JPS5864010A - Leading out device of lead wire in oil for electric induction apparatus - Google Patents

Abstract

PURPOSE:To enable a leading out device of lead wire in oil for electric induction apparatus to have a high voltage and to be formed in a small type without generating partial discharge and peeling off of insulation by a method wherein earthed sheilding electrodes of which the insides to face to insulating barriers are covered with an insulator are provided, and conductive or semiconductive paints are applied to the earthed shielding electrodes thereof. CONSTITUTION:Insulation of strand wires 6 is performed to a high voltage connecting lead 4 to be arranged in a pipe conduit 3 together with insulating oil, and barrier insulators 8 fractionalizing an oil gap 7 are arranged concentrically on the outer side thereof. Moreover insulatingly coated earthed shielding electrodes 9 are arranged on the outer side thereof. The earthed shielding electrodes 9 are arranged between the barrier insulator 8 and the pipe conduit 3 interposing the prescribed intervals between them. Semiconductive paints or conductive paints are applied to molded insulators 10 on the sides to face to the high voltage connecting lead 4, and are dried to form the earthed shielding electrodes 9, and after then molded insulators 11 are fixed by molding as to cover the conductive parts. Leads 12 to take electric potential against the conduit 3 or a proper earthing matter are led out from the earthed shielding electrodes 9 at the outside circumferential sides of the shielding electrodes 9.

Description

[Detailed Description of the Invention] This relates to the submerged Lee F extraction device of Honjimeisha Induction Electric Appliances, q!
The present invention relates to a submerged lead extraction device suitable for connecting between each unit in an induction electric appliance such as a transformer or a reactor, which is configured by dividing the iK-phase or three phases into multiple units.

In recent years, as the demand for electric power has increased and ultra-high voltage, large-capacity power transmission has been desired, the unit capacity of transformers has also increased. In order to keep the size of transformers that are increasing in size to below the transport limit, the transformer is divided into nine transformers (9 transformers) and (22) each phase or multiple phases.

It consists of

Figure #I1 shows an example of this, and each of the multi-divided transformers 22 and 2 consists of a transformer body 1 housed in a tank together with an insulating medium such as insulating oil. They are connected by a filled line 3 or directly in a tank, between which a connecting lead 4 is arranged and assembled into a three-phase transformer or an autotransformer. Note that 5 in the figure indicates high pressure pushing 7.

By the way, in order to reduce the size of the above-mentioned transformer JL, especially the insulation part, the insulation part between the high and low voltage windings, between the winding and the tank, or between the Lee ρ and the tank is subdivided with multiple layers of insulation purriers. As is well known, in a structure of a transformer made of insulating oil and a solid insulator, the dielectric strength is almost determined by the gap length of the insulating oil. The dielectric strength is maintained within the dimensions of . At this time, in order to reduce the size of the insulating portion of the connection lead, a purrier structure is used to improve dielectric strength.

Generally, in the case of a lead passing through a conduit, the stress E of each oil gap in the round, lead surface, lead insulating lateral surface, and purrier, which are arranged in a coaxial cylinder, is calculated using the following formula (1).
is required.

□ (Here, gyg * 11 is the specific electric constant and medium diameter of the part to be calculated, 'i * Pi eri ``1 is the relative dielectric constant of the insulating oil or platter of the purrier insulation component and the medium diameter of that part. ) Also, the oil conduction dimensions are 6 cm electric field and /4
- The permissible limit of oil conduction in rear insulation is appropriately determined using the experimental formula (2).

E-K・α-a (kη伽) ・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・(2) In other words, the closer the electric field is to the high-voltage electrode, the smaller the oil conduction dimension, and the closer to the shield electrode, the smaller the oil conduction dimension. The margin for destruction of each oil guide is approximately the same by selecting a large number.

However, in the actual lead insulation of a transformer constructed in this manner, the stress on the conduit that serves as the ground increases as the conduit becomes smaller. At this time, while the high-voltage connection lead is insulated with bare wires and has a purrier structure, the metal surface on the electrical circuit side directly faces the purrier insulation component, which tends to make the insulation structure unstable.

That is, conventionally used metal pipes are made of iron or stainless steel, and the oil side is coated after chemical conversion treatment. When the electric field is high, a high electric field causes partial discharge because the surface is uneven or uneven due to the chemical conversion treatment.

Even if an insulating material such as a wire is attached by a press so that it fits tightly onto the pipe, dimensional errors and dimensional distortion due to the drying process of the insulator will cause oil gears and gaps to form between the pipe and the pipe. Partial discharge occurs.

In view of the above points, the present invention suppresses the occurrence of partial discharge under a high electric field around the high voltage leads that connect each unit via a pipe or a tank wall, and provides a highly reliable submerged lead extraction device. The purpose is to provide

In order to achieve this object, the present invention provides a grounding shield electrode with an insulating coating on at least the inner surface of the V side of the high voltage lead on the pipe or tank wall around the high voltage lead to prevent direct stress from being applied to the pipe, etc. By applying conductive paint or semi-conductive paint to the cooled electrode coating insulator, it increases adhesion to the insulation coating and prevents peeling, thereby preventing partial discharge under high electric fields. It is characterized by being made to do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a detailed sectional view of a submerged lead submerged lead extractor device, that is, a high pressure reed extractor part according to an embodiment of the present invention;
The figure shows the AA cross-sectional view.

A high-pressure connection lead 4 arranged with insulating oil in the pipe line 3
is provided with wire insulation 6, and an oil gear and an oil gear are placed concentrically on the outside.
! 7 is subdivided/sized insulator 8 is arranged. j
! A ground shield electrode 9 coated with insulation is placed on the outside thereof.

In this way, by arranging the ground shield electrode 9 at a predetermined distance between the purrier insulator 8 and the conduit 3, stress on the conduit 3 can be removed.

By the way, in this case, if the ground shield electrode 9 is made of a gold lI4 plate or the like, the metal and the molded insulator will peel off due to the difference in thermal expansion coefficient due to the drying process during the insulation coating molding, resulting in a gap. In some cases, when minute surface oil gaps are created in a molded insulator, the stress applied to the oil gaps increases due to the difference in specific sieve rate, which may cause partial discharge in the oil gap areas.

To prevent this, in this embodiment, as shown in FIG. 4, a semiconductive paint such as carton paint or a conductive paint is applied to the molded insulator 10 on the side facing the high voltage connection lead 4. The coated insulator 11 is applied and dried to form the ground shield electrode 9, and then the molded insulator 11 is fixed to the 7-ru Y so that the conductive portion is removed. Further, from the ground shield electrode 9, a glue 12 is drawn out from the outer periphery of the shield electrode 9 to obtain a potential with the conduit 3To or a suitable ground object.

When constructing the ground shield electrode 9 in this way, since the electrode surface is coated with a molded insulator 10Vc, there is no possibility that the electrode surface and the molded insulator 10 will peel off during heating or assembly. There is no possibility of an oil gap occurring on the surface of the grounded shield electrode 9.

Furthermore, since there is no fear of peeling during drying before assembling into a transformer, it is possible to obtain an oil submerged lead drawing device with stable insulation performance. In addition, since paint is used as the ground electrode, it is lighter in weight than a metal electrode, making handling and workability easier.

Further, there is an advantage that complex structures such as the ground shield electrode of the T-shaped branch of the lead can be easily addressed.

In the above embodiment, the ground shield electrode 9 is formed by coating and forming on the molded insulator 10, and the ground shield electrode 9 is further superimposed with 11 ft of molded insulator, but the conduit 3 The state of the electric field formed inside 1! Depending on the IK, it is also possible to omit the molded insulator 11.

Further, in the above embodiment, the insulating medium filled in the lead pull-out portion is described as insulating oil, but it goes without saying that an insulating medium such as gas may also be used.

As described above, according to the present invention, grounding shield electrodes are provided at predetermined intervals on the outer periphery of the d1 insulation/4-rear, and at least the inner surface is covered with an insulating material. The stress of is gone. Furthermore, since the ground shield electrode is formed by applying conductive or semiconductive paint to the molded insulator, partial discharge or insulation peeling from the ground shield electrode surface will not occur. As a result, it is possible to obtain a submerged shield drawing device which is highly reliable in terms of quantity and can be made high in voltage and downsized.

[Brief explanation of the drawing]

FIG. 1 is a top view of the transformer unit connection for explaining the lead extraction section, and FIG. ! J is a sectional view of the human body, and figure #I4 is a broken sectional view of the ground shield electrode structure. ■...Transformer body, 2-Transformer-"=, ), 3...
Pipe line, 4.12--lead, 5--high pressure pump, thing,
6...Cable wire insulation, 7--oil gap, 8--purrier insulator, 9--ground shield electrode, 10.11...
Molding) Insulators. Figure 1 Figure 4 IO

Claims (1)

[Scope of Claims] (1) In an oil submerged lead pulling device for an induction electric appliance, which comprises a cylindrical insulating purrier arranged at a predetermined interval O around the outer periphery of at least one insulated lead core wire, the insulating purrier Furthermore, shield electrodes formed by applying conductive paint or semi-conductive paint to the outer peripheral surface of the molded insulator formed in a cylindrical shape are placed at predetermined intervals on the outer periphery of the cylindrical insulator. A submerged lead extraction device for an induction electric appliance, characterized in that it is connected to a counter electrode placed on the outside. A submerged lead extraction device for an induction electric appliance, characterized in that a molded insulator is further superimposed on the lead electrode and molded integrally. (3) '? 1. The submerged-V-V extraction device for an induction electric appliance as set forth in claim 1, wherein the outer facing electrode is coated with an insulator.