JPH03138916A - Static induction device - Google Patents

Abstract

PURPOSE:To provide a small induction device while improving insulation at fine gaps formed between a strand and a spacer or rail by impregnating or coating the strand insulator with semi-solid insulating material. CONSTITUTION:A strand 10 includes a flat copper conductor 7 wrapped in insulator 8 made of turns of insulating paper or plastic film. The insulator is impregnated or coated with semi-solid insulating material 11 such as silicone gel or butadiene gel. When the strand is wound, its tension compresses the semi-solid insulating material 11, which in turn fills voids and gaps between the strand and a rail or spacer. In addition, the insulating material prevents the formation of fine gaps between windings of the strand.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a static induction device such as a transformer formed by winding a winding around an iron core.

(Prior Art) In the event of a fire, explosion, etc. occurring at substations or underground substations around large cities, the impact on society would be immeasurably large.

In particular, in the case of transformers, reactors, etc. that use insulating oil as an insulating medium, there is a high risk of fire and explosion, so in order to make the equipment nonflammable, SF is used instead of insulating oil.
Application of a gas insulated transformer using a nonflammable insulating gas such as 6 gas as an insulating medium is being considered.

FIGS. 3 and 4 show the configuration of a typical transformer winding as an example of such a stationary induction device.

That is, a rail 9 for securing a cooling path is provided on the basic insulating cylinder 1, and the strands 2 coated with insulation are placed on the rail 9.
is wound into a disk shape, and a spacer 6 is provided between each strand 2 to form a constant gap between them, and these are overlapped in the axial direction to form the transformer winding 3. It is configured. In addition, in order to control the electric field at the end of the winding 3, a molded insulating material 4 whose one end is supported and fixed to the basic insulating cylinder 1 and an electrostatic ring fixed thereto are provided on the upper part of the winding 3. 5
is installed.

In the conventional transformer winding constructed in this manner, the insulation strength depends on the insulating oil or insulating gas as the insulating medium. That is, as is well known, the dielectric breakdown voltage of insulating oil changes depending on the gap length, and the shorter the gap length, the higher the dielectric breakdown electric field. On the other hand, the dielectric breakdown electric field of the insulating gas has little dependence on the gap length, and is of an electric field dependent type in which the highest electric field is the starting point of dielectric breakdown.

Furthermore, due to the difference in dielectric constant between the insulating gas and the insulating oil, in a composite insulation configuration such as a transformer, the electric field in the gas portion is higher than in the case of the insulating oil. Therefore, in the insulation configuration of a gas insulated transformer, it is necessary to eliminate electric field inequality more than in an oil insulated transformer.

(Problems to be Solved by the Invention) However, in the conventional stationary guidance equipment as described above, there are problems to be solved as described below. In addition,
Here, a gas insulated transformer will be described as an example of a stationary induction device.

That is, in gas insulated transformers as shown in Figs. 3 and 4, insulated wires are wound, but in such windings, as shown in Fig. 5, A wedge is formed between the spacer 6 disposed between each section and the insulation coating 8 provided around the rectangular copper wire 7 constituting the winding, and between the rail 9 and the insulation coating 8. A gap of "8 degrees" is formed.The electric field in the minute gas gap part surrounded by the insulators such as the spacer 6 and the rail 9 and the insulating coated strands is extremely large compared to other parts. Such a small gap is not a big problem in a transformer using insulating oil because the dielectric breakdown electric field is high, but in the case of a gas-insulated transformer, the electric field at such a small gap is This was a big problem because it determines the insulation strength of the winding.In order to reduce the electric field in such a small gap, it is necessary to increase the insulation distance. In the case of the above-mentioned unequal electric field, the electric field does not decrease in proportion to the insulation distance, so a very large insulation distance is required, which has the disadvantage of leading to an increase in the size of the gas-insulated transformer.

The present invention was proposed in order to eliminate the above-mentioned drawbacks, and its purpose is to improve the insulation structure of the minute gas gap portion formed at the contact portion of the insulated wire and the spacer or rail, An object of the present invention is to provide a stationary guidance device that can avoid increasing the size of the device.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a stationary induction device in which a winding is constructed by winding an insulated wire around an iron core. , which is characterized by being impregnated or coated with a semi-solid insulating material.

(Function) According to the stationary induction device of the present invention, since the semi-solid insulating material is compressed by the tension applied to the right side of the wire, the minute gas gap or wedge formed at the contact portion between the wire and the rail or spacer is The gap can be filled with the semi-solid insulating material, and furthermore, the formation of minute gaps caused by misalignment between the strands can be prevented.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIGS. 1 and 2. Note that the same members as those of the conventional type shown in FIGS. 3 to 5 are designated by the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, as shown in FIG. 1, the strands 10 forming the transformer winding are made by wrapping multiple layers of insulating paper or plastic film around the rectangular copper wire 7 to form an insulating coating 8.
, and the surface thereof is further impregnated or coated with a semi-solid insulating material 11 (for example, silicone gel, polybutadiene gel, etc.). As shown in FIGS. 2 and 4, the wire 10 constructed in this manner is wound around the rail 9 disposed on the basic insulating tube 1, with a spacer 6 between each section. The transformer winding is formed by winding the transformer winding a predetermined number of times.

In the gas insulated transformer of this embodiment having such a configuration, since the semi-solid insulating material 11 is compressed by the tension when the wire 10 is wound, the contact between the wire 10 and the rail 9 or the spacer 6 is reduced. The small gas gap or wedge gap formed in the section is filled with the semi-solid insulating material 11. Furthermore, since there is no microscopic gas drop caused by misalignment between wires, insulation performance is greatly improved, and there is no need for large insulation distances.
It also becomes possible to downsize the transformer.

As described above, according to this embodiment, by impregnating or coating the surface of the insulation coating of the strands with a semi-solid insulating material to form the transformer winding, the micro-gas, which has traditionally been a weak point in insulation, can be removed. Since the formation of gaps and wedge gaps can be prevented, transformer windings with high insulation strength can be obtained. Furthermore, it is possible to provide a gas insulated transformer that is compact and has high insulation reliability.

Note that the present invention is not limited to the above-mentioned embodiments, and can be applied not only to disk windings as shown in FIG. It can also be applied to various winding configurations. Further, by appropriately changing the external structure of the semi-solid insulating material in accordance with the winding configuration, optimum insulation strength can be obtained. Further, in the above embodiments, a gas insulated transformer was explained as an example, but it goes without saying that the present invention can be applied to other stationary induction devices such as an oil insulated transformer and a reactor. Similar effects can be obtained in these cases as well.

[Effects of the Invention] As described above, according to the present invention, insulation-coated strands and spacers or rails can be formed by simply impregnating or coating the insulation-coated surface of the strands with a semi-solid insulating material. It is possible to provide a stationary induction device that can avoid increasing the size of the device by improving the insulation structure of the small gas gap portion formed in the contact portion of the device.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the wire configuration of the stationary induction device of the present invention, Fig. 2 is a sectional view showing the state in which the strand shown in Fig. 1 is wound, and Fig. 3 is a conventional 4 is a sectional view showing an example of a static induction device, FIG. 4 is a sectional view showing the configuration of a winding portion, and FIG. 5 is a sectional view showing an example of a conventional strand structure. DESCRIPTION OF SYMBOLS 1... Basic insulation cylinder, 2... Element wire, 3... Transformer winding, 4... Molded insulation material, 5... Electrostatic ring, 6...
・Spacer, 7...Flat copper wire, 8...Insulation coating, 9
...Rail, 10...Element wire, 11...Semi-solid insulating material.

Claims (1)

[Claims] In a stationary induction device in which a winding is constructed by winding an insulating coated wire around an iron core, a semi-solid insulating material is impregnated or coated on the surface of the insulating coat of the wire. Characteristic stationary guidance equipment.