JPH0992558A - Primary winding of transformer for meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a primary winding of a transformer for a meter, which can be made uniform in the distribution of voltage between layers from the inner peripheral part of a spool to the outer peripheral part of the spool. SOLUTION: A multitude of winding layers W1 to Wn are wound on the outer periphery of a spool B in a state that insulating layers L1 to Ln-1 are made to interpose between the winding layers. The numbers of turns of all the layers M1 to Mn are made roughly equal. The layer Wn located at the position most apart from the spool B is evenly wound in the axis direction of wounding of a winding. The layers W1 to Wn-1 , which are positioned inside of the layer Wn , are divided into winding parts W1a to Wna , and winding parts W1b to Wnb and these winding parts are respectively arranged on both end sides in the axis direction of winding of the winding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument transformer which is connected to a bus bar or a line of an electric station such as a substation to transform a voltage and supply the voltage to instruments and relays. It concerns the primary winding.

[0002]

2. Description of the Related Art A transformer for an instrument is a primary winding (high voltage winding)
A transformer main body having a structure in which the secondary winding (low-voltage winding) and the secondary winding are concentrically arranged inside and wound around an iron core; Normally, SF ₆ gas) or a portion to be accommodated together with an insulating medium made of insulating oil. As the iron core of the transformer main body, a rectangular iron core is usually used, and the primary winding and the secondary winding have their winding axes oriented in the horizontal direction on the legs of the iron core extending in the horizontal direction. Is wrapped in.

Generally, as a primary winding of a transformer for an instrument,
A layer winding having a structure in which a plurality of cylindrical winding layers are concentrically wound around an outer circumference of a cylindrical winding frame with an insulating layer interposed therebetween is used.

In a conventional primary winding of this type, a plurality of winding layers are set to have the same dimension in the winding axis direction, and a longitudinal section of a half portion along a plane including the winding axis has a substantially rectangular shape. And the winding axis of the innermost winding layer closest to the winding frame in the direction of the winding axis, and the winding axis of the outermost winding layer farthest from the winding frame. In order to minimize the directional dimension, the winding axial direction is successively reduced from the inner circumference side to the outer circumference side, and the winding is performed, and the longitudinal half section along the plane including the winding axis has a trapezoidal shape. There is one that is made like this (hereinafter referred to as a trapezoidal winding).

Of these windings, the trapezoidal winding is arranged such that the winding end portion on the winding start side where the potential is low (the end portion located on the inner peripheral side of the winding) is close to the window portion of the iron core. The end of the winding with a high potential (the end on the outer periphery of the winding) is located farther from the window of the iron core, so the electric field distribution becomes gentle and It is advantageous in terms of electrical insulation. Further, the trapezoidal winding has a trapezoidal vertical cross section and has a large load area, and thus has a mechanically stable structure.

FIG. 4 is a half longitudinal sectional view showing the structure of a trapezoidal winding that has been used as a primary winding of a conventional transformer for an instrument, and this winding has a cylindrical winding frame. B and a number of winding layers W1 and W concentrically wound around the outer circumference of the winding frame B.
2, ... Wn (n is an integer of 2 or more) and the winding layers W1 and W2
, ... Wn formed between the interlayer insulating layers L1, L2, ... Ln-1, an outer peripheral insulating layer Ln formed so as to cover the outer periphery of the outermost winding layer Wn, and an outer periphery. And an annular electric field relaxation shield S arranged so as to surround the outer periphery of the side insulating layer Ln.

In the illustrated primary winding, the winding frame B is formed of a press board or phenol resin when the insulating medium is oil, and is a fader when the insulating medium is insulating gas such as SF ₆ gas. It is formed of a nole resin, an epoxy resin, or the like.

Each winding layer is formed by winding an enameled wire (magnet wire) in a cylindrical shape along the winding axis line, and a series of winding layers W1, W2, ... , The maximum winding axial dimension of the winding layer W1
The outermost winding layer Wn is wound in such a manner that the dimension in the winding axis direction is sequentially shortened from the inner circumference side to the outer circumference side so as to minimize the dimension in the winding axis direction.

The interlayer insulating layers L1, L2, ... Ln-1 and the outer peripheral insulating layer Ln are formed by winding insulating paper or an insulating film so as to obtain a predetermined thickness.

The electric field mitigating shield S is made of a metal having good conductivity such as aluminum or copper so as not to form one turn, and the end portion of the outermost winding layer Wn (the winding of the primary winding is wound). The end portion on the end side) is connected to the shield S, whereby the potential of the shield S is fixed to the potential of the end portion on the high potential side of the primary winding.

Although not shown, the electric field mitigating shield S is provided with a primary terminal, and the primary terminal is connected to a busbar or a line of an electric station.

The primary winding shown in FIG. 4, together with a secondary winding (not shown) arranged concentrically inside the winding frame B,
The winding axis is arranged in the horizontal direction, and the winding is wound around the leg portion of the rectangular iron core (not shown) extending in the horizontal direction. The primary winding shown in FIG. 4, a secondary winding (not shown), and an iron core constitute a main body of the instrument transformer, and the main body is placed in a tank together with an insulating medium made of insulating oil or insulating gas such as SF ₆ gas. It is housed to form a voltage transformer.

[0013]

As described above, in a winding having a structure in which a plurality of winding layers are laminated with an interlayer insulating layer interposed, it is necessary to withstand a voltage (layer bolt) applied between adjacent winding layers. It is necessary to set the thickness of the interlayer insulating layer.

When the voltage applied to the entire primary winding is V1, the total number of turns of the primary winding is N1, and the voltage (turn voltage) applied per turn of the primary winding is Vt, the turn voltage Vt is Vt = V1 / N1 (1) When the number of turns of one winding layer is NL, the layer bolt VL is given by VL = Vt.times.NL.times.2 (2).

In the conventional trapezoidal winding shown in FIG. 4, since all the winding layers are wound uniformly along the winding axis direction, the number of turns of a series of winding layers W1, W2 ,. However, the number of turns of the innermost winding layer W1 located closest to the winding frame is maximum. Therefore, the layer bolt VL becomes high on the inner peripheral side of the winding close to the winding frame, and it is necessary to increase the thickness of the interlayer insulating layer in order to withstand this high layer bolt, but the withstand voltage of the insulator is about the same. Since the thickness of the interlayer insulating layer increases in proportion to the 0.5th power and in proportion to the square of the layer bolt VL, the thickness of the interlayer insulating layer significantly increases on the inner peripheral side of the winding. Therefore, in the conventional winding, not only is the amount of insulator forming the interlayer insulating layer on the inner peripheral side increased, which is uneconomical, but also the radial dimension of the winding increases and the primary winding becomes larger. There was a problem of doing.

Further, in the conventional winding, it is necessary to make the thickness of a series of interlayer insulating layers different on the inner peripheral side of the winding.
There is a problem that the winding work becomes complicated.

An object of the present invention is to eliminate the necessity of making the layer bolts of each part of the winding substantially uniform to increase the thickness of the interlayer insulating layer inside the winding, and to make the thickness of all the interlayer insulating layers almost the same. It is to provide a primary winding of a transformer for an instrument which can be made the same.

[0018]

The present invention comprises a cylindrical bobbin and a plurality of winding layers concentrically wound around the outer periphery of the bobbin with an insulating layer interposed therebetween. , The inner circumference side should be set so that the winding axial dimension of the winding layer closest to the winding frame is maximized and the winding axial dimension of the winding layer furthest from the winding frame is minimized. The primary winding of the transformer for instruments has a structure in which the winding axial dimension of the winding layers is successively reduced toward the outer peripheral side from.

In the present invention, the number of turns of the plurality of winding layers is set to be substantially equal. Then, at the position where each winding layer is divided into two in the winding axis direction, on both sides of a plane orthogonal to the winding axis,
The positions of the ends of the two winding portions located on the side opposite to the plane are symmetrical so that the two winding portions having a substantially equal number of turns wound with a tight winding pitch are present symmetrically. Each winding layer is wound so as to substantially match the positions of both ends of each winding layer.

Of the plurality of winding layers, at least one winding layer farthest from the winding frame is preferably wound uniformly along the winding axis direction. In this case, each of the inner winding layers located inside the uniformly wound winding layer is divided into two winding portions having substantially the same number of turns, and the two winding portions are wound. The inner winding layers, which are respectively arranged on both ends in the axial direction and located closer to the winding frame, have a larger interval between the two winding portions.

According to the present invention, each of the inner winding layers located inside the uniformly wound winding layers is
Winding is performed with the winding pitches of the parts located on both ends in the winding axis direction made dense, and the winding positions of the parts located near the center being made coarse, and the number of turns in the dense winding pitch being set. You may make it set substantially equal.

By winding each winding layer as described above, a trapezoidal winding having a balanced and stable structure can be obtained even if the number of turns of all the winding layers is substantially equal.

As described above, according to the present invention, since the number of turns of all the winding layers can be made approximately equal, the layer bolts can be made substantially uniform in all portions from the inner circumference to the outer circumference of the winding. it can. Therefore, the thickness of all the interlayer insulating layers can be made almost uniform, the thickness of the interlayer insulating layer on the inner circumference side of the winding can be prevented from increasing significantly, and The size can be reduced.

Further, since the thicknesses of all the interlayer insulating layers can be made substantially uniform, the thicknesses of all the interlayer insulating layers can be made substantially the same, which saves the insulating material and simplifies the winding work. It is possible to reduce the manufacturing cost of the trapezoidal winding.

In the present invention, the number of turns of the plurality of winding layers is set to be "substantially" equal to each other. It is not necessary that the number of turns of the plurality of winding layers is equal in a strict sense, and the number of turns of a series of interlayer insulating layers is The number of turns in some of the winding layers may be different to some extent, as long as the effect of making the thicknesses the same is not lost (the layer bolts may be slightly different in some of the windings). It is good).

Similarly, the number of turns of the two winding portions of each winding layer is set to be “substantially” equal to the extent that the balance of the mechanical structure of the trapezoidal winding is not disturbed and the electric field distribution is disturbed. It means that the number of turns of the two winding portions may be slightly different as long as the number of turns does not exist.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, in which B is a cylindrical winding frame, and W1, W2, ... Wn are outer circumferences of the winding frame B. Is a number of winding layers that are wound concentrically. Winding layers W1, W2, ... W
Interlayer insulating layers L1, L2, ... L so as to be interposed between n
n-1 is formed, and the outer peripheral insulating layer Ln is formed so as to cover the outer periphery of the outermost winding layer Wn. Outer insulating layer L
An annular electric field relaxation shield S surrounding the outer periphery of n
Is arranged. This shield S is constructed so as not to form one turn.

In the present invention, all the winding layers W1, W
2. The number of turns of Wn is set to be approximately equal, and the number of turns wound densely on both sides of a plane orthogonal to the winding axis at a position where each winding layer is divided into two in the winding axis direction. So that there are two winding parts that are substantially equal to each other, and
Wind each winding layer so that the positions of the ends on the opposite sides of the planes of the two windings approximately match the positions of both ends of each winding layer, and balance the longitudinal section of the half of the entire winding. It should have a trapezoidal shape.

When each winding layer is wound as described above, two winding portions are arranged at intervals in the winding axis direction in at least the winding layer close to the winding frame. The distance between the two winding portions is greater in the winding layers located farther from the winding frame.

In the example shown in FIG. 1, one winding layer Wn located farthest from the winding frame B is uniformly wound along the winding axis direction while keeping the winding pitch substantially constant. ing.
In the present invention, the winding layers W1 to Wn-1 located inside the uniformly wound winding layer Wn are the inner winding layers, and each of the inner winding layers W1 to Wn-1 is Two winding parts W1a, W2a wound at the same winding pitch as the winding layer Wn,
... Wn-1a and W1b, W2b, ... Wn-1b. Then, the two divided winding portions of the inner winding layers W1, W2, ... Wn-1 are arranged at both ends in the winding axis direction, and the inner winding layers closer to the winding frame B are By setting a large interval between the two divided winding portions, the two divided winding portions W1a, W2a, ... Wn-1a and W1b, W2b, ... Of the winding layers W1 to Wn-1. Wn-1b is arranged along the two hypotenuses of the trapezoid. In the illustrated example, the winding portions W1a, W2a, ... Wn-1a and the winding portion W
The numbers of turns of 1b, W2b, ... Wn-1b are made equal.

As described above, in order to configure each winding layer by the divided two winding portions, for example, the winding machine 1 shown in FIG. 2 is used. This winding machine 1 includes screw rods 2a and 2b which are rotationally driven by an electric motor (not shown) and both screw rods 2
nuts 3a and 3b screwed to a and 2b respectively and moved in the axial direction of the winding frame B with the rotation of the screw rods 2a and 2b, and attached to the nuts 3a and 3b to hold the electric wires 4a and 4b. Meanwhile, the electric wire adjusters 5a and 5b that are moved (traverse) in the axial direction of the winding frame together with the nuts 3a and 3b are provided. When winding a winding using this winding machine, the electric wires 4a and 4b guided by the electric wire adjusters 5a and 5b are guided to the outer circumference of the winding frame B to rotate the screw rods 2a and 2b simultaneously. , The reel B while moving the electric wire adjusters 5a and 5b in the winding axis direction.
The two winding portions W1a and W1b are simultaneously wound around the outer circumference of the winding frame B at intervals in the winding axis direction by rotating. After the winding portions W1a and W1b having a predetermined number of turns are wound, the winding end portion of one winding portion W1a is connected to the winding start end portion of the other winding portion W1b. The wire portions W1a and W1b are connected in series to form the first winding layer W1. Then, an insulating material such as an insulating film is wound around the outer periphery of the winding layer W1 to form an interlayer insulating layer L1, and the second winding layer W2 is formed on the outer periphery of the interlayer insulating layer L1 by the same method as described above. The two winding parts W
2a and W2b are wound at the same time with a spacing smaller than the spacing between the winding portions W1a and W1b. The same operation is repeated thereafter to wind a series of winding layers W1 to Wn-1. Finally, the outermost peripheral winding layer Wn is uniformly wound, and the outer peripheral insulating layer Ln is formed on the outer periphery of the winding layer Wn.

When performing the winding work using the winding machine 1 of FIG. 2, as the winding layers are successively wound from the inner circumference side to the outer circumference side, the winding of each winding layer is continued. Although it is necessary to shift the initial positions of the electric wire adjusters 5a and 5b at the time of starting, the initial positions of the electric wire adjusters 5a and 5b and the number of turns of each winding part are the rotation of the screw rods 2a and 2b and the winding frame. The rotation of B can be set appropriately by controlling the rotation of B using a microcomputer or a programmable controller.

In the above example, the inner winding layers are each divided into two winding portions, and the two winding portions are connected in series to form each winding layer. As shown in FIG. 3, one screw rod 2 and the screw rod 2
A wire winding machine 1 having a nut 3 that is screwed into a screw and is moved in the winding axis direction with the rotation of the screw rod, and a wire winding machine 5 attached to the nut 3 is used.
By controlling the traverse speed of each winding layer, the winding pitch of each end of each winding layer in the winding axis direction is made dense, and the winding pitch of the portion of each winding layer from the center in the winding axis direction is made coarse. You may do it. FIG. 3 shows a state in which the first winding layer W1 is wound. In this example, the portions corresponding to the winding portions W1a and W1b in FIG. 1 are wound with a fine winding pitch. The portion W1c near the center in the winding axis direction is wound with a coarse winding pitch. Such a winding layer slows down the traverse speed of the electric wire 4 at both end sides in the winding axis direction, and increases the traverse speed of the electric wire 4 near the central portion in the winding axis direction. It can be wound by controlling. After winding the winding layer W1, an insulating material is wound around the winding layer W1 to form an interlayer insulating layer L1, and the interlayer insulating layer L1 is formed.
A second winding layer W2 is wound around the outer periphery of the. This winding layer W
When 2 is wound, the winding portions W2a and W2b having a dense winding pitch are wound closer to the inside than the winding portions W1a and W1b of the winding layer W1, and the winding pitch is coarse. The axial dimension of the portion is made shorter than the axial dimension of the corresponding portion of the winding layer W1. Thereafter, the same operation is repeated to wind the winding layer Wn-1, and the interlayer insulating layer Ln-1 is formed on the outer periphery of the winding layer Wn-1. After that, the winding layer Wn is uniformly wound around the outer periphery of the interlayer insulating layer Ln-1 with a dense winding pitch, and the outer peripheral insulating layer Ln is formed on the outer periphery of the winding layer Wn.

[0034]

As described above, according to the present invention, since the number of turns of all the winding layers can be made approximately equal, the layer bolts can be made substantially uniform in all the portions from the inner circumference to the outer circumference of the winding. can do. Therefore, the thickness of all interlayer insulation layers can be made almost uniform, the thickness of the interlayer insulation layer on the inner circumference side of the winding can be prevented from increasing significantly, and the diameter of the primary winding The directional dimension can be reduced.

Further, according to the present invention, since the thickness of all the interlayer insulating layers can be made substantially uniform, the thickness of all the interlayer insulating layers can be made substantially the same to save the insulating material and the winding. The work can be simplified and the manufacturing cost of the trapezoidal primary winding can be reduced.

[Brief description of drawings]

FIG. 1 is a half longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an example of a winding machine used when winding a primary winding according to the present invention and a winding wound by the winding machine.

FIG. 3 is a perspective view showing another example of a winding machine used when winding a primary winding according to the present invention and a winding wound by the winding machine.

FIG. 4 is a half longitudinal sectional view showing a conventional winding.

[Explanation of symbols]

 B winding frame W1 to Wn winding layer W1a to Wn-1a winding portion arranged on one end side of the winding layer W1b to Wn-1b winding portion arranged on the other end side of the winding layer L1 to Ln- 1 Interlayer insulation layer

Claims (3)

[Claims] 1. A winding frame having a cylindrical shape, and a plurality of winding layers concentrically wound around an outer periphery of the winding frame with an insulating layer interposed between the winding layers. Is the maximum winding axis direction dimension of the winding layer in the position closest to the winding frame,
An instrument that is wound by decreasing the winding axial direction dimension from the inner circumference side to the outer circumference side so that the winding axis direction dimension of the winding layer furthest from the winding frame is minimized. In the primary winding of the transformer, the number of turns of the plurality of winding layers is set to be substantially equal to each other, and each winding layer is orthogonal to the winding axis at a position dividing the winding layer into two in the winding axis direction. Positioned on both sides of the plane such that two winding portions having substantially the same number of turns with a substantially constant winding pitch exist symmetrically and on the opposite side of the two winding portions from the plane. A primary winding of a transformer for an instrument, characterized in that the winding is wound so that the positions of the ends of the windings substantially match the positions of both ends of each winding layer in the winding axis direction. 2. A cylindrical winding frame and a plurality of winding layers concentrically wound around the outer periphery of the winding frame with an insulating layer interposed between the winding layers. Is the maximum winding axis direction dimension of the winding layer in the position closest to the winding frame,
An instrument that is wound by decreasing the winding axial direction dimension from the inner circumference side to the outer circumference side so that the winding axis direction dimension of the winding layer furthest from the winding frame is minimized. In the primary winding of the transformer, the number of turns of the plurality of winding layers is set to be substantially equal, and at least one winding layer among the plurality of winding layers is located at a position farthest from the winding frame. Each of the inner winding layers located inside the uniformly wound winding layer is uniformly wound along the direction, and each of the inner winding layers is divided into two winding portions having substantially the same number of turns. The two divided winding parts are arranged on both ends in the winding axis direction, and the inner winding layer closer to the winding frame has a larger interval between the two divided winding parts. The primary winding of an instrument transformer, which is characterized in that 3. A winding frame having a cylindrical shape, and a plurality of winding layers concentrically wound around the outer circumference of the winding frame with an insulating layer interposed between the winding layers. Is the maximum winding axis direction dimension of the winding layer in the position closest to the winding frame,
An instrument that is wound by decreasing the winding axial direction dimension from the inner circumference side to the outer circumference side so that the winding axis direction dimension of the winding layer furthest from the winding frame is minimized. In the primary winding of the transformer, the number of turns of the plurality of winding layers is set to be substantially equal, and at least one winding layer among the plurality of winding layers has a winding axis line at a position farthest from the winding frame. Windings are uniformly wound along the direction, and each of the inner winding layers located inside the uniformly wound winding layer is a winding of a portion located at both ends in the winding axis direction. It is wound in a state where the pitch is made dense and the winding pitch of the portion located near the center is made coarse, and the number of turns of the dense winding pitch portion is set to be substantially equal. Primary winding of the transformer.