JPS61218123A - Stationary induction electric apparatus winding - Google Patents

Abstract

PURPOSE:To alleviate the concentration of an electric field of an end by replacing the conductor of an end section with a conductor having different sectional shape only by one turn to form a twisted wire shield provided with an insulation coating layer. CONSTITUTION:In a core type transformer, low and high voltage windings 2, 3 are wound from inside in a core 1. The winding 2 is formed of a helical winding. The winding 2 is wound helically while forming a section 5 in a horizontal duct 6. One turn of the end of the winding 2 is reconnected with a twisted wire shield 7. The shield 7 is formed of a twisted wire 7a and an insulating coating layer 7b for coating the outside of the wire 7a.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to static induction electric appliance windings, and in particular to a structure for mitigating electric field concentration at the winding ends of helical windings, which are often used as low-voltage windings. Regarding improvements.

[Technical background of the invention and its problems]

As shown in FIG. 3, a stationary induction electric appliance 1, such as a core type transformer, generally has a low voltage winding 2 and a high voltage winding 11A3 coaxially wound around an iron core 1 from the inside.

In a transformer having such a structure, an electrostatic shield 4a is provided at the end of the high voltage winding 3 to alleviate electric field concentration.
However, in order to prevent the electric field from concentrating on the end of the low voltage winding 2 as well as on the corner of the side facing the high voltage winding 3,
Similar to the high voltage winding 3, it is common to attach an electrostatic shield 4 to the end.

However, the low voltage winding 2 generally has a small number of windings, and is often formed by so-called helical winding, in which sections of a plurality of parallel conductors stacked in the radial direction are wound in a helical shape while creating a horizontal duct.

When the electrostatic shield is placed at the end of the helical winding in this way, as shown in FIGS. 4 and 5, there is a large gap between the end of the low voltage winding 2 and the electrostatic shield 4. A portion forming a gap occurs, and a corner A of this portion at the end of the winding
The electric field is concentrated at To prevent this, an additional lead wire may be inserted between the electrostatic shield 4 and the end of the winding (
(Refer to Japanese Patent Laid-Open No. 53-20526), a method of adding a special shield has been proposed. Further, the shape of the electrostatic shield 4 itself has been made into a shape as shown in FIG. 6, which matches the slope of the end of the low voltage winding 2 consisting of a helical winding.

However, all of these methods have disadvantages in that the structure of the electrostatic shield 4 becomes complicated, and that a large number of man-hours are required to manufacture the winding.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a stationary induction electric appliance winding having a helical winding in which electric field concentration at the end is more relaxed.

[Summary of the invention]

In order to achieve this object, according to the present invention, a part of the parallel conductor constituting the end section of the helical winding is replaced with a conductor having a different cross-sectional shape by one turn. By arranging a stranded wire shield with a large radius of curvature at the end of the helical winding, electric field concentration at the end of the helical winding can be alleviated without using a special electrostatic shield.

The end sections are rearranged into two rows of sections with a horizontal duct in the middle, and the radial direction of these sections is approximately half of the original, and the two rows of sections are placed on the side not facing the high voltage winding. Yose.

Preferably, a stranded wire shield having a height equal to the axial height of the two rows of sections and having a cross-sectional shape different from that of the general portion is disposed on the side facing the high voltage winding.

The conductor on the side facing the high-voltage winding of the end section is formed by twisting thin wires each having an insulation coating to form a stranded wire shield having a substantially rectangular cross section and having an insulation coating layer applied throughout;
It is preferable that only the radius of curvature of the corner of the stranded wire shield of the bracket facing the yoke core and the high voltage winding is larger than the radius of curvature of the other corners.

It is preferable to form the insulation coating layer of the stranded wire shield to be thicker than the insulation coating of the conductor in the general portion.

[Embodiments of the invention]

An embodiment of the stationary induction electric appliance winding of the present invention will be described below with reference to FIG. The same parts as in FIG. 3 are given the same reference numerals. In a stationary induction appliance, such as a core type transformer, a low voltage winding 2 and a high voltage winding 3 are wound around an iron core 1 from the inside. The low voltage winding 2 is composed of a helical winding.

As shown in the figure, this low voltage winding 2 is helically wound with a section 5 formed by radially stacking parallel conductors consisting of eight rectangular wires forming a horizontal duct 6. One turn at the end of the low voltage winding 2 is then connected to one stranded wire shield 7 instead of the two rectangular wires on the side of the end section 2a facing the high voltage winding 3.

This stranded wire shield 7 consists of a stranded wire portion 7a and an insulating coating layer 7b covering the outside thereof. The stranded wire portion 7a is constructed by twisting formal-coated fine wires each having a circular cross section, and its cross-sectional shape forms a substantially rectangular shape with rounded corners. Only the portion corresponding to the opposing corner portion 7c has a radius of curvature larger than the other portions.

Further, the insulating coating layer 7b is formed to be thicker than the coating of the conductor in the general portion, that is, the conductor in a portion other than the end portion of the low voltage winding 2 such as the section 5.

Then, if the cross-sectional area of the stranded wire shield 7 is equal to the total cross-sectional area of the two replaced rectangular wires, the area on the insulating surface due to the poor space factor on the stranded wire conductor and the thickness of the insulating coating layer 7b. Although the height of the conductor is higher than the general height, for example, the dimension d, a spacer 8 made of an insulating member with a thickness corresponding to this height difference is provided in this portion.

Next, the effects of the present invention configured as described above will be explained. By providing such a stranded wire shield 7 in a part of the end section 2a, it is possible to avoid the need for a conventional electrostatic shield 4 (see FIG. The electric field concentration at the corner 7c at the end of the voltage winding 2 is relaxed, and since the insulating layer 7b at the corner 7C is formed thick, the insulation strength can also be increased.

Next, another embodiment of the present invention will be described with reference to FIG.

The same parts or parts having the same functions as those in FIG. 1 are given the same reference numerals. That is, a low voltage winding 2 and a high voltage winding 3 are wound around the iron core 1, and the low voltage winding 2 is configured as a helical winding. The end section 2a of the low voltage winding 2 is formed by arranging one turn in two rows and moving it closer to the iron core 1 side. Further, on the side facing the high voltage winding 3, a stranded wire shield 7 is arranged which has two rows of sections and the same axial height above the insulating surface. This stranded wire shield 7 has a large radius of curvature at the corner 7c of the stranded wire portion 7a facing the high voltage winding 3, and the insulating coating layer 7b is formed thicker than the insulating coating of the general conductor.

With this configuration, the radius of curvature of the corner 7c of the stranded wire shield 7 facing the high voltage winding 3 can be made larger than that of the conventional example shown in FIG. 7b can also be made thicker. Therefore, it is effective when sufficient insulation strength is required compared to the conventional example shown in FIG. 5 in terms of insulation.

In addition, in this example, there is plenty of space to place the stranded wire shield 7, so even if the insulation coating layer 7b is thick, the conductor cross-sectional area can be made sufficiently larger than the total cross-sectional area of the original rectangular wires that were reconnected. , the current density becomes small and the temperature rise of the conductor does not become higher than that of the general part.

〔Effect of the invention〕

As explained above, according to the present invention, a part of the conductor in the end section is replaced with a conductor having a different cross-sectional shape by one turn, and a stranded wire shield is formed by providing an insulating coating layer thereon. This allows the complicated electrostatic shielding of the low-voltage winding to be omitted, and the insulation distance from the end of the low-voltage winding to the core yoke and high-voltage winding can be reduced, resulting in reduction of the winding. It is possible to provide a stationary induction electric appliance winding that achieves

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a stationary induction electric winding according to the present invention, FIG. 2 is a cross-sectional view of another embodiment of the present invention, and FIGS. 3 to 6 each show a conventional static induction electric winding. 3 is a sectional view, FIG. 4 is a front view, FIG. 5 is a sectional view taken along the line V-V#I in FIG. 4, and FIG. 6 is a front view. DESCRIPTION OF SYMBOLS 1... Iron core, 2... Low voltage winding, 2a... End section, 3... High voltage winding, 4a
... Electrostatic shield, 5... Section, 6... Horizontal duct, 7... Stranded wire shield, 7a... Twisted wire portion, 7b... Insulation coating portion, 7c... Corner Part, 8.
··Spacer.

Claims (4)

[Claims] (1) A stationary device equipped with a helical winding, in which a parallel conductor consisting of multiple rectangular wires is stacked in the radial direction to form one turn, and is wound in a helical shape while forming a horizontal duct between the turns. In an induction electric winding, one of the parallel conductors at both the upper and lower end sections of the winding or at one end section, located on the side facing the high voltage winding.
A stationary induction electric appliance winding characterized in that it is a stranded wire shield composed of a conductor or a plurality of conductors having a cross-sectional shape different from the general part for one turn. (2) The end sections are rearranged into two rows of sections with a horizontal duct in the middle, and the radial direction of this section is approximately 1/2 of the original, and the two rows of sections are opposite to the high voltage winding. A stranded wire shield having a height substantially equal to the axial height of the two rows of sections and having a cross-sectional shape different from that of the general portion is disposed on the side facing the high voltage winding. The stationary induction electric appliance winding according to item 1. (3) The stranded wire shield on the side facing the high voltage winding of the end section is made by twisting thin wires each coated with insulation to form an insulating coating layer around the entire periphery of the stranded wire portion having a substantially rectangular cross section; In addition, the static induction according to claim 1 or 2, wherein only the radius of curvature of the corner facing the yoke core and the high voltage winding of the stranded wire shield is made larger than the radius of curvature of the other corners. Electrical winding. (4) The stationary induction electric appliance winding according to claim 3, wherein the insulation coating layer of the stranded wire shield at the end of the winding is formed to be thicker than the insulation coating of the conductor in the general portion.