JPH08288153A - Stationary induction apparatus - Google Patents

Abstract

PURPOSE: To provide a stationary induction apparatus in which load loss and short-circuit mechanical force in the axial direction are reduced and the manufacturing steps and its cost are also reduced. CONSTITUTION: A low-voltage winding 2 is wound around the outer periphery of a core leg 1, and a high-voltage winding 3 that is composed of two separated high-voltage windings 3A and 3B in the axial direction is wound around the outer periphery of the winding 2, then a tap center 4 for pulling out taps is prepared in the central part of the windings 3A and 3B. Then, a magnetic ring 5 made of high permeability material (silicon steel plate, etc.) where a gap part G is formed on its circumference for insulation in a manner not to form one turn is prepared in the intermediate part in the axial direction of the tap center 4, and it is connected with the winding 3, thereby realizing the same potential.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the internal structure of a static induction device, and more particularly to a magnetic ring for suppressing an increase in a radial component of a leakage flux of a winding and promoting an increase in an axial component. Is.

[0002]

2. Description of the Related Art In a static induction device of a voltageless tap switching system, the magnetic flux potential in the winding changes greatly at the maximum and minimum tap voltages.

FIG. 8 is a winding layout diagram showing an example of the internal structure of a conventional static induction device of the one-step tap switching system.
A low-voltage winding 22 is wound around the outer circumference of 1, and a vertically divided high-voltage winding 23 is arranged on the outer side thereof. This high voltage winding 23
The tap is pulled out from the center of the tap center 24.

FIGS. 9 and 10 show the leakage flux showing the relationship between the winding arrangement position and the leakage flux potential in the case of the highest tap voltage and the lowest tap voltage of this static induction device of the one-stage tap switching system. The potential map of is shown.

In the case of the highest tap voltage, as shown in FIG. 9, the axial component in the winding is large and the radial component is small.

On the other hand, when the tap voltage becomes the minimum voltage, as shown in FIG. 10, a state in which a part of the winding at the center tap 24 is removed is brought about. The radial component of the leakage magnetic flux increases and the axial component of the leakage magnetic flux decreases in the part where the winding is removed and the winding adjacent thereto.

When the leakage flux of the radial component increases, a large axial short-circuit mechanical force is generated. In order to reduce this short-circuit mechanical force in the axial direction, the conventional one-stage tap switching system is changed to a two-stage tap switching system as shown in FIG. 11 to increase the radial component of the leakage magnetic flux at the winding escape portion. It suppresses and makes the leakage flux distribution uniform.

FIG. 11 is a winding layout diagram showing an example of the layout of the windings and the potential of the leakage flux in the case of the minimum tap voltage in this two-stage tap switching system. In FIG. 22 is wound, and three high voltage windings 25, which are divided into three, are arranged on the outer side of the winding 22 at upper and lower positions in the height direction and at positions of a quarter. The high voltage winding 25 includes an upper high voltage winding 25A, a central high voltage winding 25B and a lower high voltage winding 25A.
The upper high voltage winding 25A and the central high voltage winding 2
The taps are drawn out from two tap centers, that is, the upper tap center 26 between 5B and the lower tap center 27 between the central high voltage winding 25B and the lower high voltage winding 25C. For the lowest tap voltage,
Similar to FIG. 10, the tap center coil is shown in a removed state.

In addition, in the conventional static induction device, in order to suppress loss and temperature rise of the upper and lower clamps as the ultra-high pressure and capacity increase, the surface of the clamps facing the coil is suppressed. A magnetic shield made of a material having high magnetic permeability (silicon steel plate) is installed.

FIG. 12 is a sectional view showing an example of the internal structure of a conventional stationary induction device. In FIG. 12, an iron core 31 is provided with an upper fastening member 32 and a lower fastening member 33. On top of the lower clamp 33, the upper clamp 3
2 and the magnetic shield 34 for suppressing the loss of the lower clamp 33 and the temperature rise are attached to the coil base 3
5, a winding wire 37 having electrostatic shield rings 36 at the upper and lower ends is arranged, and an upper tightening metal fitting 3 is provided via a clamp ring 38 and a holding plate 39 arranged on the winding wire 37.
The winding 37 is fastened and fixed in the axial direction by the coil tightening bolt 40 attached to the coil 2.

Due to the influence of the magnetic shield 34, the winding 3
Since the axial component of the magnetic flux inside 7 increases and the radial component decreases, the magnetic flux approaches a straight line (hereinafter referred to as linearization of the magnetic flux). As a result, the eddy current loss at the upper and lower ends of the winding 37 is reduced, and the loss inside the winding 37 is reduced.

[0012]

In the conventional static induction equipment, as the first problem, when the tap switching is changed from the one-step tap switching method to the two-step tap switching method, the work amount relating to the taps at the time of manufacturing the winding is doubled. However, two tap selectors are required for each phase, and there is a problem that the number of manufacturing steps and the cost increase.

Further, as a second problem, since the magnetic shield of the tightening fitting is equal to the ground potential, the magnetic shield must be installed at a distance necessary for insulation from the winding. As the static induction device becomes ultra-high voltage and large capacity, the insulation distance becomes longer and the product becomes larger. Therefore, there is a problem that the linearization of the magnetic flux, which is one of the effects of the magnetic shield of the tightening fitting, becomes small.

The static induction device of the present invention has been made in view of the above problems of the prior art. It reduces load loss and axial short-circuit mechanical force, or reduces the magnetic flux at the ends of windings. It is an object of the present invention to provide a stationary induction device in which the number of bends is reduced and the number of manufacturing steps and costs are reduced.

[0015]

In order to achieve the above object, the first invention of the static induction device of the present invention is to provide a magnetic ring of a high magnetic permeability material (such as a silicon steel plate) formed in a ring shape, It was installed in the tap center of the high-voltage winding divided into two parts at the top and bottom, and was connected to the tap winding to apply the same potential.

A second aspect of the static induction device according to the present invention is to install a magnetic ring made of a high magnetic permeability material (such as a silicon steel plate) formed in a ring shape between the winding and the shield ring and connect the winding to the winding. Then, the same potential is applied.

A third aspect of the static induction device of the present invention is that a shield ring conductor is arranged on the outer surface of a magnetic ring made of a high magnetic permeability material (such as a silicon steel plate) formed in a ring shape, and each of the windings is connected to the winding. It was configured to connect and apply the same potential.

[0018]

As described above, the static induction device according to the first invention is
By installing a ring-shaped high-permeability material at the tap center of the tap winding, it is possible to suppress the increase in the radial component of the leakage flux in the winding drop-out part and its vicinity, and to increase the axial component. Since this facilitates, the short-circuit mechanical force in the axial direction is suppressed, the application range of the first tap is widened, the eddy current loss at the winding end portion on the tap center side is reduced, and the load loss is reduced.

Further, in the stationary induction device of the second invention, a magnetic ring made of a high magnetic permeability material (such as a silicon steel plate) formed in a ring shape is installed between the winding and the shield ring, and is connected to the winding. By applying the same potential by suppressing the increase in the radial component of the leakage flux at the upper and lower ends of the winding and promoting the increase in the axial component, the short-circuit mechanical force in the axial direction is suppressed, Eddy current loss at the end of the wire is reduced, and load loss is reduced.

Further, in the static induction device according to the third aspect of the invention, a shield ring conductor is arranged on the outer surface of a magnetic ring of a high magnetic permeability material (such as a silicon steel plate) formed in a ring shape and connected to each winding. However, by applying the same potential, the increase of the radial component of the leakage flux at the upper and lower ends of the winding is suppressed and the increase of the axial component is promoted, so that the short-circuit mechanical force in the axial direction is suppressed, Eddy current loss at the end of the wire is reduced, and load loss is reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the static induction device of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the internal structure and leakage flux distribution of the first embodiment of the static induction device of the present invention.
Is an explanatory view of the structure of the shield ring of the stationary induction device, (a) is a plan view, (b) is a longitudinal sectional view, and as shown in FIG. 1, the low-voltage winding 2 is wound around the outer periphery of the iron core leg 1. Then, the high voltage windings 3A and 3B, which are divided into two in the axial direction, are wound around the outer circumference of the low voltage winding 2, and a tap center 4 for tapping is provided in the middle of the high voltage windings 3A and 3B. Around a ring of a high magnetic permeability material (silicon steel plate or the like) in which a gap G is provided on the circumference so as not to form one turn in the axial center portion of the tap center 4 as shown in FIG. A magnetic induction ring 5 is installed and is connected to the high-voltage winding to form a static induction device having the same potential. The magnetic ring 5 may be formed by winding a steel strip of a high magnetic permeability material (such as a silicon steel plate) or by laminating ring-shaped steel plates.

In the static induction device constructed as described above, since the increase in the radial component of the leakage magnetic flux at the portion where the tap of the high voltage winding comes out and the vicinity thereof is suppressed and the increase of the axial component is promoted, Axial short circuit mechanical force is suppressed,
The application range of one tap is expanded. Furthermore, the eddy current loss at the winding end (on the tap center side) is reduced, and the load loss is reduced.

FIG. 3 is a longitudinal sectional view of an essential part showing the internal structure of the second embodiment of the static induction device of the present invention, FIG. 4 is an explanatory view of its shield ring, (a) is a plan view, b) is a longitudinal sectional view in which the low-voltage winding 7 and the high-voltage winding 8 are wound around the outer periphery of the iron core leg 6, and either one of the low-voltage winding 6 and the high-voltage winding 7 or both ends of the winding are wound. A magnetic ring 14 is provided between the electrostatic shield ring 15 and the winding, the magnetic ring 14 being insulated from the circumference of a ring of a high-permeability material (such as a silicon steel plate) provided with a void on the circumference so as not to form one turn. Is a static induction device installed in the high-voltage winding 8 or the low-voltage winding 7 to have the same potential. The magnetic ring 14 may be formed by winding a steel strip of a high magnetic permeability material (such as a silicon steel plate) or may be formed by stacking ring-shaped steel plates.

FIG. 5 is a sectional view showing the internal structure of a third embodiment of the stationary induction device of the present invention, and FIG. 6 is an explanatory view of the structure of the shield ring of the stationary induction device. FIG. 5 is a plan view, (b) is a vertical sectional view, and FIG. 7 is a detailed vertical sectional view showing the details of the structure of the shield ring of the stationary induction device.
As shown in FIG. 1, either one of the low-voltage winding 7 and the high-voltage winding 8 of a static induction device in which the low-voltage winding 7 and the high-voltage winding 8 are wound around the outer periphery of the iron core leg 6, or the ends of both windings. In addition, as shown in FIGS. 6 and 7, the insulating material 10 covers the circumference of the magnetic ring 9 made of a high-permeability material (such as a silicon steel plate) having a gap G on the circumference so as not to form one turn. Then, a magnetic ring-containing shield ring 13 formed by covering the inner or outer peripheral side and the electrostatic shield conductor ring 11 having a curved surface covering the upper part to be integrated, and further applying an insulating coating 12 thereon is used. It is a static induction device connected to each of the voltage winding 8 or the low voltage winding 7 so as to have the same potential. The magnetic ring 9 may be formed by winding a steel strip of a high magnetic permeability material (silicon steel plate or the like) or may be formed by stacking ring-shaped steel plates.

In the static induction device constructed as described above, the linearization of the magnetic flux in the winding progresses, the increase in the radial component of the leakage flux at the upper and lower ends of the winding is suppressed, and the increase in the axial component. Therefore, the short-circuit mechanical force in the axial direction is suppressed, the eddy current loss at the winding end portion is reduced, and the load loss is reduced.

In the static induction device constructed as described above, the increase of the radial component of the leakage flux at the upper and lower ends of the winding is suppressed and the increase of the axial component is promoted. Is suppressed, eddy current loss at the winding end is reduced,
Load loss is reduced.

[0028]

The static induction device of the present invention has the following effects.

According to the first aspect of the present invention, a ring-shaped high-permeability material (such as a silicon steel plate) is installed at the tap center of the tap winding, so that the leakage flux of the leakage magnetic flux in the portion where the winding comes out and in the vicinity thereof is reduced. Since the increase of the radial component is suppressed and the increase of the axial component is promoted, the short-circuit mechanical force in the axial direction is suppressed, and the applicable range of one tap is widened. Furthermore, the eddy current loss at the winding end (on the tap center side) is reduced, and the load loss is reduced.

In the second aspect of the present invention, a ring-shaped high-permeability material (such as a silicon steel plate) is placed between the winding and the shield ring and applied at the same potential as the winding to insulate the winding. Since it is possible to install the coil closely to the winding regardless of the class, the magnetic flux in the winding is linearized and the loss in the winding can be reduced.

According to the third invention, the same effect as that of the second invention can be obtained. However, in the present invention, the magnetic ring is housed in the shield ring. The size of can be shortened and miniaturized. On the other hand, compared with the second aspect of the invention, the cross-sectional area of the high magnetic permeability material (silicon steel plate or the like) covering the upper surface of the winding becomes small, so that the effect of reducing the loss in the winding is slightly small.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main portion showing a content structure and a leakage magnetic flux distribution of a first embodiment of a stationary induction device of the present invention.

FIG. 2 is an explanatory diagram of the configuration of the shield ring of the first embodiment of the stationary induction device of the present invention.

FIG. 3 is a longitudinal sectional view of a main part showing the internal structure of the second embodiment of the stationary induction device of the present invention.

FIG. 4 is an explanatory view of the configuration of the shield ring of the second embodiment of the stationary induction device of the present invention.

FIG. 5 is a longitudinal sectional view of a main part showing the internal structure of the third embodiment of the stationary induction device of the present invention.

FIG. 6 is an explanatory view of the configuration of a shield ring of a third embodiment of the stationary induction device of the present invention.

FIG. 7 is a detailed vertical sectional view showing the structure of the shield ring of the third embodiment of the stationary induction device of the present invention.

FIG. 8 is a winding layout diagram showing an example of the internal structure of a conventional static induction device of a one-step tap switching system.

FIG. 9 is a leakage magnetic flux distribution map in the case of a conventional one-stage tap switching type static induction device and the maximum tap voltage.

FIG. 10 is a leakage magnetic flux distribution map in the case of a conventional one-stage tap switching system static induction device and the minimum tap voltage.

FIG. 11 is a winding layout and leakage magnetic flux distribution diagram in the case of the lowest tap voltage in the internal structure of the conventional two-stage tap switching type static induction device.

FIG. 12 is a sectional view showing an example of the internal structure of a conventional stationary induction device.

[Explanation of symbols]

 1 ... Iron core leg 2 ... Low voltage winding 3 ... High voltage winding 3A ... Upper high voltage winding 3B ... Lower high voltage winding 4 ... Tap center 5 ... Magnetic ring 6 ... Iron core 7 ... Low voltage winding 8 ... High voltage winding 9 ... Magnetic ring 10 ... Insulator 11 ... Electrostatic shield conductor ring 12 ... Insulating coating 13 ... Shield ring with magnetic ring 14 ... Magnetic ring 15 ... Electrostatic shield ring G ... Void

Claims (3)

[Claims] 1. A non-voltage tap changer comprising a low-voltage winding and a high-voltage winding wound around the outer periphery of an iron core leg, and a tap center for tapping provided in a central portion of the high-voltage winding divided into two in the axial direction. In the static induction device of the system, a magnetic ring is installed in the middle of the tap center in the axial direction to insulate the circumference of a ring of high magnetic permeability material that has a void on the circumference so as not to form one turn. A static induction device connected to the high-voltage winding to have the same potential. 2. A static induction machine in which a low-voltage winding and a high-voltage winding are wound around the outer periphery of an iron core leg, and one turn is provided at an end of one or both of the low-voltage winding and the high-voltage winding. A magnetic ring is provided between the electrostatic shield ring and the winding to insulate the circumference of a ring of high magnetic permeability material with a gap on the circumference so as not to form A static induction device characterized by being connected to a wire and having the same potential. 3. A static induction device comprising a low-voltage winding and a high-voltage winding wound around the outer circumference of an iron core leg, wherein one turn is provided at an end of one or both of the low-voltage winding and the high-voltage winding. To prevent the formation of a gap, a magnetic ring made of a high-permeability material with a gap on the circumference is covered with an insulating material, and an electrostatic shield conductor ring with a curved surface covering the inner side or outer side and the upper part is formed. A static induction device in which a shield ring with a magnetic ring formed by covering it with an insulating coating is connected to the high-voltage winding or the low-voltage winding to have the same potential.