JPS6114646B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in high voltage single phase autotransformers.

In recent years, as power demand has increased, 500kV power transmission has been realized, and even higher voltage power transmission is planned in the near future. Autotransformers are often used as these ultra-high voltage power transmission transformers.

On the other hand, due to severe transportation limitations in our country,
The transformer must be a single-phase transformer.

The present invention improves the means for connecting the lead wire of the shunt winding and the configuration of the tank in the single-phase autotransformer, thereby making the transformer body compact and making it possible to assemble and transport the main cover. , to improve reliability.

FIG. 1 shows the winding arrangement and connections inside an autotransformer.

A tertiary winding 2, a shunt winding 3, and a series winding 4 are arranged around the iron core 1 in this order from the inside.

When an autotransformer connects 500kV and 275kV, 500kV is applied to the primary terminal 8 and 500kV is applied to the secondary terminal 9.
Each is charged with a high voltage of 275kV. A primary terminal lead 5 of the series winding 4 is drawn out from the center of the height of the winding in consideration of ground insulation, and lead leads 5' connected to the secondary terminal 9 are drawn out from the upper and lower ends.

A lead 6 connected to a secondary terminal 9 is drawn out from the upper end of the shunt winding 3, and a neutral point lead 7 common to the primary and secondary windings is drawn out from the lower end.

Further, due to transportation limitations associated with higher voltage and larger capacity, the windings are distributed over a plurality of legs (2 to 4 legs) of the iron core, and these are connected in parallel or in series.

FIG. 2 is a diagram showing the internal connections of the conventional device.

The series windings are placed on the outermost side, so each leg 1
The windings distributed in a, 1b, and 1c can be easily connected by crossover wires. For example, the connection between the primary terminal 8 and the windings of each core leg is via crossover wires 5a, 5b built into the windings. Therefore, there are no insulation problems for the tank 12.

However, since the shunt winding 3 is placed inside the series winding 4, the connection to the secondary terminal 9 is made by raising the leads 6a, 6b, and 6c from the shunt winding placed on each core leg, respectively. Connections must be made by internal leads 11 outside the line.

On the other hand, in an ultra-high voltage autotransformer, the voltage at the secondary terminal 9 is a high voltage such as 275 kV or 500 kV.

FIG. 3 is an enlarged view taken along the line "X"--"X" in FIG.

The tank size increases in order to ensure an insulating distance between the openings 6a and 6b and the internal lead 11, the clamp 10, and the inner surface of the tank cover 13. Therefore, it is no longer possible to assemble and transport the tank cover 13 with it attached, and it becomes necessary to replace it with the temporary cover 18.

Therefore, after the factory test verification, the tank cover 13 must be disassembled and reassembled, which increases the assembly cost.
During on-site assembly, there is a risk of internal moisture absorption and foreign matter contamination, which is a disadvantage in ensuring transformer quality.

Here, the present invention eliminates the above-mentioned conventional drawbacks, realizes a compact transformer main body, and improves the economical efficiency and reliability of the transformer.

FIG. 4 is a front sectional view of one embodiment of the present invention, and FIG. 5 is a partial side sectional view (an enlarged view taken along the arrows "Y" and "Y"). Note that the same symbols in the drawings indicate the same members. Here, tank cover 1
Openings 14a to 14c are provided in the parts opposite to the high voltage side outlets 6a to 6c of the shunt windings distributed on each of the main legs of the iron core of 3, and the duct 15 to which the secondary terminal 9 is attached is connected to the openings 14a to 14c. However, the shunt windings are connected to each other by an internal lead 16 inside the shunt winding.

Each of the openings 6a to 6c and the internal lead 16 are inserted directly into the duct 15 through the openings 14a to 14c without being stretched around the clamp 10 or the tank cover 13.

Therefore, the tank cover 13 can be brought close to the winding as far as insulation from the end of the winding allows, and can be made into a sufficiently compact shape, and there is no need to replace or reassemble the transport cover even when transporting to the site. becomes.

After the factory test, the duct 15 to which the secondary terminal 9 and internal lead 16 are attached is disassembled from the flange of the opening 14 and reassembled on site. In addition, the internal lead 16 and each opening 6a to 6c can be connected by using bolt tightening terminals 17a to 17c.
Easy to disassemble and connect.

By forming the duct 15 into a simple shape such as a circle, the insulation distance from the internal leads can be reduced, and the arrangement of the secondary terminals 9 is not restricted.

As described above, according to the present invention, in a single-phase autotransformer, the shunt winding end
Even in the case of high voltage such as, the tank size is sufficiently compact and the main lid can be assembled and transported.

Moreover, with the conventional structure, the higher the voltage at the end of the shunt winding, the more difficult it is to assemble and transport the main lid to ensure insulation of the internal leads.Furthermore, the higher the voltage of the transformer, the more the contents are exposed during on-site assembly. It was necessary to shorten the time and prevent moisture absorption, and it was also necessary to completely prevent metal foreign matter generated outside the tank when replacing the transport cover.

In order to solve these problems, the present invention installs a secondary terminal and separates and connects from the main tank a duct containing internal leads that connect the shunt windings distributed on each core main leg. This has the outstanding effect of making it possible to assemble and transport the main cover, and also to reduce the cost required for disassembling and reassembling the transformer.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the winding arrangement and connections inside an autotransformer, Figures 2 and 3 are diagrams of the internal connections of a conventional device, and Figure 4 is a front cross-sectional view of an embodiment of the present invention. , FIG. 5 is a partial side sectional view (an enlarged view taken along the arrows "X" and "X"). 1... Iron core, 1a to 1c... Each leg, 2... Tertiary winding,
3... Shunt winding, 4... Series winding, 5... Outlet of series winding 4, 5'... Outlet lead, 5a, 5b... Crossover wire, 6... Outlet connected to secondary terminal 9, 6a to 6
c...Top end of each shunt winding, 7...neutral point common to primary and secondary, 8...primary terminal, 9...secondary terminal,
10... Clamp, 11... Internal lead, 12... Tank, 13... Tank cover, 14.14a-14c
...Opening, 15...Duct, 16...Internal lead, 1
7.17a-17c...Bolt tightening terminals.

Claims (1)

[Claims] 1 Windings consisting of shunt windings and series windings are arranged in a distributed manner on at least two main legs of the core, two or more openings are provided in the tank side plate near the outlet of the shunt winding, and the said distributed arrangement is carried out. 1. A single-phase single-turn transformer, comprising an internal lead in which shunt windings connected to each other are housed, and a duct provided with shunt winding line end bushings is connected to the opening.