JPH0283908A - Stationary induction apparatus - Google Patents

Abstract

PURPOSE:To decrease generation loss at a tank by arranging the shapes of inner and outer windings consisting of foil windings which are wound coaxially around an iron core foot so that the resisting force of the outer winding to the dimensional component of leaked magnetic flux may be larger than that of the inner winding. CONSTITUTION:Inner winding 2a and outer winding 2b being foil windings are wound around an iron core foot 1 and these whole is stored in a tank 3. That is, the windings 2a and 2b are divided in height direction, and the number of divisions of the winding 2a is made larger. That is, the width l1 of a metallic sheet of the winding 2a is taken enough smaller than the width l2 of the winding 2b. However, for the height of the whole both windings are almost equal. As a result, the magnetic flux resisting force of the metallic sheet in the radial direction of the leaked magnetic flux which is caused by load currents produces great difference between both windings 2a and 2b, and the most of the leaked magnetic flux go to the side of the winding 2a which is weak in resisting force, that is, the side of iron core foot 1 as shown by arrows of dotted lines, and the magnetic flux invading the tank 3 is sharply reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to stationary induction electric appliances such as transformers, and more particularly to stationary induction electric appliances using foil windings formed by winding sheet strands.

[Prior Art] Recently, progress has been made to increase the high voltage and capacity of stationary induction appliances equipped with foil windings formed by winding metal sheets around iron core legs. This type of stationary induction electric appliance has a better winding space factor than a stationary induction electric appliance using ordinary windings, so it has the advantage of being smaller and lighter, and has already gone from several tens of KVA to several tens of KVA.
It has been put to practical use in low-voltage, small-capacity transformers of about 0.00 KVA.

However, in stationary induction appliances using foil windings, there is a phenomenon in which eddy currents are significantly concentrated near the upper and lower ends of the windings.
This will be explained with reference to FIG.

FIG. 5A is a longitudinal cross-sectional view showing the vicinity of the winding, which has an inner winding 2a and an outer winding 2b wound around the core leg 1, and is entirely constructed within the tank 3. Both windings 2a.

When a load current flows through the windings 2b, a leakage magnetic flux roughly shown by the dotted line is generated, and this leakage magnetic flux generates a large /rAtft current in both the windings 2a and 2b. This eddy current is generated when the radial component of the leakage magnetic flux, which reaches its maximum near the upper and lower ends of the winding, interlinks the metal sheets that make up the foil winding, as shown in the same figure ('b).

Not only does it excessively concentrate overcurrent near the upper and lower ends of both windings 2a and 2b, but it also greatly distorts the original leakage magnetic flux distribution, causing metal objects that exist near both windings 2a and 2b, such as This increases the loss generated in the tank 3. This point will be further explained with reference to FIG.

FIG. 9(a) is an example of calculating the leakage magnetic flux distribution when both the inner winding 11A2a and the outer winding 2b are made of rectangular wires, and FIG. This is an example of calculation of leakage magnetic flux distribution when configured with foil winding. When using the rectangular electric wire shown in Fig. 3(a), a large amount of leakage magnetic flux intrudes toward the iron core leg 1 side, and less intrusion into the tank 3 side, so there are fewer problems such as heat generation in the tank 3.
However, the diagram (b) in which foil windings are used differs from the diagram (a) in that the leakage magnetic flux distribution is unique in that the magnetic flux suddenly scatters at the upper and lower ends of the windings 2a and 2b. This is because when foil windings are used, the leakage magnetic flux is trapped in the windings 2a and 2b due to the repulsive force of the magnetic flux generated by the eddy current flowing through the metal sheet, and the upper and lower ends of the windings 1i2a and 2b This is because they are distributed separately on the iron core leg 1 and tank 3 sides. Therefore, the leakage magnetic flux to tank 3 is as shown in the same figure (a).
, which causes problems such as overheating in the tank 3.

Therefore, in conventional static induction electric appliances,
As shown in Japanese Patent Application Laid-Open No. 85509 and 1985-85510, the distribution of leakage magnetic flux at the upper and lower ends of the winding is corrected by using magnetic shields and auxiliary windings.
As shown in Japanese Patent Application Laid-open No. 2-126611, Japanese Patent Application Laid-open No. 1983-109307, and Japanese Utility Model Publication No. 50-33619, the widths of the metal sheets constituting the foil windings of the inner and outer windings are made different. Therefore, the leakage magnetic flux distribution at the upper and lower ends of the winding was changed.

[Problem to be solved by the invention] As mentioned above, conventional stationary induction electric appliances use magnetic shields and auxiliary windings to prevent scattering of leakage magnetic fields at the upper and lower ends of the foil windings, and it is difficult to increase the capacity. Accordingly, these additional control means must be disposed over a wider area, making the structure complex and making it difficult to put it into practical use. In addition, by making a difference in the width of the metal sheets that make up the foil winding, it is possible to slightly change the scattering of leakage magnetic flux at the upper and lower ends of one winding, but this method does not have the effect of reducing the loss generated in the tank. I couldn't live up to my expectations.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a stationary induction electric appliance that suppresses excessive loss generated in a tank located near a foil winding.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a core leg, an inner winding group and an outer winding group wound approximately concentrically around the core leg, In a stationary induction electric appliance in which a winding group is formed by overlapping metal sheets, the shape of the inner winding group and the outer winding group is such that the repulsive force of the outer winding against the radial component of the leakage magnetic flux is the inner winding. It is characterized by being constructed so that the repulsive force is greater than that of the group.

[Function] Since the stationary induction electric appliance of the present invention has the above-described configuration, the repulsive force against the radial component of the leakage magnetic flux is larger in the outer winding near the tank, so most of the 1m leakage magnetic flux goes toward the core leg side. As a result, a stationary induction electric appliance can be obtained in which the magnetic flux that enters the tank is significantly reduced, and the loss generated in the tank is significantly suppressed.

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

Figure 1 is a longitudinal cross-sectional view showing the vicinity of the windings of the transformer.
An inner winding 2a and an outer winding 2b, which are foil windings, are wound around the inner winding 2a and the outer winding 2b, and these are all housed in the tank 3. Both windings fi2a and fi2b are divided in the height direction, but the number of divisions in the inner winding 49i2a is greater than that in the outer winding 2b. In other words, the widths of the metal sheets composing the two windings 1i2a and 2b are different, and the width Q1 of the metal sheet of the inner winding 2a is larger than the width Q2 of the metal sheet of the outer winding 2b.
By selecting the number of divisions in the height direction of both windings 2a and 2b, the overall height h is made substantially equal for both windings 2a and 2b.
There is a large difference in the magnetic flux reaction force of the metal sheet between the two windings 2a and 2b against the radial component of the leakage magnetic flux generated by the load current, and most of the leakage magnetic flux is on the inner winding 2a side where the reaction force is weaker, that is, It is directed toward the iron core leg 1 side as shown by the dotted arrow, and the magnetic flux penetrating into the tank 3 can be significantly reduced.

Generally, if the width of the metal sheet of N windings is a, and the electrical efficiency of the metal sheet is ρ, then the magnetic flux reaction force Bi against the leakage magnetic flux that attempts to enter the metal sheet at right angles is:

B, ceQ"-(1) ρ becomes. However, n=2 to 3 and m=o to 1.

Therefore, when the width a of the metal sheet is changed, the metal sheet 1
This will most effectively control the magnetic flux reaction force of -.

FIG. 2 is a longitudinal sectional view showing the vicinity of the windings of a transformer according to another embodiment of the present invention. The outer winding 2b is divided into widths Ω2 in the height direction as in the case of FIG. The relationship between each ring is set as Q13〉α, 2〉Q□□ so that the width becomes narrower as the width becomes closer to However, the magnetic flux reaction force is reduced near the upper and lower ends of the inner winding 2a where the eddy current is large.

Therefore, the number of divisions of the inner winding 2a is reduced as much as possible to effectively direct the leakage magnetic flux toward the core leg 1 side, thereby significantly reducing the magnetic flux entering the tank and reducing the loss in the intermediate portion. Can be done.

FIG. 3 is a longitudinal cross-sectional view of the vicinity of the winding according to a further different embodiment. In this embodiment, the width Q of the metal sheet of the inner winding 2a is made sufficiently smaller than @cz of the metal sheets 1 to 1 of the outer winding 2b, and the overall height hl of the inner winding 2a is made smaller than the width Q of the metal sheet of the outer winding 2b. ! It is made to be lower than the overall height h2 of 2b.

According to such a configuration, by reducing the width Q□ of the metal sheet of the inner winding 2a, the magnetic flux reaction force against the radial component of the leakage magnetic flux becomes weaker.

Furthermore, by reducing the height h of the inner winding 2a, the apparent magnetic flux repulsion force of the outer winding 2b is promoted, and as a result, the leakage magnetic flux is directed toward the Ichireki iron core leg 1 side as shown by the dotted arrow. , the loss in tank 3 is reduced.

FIG. 4 is a longitudinal sectional view showing the vicinity of the winding according to still another embodiment of the present invention. In this embodiment, the inner winding 1i2a is the first
Width Q of the metal sheet of the outer winding 2b as in the case of the figure
It is said to be a metal sheet with a width Q, which is sufficiently smaller than 2.

Further, the thickness L of the metal sheet of the inner winding 2a is made sufficiently larger than the thickness t2 of the metal sheet of the outer peripheral winding 2b,
A rectangular wire can also be used as the inner winding 2a.

According to this configuration, it is possible to obtain the same effect as in the case of FIG. 1, and by increasing the conductor cross-sectional area of the inner winding 2a, it is possible to simplify the winding structure and obtain a transformer that is strong against electromagnetic mechanical forces. .

FIG. 5 is a longitudinal sectional view showing the vicinity of the winding according to still another embodiment of the present invention. The basic structure in this embodiment is the same as that shown in FIG. 1, and the width α of the metal sheet of the inner winding 2a is
, is made sufficiently smaller than the width of the remaining sheet of the outer winding 2b +22. Also, if we pay attention to the material of the metal sheet of the inner winding 2a, we can see that the electrical resistivity ρ2 of that of the outer winding 2b is
A material having an electrical resistivity ρ1 larger than that is selected.

Therefore, almost the same effect as in the case of Fig. 1 can be obtained, and as can be seen from equation (1), leakage magnetic flux can be further reduced by
It can be turned to the side, and losses generated in the tank 3 can be reduced.

FIG. 6 is a longitudinal sectional view of the vicinity of the winding according to still another embodiment of the present invention. In all of the previous embodiments, the outer winding 2b was divided in the height direction like the inner winding 2a, but the outer winding 2b in this embodiment was not divided in the height direction.
It is composed of 'l'it Q2 with the same height. Therefore, the magnetic flux reaction force of the outer winding l/A2b becomes large, and together with the effect of making the inner winding 2a sufficiently small @(1), the leakage magnetic flux is directed toward the iron core leg 1 side, and leakage to the tank 3 is reduced. Intrusion of magnetic flux can be reduced.

FIG. 7 is a longitudinal sectional view of the vicinity of the winding according to yet another embodiment of the present invention, and the winding in this embodiment has a three-winding structure. Each winding 2a, 2a b.

2b, each metal sheet is divided in the height direction, but if you pay attention to the width of the division, the winding closer to the core leg 1 is smaller. Therefore, the magnetic flux reaction force is tank 3
The winding close to the tank 3 becomes larger, and losses due to leakage magnetic flux of the tank 3 can be reduced.

In this way, in each of the above embodiments, in a device having a plurality of windings, by making the repulsive force of the leakage magnetic flux on the tank side larger than that on the core leg side, the leakage magnetic flux is suppressed from entering the tank, and the loss in the tank is reduced. can be reduced.

[Effects of the Invention] As explained above, in the present invention, the magnetic flux reaction force of the outer winding near the tank side is made larger than that of the inner winding, so that leakage magnetic flux can be directed toward the iron core leg side. This makes it possible to reduce losses generated in the tank.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the vicinity of the winding of a transformer according to an embodiment of the present invention, and FIGS. FIGS. 8(a) and 8(a) are vertical cross-sectional views showing the vicinity of the windings of transformers according to other different embodiments, respectively.
b) is a vertical cross-sectional view and magnetic flux density distribution diagram showing the vicinity of the winding of a conventional transformer, and Figures 9 (a) and (b) show leakage when the winding is configured with conventional rectangular electric wire and foil winding. It is a magnetic flux distribution characteristic diagram. 1... Iron core leg, 2a... Inner winding, 2b
...outer winding, 3...tank. Figure Figure Funeral Figure Figure Funeral Figure Funeral Figure Funeral Figure Funeral Figure Funeral Figure Funeral Figure (CI) (b) Figure (G) tf, Comeback Figure (b) Q

Claims (8)

[Claims] 1. In a stationary induction electric appliance comprising an iron core leg, and an inner winding group and an outer winding group wound approximately concentrically around the iron core leg, the outer winding group being formed by stacking metal sheets, the inner winding A stationary induction electric appliance, characterized in that the form of the group and the outer winding group are configured such that the repulsive force of the outer winding against the radial component of leakage magnetic flux is larger than the repulsive force of the inner winding group. 2. 2. The stationary induction electric appliance according to claim 1, wherein the inner winding group is composed of a plurality of metal sheets having a width narrower than the width of the metal sheets constituting the outer winding group. 3. 3. The stationary induction electric appliance according to claim 2, wherein the plurality of metal sheets of the inner winding group have different widths with a minimum width on an end side of the inner winding. 4. In claim 1, the inner winding group is composed of a plurality of metal sheets having a width narrower than the width of the metal sheets constituting the outer winding group, and the overall height is equal to the overall height of the outer winding group. A stationary induction electric appliance characterized by having a structure lower than the height. 5. In claim 1, the inner winding group is composed of a plurality of conductors having a width narrower than the width of the metal sheet constituting the outer winding group and thicker than the metal sheet. Stationary induction appliance. 6. In claim 1, the inner winding group comprises a plurality of metal sheets having a width narrower than the width of the metal sheets constituting the outer winding group and having an electrical resistivity greater than the electrical resistivity of the metal sheets. A stationary induction electric appliance characterized by the following configuration. 7. In claim 1, the outer winding group is composed of a single metal sheet, and the inner winding group is composed of a plurality of metal sheets having a width narrower than the width of the metal sheet. Stationary induction electric appliance. 8. In a stationary induction electric appliance comprising a core leg, and an inner winding group and an outer winding group made of metal sheets substantially concentrically wound around the core leg, the inner winding group and the outer winding group are An intermediate winding group made of a metal sheet is provided between the
A stationary induction electric appliance characterized in that among the inner winding group, the intermediate winding group, and the outer winding group, the width of the metal sheet of the one located closer to the core leg side is made smaller.