] In FIGS. 8 and 9, a winding 3 composed of a hollow annular narrow tube container 2 is placed on an insulating tube 1.
Is wound. The working fluid is sealed in the thin tube container 2 from the winding start end 2a or the winding end end 2b, so that the winding 3 is configured as a non-loop type thin tube heat pipe. The winding 3 is configured by stacking a predetermined number of disk-shaped winding units 3a in the vertical direction with spacing pieces 4 interposed therebetween. Further, a heat collecting portion 5a as a predetermined portion of the cooling pipe 5 is interposed at a predetermined position between the layers of the disc-shaped winding unit 3a and is in close contact therewith. A heat exchanger and a refrigerant circulation pump are provided in the remaining predetermined portion of the cooling pipe 5, and the refrigerant sealed in the cooling pipe 5 is forcibly circulated. The heat exchanger and the refrigerant circulation pump are arranged outside the transformer.

In the case of this configuration, the heat generated in the winding 3 is
The hydraulic fluid in the thin tube container 2 is transported to the heat radiating portion of the non-loop type thin tube heat pipe, where it is transmitted to the heat collecting portion 5a side of the cooling pipe 5. The heat transmitted to the heat collecting portion 5a is transported by the refrigerant to the heat exchanger of the cooling pipe 5, where the heat is radiated to the outside. Thereby, the cooling performance of the winding 3 is greatly improved.

[0008]

In the case where the winding cooling structure having the above structure is applied to a high-voltage transformer, the cooling pipe 5 is made of an insulating material such as Teflon or vinylidene chloride due to a demand for an insulating structure. It is necessary to use a resin having an insulating property as well as being composed of the above-mentioned resin. In this case, if the cooling pipe 5 is a resin pipe,
Even if the heat collecting portion 5a is sandwiched between the layers of the disk-shaped winding unit 3a of the winding 3, the heat conductivity of the resin is low and the pipe 5
Has a circular cross section, it becomes difficult for heat from the windings 3 to be transmitted to the heat collecting portion 5a, and the cooling efficiency of the windings 3 deteriorates.

On the other hand, when the cooling pipe is made of, for example, aluminum nitride, which is a fine ceramic material having insulating properties and high thermal conductivity, heat is easily transmitted to some extent. However, since the fine ceramic material is hard and inflexible, its heat collecting portion 5a is
Even if it is sandwiched between the layers of the disc-shaped winding unit 3a, the contact area between the heat collecting portion 5a and the winding 3 is smaller than in the case of the resin material. For this reason, even if the above-mentioned ceramic material is used, there is a problem that heat from the winding 3 is hardly transmitted to the heat collecting portion 5a.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stationary induction device capable of easily transferring heat from a winding to a heat collecting portion of a cooling pipe to improve the cooling performance of the winding and to reduce the size and weight of the structure. An object of the present invention is to provide a cooling structure for a device winding.

[0011]

SUMMARY OF THE INVENTION A cooling structure for a winding of a stationary induction machine according to the present invention comprises a winding formed of a non-loop type thin tube heat pipe in which a working fluid is sealed inside a hollow tubular thin tube container. A cooling pipe configured to have a heat collecting part, an external heat exchanger, and a refrigerant circulation pump that are in close contact with a predetermined heat radiating part of the non-loop type thin tube heat pipe, and configured to circulate a refrigerant inside; , The heat collecting section,
It is characterized in that it is configured to have a shape having a sufficient contact area with the winding with metal, and that at least a portion of the cooling pipe connected to the refrigerant flow path of the heat collecting unit is formed of an insulating material.

In this case, the heat collecting portion can be formed in a flat plate shape, a plurality of metal pipes arranged side by side, or a magnetic material interposed between the metal pipes. Further, it is also a preferable embodiment that the heat collecting portion is configured as an electrostatic shielding plate. On the other hand, it is also preferable that the heat collecting portion of the cooling pipe is made of ceramic having high insulating property and high thermal conductivity instead of metal.

[0013]

According to the above means, the heat collecting portion of the cooling pipe is formed in a shape having a sufficient contact area with the winding by metal, for example, a flat plate or a shape in which a plurality of metal pipes are arranged. Since at least a portion of the cooling pipe connected to the refrigerant flow path of the heat collecting portion is made of an insulating material, heat is easily transmitted from a heat radiating portion of the winding to a heat collecting portion of the cooling pipe, and cooling efficiency of the winding is improved. Can be greatly improved. When the heat collecting portion is configured by arranging metal pipes and a magnetic material is interposed between the metal pipes, most of the magnetic flux can be passed through the magnetic material, and eddy current loss can be reduced.

Further, by electrically connecting the metal heat collecting portion to a predetermined portion of the winding and fixing it at a predetermined potential, the metal heat collecting portion can also be used as an electrostatic shielding plate. It is also possible to improve the initial potential distribution of the winding when the surge voltage enters.

In addition, instead of using a metal for the heat collecting portion of the cooling pipe, a ceramic having both insulating properties and high thermal conductivity may be used. As a result, the cooling efficiency of the winding can be greatly improved, and sufficient insulation performance can be obtained.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to a transformer winding will be described below with reference to FIGS. Note that a transformer is usually composed of two windings, a low-voltage winding and a high-voltage winding, but in the following description, only one winding will be described, and the other winding will be described and illustrated. I omit it.

First, in FIGS. 1 and 2 showing a schematic configuration of the entire cylindrical winding, a thin tube container 12 formed as a hollow annular electrically insulated conductor is wound on an insulating tube 11 at a winding start end 12a. The winding 13 is formed by winding concentrically from to the winding end 12b. The thin tube container 12 is formed by providing an insulating layer having a predetermined thickness on the outer peripheral surface of a hollow annular conductor made of, for example, copper or aluminum, and the insulating layer is formed from a material having high thermal conductivity. Is preferred. The winding start end 12 a or the winding end 12 a
b is filled with a hydraulic fluid, whereby the winding 1
3 is configured as a non-loop type thin tube heat pipe. As the working fluid, for example, pure water or a fluorinated liquid is used.

The winding 13 is a disc-shaped winding unit 1.
3a are stacked in the vertical direction via a spacing piece 14 for insulation. Each disk-shaped winding unit 13
a is configured by winding a total of seven turns from the innermost to the outermost. A heat collecting portion 16 as a predetermined portion of the cooling pipe 15 is sandwiched between predetermined portions between the layers of the disc-shaped winding unit 13a so as to also serve as a spacing piece. Tube container 12 of spirally wound unit 13a
Are closely related to each other. A heat exchanger and a refrigerant circulation pump (both not shown) are provided in the remaining predetermined portion of the cooling pipe 15. Thereby, the cooling pipe 15 has a configuration including the heat collecting unit 16, the heat exchanger, and the refrigerant circulation pump. In this case, by driving the refrigerant circulation pump, the refrigerant sealed in the cooling pipe 5 is forcibly circulated, and the heat collected in the heat collecting unit 16 is transported to the heat exchanger and radiated to the outside here. It has become so. Note that the heat exchanger and the refrigerant circulation pump are disposed outside the transformer.

As shown in FIG. 3, the heat collecting section 16 is made of a metal (for example, copper or aluminum) plate member, and has a hollow U-shaped hollow tubular refrigerant flow therein. A passage 16a is formed. Thereby, the heat collecting section 16
Has a shape having a sufficient contact area with the thin tube container 12 of the disk-shaped winding unit 13a of the winding 13. The surface of the heat collecting section 16 is coated with an insulating coating made of, for example, epoxy resin. The cooling pipe 1 is provided at both ends of the refrigerant passage 16a of the heat collecting section 16.
5 is connected via pipe connections 17, 17.
The cooling pipe is made of an insulating material, for example, a resin such as Teflon or vinylidene chloride, and has an insulating refrigerant sealed therein. In this case, the entire cooling pipe 15 does not need to be formed of an insulating material, and at least a portion of the cooling pipe 15 connected to the refrigerant flow path 16a of the heat collecting section 16 may be formed of the insulating material.

In the case of the above configuration, when forming the windings 13, since the thin tube container 12 constituting the non-loop type thin tube heat pipe is used, the winding operation can be performed in the same manner as a normal winding conductor. It is not necessary to form a loop in the thin tube container 12, and it is not necessary to draw out a conductor from the middle of the winding to form a heat radiating portion.
Since there is no need to attach a valve body, the winding can be easily formed without any difference from the conventional winding process, and an optimum configuration can be obtained in terms of insulation.

On the other hand, in the thin tube container 12 constituting the non-loop type thin tube heat pipe, it is necessary to disperse the heat radiating portions appropriately. Since the heat collecting portion 16 is configured to be sandwiched between predetermined positions between the layers of the disc-shaped winding unit 13a forming a pair of the windings 13 so as to be in close contact with each other, a heat radiating portion exists every turn, and the heat radiating portion is provided. It can be distributed.
For this reason, since the winding 13 operates effectively as a non-loop type thin tube heat pipe, it is possible to make the internal temperature distribution of the winding 13 uniform.

In the above configuration, the heat generated in the windings 13 by energization is first caused by the operation of the non-loop type thin tube heat pipe, that is, the axial vibration of the working fluid sealed in the thin tube container 12. The heat is transferred toward the heat radiating portion of the non-loop type thin tube heat pipe, that is, the portion where the heat collecting portion 16 of the cooling pipe 15 is in close contact. This transferred heat is
Here, the heat transmitted to the heat collecting unit 16 side of the cooling pipe 15 and further transmitted to the heat collecting unit 16 side is transported to the heat exchanger of the cooling pipe 15 by the circulating action of the refrigerant. The heat is radiated to

In this case, the heat collecting section 16 of the cooling pipe 15
Is made of metal and has a shape having a sufficient contact area with the winding 13, specifically, a flat plate shape, so that heat is radiated from the heat radiating portion of the winding 13 to the heat collecting portion 16 of the cooling pipe 15. This facilitates transmission, and the cooling efficiency of the winding 13 can be greatly improved. Even if the heat collecting section 16 is made of metal, the cooling pipe 15 connected to the refrigerant flow path 16a of the heat collecting section 16 is made of an insulating material, so that the cooling pipe 15 is insulated from the ground potential. Even when the present invention is applied to a winding, sufficient insulation performance can be obtained only by applying an insulating coating to the surface of the heat collecting portion 16.

In the above embodiment, the metal heat collecting section 1
6 is configured to be in an electrically floating state. In this case, two disk-shaped winding units 13a sandwiching the heat collecting unit 16 are provided.
Of the two disk-shaped winding units 13a
Therefore, stable insulation performance can be maintained even in a transient state.

Generally, when a voltage having a steep crest, such as a lightning voltage, is applied to a winding terminal of a transformer, a non-uniform initial potential distribution increases a potential gradient at an end portion of the winding line, resulting in an increase in insulation. However, in the above embodiment, the metal heat collecting portion 16 is inserted between the disk-shaped winding units 13a, so that the static electricity between the disk-shaped winding units 13a is reduced. Since the capacitance is increased, an effect of making the initial potential distribution uniform is produced. Further, a predetermined portion of the metal heat collecting portion 16 is electrically connected to a winding line end which is a predetermined portion of the winding 13, and a potential of the heat collecting portion 16 is a predetermined potential of a winding line end portion potential. In this case, it is possible to function as an electrostatic shielding plate and to improve the initial potential distribution of the winding when a surge voltage enters.

FIG. 4 shows a second embodiment of the present invention, and the points different from the first embodiment will be described. FIG.
As shown in FIG. 7, instead of applying an insulating coating to both upper and lower surfaces of the heat collecting portion 16, a sheet 18 having an insulating property and a high thermal conductivity is attached and then inserted between the disc-shaped winding units 13a. It is configured to sandwich it. The sheet 18 is formed by mixing a heat-resistant rubber 19 made of, for example, silicone rubber or the like with a ceramic powder 20 having high thermal conductivity and insulation properties such as aluminum nitride, and molding it into a plate shape. Therefore, in the second embodiment, substantially the same operation and effect as those of the first embodiment can be obtained. In particular, in the second embodiment, insulation reliability when applied to a high-voltage winding can be further improved.

FIGS. 5 and 6 show a third embodiment of the present invention, and the points different from the first embodiment will be described. 5 and 6, a heat collecting part 21 instead of the heat collecting part 16 is formed of five metal pipes, for example, copper pipes 22 each having a rectangular cross section having a rectangular cross section and having an outer peripheral surface coated with an insulating coating. It is formed by bending the parts connected in a line so as to form a substantially U-shape as a whole. In this case, each of the five pipes 22 constitutes a refrigerant passage. As a result, the heat collecting section 21
Has a sufficient contact area with the thin tube container 12 of the disc-shaped winding unit 13a. Cooling pipes 15 are connected to both ends of the five pipes 22 via pipe connecting parts 23, 23. Therefore, in the third embodiment, substantially the same operation and effect as those of the first embodiment can be obtained.

FIG. 7 shows a fourth embodiment of the present invention. The difference from the third embodiment is that a magnetic material is interposed between metal pipes. Specifically, a configuration was adopted in which a silicon steel plate 25 was used as a magnetic material between copper pipes 24 to connect them. In this case, since the silicon steel plate 25 is provided with an insulating coating on both side surfaces (connection surfaces),
It is not necessary to use a copper pipe 24 having an insulating coating on the entire outer peripheral surface. The heat collecting section 26 thus configured is provided with an insulating coating on both upper and lower surfaces, or after attaching the sheet 18 described above,
The winding 13 is inserted between and sandwiched between the disk-shaped winding units 13a. Therefore, also in the fourth embodiment, it is possible to obtain substantially the same operation and effect as in the third embodiment.
In particular, in the fourth embodiment, most of the magnetic flux passes through the silicon steel plate 25 having high magnetic permeability, so that the eddy current loss can be reduced.

In each of the above embodiments, the heat collecting sections 16, 2
Although the metal 1 and 26 are made of metal, they may be made of ceramic (for example, aluminum nitride) having insulating properties and high thermal conductivity instead. When the heat collecting portion is made of such a ceramic, the effect of improving the initial potential distribution of the winding which obtains sufficient performance is lost, but the occurrence of eddy current loss can be prevented and the insulation reliability can be further improved. Of course, also in this case, the heat is easily transmitted from the heat radiating portion of the winding to the heat collecting portion, so that the cooling efficiency of the winding can be greatly improved.

[0030]

According to the present invention, as is apparent from the above description, the heat collecting portion of the cooling pipe is formed by arranging a metal plate having a sufficient contact area with the winding, for example, a flat plate or a plurality of metal pipes. In addition to being configured in a shape and the like, at least a portion of the cooling pipe connected to the refrigerant flow path of the heat collecting portion is formed of an insulating material, so that heat is easily transmitted from the heat radiating portion of the winding to the heat collecting portion of the cooling pipe. As a result, there is an excellent effect that the cooling efficiency of the winding can be greatly improved, and the configuration can be reduced in size and weight.

In this case, by configuring the heat collecting portion with a magnetic material interposed between a plurality of metal pipes, most of the magnetic flux can be passed through the magnetic material, and eddy current loss can be reduced. Further, by electrically connecting the metal heat collecting portion to a predetermined portion of the winding and fixing it at a predetermined potential, the metal heat collecting portion can also be used as an electrostatic shielding plate. Also, it is possible to improve the initial potential distribution of the winding when a surge voltage enters.

Further, even if the heat collecting portion of the cooling pipe is made of ceramic having both insulating properties and high thermal conductivity instead of being made of metal, the heat collecting portion of the cooling pipe can be moved from the heat radiating portion of the winding to the heat collecting portion of the cooling pipe. Heat is easily transmitted, and the cooling efficiency of the windings can be greatly improved, and sufficient insulation performance can be obtained. In this case, particularly, it is possible to prevent eddy current loss from occurring.

[Brief description of the drawings]

FIG. 1 is a perspective view of an entire winding showing a first embodiment of the present invention.

FIG. 2 is a partial longitudinal sectional view of a winding;

FIG. 3 is a perspective view of a heat collecting unit.

FIG. 4 is a view corresponding to FIG. 3, showing a second embodiment of the present invention;

FIG. 5 is a view corresponding to FIG. 3, showing a third embodiment of the present invention.

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5;

FIG. 7 is a view corresponding to FIG. 6, showing a fourth embodiment of the present invention;

FIG. 8 is a diagram corresponding to FIG. 1 showing a conventional configuration.

FIG. 9 is a diagram corresponding to FIG. 2 showing a conventional configuration.

[Explanation of symbols]

11 is an insulating tube, 12 is a thin tube container, 13 is a winding, 14
Is a spacing piece, 15 is a cooling pipe, 16 is a heat collector, 18 is a sheet, 21 is a heat collector, 22 is a pipe, 24 is a pipe,
5 is a silicon steel plate, 26 is a heat collecting part.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasufumi Nagata 1-1-1, Shibaura, Minato-ku, Tokyo Inside the head office of Toshiba Corporation (56) References JP-A-64-84699 (JP, A) JP-A-5-29783 (JP, A) JP-A-57-118613 (JP, A) JP-A-2-75716 (JP, U) JP-B-48-17806 (JP, B1) (58) Int.Cl. ⁷ , DB name) H01F 27/28

Claims (6)

(57) [Claims] 1. A winding constituted by a non-loop type thin tube heat pipe in which a working fluid is sealed in a hollow tubular thin tube container, and a heat collecting unit to be brought into close contact with a predetermined heat radiating portion of the non-loop type thin tube heat pipe. And a cooling pipe having an external heat exchanger and a refrigerant circulation pump, and configured to circulate the refrigerant inside.The heat collecting portion has a sufficient contact area with the winding by metal. A cooling structure for a static induction device winding, wherein at least a portion of the cooling pipe connected to the refrigerant flow path of the heat collecting unit is formed of an insulating material. 2. The cooling structure for a winding of a stationary induction machine according to claim 1, wherein said heat collecting section is formed in a flat plate shape. 3. The cooling structure for a winding of a static induction device according to claim 1, wherein said heat collecting section is constituted by arranging a plurality of metal pipes. 4. The stationary induction machine winding according to claim 1, wherein said heat collecting section is constituted by arranging a plurality of metal pipes and interposing a magnetic material between said metal pipes. Wire cooling structure. 5. The cooling structure for a winding of a static induction device according to claim 1, wherein said heat collecting portion is formed as an electrostatic shielding plate. 6. A winding constituted by a non-loop-type thin tube heat pipe in which a working fluid is sealed in a hollow tubular thin-tube container, and a heat collecting unit to be brought into close contact with a predetermined heat radiating portion of the non-loop type thin tube heat pipe. And a cooling pipe having an external heat exchanger and a refrigerant circulation pump, and configured to circulate the refrigerant therein.The heat collecting portion is made of ceramic having insulating properties and high thermal conductivity. A stationary induction machine characterized in that it is configured to have a shape having a sufficient contact area with a winding, and at least a portion of the cooling pipe connected to the refrigerant flow path of the heat collecting unit is formed of an insulating material. Winding cooling structure.