JPH0992557A - Primary winding of transformer for meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the primary winding of a transformer for a meter, which can prevent voltage between layers from becoming high and interlayer insulating layer from becoming thick on the inner side part of a winding. SOLUTION: Groups W1 to Wn of winding layers 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, and the sectional form of the half of the whole winding is formed into a trapezoid shape. The groups of the winding layers are divided into the first groups W1 to Wm of the winding layers, which are positioned on the side close to the spool, and the second groups Wm+1 to Wn of the winding layers, which are positioned on the outsides of the first groups of the winding layers. The first groups W1 to Wm of the winding layers are formed by winding two parallel conductors C1 and C2 and the second groups Wm+1 to Wn of the winding layers are formed by winding one conductor C.

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).

Among these windings, the trapezoidal winding is arranged such that the starting end portion (terminal portion on the winding start side) of the winding having a low electric potential is located near the window of the iron core and the trapezoidal winding has a high electric potential. Since the terminal end portion (terminal portion on the winding end side) is arranged at a position further away from the window portion of the iron core, the electric field distribution becomes gentle, which 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 are formed by winding insulating paper or 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 (terminal on the winding end side). Part) is connected to the shield S, whereby the potential of the shield S is fixed to the potential of the end portion 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.

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

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).

[0015]

In the conventional trapezoidal primary winding shown in FIG. 4, all winding layers have a single conductor wound uniformly along the winding axis direction. , The winding numbers of the series of winding layers W1, W2, ... Are different, and the winding number of the innermost winding layer W1 closest to the winding frame is maximum. Therefore, on the inner circumference side of the winding near the winding frame,
The layer bolt VL becomes high, 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 approximately proportional to the 0.5th power of the thickness,
Since the thickness of the interlayer insulating layer increases in proportion to the square of the layer bolt VL, the thickness of the interlayer insulating layer increases on the inner peripheral side of the winding. Therefore, in the conventional winding, not only is the amount of insulating material forming the interlayer insulating layer increased in the inner portion close to the winding frame, which is uneconomical, but also the radial dimension of the winding is increased and the primary winding is There was the problem of becoming larger.

An object of the present invention is to prevent the layer bolts from becoming high in the inner portion of the winding, to make the thickness of the interlayer insulating layer thinner than before, and to reduce the amount of the insulator forming the interlayer insulating layer. Thus, it is intended to provide a primary winding of a transformer for an instrument, which can reduce the cost and also reduce the radial dimension of the winding.

[0017]

The present invention comprises a cylindrical winding frame and a winding layer group which is concentrically wound around the outer periphery of the winding frame with an insulating layer interposed between the winding layers. A series of winding layers forming a layer group has the maximum winding axis direction dimension of the winding start side winding layer closest to the winding frame and the winding end side farthest position from the winding frame. Related to the primary winding of the transformer for the instrument, which 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 is minimized. It is a thing.

In the present invention, the above-mentioned winding layer group includes a first winding layer group arranged on the side close to the winding frame and a second winding layer group arranged outside the first winding layer group. Each of the winding layers constituting the first winding layer group is formed by winding two conductors (insulated wire such as an enamel wire) in parallel. On the starting end side and the ending end side of one winding layer group, the starting ends and the ending ends of the two windings respectively formed by the two conductors are connected to each other. In addition, each winding layer forming the second winding layer group is formed by winding one conductor.

The winding of two conductors in parallel means that the two conductors are wound at the same time in a state of being aligned in the winding axis direction. Since the starting end portions and the terminating end portions of the windings, which are respectively formed by two conductors on the starting end portion side and the terminal end portion side of the first winding layer group, are connected to each other, both windings are parallel to each other. Will be connected. Therefore, the total number of turns of the first winding layer group is 1 / the number of turns when the first winding layer group is wound with one conductor.
It becomes 2. Moreover, in this case, the dimension of each winding layer of the first winding layer group in the winding axis direction maintains the size required for making the cross-sectional shape of the half part of the entire primary winding trapezoidal. Therefore, the features of the trapezoidal winding are never lost.

In the present specification, the "starting end" means the end of the winding on the winding start side, and the "end" means the end of the winding on the winding end. For each winding layer and each winding layer group, the starting end portion and the terminating end portion are used as terms that mean the end portions on the winding start side and the winding end side, respectively.

In order to connect between the terminal end of the first winding layer group and the starting end of the second winding layer group, the first winding layer group and the second winding layer group are connected to each other. A relay plate made of a conductive plate is disposed so as to be interposed between the end portions of the outermost winding layer of the first winding layer group and the innermost periphery of the second winding layer group. It is preferable that the starting end of the winding layer is connected to the relay plate.

As described above, the first winding layer group in which the winding layer group is arranged in a position close to the winding frame and the second winding layer arranged outside the first winding layer group When each winding layer constituting the first winding layer group is wound by two parallel conductors separately from the layer group, the number of turns of each winding layer of the first winding layer group is Since it is approximately 1/2, the layer bolt in the first winding layer group is approximately 1/2 of the layer bolt in the corresponding portion of the conventional primary winding.

As described above, according to the present invention, the rise of the layer bolt in the inner portion of the winding close to the winding frame is suppressed and the inner portion of the winding is prevented without impairing the characteristics of the trapezoidal winding. Thus, the interlayer insulating layer can be prevented from being thickened, and the radial dimension of the trapezoidal primary winding can be reduced as compared with the conventional one. Further, since the thickness of the interlayer insulating layer can be reduced in the inner portion of the winding, the amount of insulating material forming the interlayer insulating layer can be reduced, and the cost can be reduced.

Further, since the winding layers constituting the first winding layer group are formed by winding two conductors in parallel, the resistance value thereof is low. Therefore, it is possible to reduce heat generation in the first winding layer group, and it is possible to prevent the temperature of the inner portion of the winding from rising locally and deterioration of the insulator.

[0025]

1 to 3 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a half portion showing the overall structure, and FIG. 2 is a winding winding. FIG. 3 is a half longitudinal sectional view for explaining the structure, and FIG. 3 is a perspective view showing the structure near the boundary between the first and second winding layer groups. In FIGS. 1 and 2, B is a cylindrical bobbin, W1, W2, ..., Wm,
Wm + 1, ..., Wn-1, Wn (2 <m <n) are a large number of winding layers concentrically wound around the outer circumference of the winding frame B. Interlayer insulating layers L1, L2, ..., Lm made of a wound body of insulating paper or insulating film so as to be interposed between the winding layers W1, W2, ..., Wm, Wm + 1, ..., Wn-1, Wn. , Lm + 1,
, Ln-1 are formed, and the outer peripheral insulating layer Ln is formed so as to cover the outer periphery of the outermost winding layer Wn. An annular electric field relaxing shield S is arranged so as to surround the outer circumference of the outer insulating layer Ln. This shield S is constructed so as not to form one turn.

In the present invention, the winding layer groups W1, W2,
, Wm, Wm + 1, ..., Wn-1, Wn, for example, at a substantially middle position in the radial direction, the first winding layer group W1, W2, ..., Wm arranged near the winding frame B. And a second winding layer group Wm + 1, ..., Wn-1, arranged outside the first winding layer group.
Divide into Wn. The winding layers W1, W2, ..., Wm, Wm + 1, ..., Wn-1, Wn forming the first winding layer group
As shown in FIG. 2, two conductors C1 and C2 made of magnet wire (enamel wire) are wound side by side in parallel (two conductors C1 and C2 are aligned in the winding axis direction at the same time). 2) to form the starting end of the first winding layer group (the starting end of the winding layer W1) 2
The ends C1a and C2a of the conductors C1 and C2 are connected to each other, and the ends C1b and C2b of the conductors forming the end part of the first winding layer group (the end part of the winding layer Wm) are connected to each other. , The windings respectively formed by the two conductors C1 and C2 are connected in parallel. In addition, the winding layer Wm + 1 constituting the second winding layer group
, ..., Wn-1 and Wn are formed by winding one conductor C as in the conventional one.

In order to connect the terminal end of the first winding layer group and the starting end of the second winding layer group, as shown in FIG.
Insulating layer Lma is formed on the outer periphery of the outermost winding layer Wm of the winding layer group of
Is formed, and a relay plate P made of a plate of both conductive materials such as a copper plate is wound around the outer periphery of the insulating layer Lma. The relay plate P is formed to have a width dimension narrower than that of the insulating layer Lma and a length slightly longer than the circumferential length of the insulating layer Lma. An insulating film F is inserted between the overlapped portions on both ends of the plate P. The insulating film F insulates both ends of the relay board P and prevents the relay board from forming a one-turn short circuit. On one end side in the width direction of the relay plate P, the terminal portions C1b and C2b of the conductors forming the terminal end portion (terminal end portion of the winding layer Wm) of the first winding layer group are soldered, and the terminal ends of the conductors are soldered. Adhesive tape T1 near parts C1b and C2b
It is fixed to the relay plate P by. Further, on the other end side in the width direction of the relay plate P, the starting end of the second winding layer group (winding layer Wm + 1
The end portion Ca of one conductor C constituting the start portion) is soldered, and the vicinity of the end portion Ca of the conductor C is fixed to the relay plate P by the adhesive tape T2. An insulating layer Lmb is formed to cover the relay plate P and the conductor soldered to the relay plate, and the insulating layers Lma and Lmb insulate the winding layers Wm and Wm + 1 from each other. Is configured. The conductor C soldered to the relay conductor P is transferred to the outer circumference of the insulating layer Lmb, and the conductor C causes the second layer of the winding layer Wm + 1 and thereafter.
Each winding layer of the winding layer group is wound.

As described above, when the first winding layer group is wound by the two parallel conductors, the number of turns of each winding layer of the first winding layer group is about half that of the conventional one. The layer bolts at the respective portions of the first winding layer group are approximately 1/2 of the layer bolts at the corresponding portions of the conventional primary winding. Moreover, in this case, the dimension of each winding layer of the first winding layer group in the winding axis direction maintains the size required for making the cross-sectional shape of the half part of the entire primary winding trapezoidal. Therefore, the features of the trapezoidal winding are never lost.

As described above, according to the present invention, the rise of the layer bolt at the inner portion of the winding close to the winding frame is suppressed without damaging the characteristics of the trapezoidal winding, and the inside of the winding is suppressed. It is possible to prevent the interlayer insulating layer from becoming thicker in the part,
The radial dimension of the trapezoidal primary winding can be reduced more than ever before. Further, since the thickness of the interlayer insulating layer can be reduced in the inner portion of the winding, the amount of insulating material forming the interlayer insulating layer can be reduced, and the cost can be reduced.

Further, since the winding layers constituting the first winding layer group are formed by winding two conductors in parallel, the resistance value thereof can be lowered and the first winding It is possible to reduce the heat generation in the layer group and prevent the temperature from rising locally in the inner portion of the winding.

In the above example, the winding layer group is divided into the first winding layer group and the second winding layer group at the radial intermediate position, but in the present invention, the conventional layer bolt is used. The inner part of the winding (the part near the bobbin) that had been raised
The number of windings of each winding layer forming the inner part of the winding is halved from that of the conventional one by winding the two parallel conductors.
Since the purpose is to reduce the layer bolt thickness and to make the thickness of the interlayer insulating layer thinner in the inner portion of the winding than in the conventional case, the winding layer group is not necessarily formed in the first portion in the radial direction.
Of the winding layer group and the second winding layer group (the number of winding layers forming the first winding layer group and the number of winding layers forming the second winding layer group are It is not necessary to make the same), so that the effect of reducing the layer bolt in the inner part of the winding (especially the effect of reducing the radial dimension of the winding by reducing the thickness of the interlayer insulating layer) can be effectively obtained. The first winding layer group and the second winding layer group
The distribution of the number of winding layers forming each winding layer group may be determined.

[0032]

As described above, according to the present invention, since the rise of the layer bolt in the inner portion of the winding close to the winding frame can be suppressed, the interlayer insulating layer becomes thicker in the inner portion of the winding. It is possible to prevent the above, and it is possible to reduce the radial dimension of the trapezoidal primary winding as compared with the conventional case.

Further, according to the present invention, since the thickness of the interlayer insulating layer can be reduced in the inner portion of the winding, the amount of insulating material forming the interlayer insulating layer can be reduced and the cost can be reduced. be able to.

Further, according to the present invention, since the winding layer forming the first winding layer group is formed by winding two conductors in parallel, the resistance value thereof is reduced to the first winding layer group. It is possible to reduce heat generation in the winding layer group, and it is possible to prevent the temperature of the inner portion of the winding from rising locally and deterioration of the insulator.

[Brief description of drawings]

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

FIG. 2 is a half-longitudinal cross-sectional view showing exaggeratedly the dimensions of conductors for explaining the winding structure adopted in the embodiment of FIG.

FIG. 3 is a perspective view for explaining an example of a connection structure between a terminal end of the first winding layer group and a starting end of the second winding layer group.

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

[Explanation of symbols]

 B winding frame W1 to Wm first winding layer group Wm + 1 to Wn second winding layer group L1 to Ln-1 interlayer insulating layer C1, C2, C conductor

Claims (2)

[Claims] 1. A winding frame group comprising a cylindrical winding frame and a winding layer group concentrically wound around an outer periphery of the winding frame with an insulating layer interposed between the winding layers. The series of winding layers has the maximum winding axial direction dimension of the winding start side winding layer closest to the winding frame, and the winding end side winding layer farthest from the winding frame. In the primary winding of the instrument transformer, which is wound by decreasing the winding axis direction dimension from the inner circumference side to the outer circumference side in order to minimize the winding axis direction dimension, the winding layer The group includes a first winding layer group arranged on the side close to the winding frame and a second winding layer group arranged outside the first winding layer group.
Each of the winding layers constituting the first winding layer group is formed by winding two conductors in parallel, and the first winding layer group Of the windings formed by two conductors on the starting end side and the terminal end side of the winding are connected to each other, and each winding layer forming the second winding layer group is 1 A primary winding of a transformer for an instrument, which is formed by winding a conductor of a book. 2. The winding layer group comprises a cylindrical winding frame and a winding layer group wound concentrically around the outer periphery of the winding frame with an insulating layer interposed between the winding layers. The series of winding layers has the maximum winding axial direction dimension of the winding start side winding layer closest to the winding frame, and the winding end side winding layer farthest from the winding frame. In the primary winding of the instrument transformer, which is wound by decreasing the winding axis direction dimension from the inner circumference side to the outer circumference side in order to minimize the winding axis direction dimension, the winding layer The group includes a first winding layer group arranged on the side close to the winding frame and a second winding layer group arranged outside the first winding layer group.
Each of the winding layers constituting the first winding layer group is formed by winding two conductors in parallel, and each winding layer is formed by the two conductors. Starting ends of the wound windings are connected to each other, and each winding layer forming the second winding layer group is formed by winding one conductor, and the first winding layer group and A relay plate made of a conductive plate is arranged so as to intervene between the second winding layer group, and the terminal end of the outermost winding layer of the first winding layer group and the second winding layer group. A primary winding of a transformer for an instrument, wherein the starting end of the innermost winding layer of the winding layer group is connected to the relay plate.