JP2861695B2 - Primary coil of instrument transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer used in an instrument transformer.
It concerns the next coil.

[0002]

2. Description of the Related Art FIGS. 9 and 10 show an example of the structure of an instrument transformer VT. In these figures, 1 is an iron core, and 2 is a secondary coil (low-voltage coil) wound around an iron core 1. Reference numeral 3 denotes a primary coil (high-voltage coil) wound around the secondary coil 2 concentrically with the secondary coil. The primary coil 3 is formed by laminating a multi-layer coil with a layer insulating layer interposed between layers, and the layer insulating layer is formed by winding a thin insulating paper or an insulating plastic film until a predetermined thickness is obtained. Consists of An annular high voltage shield 4 is arranged outside the primary coil 3, and the potential of the high voltage side shield 4 is fixed to the potential of one end of the primary coil 3. A low-voltage side shield 5 is provided at both ends of the secondary coil 2.
Is arranged. An iron transformer 1, a secondary coil 2, a primary coil 3, a high-voltage shield 4 and a low-voltage shield 5 constitute a main transformer body for an instrument. The main transformer body is housed in a tank 6. An insulating spacer 7 is attached so as to close an opening provided at the upper end of the tank 6, and the shield 4 is connected to a conductor 8 provided through the insulating spacer. A primary voltage is applied to the primary coil 3 through the conductor 8 and the shield 4. The tank 6 is filled with an insulating medium such as SF ₆ gas or insulating oil.

[0003] The 1 used in the instrument transformer as described above
The secondary coil 3 has a structure in which a layered insulating layer formed of a winding body of a thin insulating sheet made of insulating paper or an insulating plastic film and a coil formed by winding an electric wire in a cylindrical shape are alternately and concentrically laminated. Therefore, there is a problem that the electric wire is easily shifted in the axial direction. Therefore, conventionally, a double-sided adhesive tape was interposed between the coil and the layer insulating layer, or a semi-cured thermosetting resin was coated on an insulating sheet forming the layer insulating layer, and the coil was wound. Later, the resin is heated and cured to fix the electric wire.

FIG. 5 shows the structure of a conventional primary coil using an insulating sheet coated on one side with a resin in a semi-cured state. The primary coil 3 has a structure in which layer insulation layers 3a and coils 3b are alternately wound, and the layer insulation layer 3a is an insulating sheet 301 in which a semi-cured thermosetting resin 300 is coated on one side entirely. Is wound until a predetermined thickness is obtained. This one
As shown in FIG. 6, the next coil is formed by winding the electric wire 10 around the winding form 9 while winding an insulating sheet 301 coated on one side with a resin 300 in a semi-cured state between layers. After the coil is wound, the resin 300 is cured and the coil 3b is fixed.

FIG. 7 shows a structure of a conventional primary coil using an insulating sheet 301 in which both surfaces of an insulating sheet are coated with a resin 300 in a semi-cured state. As shown in FIG. 8, the primary coil 3 is formed by winding an electric wire 10 around a winding form 9 while winding an insulating sheet 301 coated on both sides with a resin 300 in a semi-cured state between layers. . After the coil is wound, the resin 300 on both sides of the insulating sheet is cured, and the coil 3b is fixed.

[0006]

When a double-sided adhesive tape is interposed between the coil and the layer insulating layer, it is necessary to stop the winding machine to attach the adhesive tape to the coil. There was a problem of poor sex.

In addition, as shown in FIG. 5, when one surface of the insulating sheet is coated with a semi-cured resin, the entire inner surface or the outer surface of the coil of each layer is entirely fixed by the resin. In this state, the insulation medium can be permeated between the layers to enhance the insulation performance.However, there is a shift in the electric wire between the surface of the coil of each layer that is not fixed by the resin and the layer insulation layer. There was a problem that it became easier.

As shown in FIG. 7, when the resin in a semi-cured state is coated on both sides of the insulating sheet, the mechanical strength can be increased, but the resin entering between the layers is not as shown in FIG. Therefore, there is a problem that the diameter of the primary coil becomes large and the transformer for the instrument becomes large.

[0009] Furthermore, when configured as shown in FIG. 7, since the insulating medium of SF ₆ gas or an insulating oil or the like between Reya impermeable, insulation between Reya rely only on the insulating performance of the resin and the insulation sheet As a result, it is difficult to improve the insulation performance.

When a resin is interposed between the layers, if bubbles remain in the resin, the insulation performance deteriorates. Therefore, it is necessary to minimize the bubbles. However, as shown in FIG. When an insulating sheet coated with a resin is used, the resin surface overlaps with the resin surface, so that there is a problem that air bubbles easily remain between the resins as compared with the case of single-side coating.

An object of the present invention is to provide an instrument transformer capable of improving the mechanical strength without increasing the size of the coil and without lowering the insulation performance.
It is to provide a secondary coil.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a primary coil of an instrument transformer in which a multilayer coil is superposed and wound via a layer insulating layer formed of a winding body of an insulating sheet.

According to the first aspect of the present invention, the resin coating region in which the semi-cured thermosetting resin is coated on the front surface and the back surface of the insulating sheet is locally (not over the entire surface). Have. The resin coating areas on the front and back surfaces of the insulating sheet are provided so as to be continuous in the longitudinal direction of the insulating sheet, and the resin coating areas on the front and back sides so that the resins do not overlap when the insulating sheet is wound. Are shifted in the width direction of the insulating sheet. The resin in each resin coating area is cured while the multilayer coil is wound.

According to the second aspect of the present invention, the resin coating regions formed on the front surface and the back surface of the insulating sheet are provided discontinuously at regular intervals in the longitudinal direction of the insulating sheet. The positions of the resin coating regions on the front and back surfaces are shifted in the width direction of the insulating sheet so that the resins do not overlap when the insulating sheet is wound. Other points are the same as those of the first aspect.

In the present invention, which side of the insulating sheet is the front side and which side is the rear side is arbitrary.

[0016]

The resin coating regions are locally provided on the front and back surfaces of the insulating sheet as described above, and the positions of the resin coating regions on the front and back surfaces are such that the resins do not overlap when the insulating sheet is wound. When the resin is shifted, the resin does not overlap between the layers, so that the radial dimension of the coil does not increase as in the case of coating the entire resin on both surfaces of the insulating sheet.

Further, with the above configuration, the inner peripheral surface and the outer peripheral surface of the coil of each layer always have a portion fixed by resin, so that the mechanical strength of the coil can be increased, The position of the electric wire can be prevented from shifting due to the electromagnetic mechanical force acting on the wire.

Further, with the above configuration, since the resins do not overlap each other between the layers, it is difficult for air bubbles to remain in the resin, and it is possible to prevent insulation performance from deteriorating due to the air bubbles remaining.

Further, since a portion where the resin does not exist is left between the layers, an insulating medium can be permeated between the layers to improve the insulating performance.

[0020]

FIG. 1 shows a partial cross section of an embodiment of the present invention. In this embodiment, a primary coil 3 includes a layer insulating layer 3a.
And the coil 3b are wound alternately. Layer insulating layer 3a, semi-cured thermosetting resin (for example, epoxy resin) 300a and 30
An insulating sheet 301 locally having a resin coating region coated with Ob is wound until a predetermined thickness is obtained. In the present embodiment, the resin coating areas on the front and back surfaces of the insulating sheet 301 are provided so as to be continuous in the longitudinal direction of the insulating sheet, and the front side and the side so that the resins do not overlap when the insulating sheet is wound. The position of the resin coating area on the back side is shifted in the width direction of the insulating sheet.

As shown in FIG. 2, the primary coil has semi-cured resins 300a and 300
The wire 10 is formed by winding the electric wire 10 around the winding form 9 while winding the insulating sheet 301 coated with 00b between layers. After the coil is wound, the resin 300a and 3
00b is cured to fix the coil 3b.

After the coil is wound, the whole is put into a heating furnace and heat-treated while vacuuming. When heat treatment is performed, the resin in a semi-cured state is once melted and cured while penetrating between the electric wires constituting the coil as shown in the figure. The electric wire of the coil of each layer is fixed by the cured resin.

In the case of the above embodiment, since the resin does not overlap between the layers, the radial dimension of the coil is increased as in the case where the resin is coated on both sides of the insulating sheet as shown in FIG. There is no.

Further, in the configuration as in the above embodiment, since the inner and outer peripheral surfaces of the coil 3b of each layer always have portions fixed with resin, it is possible to increase the mechanical strength of the coil. it can.

Further, when the structure is made as in the above embodiment, the resin does not overlap between the layers, and it is difficult for air bubbles to remain in the resin. Therefore, it is possible to prevent the insulation performance from being deteriorated due to the air bubbles remaining. .

Further, since a portion where no resin exists between the layers is left, an insulating medium such as SF ₆ gas or insulating oil can be permeated between the layers to improve the insulating performance.

In the above embodiment, the resin coating areas on the front and back surfaces of the insulating sheet 301 are provided so as to be continuous in the longitudinal direction of the insulating sheet. However, as shown in FIG. 3 or FIG. Thermosetting resins 300a and 300 in a semi-cured state
The resin-coated regions coated with b may be provided discontinuously at regular intervals in the longitudinal direction of the insulating sheet.

[0028]

As described above, according to the present invention, a resin coating region is locally provided on each of the front and back surfaces of the insulating sheet so that the resin does not overlap when the insulating sheet is wound. Also, by shifting the position of the resin coating area on the back side so that the resins do not overlap each other between the layers, the radial dimension of the coil increases as in the case of coating the entire resin on both sides of the insulating sheet There is no.

Further, according to the present invention, since the inner and outer peripheral surfaces of the coil of each layer always have a portion fixed by resin, the mechanical strength of the coil can be increased, and the electromagnetic machine acting on the coil can be improved. The displacement of the position of the electric wire due to the force can be prevented.

Further, according to the present invention, since the resins do not overlap each other between the layers, it is difficult for air bubbles to remain in the resin, and it is possible to prevent the insulation performance from being reduced due to the air bubbles remaining.

Further, according to the present invention, since a portion where no resin is present is left between the layers, an insulating medium can be permeated between the layers to improve the insulating performance.

Therefore, according to the present invention, there is provided an instrument for an instrument having the same mechanical strength as when the entire surface of the insulating sheet is coated with resin, and the same insulating performance as when only one surface of the insulating sheet is coated with resin. There is an advantage that a primary coil of the transformer can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state in which the coil of FIG. 1 is wound.

FIG. 3 is a main part plan view showing another example of an insulating sheet that can be used in the present invention.

FIG. 4 is a plan view of a main part showing still another example of an insulating sheet that can be used in the present invention.

FIG. 5 is a sectional view of a main part showing an example of the structure of a conventional primary coil.

FIG. 6 is an explanatory diagram showing a state where the primary coil of FIG. 5 is wound.

FIG. 7 is a sectional view of a main part showing a structure of another conventional primary coil.

FIG. 8 is an explanatory diagram showing a state where the primary coil of FIG. 7 is wound.

FIG. 9 is a cross-sectional view showing an example of the structure of the instrument transformer.

FIG. 10 is a cross-sectional view showing a structure of the instrument transformer of FIG. 9 taken along a line AA in FIG. 9;

[Explanation of symbols]

 3 Primary coil 3a Layer insulating layer 3b Coil 300a Semi-cured resin 300b Semi-cured resin 301 Insulating sheet

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01F 38/24 H01F 27/32

Claims (2)

(57) [Claims] 1. A primary coil of a transformer for an instrument formed by laminating a multi-layered coil via a layer insulating layer comprising a wound body of an insulating sheet, wherein the insulating sheet is semi-cured on its front and back surfaces, respectively. A resin coating region locally coated with a thermosetting resin in a state, wherein the resin coating regions on the front and back surfaces of the insulating sheet are provided so as to be continuous in a longitudinal direction of the insulating sheet; The positions of the resin coating areas on the front side and the back side are shifted in the width direction of the insulating sheet so that the resins do not overlap each other when wound, and each resin coating is wound in a state where the multilayer coil is wound. A primary coil of an instrument transformer, wherein a resin in a region is hardened. 2. A primary coil of a transformer for an instrument, wherein a multilayer coil is wrapped over a layer insulating layer comprising a wound body of an insulating sheet, wherein the insulating sheet is semi-cured on its front and back surfaces, respectively. Locally having a resin coating region coated with a thermosetting resin in a state, wherein the resin coating regions on the front surface and the back surface of the insulating sheet are discontinuous with a certain interval in a longitudinal direction of the insulating sheet. The positions of the resin coating regions on the front side and the back side are shifted in the width direction of the insulating sheet so that the resins do not overlap each other when the insulating sheet is wound, and the multilayer coil is wound. The primary coil of the instrument transformer, wherein the resin in each resin coating area is cured in a state of being set.