JPH05299264A - Transformer - Google Patents

Abstract

PURPOSE:To obtain a transformer provided with windings which are small in eddy current loss, high in efficiency, and free from local overheat. CONSTITUTION:A cylindrical winding is wound on an iron core 1, where the cross-sectional long sides of conductors A and B located at a winding center 8 are set parallel with the axial direction of the winding, and the cross-sectional short sides of conductors A and B located at a winding upper end 9 and a winding lower end 10 are set parallel with the axial direction of the winding. Therefore, a transformer of this design can be lessened in eddy current loss by decreasing the width of the conductors A and B which a leakage flux penetrates at both the ends 9 and 10 of the winding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding structure for a transformer.

[0002]

2. Description of the Related Art FIG. 7 is an explanatory view of a winding structure of a conventional transformer shown in, for example, the transformer design work method (Denki Shoin, published in 1970). In the figure, 1 is an iron core, 2 and 3 are primary windings and secondary windings, respectively, and a conductor is wound around the iron core 1 in a cylindrical shape. In FIG. 8, reference numeral 5 denotes a rectangular conductor having a rectangular cross section with side lengths a and b used for the primary and secondary windings. 9 is an enlarged view of the vicinity of the primary winding 2 of FIG. 7, and A and B are conductors, which are connected in parallel as shown in FIG. Secondary winding 3
Also has the same structure as the primary winding 2.

In FIG. 7, an arrow 4 indicates a leakage magnetic flux. This leakage flux is in the direction of the magnetic flux φ in the iron core 1, that is,
Most of the components are parallel to the axial direction of the winding. However, in FIG. 7, the leakage magnetic flux returns at the upper and lower ends of the primary winding 2 and the secondary winding 3, so that there is a component in the direction perpendicular to the axial direction of the winding. The eddy current loss becomes larger as the area of the conductor in the portion perpendicular to the direction of the magnetic flux becomes larger. Therefore, as shown in FIG. 9, the rectangular conductor 5 is arranged in the direction of φ of the iron core 1, that is, 1
The axial direction of the secondary and secondary windings 2 and 3 is aligned with the direction of the long side of the rectangular cross section of the conductor 5, and the width b of the conductor in the portion where the leakage magnetic flux enters is reduced. This reduces the eddy current loss. Fig. 11 shows a case where two conductors are arranged in parallel. The conductor A and the conductor B are stacked and wound in a cylindrical shape, and the conductors are transposed at the center of the winding to make the impedance of the parallel windings equal. is there.

[0004]

Since the conventional transformer is constructed as described above, leakage magnetic flux enters from the long side direction of the cross section of the conductor at both ends of the winding, resulting in a large eddy current loss. However, there was a problem that the efficiency was lowered and local overheating was caused.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a transformer which has high efficiency and does not cause local overheating because of small eddy current loss.

[0006]

DISCLOSURE OF THE INVENTION A transformer according to the present invention has a conductor cross section having a long side of the conductor cross section in the axial direction of the winding at the axial center portion of the winding and at both axial end portions of the winding. It has the short side of the coil in the axial direction of the winding.

[0007]

In the transformer according to the present invention, the short sides of the conductor cross section are made parallel to the axial direction of the winding at both ends of the winding.
Since the width of the conductor through which the leakage magnetic flux passes is reduced at both ends of the winding, the eddy current loss can be reduced.

[0008]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. The overall configuration is similar to the conventional example. FIG. 1 is an enlarged view of the vicinity of the primary winding 2, and illustration of the secondary winding 3 is omitted below. In FIG. 1, 1, A and B are the same as or equivalent to those of the conventional example. 8 and 9 and 10 form a winding, and 8 is the central portion of the winding, and the long sides of the cross sections of the conductors A and B of the parallel conductors are in the axial direction of the winding, and 9 and 10 are the ends of the winding. At the upper end of the winding and the lower end of the winding, the short sides of the cross sections of the conductors A and B of the parallel conductor are provided in the axial direction of the winding. That is, as shown in the detailed structural diagram of the conductors A and B in FIG. 2, assuming that the lengths a and b of the long sides of the cross sections of the conductors A and B are the upper ends 9 of the windings.
2) At the lower end 10 of the winding, the short side is aligned with the axial direction of the winding as shown in FIG.
Align the long side with the axial direction of the winding as shown in.

In this embodiment, leakage magnetic flux at the winding upper end 9 and the winding lower end 10 at both ends of the winding enters from the short sides of the cross sections of the conductor A and the conductor B, and is a portion perpendicular to the direction of the magnetic flux. The size of the conductor is reduced as compared with the conventional example, and the eddy current loss is reduced.

Embodiment 2. FIG. 3 shows another embodiment. This is an example in which two conductors are used and dislocations occur at the winding central portion 8. In this case, the impedances of the two conductors are balanced. Figure 4 shows the case of three conductors
In this example, the central portion 8 of the winding is dislocated. In FIGS. 3 and 4, two and three conductors are shown as examples, but four or more conductors may be similarly displaced.

Embodiment 3. FIG. 5 shows another embodiment. C is a conductor. At the winding central portion 8, the long side of the cross section of the conductor B is arranged in the axial direction of the winding, and at the winding upper end portion 9 and the winding lower end portion 10,
The short sides of the cross sections of the conductors A and C are provided in the axial direction of the winding. The conductors A, B and C are connected in parallel as shown in FIG. 5 (b).

Embodiment 4. FIG. 6 shows another embodiment, which is an example in which the winding central portion 8, the winding upper end portion 9 and the winding lower end portion 10 in FIG. 5 are made of a plurality of conductors, and D, E and F are conductors.
The directions of the sides of the cross sections of the conductors A, B, C, D, E, and F at the winding central portion 8, the winding upper end portion 9, and the winding lower end portion 10 are arranged in the same manner as in the third embodiment. Conductors A, B, C,
D, E and F are connected as shown in FIG. 6 (b). 1
Although the structure of the secondary winding 2 is shown, the same applies to the secondary winding 3.

[0013]

As described above, according to the present invention, the long side of the conductor cross section is provided in the axial center of the winding in the axial direction of the winding, and the conductor is provided at both axial ends of the winding. Since the short side of the cross section is arranged in the axial direction of the winding, the eddy current loss at both ends of the winding is reduced, the efficiency is improved, and local overheating does not occur.

[Brief description of drawings]

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

2 is a detailed view of the configuration of conductors of the transformer of FIG.

FIG. 3 is a sectional view of a transformer showing another embodiment of the present invention.

FIG. 4 is a sectional view of a transformer showing still another embodiment of the present invention.

FIG. 5 is a sectional view of a transformer showing another embodiment of the present invention.

FIG. 6 is a sectional view of a transformer showing still another embodiment of the present invention.

FIG. 7 is a sectional view showing a conventional transformer.

8 is a cross-sectional view showing a conductor of the transformer of FIG.

9 is a cross-sectional view showing windings of the transformer of FIG.

FIG. 10 is a diagram showing a wire connection of the winding wire shown in FIG. 9;

11 is a cross-sectional view showing another winding of the transformer of FIG.

[Explanation of symbols]

 A, B, C, D, E, F Conductor 2 Primary winding 3 Secondary winding 8 Winding central part 9 Winding upper end 10 Winding lower end

Claims (1)

[Claims] 1. A transformer for winding a conductor having a rectangular cross section wound in a tubular shape, wherein a long side of a cross section of the conductor at a central portion in the axial direction of the winding is arranged in the axial direction of the winding. A transformer characterized in that it has short sides of a cross section of the conductor at both axial ends of the winding in the axial direction of the winding.