JP2002217041A - Cooling structure of static induction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling structure of static induction apparatus which prevents the abnormal overheating due to intrusion of a leaking flux and ensures a cold flow needed for cooling coils. SOLUTION: The cooling structure of a static induction apparatus has coils 11, 12 wound around cores 10, a plurality of refrigerant passages 16a-16d for flowing a refrigerant from below to above along the coils 11, 12, and a coil retainer board 17 disposed at the ends of the coils 11, 12. The retainer board 17 is made of a nonmetallic or nonmagnetic material and has a plurality of pass holes 18 for flowing the refrigerant into the refrigerant passages 16a-16d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cooling structure for stationary induction equipment such as a transformer and a reactor, in particular, to reduce the number of manufacturing steps, to prevent abnormal overheating due to leakage magnetic flux penetration, and to improve the coil cooling ability. The present invention relates to improvement of a cooling structure of a stationary induction device.

[0002]

2. Description of the Related Art With the recent increase in demand for electric power, stationary induction devices tend to increase in size and capacity. Under such circumstances, when the capacity of the stationary induction device increases, the amount of leakage magnetic flux increases, which increases stray loss and increases power loss. Therefore, various devices have been devised to reduce power loss. An example of a transformer as a stationary induction device will be described with reference to FIGS. FIG. 4 is a cross-sectional view of the lower structure of the transformer, and FIG. 5 is a plan view of the coil as viewed from above.
4 and 5, reference numeral 1 denotes an iron core, 2 and 3 denote low-voltage coils and high-voltage coils wound around the iron core 1, and 4 denotes a tank for storing the iron core 1, the low-voltage coil 2 and the high-voltage coil 3. Reference numeral 5 denotes a core end frame fixed to the bottom of the tank 4 and supporting the lower end of the core 1. In such a transformer, when the capacity of the transformer increases, the leakage magnetic flux generated from each of the coils 2 and 3 increases, and the tank 4 and the iron core end frame 5 increase.
Magnetic flux infiltrates into steel structures such as these, and these structures may abnormally overheat due to eddy current loss, and at the same time, stray loss increases.

In order to prevent the structure from being overheated due to the invasion of the leakage magnetic flux and to reduce the stray loss, the applicant of the present invention has described in Japanese Utility Model Publication No. 2-68618 (registered No. 2505922). (Hereinafter referred to as "proposed device"). As shown in FIG. 4, the magnetic shield 7 is divided and provided in the iron core end frame 5 immediately below the refrigerant passages 6a, 6b, 6c, 6d, and the passages 7a, 7b, 7c, 7d are provided in the magnetic shield 7. It is provided. Also,
In the core end frame 5, through holes 5a, 5b, 5c, and 5d are formed at positions corresponding to the passages 7a to 7d. With this configuration, when the refrigerant such as the insulating oil flows upward from the lower portion of the tank 4 as shown by the arrow A, the passage portion 7a
7d so as to flow substantially evenly into the refrigerant passages 6a to 6d, so that the inner coil 2 is uniformly cooled similarly to the outer coil 3.

[0004]

However, in the above-mentioned proposed device, as shown in FIG. 5, when the coils 3 for three phases are mounted on the magnetic shield 7 located below the coils, The magnetic shield 7 located at the lower part needs to be installed with high accuracy in the horizontal direction in order to stably maintain the balance of the center of gravity of the entire transformer. However, the transformer to which such a magnetic shield 7 is attached is generally a large-capacity device, and the size of the magnetic shield 7 is inevitably large, and is considerably heavy. For this reason, there is a problem that much labor is required to install the magnetic shield 7 itself with high dimensional accuracy, and that the manufacturing time for machining the same increases. Further, in order to secure the passage portions 7a to 7d and the through holes 5a to 5d for enhancing the circulation effect of the refrigerant, since the magnetic shield 7 is divided into several blocks and formed,
There is also a problem that the number of steps for assembling the magnetic shield 7 increases accordingly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and while solving the above-mentioned problems, it is intended to prevent abnormal overheating due to infiltration of leakage magnetic flux and to cool coils. It is an object of the present invention to provide a cooling structure for a stationary induction device, which can secure a cooling flow as follows.

[0006]

According to the present invention, means for solving the above-mentioned problems are as follows. (1) A cooling structure for a stationary induction device according to the present invention includes a coil wound around an iron core, a plurality of refrigerant passages for flowing a refrigerant flowing upward from below along the coil, and ends of the coil. A cooling structure for a stationary induction device having a coil pressing plate disposed in the cooling device, wherein the coil pressing plate is formed of a non-metallic and non-magnetic material, and the refrigerant flows into the refrigerant passage into the coil pressing plate. A plurality of passage holes are provided.

(2) The coil pressing plate is formed of wood.

(3) The coil pressing plate is formed of a thermosetting resin material.

(4) Further, the periphery of the passage hole is chamfered.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, the cooling structure of the stationary induction device according to the present invention will be described in detail based on the first embodiment shown in FIGS. FIG. 1 shows the first embodiment.
FIG. 2 is a schematic view of a coil holding plate used in the first embodiment, and FIG. 3 is a schematic diagram showing a relative relationship between the coil holding plate and the coil as viewed from the coil side. FIG.

In FIG. 1, reference numeral 10 denotes an iron core, 11 denotes a low-voltage coil wound around the outer periphery of the iron core 10, and 12 denotes a high-voltage coil wound around the outer periphery of the iron core 10. 13 is a tank 14
Is a core end frame fixed at the bottom of the core 10 and supporting the lower part of the iron core 10. Reference numeral 15 denotes a cooling flow guide for guiding a refrigerant such as insulating oil flowing from below the tank 14. Also,
Refrigerant passages 16a, 16b, 16c, 16d around which the refrigerant flows upward around the low-pressure coil 11 and the high-pressure coil 12
Is provided, and the refrigerant flowing into the tank 14 becomes a cooling flow shown by an arrow A, and the refrigerant passages 16a to 16d
Rises along.

Next, the coil pressing plate 17 provided at the ends of the low-voltage coil 11 and the high-voltage coil 12 will be described. The coil pressing plate 17 is made of a non-metallic and non-magnetic material, and is installed on the core end frames 13 at both upper and lower ends of the high and low voltage coils 11 and 12. As shown in FIG. 2, the coil presser plate 17 has a donut-shaped flat plate shape, and has a hollow 17 at the center thereof for installing the iron core 10.
a is provided. The coil pressing plate 17 is provided with a number of passage holes 18 for allowing the refrigerant to pass therethrough along the radial direction B of the high and low pressure coils 12 and 11, and allows the refrigerant to flow into the refrigerant passages 16a to 16d. The passage holes 18 are arranged such that the refrigerant flows evenly through the low-pressure coil 11 and the high-pressure coil 12 so that the cooling flow is not uneven, so that the two coils 11
And 12 are set to cool evenly. Note that these passage holes 18 are preferably formed in the refrigerant passages 16a.
It is preferable to provide them at positions that are aligned corresponding to 〜16d. In addition, the upper and lower ends of each passage hole 18 are provided with, for example, a rounded chamfer C so as to reduce the flow resistance loss due to the flow rate of the refrigerant.

Next, when a transformer having the above-described configuration is connected in three phases in the tank 14 to produce a stationary induction device, three iron cores 10 are installed as shown in FIG. A low-voltage coil 11 and a high-voltage coil 12 are wound around the outer periphery of the iron core 10, and a donut-shaped coil pressing plate 17 is provided on each of the iron core end frames 13 that support the lower part of each iron core 10. At this time, since each coil pressing plate 17 may be adjusted so as to maintain horizontal accuracy for each transformer, the horizontal balance of the stationary induction device as a whole can be easily adjusted and incorporated. In the cooling structure of the stationary induction device thus configured, since the coil holding plate 17 is provided with a large number of passage holes 18 having a flow cross-sectional area between the coils 11 and 12, a predetermined flow velocity can be secured. The shown cooling flow passes through the passage holes 18 and flows into the refrigerant passages 16a to 16d around the coils 11 and 12, thereby suppressing the temperature rise of each of the coils 11 and 12.

As described above, according to the first embodiment of the present invention, when a stationary induction device for connecting three-phase transformers is manufactured, the coil presser plate 17 is provided between three transformers as in the proposed device. Unlike the magnetic shield 7 provided over the coil, the coil pressing plate 17 is provided separately for each transformer, so that the horizontal accuracy of the coil pressing plate 17 can be easily increased, and the horizontal accuracy is improved. Can be installed in state. In addition, since the coil holding plate 17 is small, the manufacturing time required for it can be significantly reduced,
Further, a passage hole 18 communicating with the refrigerant passages 16a to 16d is formed.
Since the magnetic shield 7 can be easily formed simply by piercing the coil holding plate 17, unlike the case of the above-described proposed device in which the magnetic shield 7 is divided for each block, the number of assembling steps does not increase accordingly.

Further, since the coil pressing plate 17 is made of a non-metallic and non-magnetic material, the coil pressing plate 17 is different from the one formed by the magnetic shield 7 as in the above-mentioned proposed device, in that the coil pressing plate 17 is made of both coils 11. And 12 and core end frame 1
3, there is no need to set the insulation distance between the coils 11 and 12 large, so that the stationary induction device can be prevented from having a large shape. Furthermore, the use of a non-magnetic material prevents eddy current loss due to infiltration of leakage magnetic flux from the coils 11 and 12, so that the coil holding plate 17 and the core end frame 1
3. It has an effect that abnormal overheating of structures such as the coils 11 and 12 and the tank 14 can be suppressed and an increase in stray loss can be prevented. Further, since a large number of passage holes 18 through which the refrigerant passes are provided in the coil holding plate 17 along the radial direction of the low-pressure coil 11 and the high-pressure coil 12,
And 12 can be cooled efficiently. In addition, since the chamfer C is provided at the periphery of each passage hole 18, the flow resistance of the refrigerant is reduced, and the cooling effect is accordingly increased.

Embodiment 2 In the second embodiment, the coil pressing plate 17 is made of, for example, wood such as a birch material, and the other configuration is the same as that of the first embodiment. With such a configuration, there is an effect that processing becomes easy, weight can be reduced, and a low-cost cooling structure for stationary induction equipment can be obtained.

Embodiment 3 In the third embodiment, the coil pressing plate 17 is formed by using a thermosetting resin laminate such as a glass cloth base epoxy resin, and the other configuration is the same as that of the first embodiment. Things. By adopting such a configuration, there is an effect that a cooling structure for a static induction device that is excellent in high heat resistance and workability and exhibits extremely excellent performance in high dimensional stability can be obtained.

Although the present embodiment has been described in detail, the specific configuration is not limited to this embodiment.
Even a design change or the like within a range not departing from the gist of the present invention is included in the present invention. For example, in Embodiments 1 to 3,
Although the case where three single-phase transformers are arranged and three-phase connected has been described, it is needless to say that the present invention is not limited to this. For example, one transformer may be used alone, or three single-phase transformers may be combined into one.
It can also be applied to a phase transformer, in which case it can be formed using only one coil presser plate 17 as shown in FIG. In addition, a chamfer C formed on the periphery of the passage hole 18
Is preferably provided on the peripheral edges of the upper and lower surfaces of the coil holding plate 17, but may be provided on the peripheral edge of any one of the surfaces as necessary.

[0019]

As described above, the effects of the cooling structure of the stationary induction device of the present invention are as follows. (1) A cooling structure for a stationary induction device according to the present invention includes a coil wound around an iron core, a plurality of refrigerant passages for flowing a refrigerant flowing upward from below along the coil, and ends of the coil. A cooling structure for a stationary induction device having a coil pressing plate disposed in the cooling device, wherein the coil pressing plate is formed of a non-metallic and non-magnetic material, and the refrigerant flows into the refrigerant passage into the coil pressing plate. A plurality of passage holes are provided. Therefore,
Unlike the case where a magnetic shield is provided across the transformers, the coil holding plate is provided separately for each transformer, so it is easy to increase the horizontal accuracy of the coil holding plate, and the horizontal accuracy can be increased. It works. In addition, since the coil holding plate is small, the manufacturing time can be significantly shortened accordingly, and the magnetic shield is provided for each block by a simple configuration in which the passage hole leading to the refrigerant passage is simply drilled in the coil holding plate. Differently from the divided ones, it is possible to avoid an increase in the number of assembling steps.

Further, since the coil holding plate is made of a non-metallic and non-magnetic material, the coil holding plate is different from the one formed by the magnetic shield 7 as in the above-mentioned proposed device. It is not necessary to set the insulation distance between the coil and the coil large, so that an increase in the size of the stationary induction device can be avoided. Furthermore, the use of a non-magnetic material does not cause eddy current loss due to infiltration of leakage magnetic flux from the coil, so that abnormal overheating of structures such as the coil holding plate 17, the iron core end frame, the coil, and the tank can be suppressed. In addition, there is an effect that an increase in stray loss can be prevented. Further, since a large number of passage holes through which the refrigerant passes are provided in the coil holding plate along the radial direction of the low-voltage coil and the high-voltage coil, the coil can be efficiently cooled.

(2) Since the coil holding plate is formed of wood, the workability is improved, the weight is reduced, and a low-cost cooling structure for stationary induction equipment is obtained. be able to.

(3) Further, since the coil holding plate is formed of a thermosetting resin material, it has high heat resistance, excellent workability, and high dimensional stability. It is possible to obtain a cooling structure for a stationary induction device that exhibits extremely excellent performance.

(4) Further, since the periphery of the passage hole is chamfered, the flow resistance of the refrigerant flowing into the passage hole can be reduced, and the cooling efficiency of the coil can be improved accordingly.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a cooling structure of a stationary induction device according to Embodiment 1 of the present invention.

FIG. 2 is a schematic diagram of a coil holding plate used in Embodiment 1 of the present invention.

FIG. 3 is a schematic plan view showing a relative relationship between the coil presser plate and the coil as viewed from the coil side according to Embodiment 1 of the present invention.

FIG. 4 is a cross-sectional view of a conventional device (proposed device).

FIG. 5 is a schematic plan sectional view of the conventional device as viewed from above.

[Explanation of symbols]

10 iron core, 11 low voltage coil, 12 high voltage coil, 1
3 core end frame, 14 tanks, 16a-16d refrigerant passage, 17 coil holding plate, 18 passage hole, A cooling flow,
B radial direction, C chamfer.

Claims (4)

[Claims] 1. A coil wound around an iron core, a plurality of refrigerant passages through which a refrigerant flowing upward from below along the coil is provided, and a coil pressing plate disposed at an end of the coil. A cooling structure for a stationary induction device, wherein the coil pressing plate is formed of a non-metallic and non-magnetic material, and the coil pressing plate is provided with a plurality of passage holes through which the refrigerant flows into the refrigerant passage. Features a cooling structure for stationary induction equipment. 2. The cooling structure for a stationary induction device according to claim 1, wherein said coil holding plate is made of wood. 3. The cooling structure for a stationary induction device according to claim 1, wherein said coil holding plate is formed of a thermosetting resin material. 4. The cooling structure for a stationary induction device according to claim 1, wherein a peripheral edge of said passage hole is chamfered.