JPH09162040A - Winding of transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the size of the whole of a winding, by making the reduction of the temperature rise of the winding surely possible. SOLUTION: In an inside vertical duct 4, the space portion between a flow control protrusion 10 and a transformer winding 1 is made narrower and smaller than other portions to reduce the flow rate and flow velocity of an SF6 gas, and since by the flow control protrusion 10 the SF6 , gas is dispersed toward horizontal ducts 5 of the side of an opposite unit winding 3 to the protrusion 10 to make the nearly uniform flow-through of the SF6 gas in respective unit windings 3 of the transformer winding 1 possible, the respective unit windings 3 can be cooled uniformly. Therefore, a large quantity of gas flow in only one portion can be prevented, making the uniform and efficient cooling of the whole of the transformer winding 1 possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for improving the cooling performance of a winding formed by winding a disk-shaped unit winding in a tubular shape or a winding formed in a spiral shape in a transformer. It relates to a transformer winding suitable for cooling the winding with SF ₆ gas.

[0002]

2. Description of the Related Art In the case of transformers installed in cities, there is a strong demand for non-combustible transformers for disaster prevention, and there is also a strong demand for larger capacity and smaller size. A non-flammable cooling medium is used inside the transformer, but in recent years, SF ₆ gas is often used. Since the SF ₆ gas has smaller physical properties regarding cooling performance such as density, specific heat, and thermal conductivity than the liquid insulating cooling medium, it has poor cooling performance and also has low dielectric strength.
For this reason, a large volume flow rate of SF ₆ gas, which is a cooling medium, is caused to flow, while the insulation distance in the transformer winding is increased.

By the way, as a structure of a general transformer winding, a unit winding is formed around the iron core by forming the disk into a disk shape, and the unit winding is formed into a cylindrical shape.
Alternatively, there is a helical winding formed in a spiral shape. In the case of such a tubular winding or helical winding, insulating cylinders are provided on the inner circumference side and the outer circumference side in the radial direction of the winding, and vertical spacers are arranged along the insulating cylinder. A vertical duct is provided between the lines.

Further, in the case of a tubular winding, horizontal spacers are inserted at each stage of the winding in the axial direction of the winding, and a horizontal duct is formed between the horizontal spacer and the winding at each stage. Meanwhile,
A plurality of folding plates are alternately inserted along the axial direction of the winding to form a split region, and the cooling medium follows the axial flow and the radial flow in the winding is different for each split region. There are some that are configured to alternate.

In such a transformer, if the volumetric flow rate of the cooling medium is large and the horizontal duct in which the cooling medium flows has a large cross-sectional area, a large amount of the cooling medium flows in the upper horizontal duct in the flow break area, while the cooling medium flows downward. There is little flow in the horizontal duct of the section.
Therefore, there is a large difference in the temperature rise distribution of the winding, and the maximum temperature rise rate of the winding tends to be higher than the average temperature rise rate of the winding. Due to this tendency, various conventional techniques for improving the flow of the cooling medium in the winding have been proposed and put to practical use.

For example, Japanese Patent Application Laid-Open No. 4-168707 (hereinafter referred to as the first prior art) discloses a vertical duct having an inner peripheral side and an outer peripheral side and having a vertical inner peripheral side along an insulating cylinder. It is configured to have a specific width for the duct. In addition, JP-A-52-43937 and JP-A-5-43937.
Nos. 3-40820 and 54-34025 (hereinafter referred to as the second prior art) are provided with a vertical duct, and the center between the inner circumference side and the outer circumference side of the winding in the radial direction. Holes larger than the upper and lower windings are provided in the vicinity, and the vertical duct as a whole is configured with wide ducts along the axial direction at every other stage, and the vertical duct radial dimension and position are wound. The vertical duct as a whole is formed in a zigzag shape along the axial direction by making each stage different.

[0007]

However, none of the above-mentioned prior arts considers the following points.

That is, in the first prior art in which the radial width of the vertical duct is increased, a large amount of the cooling medium flows in the vertical duct on the inner peripheral side along the insulating tube among the vertical ducts, while the space between the windings is increased. Since the flow rate of the cooling medium flowing in the horizontal duct is relatively small, and the flow rate of the cooling medium becomes non-uniform, there is a problem that the efficiency of reducing the temperature rise of the winding is small.

In the second prior art, since the vertical duct in the vicinity of the center of the winding radius is formed in zigzag, the dimension of the entire winding in the radial direction is increased by the amount of the zigzag vertical duct. Have to be big,
Therefore, there is a problem that the volume of the entire transformer becomes large. This problem is particularly important in transformers installed in large cities, because there is a strong demand for miniaturization as described above. Also, when a zigzag vertical duct is provided,
Since the number of branching and merging points increases in the flow of the cooling medium, the pressure loss of the cooling medium increases correspondingly, and the flow rate of the cooling medium decreases, so that the cooling efficiency is unfavorable or the means for circulating the cooling medium has a large capacity. There is a problem that things are needed.

In view of the above-mentioned problems of the prior art, an object of the present invention is to make the flow rate distribution of gas flowing in each duct uniform and to locally overheat the winding even if SF ₆ gas is used as a cooling medium. Can be reliably prevented, and the temperature rise distribution of the winding can be made uniform, so that the temperature rise of the winding can be surely reduced, and the entire winding is surely secured. It is to provide a transformer winding that can be miniaturized.

[0011]

According to the present invention, the insulating cylinder on the inner peripheral side and the insulating cylinder on the outer peripheral side are arranged along the axial direction and are defined between the insulating cylinder on the inner peripheral side. An outer vertical duct defined between the inner vertical duct and the outer insulating cylinder, and a horizontal duct defined between the unit windings of each stage and connecting the inner and outer vertical ducts. , The inner and outer insulating cylinders are alternately mounted along the axial direction with a desired number of unit windings separated from each other to form bent flow areas, and the tip and the inner and outer insulating cylinders are separated from each other. And a plurality of bent plates that alternately form the inflow and outflow portions of the cooling medium in the axial direction between them, and the winding for transformer that allows the cooling medium to flow in the zigzag shape along the axial direction in each of the bent regions. In each of the flow diverted areas, the inflow and outflow for the cooling medium to flow into either the insulating cylinder on the outer peripheral side And a flow control protrusion arranged on the same side as the flow control protrusion, the flow control protrusion restricts the flow rate of the cooling medium flowing into each of the flow diverting areas along the inner and outer vertical ducts, and part of the cooling medium, It is characterized in that the flow rate is controlled so as to be directed in a desired unit winding direction.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 to 5 show a first embodiment of a transformer winding according to the present invention. The transformer winding 1 of the embodiment shown in FIG. 1 is formed between an inner peripheral insulating cylinder 2 and an outer peripheral insulating cylinder 2'in the axial direction. In this transformer winding 1, a unit winding 3 is formed by winding a strand of wire in a disk shape in this example, and a plurality of the unit windings 3 are formed in the axial direction to form a cylinder. Although the shaped winding is formed, a helical winding formed in a spiral shape may be formed. Then, the space between the insulating cylinder 2 on the inner circumference side and the inner circumference of the transformer winding 1 and the vertical spacer 9 shown in FIG. 2 defines the inner vertical duct 4 and the outer circumference of the transformer winding 1. A space between the outer peripheral insulating cylinder 2'and a vertical spacer (not shown) defines an outer vertical duct 4 ', and a horizontal spacer (not shown) is inserted between the unit windings 3 so that A horizontal duct 5 is defined between the unit windings 3. The vertical spacers 9 that define the inner vertical ducts 4 are
As shown in FIG. 2, a plurality of insulating cylinders 2 on the inner peripheral side are arranged at appropriate intervals and along the axial direction, but a plurality of outer vertical ducts 4 ′ which are not shown are formed. As with the vertical spacers 9, a plurality of vertical spacers are arranged on the inner peripheral portion of the insulating cylinder 2'on the outer peripheral side at appropriate intervals and along the axial direction.

In addition, a plurality of folding plates 6 are attached to the insulating cylinder 2 on the inner peripheral side and the insulating cylinder 2'on the outer peripheral side in a staggered manner along the axial direction. The plurality of flow distribution plates 6 are thin plates formed in an annular shape, and when attached to the inner peripheral insulating cylinder 2, for example, the inflow / outflow portion 7b is provided between the tip of the inner flow insulating plate 2 and the outer peripheral insulating cylinder 2 '. , 7d, and when attached to the outer peripheral insulating cylinder 2 ', the inflow / outflow portions 7a, 7c are formed between the tip of the outer peripheral insulating cylinder 2'and the inner peripheral insulating cylinder 2'.

More specifically, referring to FIG. 1, for example, when the first folding plate 6a is horizontally attached to the lower portion of the insulating cylinder 2'on the outer peripheral side, the tip of the folding plate 6a and the inner periphery thereof are arranged. An inflow / outflow portion 7a is formed between the side insulating cylinder 2 and the side insulating cylinder 2. In addition, by attaching the second folding plate 6b to the insulating cylinder 2 on the inner peripheral side at a position above the first folding plate 6a and beyond the unit windings 10 of 10 stages, An inflow / outflow portion 7b is formed between the flow fold plate 6b and the outer peripheral insulating cylinder 2 '. Then, at a position above the second folding plate 6b and beyond the unit winding 3 of 10 steps, the third folding plate 6c is attached to the outer peripheral insulating cylinder 2 ', so that An inflow / outflow portion 7c is formed between the flow plate 6c and the inner peripheral insulating cylinder 2, and the inner peripheral insulating cylinder 2 beyond the ten unit windings 3 from the third folding plate 6c. Since the fourth folding plate 6d is attached to the front end of the folding plate 6d and the outer peripheral insulating tube 2 '.
An inflow / outflow portion 7d is formed between and. Each break area 8a ~
The inflow / outflow portions 7a to 7d provided in the lower portion of 8c are for the SF ₆ gas to flow into each of the flow-flow areas 8a.

Therefore, when the folding plates 6a to 6d are provided alternately in the inner peripheral insulating cylinder 2 and the outer peripheral insulating cylinder 2'in the axial direction, they serve as a cooling medium from the lower side to the upper side. When the SF ₆ gas is supplied, the SF ₆ gas passes through the inflow / outflow portion 7a on the side of the first flow fold plate 6a, and flows through the flow fold plate 6a.
And the second folding plate 6b, which is the region of the folding region 8a, passes through the inner vertical duct 4, the horizontal duct 5, and the outer vertical duct 4'in the folding region 8a, and proceeds upward. Then, it passes through the inflow / outflow portion 7b on the side of the second folding plate 6b, enters the folding region 8b which is the region between the folding plate 6b and the third folding plate 6c, and inside the folding region 8b. By passing through the outer vertical duct 4 ′, the horizontal duct 5 and the inner vertical duct 4 and going further upward, and similarly passing through the upper bent region 8 c as well, SF ₆ gas respectively flows in the bent regions 8 a to 8 a. 8c
Are circulated in a zigzag shape in the axial direction, thus cooling the surface of the unit winding 3 to cool the entire transformer winding 1.

That is, this transformer winding is arranged axially between the inner peripheral insulating cylinder 2 and the outer peripheral insulating tube 2 ', and between the inner peripheral insulating cylinder 2 and the inner peripheral insulating cylinder 2'. The inner vertical duct 4 defined between the outer vertical duct 4'and the outer vertical duct 4'defined between the outer peripheral insulating tube 2'and the unit winding 3 of each stage, and The horizontal duct 5 communicating with the outer vertical ducts 4 and 4'and the insulating cylinders 2 and 2'on the inner and outer peripheries are alternately mounted with unit windings of a desired number of stages separated from each other and along the axial direction. And a plurality of folding plates 6a to 6d for forming the inflow / outflow portions 7a to 7d of SF ₆ gas alternately in the axial direction between the inner and outer insulating cylinders 2 and 2 '. The flow plates 6a to 6d form a flow-flow area between the flow-flow plates adjacent to each other, and the SF ₆ gas is axially formed in each flow-flow area. Is configured to be distributed in a zigzag shape.

It should be noted that description of means for supplying SF ₆ gas from the lower side to the upper side of the transformer winding 1 for circulation is omitted.

Therefore, the inner and outer insulation cylinders 2 and 2'of each of the flow-divided zones 8a to 8c are on the same side as the lower inflow / outflow portion for the SF ₆ gas to flow in, and are specified. Flow control projection 1 arranged at a position facing the unit winding 3 of
0 is attached.

More specifically, the flow control protrusion 10
As shown in FIGS. 1 and 2, each has a triangular shape whose top portion is arranged to face the unit winding 3. The flow control protrusion 10 is made of a material that does not affect the magnetic lines of force and current generated by the winding and is not deteriorated by SF ₆ gas as a cooling medium, for example, tetrafluoroethylene / hexafluoro. It is composed of a propylene copolymer (FEP).

Further, each of the flow control projections 10 has inflow / outflow portions 7a to 7 to which SF ₆ gas is to flow in in each of the flow fold regions 8a to 8c of the inner and outer insulating cylinders 2 and 2 '.
It is a position on the same side as c, for example, each of the flow-bending areas 8a-8
It is arranged at a position facing the unit winding 3 of the fourth stage in c. In that case, as shown in FIG. 3, the flow control projection 10 has both ends mounted between the vertical spacers 9 and 9, and the bottom portion 10a is closely attached to the inner and outer insulating cylinders 2 and 2 '. Moreover, the top part thereof faces the unit winding 3 of the fourth stage.

In each of the flow control protrusions 10a to 10c, the SF ₆ gas inflow / outflow portion 7 of each of the flow diverting sections 8a to 8c is supplied.
When the SF ₆ gas flows from the a, 7b, and 7c into each of the flow diverting sections 8a to 8c, the SF ₆ gas flows along the outer vertical ducts 4 and 4 ′ at the position of the inflow, but the top of the flow control protrusion 10 Since a part of the inner and outer vertical ducts 4 and 4 ′ is narrowed between the unit winding 3 and the unit winding 3 which faces this,
SF ₆ with Filter flow rate of the gas, SF by flowing along the ₆ inlet-side slope portion 10b of the control projection 10 gas flows, SF ₆ unit winding 3 of one step below the unit winding 3 gas fourth stage The dispersion is controlled so as to face the horizontal ducts 5a above and below.

Therefore, each of the flow control protrusions 10 narrows a part of the inner and outer vertical ducts 4 and 4'at the top and the unit winding 3, and SF ₆ along the inflow side slope 10b. It has a triangular shape so that the flow direction of the gas can be controlled in a distributed manner, and its size is slightly different depending on the flow rate of SF ₆ gas and the size of the components of the transformer winding 1, but in this example, When the horizontal width of the outer vertical ducts 4 and 4'is 20 mm, the bottom portion 10a and the inflow side slope portion 10b
The angle between the bottom side 10a and the outflow side slope 1 is 45 degrees.
The angle with 0c is 30 degrees, and the height is the ducts 4, 4 '
The width is approximately 1/3 of the width.

Since the transformer winding 1 of the embodiment has the above-mentioned structure, its operation will be described below.

Now, as shown in FIG. 1, the SF ₆ gas is supplied from below to cause the SF ₆ gas to flow into the lower inflow / outflow portion 7
When entering the first-stage flow divergence area 8a from a, the SF ₆ gas rises in the inner vertical duct 4 along the insulating cylinder 2 on the inner peripheral side, while part of the SF ₆ gas is between the unit windings 3. Each unit winding 3 is cooled by reaching the outer insulating cylinder 2'through the horizontal duct 5. In addition, S from the first-stage fold area 8a
When the F ₆ gas enters from the upper inflow / outflow portion 7b to the second-stage fold flow area 8b, the F ₆ gas rises in the outer vertical duct 4 ′ along the outer peripheral insulating tube 2 ′, while a part of each unit Each unit winding 3 is cooled by reaching the inner insulating tube 2 through the horizontal duct 5 between the windings 3. This cooling action is performed every time the SF ₆ gas flows into each of the flow diverting sections 8a to 8c.

In the prior art in which the flow control projection 10 is not provided during the cooling, as shown in FIG. 4, the SF ₆ gas which has flowed into the flow diverting area 8a follows the inner vertical duct 4 along the insulating cylinder on the inner peripheral side. The rising SF ₆ gas is
In the width direction of the inner vertical duct 4, the flow velocity is large at the portion closest to the insulating cylinder on the inner peripheral side, and the flow velocity is significantly reduced as the distance from the insulating cylinder increases. Therefore, SF flowing from the flow fold plate 6a into the horizontal ducts 5 above and below the unit winding 3 of the third stage in the flow fold area 8a.
Compared with the flow velocity at the inflow / outflow part 6a, the flow velocity of ₆ gas is 1 /
Since it is 10 or less and is almost stagnant, the temperature of the unit winding 3 of the third stage, the fourth stage, and the second stage is remarkably increased, and there is a problem that the winding locally overheats.

In the prior art, as shown in FIG.
On the side of the unit windings of the sixth and ninth stages existing above the unit windings of the second to fourth stages, the flow velocity of SF ₆ gas decreases as the distance from the insulating cylinder 2 on the inner peripheral side increases. Since the flow velocity on the side of the horizontal duct 5 located above and below the unit winding 3 in the third stage is higher, more SF ₆ gas flows into the horizontal duct toward the upper part in each of the flow diverting sections 8a to 8c. Becomes Therefore, in the prior art, as shown by the white circles in FIG. 5, the cooling effect was higher toward the upper part in each of the flow-flow areas 8a to 8c.

However, in the embodiment, since the flow control protrusion 10 is arranged in the inner vertical duct 4, the SF ₆ gas which has risen in the inner vertical duct 4 during the cooling is arranged in the inner vertical duct 4. When reaching the flow control protrusion 10, the space portion of the inner vertical duct 4 between the flow control protrusion 10 and the transformer winding 1 is narrower than the other portions, so that the flow amount and the flow rate are reduced. At this time, at the same time, the SF ₆ gas flows along the inflow side slope 10b of the flow control protrusion 10 to cause the flow control protrusion 10 to flow.
Flow toward the unit winding 3 side facing the
The F ₆ gas is lower than the unit winding 3 facing the flow control protrusion 10 in the vertical direction of the unit winding 3, that is, to the horizontal ducts 5a and 5b side above and below the unit winding 3 in the third stage, In FIG. 1, the flow flows from the left to the right, and the flow becomes a relatively fast flow along the inflow side slope 10b of the flow control projection 10 into the horizontal duct 5. Multiple unit windings 3 in the vicinity
Can be cooled evenly. That is, since SF ₆ gas rapidly flows through the horizontal ducts 5a and 5b above and below the unit winding 3 of the third stage, as shown by black circles in FIG.
It is possible to effectively cool the unit windings 3 of the stage, and it is possible to cool each of the unit windings 3 in each of the bent-flow sections 8a to 8c substantially uniformly.

As a result, in the inner vertical duct 4, as described above, the space between the flow control projection 10 and the transformer winding 1 becomes narrower than the other portions, so that the flow rate and flow velocity of SF ₆ gas are reduced. In addition, the flow control projection 10 causes the horizontal duct 5 on the side of the unit winding 3 that faces the flow control projection 10 to be S-shaped.
Since the F ₆ gas can be dispersed and the SF ₆ gas can flow through the unit windings 3 of the transformer winding 1 almost uniformly, the unit windings 3 can be cooled evenly, and therefore It can be prevented that a large amount of gas flows only in a part as in the conventional technique, and the entire transformer winding 1 can be cooled uniformly and efficiently.

Further, since the width of the vertical duct is not increased or the gas duct having the different width for each stage is not provided at the middle position in the radial direction of the unit winding as in the second prior art, The size of the transformer winding 1 does not increase, and it is possible to prevent the volume of the entire transformer from increasing, and thus it is possible to meet the demand for miniaturization. Besides, inside,
By outer vertical ducts 4,4 'and the horizontal ducts 5 other duct is not required, there is no branching point to the flow of SF ₆ gas, therefore, it is possible to avoid an increase in pressure loss of the SF ₆ gas, It is not necessary to use a large SF ₆ gas supply means.

Further, when the flow control protrusion 10 is provided,
As described above, since the space portion of the inner vertical duct 4 between the flow control protrusion 10 and the winding transformer winding 1 is narrower than the other portions, the flow velocity is reduced by being narrowed down. There is no problem because it is sufficient for cooling the winding.

Incidentally, FIG. 5 shows the data obtained by the test device regarding the relationship between each unit winding and the temperature rise in the bent-flow area. The test apparatus in this case is composed of a container accommodating the transformer shown in FIG. 1, a cooler for SF ₆ gas and a blower as its supply means, various measuring instruments, piping, etc.
It is configured to circulate ₆ gases. Transformer winding 1
As a conductor, a heater and a thermocouple are embedded in a copper wire having a width of 6 mm and a height of 15 mm, and an insulating film is wound around the copper wire to form a simulated conductor. It was configured by providing 10 stages for each of the flow break areas. The flow path length (horizontal direction) of the winding is 80 mm, the height of the horizontal duct is 4 mm, and the width of the inner / outer peripheral vertical duct is 20 mm.

As such transformer windings, an embodiment having the flow control protrusion 10 having the above-described size and a conventional one having no flow control protrusion 10 were manufactured. The test method was performed by supplying a predetermined current to a heater embedded in the simulated conductor to generate heat, circulating SF ₆ gas with a blower, and measuring the temperature of the simulated conductor. However, the pressure of SF ₆ gas is 0.2 MPa, and the heat generation density of the winding is 107 kW / m ³ .

In FIG. 5, the horizontal axis represents the average temperature rise of each simulated unit winding from the gas temperature at the inflow and outflow of the lower folding area, and the horizontal axis was sequentially arranged on the lowermost folding plate. Shows the position of the unit winding. The white circles shown in the same figure are the prior art without flow control projections, and the black circles are the embodiments with flow control projections. In the embodiment, the maximum temperature rise of the winding is reduced by about 25% compared to the prior art. In addition, it was possible to reduce the variation in temperature rise in each unit winding by about 60%. In addition, in this test, the flow control protrusion 10 was set to FEP with a relative dielectric constant of 2.2.
It was confirmed that the electric field concentration that would lead to dielectric breakdown does not occur even when a high voltage is applied to the winding when manufactured in.

FIGS. 6 and 7 show a second embodiment of the transformer winding according to the invention. This embodiment is applied to the one in which the width dimension of the inner vertical duct 4 and the outer vertical duct 4'is double that of the first embodiment.

That is, when the widths of the inner and outer vertical ducts 4 and 4'are large, the flow of SF ₆ gas as a cooling medium is different from that in the first embodiment, and the unit winding 3 closest to the flow diverting plate 6a is formed. In the surrounding upper and lower horizontal ducts 5, the flow velocity becomes 1/10 or less of the flow velocity at the inflow / outflow portion 7a, and almost stagnates.
In the horizontal duct 5 located above the horizontal duct 5 closest to the unit winding 3, the flow velocity becomes large, resulting in a non-uniform state in which the flow flows from the left side to the right side in FIG. Therefore, there is a problem that the temperature increases in the unit winding 3 close to the inflow / outflow portion 7a, as indicated by a white circle in FIG.

Therefore, in this embodiment, the flow flows to a position facing the unit winding 3 on the inflow / outflow portion 7a side of the flow diverting section 8a, for example, a position facing the second unit winding 3 in the inner vertical duct 4. A control protrusion 10 is arranged. The flow control projection 10 in this case is made of the same material as that of the first embodiment and has a similar shape, but the height thereof is ½ of the width of the inner and outer vertical ducts 4, 4 '. And, the break area 8
In a, when the SF ₆ gas flows through the inner vertical duct 4, the flow control protrusion 10 and the unit winding 3 facing the flow control protrusion 10 are provided.
By narrowing the flow rate of the SF ₆ gas between them, the flow rate and the flow velocity of the SF ₆ gas flowing thereabove are reduced, and the inflow side slope portion 10b of the flow control projection 10 reduces the flow rate of the second-stage unit winding 3. vertical position of course the horizontal duct 5 which is in, by actively shunt the SF ₆ gas to the horizontal duct 5 between the first-stage unit winding 3 and the folding flow plate 6a, SF ₆ gas It flows almost uniformly between each unit winding 3,
The uniform cooling effect is obtained.

The effect is as shown in FIG. That is, FIG. 7 corresponds to FIG. 5 and shows the test results of the relationship between each unit winding and the temperature rise in the lowermost fold-flow area. The test conditions in this case were that the pressure of SF ₆ gas was 0.6 MPa, and the heat generation density of the unit winding was 496 kW /
In m ^3, the flow path length of the unit winding 3 (horizontal direction) is 147m
m, the height of the horizontal duct is 4.5 mm, and the inner and outer vertical ducts are 40 mm as described above. In FIG. 7, white circles represent the prior art without flow control projections, and black circles represent the embodiment with flow control projections,
In the embodiment, the maximum temperature rise of the unit winding 3 can be reduced to about 23%, and the variation in the temperature rise in each unit winding can be reduced to about 69%, as compared with the prior art.

In the illustrated embodiment, the innermost vertical duct 4 has only the lowermost flow fold section 8a having the flow control projections 10, but the flow control projections 10 have other flow fold areas 8a.
It may be provided also in b and 8c, or may be provided only in a desired fold section, and the point is that it may be provided in a necessary place.

Further, in the following embodiments shown in FIGS. 8 to 10,
Only the lowermost fold section 8a in which the flow projections 10 are arranged in the inner vertical duct 4 is shown, but other fold sections 8b,
8c has the same configuration.

FIG. 8 shows a third embodiment, in this case a flow control projection 10 arranged in the inner vertical duct 4.
However, the insulating cylinder 2 on the inner peripheral side and the narrow flow passage 11 are attached to each other. That is, although the flow control projection 10 is not shown in detail, both ends of the flow control projection 10 are on the inner peripheral side of the insulating cylinder 2.
Is mounted on the vertical spacers 9 fixed to the vertical spacers 9 and the vertical spacers 9 adjacent to the vertical spacers 9.
And a narrow channel 11 is separated. And the flow control protrusion 1
The flow rate of SF ₆ gas is narrowed by the top of 0 and the unit winding 3 facing this, while the SF ₆ gas is circulated through the narrow channel 11 and the gas flow rate is increased above the flow control protrusion 10. The unit winding located above is cooled more efficiently.

When the unit windings 3 are provided in a plurality of stages, the temperature of the upper unit windings may be higher than that of the lower unit windings due to the heat generation of the lower unit windings 3. However, as in the embodiment, when the flow rate of the SF ₆ gas is increased above the flow control protrusion 10, the temperature of the unit winding 3 located above the flow control projection 10 rises due to heat generation of the unit winding below the unit winding 3. This has the effect of preventing each of the unit windings 3 and cooling the unit windings 3 more uniformly.

FIG. 9 shows a fourth embodiment. That is,
In this case, as the flow control protrusion, the flow control protrusion 10 formed in substantially the same manner as the embodiment of FIG. 6 is provided, and the flow control protrusion 12 is also provided on the upstream side thereof.

The upstream flow control projection 12 is located upstream of the original flow control projection 10 in the insulating cylinder 2 on the inner peripheral side, and is located one step lower than the flow fold plate 6a.
It is attached so as to face with, and its height is about 1/4 of the inner vertical duct 4. When the SF ₆ flows inside vertical duct 4, the SF ₆ gas, by flowing along the inlet-side slope portion 12b of the flow control projection 12,
The first-stage unit winding 3 is actively cooled by flowing into the horizontal duct 5 between the folding plate 6a and the first-stage unit winding 3 arranged thereon.

Therefore, in this embodiment, the flow control projection 10
Not only that, but if another flow control protrusion 12 is provided,
It is possible to positively cool the unit winding 3 of the first stage closest to the flow distribution plate 6a, and the flow rate of SF ₆ gas to the horizontal duct 5 between the unit winding 3 of the first stage and the flow distribution plate 6a. Is increased, the gas flow rate to the outer vertical duct 4'on the opposite side of the inner vertical duct 4 is also increased, so that the cooling effect of the second and third unit windings 3 can be further enhanced. Therefore, in the test results shown in FIG. 7, the temperature increase rate of the unit windings of the first to third stages was slightly higher than that of the other unit windings. The temperature rise of the unit windings 3 can be further reduced, and the temperature of each of the unit windings 3 in one bent region can be reduced more evenly and efficiently.

According to the test results, the maximum temperature rise of the winding can be reduced to about 28%, and the variation in temperature rise of each unit winding can be reduced to about 78%. It is clear that this value is even more effective than the embodiment of FIG. 6 in which only one flow control protrusion 10 is provided.

FIG. 10 shows a fifth embodiment. This embodiment is a modification of the first embodiment, and includes the flow fold area 8
In addition to the flow control protrusion 10 provided at a position facing the fourth-stage unit winding 3 in a, the horizontal between the fourth-stage unit winding 3 and the fifth-stage unit winding 3 above it. In the duct 5a,
A flow dividing plate 13 is provided. The flow distribution plate 13 has an appropriate plate width, is attached to a horizontal spacer (not shown), and is arranged so that one end in the width direction projects into the inner vertical duct 4. In this case, the dimension at which one end of the flow dividing plate 13 projects is ⅕ of the width of the inner vertical duct 4.

When the flow control protrusion 10 is provided, the flow rate of the SF ₆ gas flowing into the horizontal duct 5c immediately above the unit winding 3 of the fourth stage opposite thereto is greater than that of the gas passing through other horizontal ducts. It may drop slightly. However, when the flow dividing plate 13 is provided as described above, the SF ₆ gas that has passed through the flow control projection 10 flows between the flow dividing plate 13 and the unit winding 3 of the fourth stage, and the SF ₆ gas that passes through the horizontal duct 5c thereof. The flow rate can be increased. Therefore, the flow control protrusion 10
Since the flow rate of SF ₆ gas to the horizontal duct 5c immediately above can be increased, the unit windings 3 can be cooled more uniformly.

The test result shows that the maximum temperature rise of the windings can be reduced by about 30% and the variation in the temperature rise in each unit winding 3 can be reduced to about 70% as compared with the conventional technique.
It was confirmed that it was more effective than the first example.

FIG. 11 shows another embodiment. In this case,
The shape of the flow control protrusion 10 is improved. That is,
In each of the above-described embodiments, the inflow side slope 10b and the outflow side slope 10c of the flow control protrusion 10 are straightly formed. However, in the present embodiment, each slope is SF ₆
The gas is formed so as to flow smoothly. More specifically, the flow control protrusion 10 has the inflow side slope 10b.
As shown in FIG. 11, the bottom portion 10a has a shape that is gently curved and recessed from the top portion to the top portion, and the top portion has a rounded shape. It is shaped so as to be recessed more gently than the side slope portion 10b.

As described above, when both the inflow side slope 10b and the outflow side slope 10c are formed in a gentle curved shape, when the SF ₆ gas flows through the flow control projection 10, the flow control projection 10 inflow-side slope portion 10b, since SF ₆ gas flows along the outlet side slope portion 10c, it is possible to reduce the pressure loss of the SF ₆ gas. In this case, although it depends on the degree of curvature of the inflow side slope portion 10b and the outflow side slope portion 10c, when the size is the same as that of the first embodiment, the test result shows that the cooling effect is almost the same as that of the first embodiment. I was able to get

In each of the embodiments described so far, the flow control projection 10 has a triangular shape with the bottom portion 10a and the inflow side slope portion 10b being 45 degrees, and the bottom portion 10a and the outflow side slope portion 10c being 30 degrees. Although the example was formed so that
The present invention is not limited to this, and although it is somewhat different depending on the pressure of the SF ₆ gas, the sizes of the vertical ducts 4, 4 ′, the unit winding 3, etc., it is selected at an appropriate angle depending on the flowing direction of the SF gas. For example, if the bottom portion 10a and the inflow side slope portion 10b have an angle of 30 degrees or more and an acute angle, and if the bottom portion 10a and the outflow side slope portion 10c have an angle of 15 degrees or more and an acute angle, the same applies. The effect of can be obtained. Further, the height of the flow control projection 10 is set to 1/3 and 1/2 of the inner and outer vertical ducts 4 and 4 ', but the size is selected to be about 1/4 to 3/4. Then, the same effect can be obtained.

As the material of the flow control protrusion 10,
In each of the examples, an example using an FEP having a relative permittivity of 2.2 was shown, but if the relative permittivity is 3 or less, it is confirmed that there is no electric field concentration even when a high voltage is applied to the winding. did. However, the material is not limited to FEP,
For example, it may be formed of a material having a low dielectric constant such as cross-linked polyethylene. Further, by forming a tape having a low dielectric constant on the structure of the flow control protrusion 10 to form the structure,
There is also an effect that inexpensive and easy manufacturing can be carried out.

[0053]

As described above, claims 1 to 5 of the present invention.
According to 3, the space between the flow control protrusion and the transformer winding is made narrower than the other portions, so that the flow rate and flow velocity of the cooling medium are reduced, and the flow control protrusion causes the unit winding facing the unit winding. The cooling medium is distributed and poured into the horizontal duct on the side so that the cooling medium can flow almost uniformly to each unit winding of the transformer winding. It has the effect of cooling the entire winding evenly and efficiently, and does not increase the size of the transformer winding, thus preventing the volume of the entire transformer from increasing, and thus addressing the demand for miniaturization. Since it is possible to prevent the increase of the pressure loss of the cooling medium, there is an effect that it is not necessary to use a large-sized cooling medium supply means.

Further, according to the fourth and fifth aspects, since the flow control projection has a triangular shape, the cooling medium can be easily and easily circulated in the desired direction, and the unit winding of the desired stage can be reliably performed. According to the fifth aspect, it is possible to enhance the cooling of the unit windings located above the flow control protrusions, so that the unit windings can be cooled more uniformly. There is.

According to the sixth aspect, the inflow side slope portion and the outflow side slope portion of the flow control projection have a curved shape, and the top between the inflow side slope portion and the outflow side slope portion has an arc shape. Since this is done, there is an effect that the flow of the cooling medium can be made smooth and the pressure loss of the cooling medium can be further reduced. According to the seventh aspect, by selecting the material of the flow control protrusion, even when a high voltage is applied to the winding, it is possible to reliably prevent the electric field concentration that causes the dielectric breakdown, and in terms of safety as well. Reliable. According to the eighth aspect, since the tape having a low dielectric constant is wound, there is also an effect that it can be manufactured at a low cost and easily.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing a first embodiment of a transformer winding according to the present invention.

FIG. 2 is a perspective view for explaining the main part of the transformer winding.

FIG. 3 is an explanatory perspective view showing an attached state of a flow control protrusion.

FIG. 4 is an explanatory diagram showing the relationship between the flow velocity of SF ₆ gas in the unit winding and the position in the width direction of the vertical duct in each of the bent-flow regions of the transformer winding of the related art.

5A and 5B are an explanatory view showing a positional relationship between each unit winding and a flow control protrusion in a folded flow area, and an explanatory view showing a test result showing a relationship between each unit winding and its temperature.

FIG. 6 is an explanatory sectional view showing a second embodiment of the transformer winding according to the present invention.

FIG. 7 is an explanatory view (a) showing a positional relationship between each unit winding and a flow control projection in a folded area, and an explanatory view (b) of a test result showing a relationship between each unit winding and its temperature.

FIG. 8 is an explanatory sectional view showing a third embodiment of the transformer winding according to the present invention.

FIG. 9 is an explanatory sectional view showing a fourth embodiment of the transformer winding according to the present invention.

FIG. 10 is an explanatory sectional view showing a fifth embodiment of a transformer winding according to the present invention.

FIG. 11 is a side view (a) and a perspective view (b) of a flow control protrusion showing another embodiment of the transformer winding according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transformer winding, 2 ... Inner peripheral insulating cylinder, 2 '... Outer peripheral insulating cylinder, 3 ... Unit winding, 4 ... Inner vertical duct, 4' ... Outer vertical duct, 5, 5a-5c ... Horizontal duct, 6a-6
d ... fold flow plate, 7a to 7d ... inflow / outflow portion, 8a to 8c ... fold flow area, 10, 10 '... flow control protrusion, 10a ... bottom portion,
10b ... Inflow side slope portion, 10c ... Outflow side slope portion, 13 ...
Flow divider.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroyuki Fujita 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside the Kokubu Plant, Hitachi, Ltd. (72) Inventor Kiyoto Hiraishi 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Kokubu Plant of Hitachi, Ltd.

Claims (8)

[Claims] 1. An inner vertical duct which is disposed axially between an inner peripheral insulating cylinder and an outer peripheral insulating cylinder and which is defined between the inner peripheral insulating cylinder and an inner peripheral insulating cylinder, and an outer periphery. Outer vertical duct defined between the inner and outer insulating ducts, a horizontal duct defined between the unit windings of each stage and connecting the inner and outer vertical ducts, and inner and outer insulating cylinders On the other hand, the unit windings of a desired number of stages are arranged in a staggered manner along the axial direction so as to form a flow-divided area, and a cooling medium flows in and out between the tip and the inner and outer insulating cylinders. In a transformer winding that has a plurality of bent plates that are alternately formed in the axial direction and that allows a cooling medium to flow in a zigzag shape along the axial direction in each bent region, , A flow control device arranged on the same side as the inflow / outflow part for inflow of the cooling medium into either one of the outer peripheral insulating cylinders. A control projection is attached, and the flow control projection restricts the flow rate of the cooling medium flowing into each of the flow-straight sections along the inner and outer vertical ducts, and directs a part of the cooling medium in a desired unit winding direction. A transformer winding characterized in that it is configured to control the flow rate. 2. An inner vertical duct, which is disposed axially between the inner peripheral insulating cylinder and the outer peripheral insulating cylinder, and is defined between the inner peripheral insulating cylinder and the inner peripheral insulating cylinder. Outer vertical duct defined between the inner and outer insulating ducts, a horizontal duct defined between the unit windings of each stage and connecting the inner and outer vertical ducts, and inner and outer insulating cylinders On the other hand, the unit windings of a desired number of stages are arranged in a staggered manner along the axial direction so as to form a flow-divided area, and a cooling medium flows in and out between the tip and the inner and outer insulating cylinders. In a transformer winding that has a plurality of bent plates that are alternately formed in the axial direction and that allows a cooling medium to flow in a zigzag shape along the axial direction in each bent region, Specified on the same side as the inflow / outflow part for the cooling medium to flow into one of the outer peripheral insulating cylinders, and A flow control protrusion arranged at a position opposed to the unit winding of the cooling medium, the flow control protrusion restricts the flow rate of the cooling medium flowing into each of the flow diverting areas along the inner and outer vertical ducts, and the cooling medium. The transformer winding is characterized in that the flow rate is controlled so that a part of the flow is circulated to a horizontal duct near a specific unit winding. 3. An inner vertical duct that is disposed along the axial direction between the inner peripheral insulating cylinder and the outer peripheral insulating cylinder and that is defined between the inner peripheral insulating cylinder and the outer peripheral insulating cylinder. Outer vertical duct defined between the inner and outer insulating ducts, a horizontal duct defined between the unit windings of each stage and connecting the inner and outer vertical ducts, and inner and outer insulating cylinders On the other hand, the unit windings of a desired number of stages are arranged in a staggered manner along the axial direction so as to form a flow-divided area, and a cooling medium flows in and out between the tip and the inner and outer insulating cylinders. In a transformer winding that has a plurality of bent plates that are alternately formed in the axial direction and that allows a cooling medium to flow in a zigzag shape along the axial direction in each bent region, Specified on the same side as the inflow / outflow part for the cooling medium to flow into one of the outer peripheral insulating cylinders, and A flow control protrusion arranged at a position opposed to the unit winding, and disposed in a horizontal duct at an upper portion of the unit winding opposed to the flow control protrusion so that one end projects to a vertical duct having the flow control protrusion. Attached to the flow control projections, the flow control projections restrict the flow rate of the cooling medium flowing into each of the flow diverting areas along the inner and outer vertical ducts, and cut a part of the cooling medium to a specific unit winding. While controlling the flow rate so as to circulate through the horizontal duct in the vicinity, it is possible to increase the flow rate of the cooling medium that has passed through the flow control projections into the horizontal duct on the downstream side of the specific unit winding by the flow dividing plate. Characteristic transformer winding. 4. The flow control protrusion has a triangular shape in which a bottom portion is closely attached to inner and outer insulating cylinders and a top portion is arranged to face a specific unit winding. The transformer winding according to any one of claims 1 to 3. 5. The flow control projection has a triangular shape in which the bottom is attached to the inner and outer insulating cylinders with a narrow flow path and the top is arranged to face a specific unit winding. The transformer winding according to any one of claims 1 to 3, wherein the transformer winding is provided. 6. The flow control protrusion has a bottom portion formed straight, an inflow side slope portion and an outflow side slope portion having a curved shape, and a space between the inflow side slope portion and the outflow side slope portion. The transformer winding according to any one of claims 4 and 5, wherein the top portion has an arc shape. 7. The flow control protrusions are made of a material having a relative dielectric constant of 3 or less.
The transformer winding according to any one of item 3. 8. The transformer according to claim 1, wherein a tape made of a material having a low dielectric constant is wound around the flow control protrusion. Winding.