JPH08148343A - Lead connector for transformer - Google Patents

Abstract

PURPOSE: To enhance insulation of a high voltage bushing lead and the positional accuracy of connection between the tap at the end of a high voltage line and a high voltage lead by arranging the high voltage lead substantially linearly between adjacent windings in the vicinity of a winding in a tank while supporting by means of a lead support secured to the content of a transformer body. CONSTITUTION: A high voltage connection duct 5 is disposed oppositely to a tank between two windings 2 being connected in parallel. A high voltage lead 4 connecting between a high voltage bushing terminal 8 and a tap 9 at the end of a line is arranged linearly and insulated by a surrounding multiple barrier 12. The high voltage lead 4 employs a rigid material and disposed closely to the high voltage bushing terminal 8 and the winding 2 in the tank while being supported by a lead support 11 secured to the content of transformer body. This structure eliminates defect in the insulation and enhances positional accuracy in the connection between the high voltage lead and the tap at the end of the line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-phase transformer, and more particularly to a transformer lead connecting device for connecting high voltage line leads of a transformer composed of two unit transformers arranged in parallel.

[0002]

2. Description of the Related Art With the recent increase in power demand, there is a tendency to increase the transmission voltage for efficient power transmission.
00kV class UHV power transmission is planned. With regard to transformers, both voltage and capacity are about twice as large as those of conventional maximum scale 500kV class transformers, which requires dramatic progress.

Further, it is difficult to carry out the transportation to the site with the same construction as the conventional one under the present severe transportation restrictions, and the divided transportation system is adopted. For example, 1000kV class 3000M
In the case of a VA transformer, the main transformer is divided into two tanks, and inside each of the two tanks, the contents of the transformer consisting of three windings that are connected in parallel with the iron core are housed, and the high voltage leads of each other are housed. Are interconnected by a high-voltage lead connection duct and connected to a high-pressure gas busbar through a high-voltage line end bushing.

[0004]

The high voltage UH
Since the V lead has a voltage twice as high as that of the conventional maximum voltage of 500 kV lead, as with the conventional 500 kV lead, it is started from the lead-out position at the center of the winding height.
In the method of connecting to the high voltage line end bushing on the cover, the insulation structure becomes complicated and the insulation reliability becomes a weak point.

Therefore, a method of directly connecting to the high voltage line end bushing by penetrating the tank long side surface from the center of the winding height is adopted. In this case, it is necessary to penetrate from the central portion between the tank reinforcing beams, and the inner diameter of the high voltage lead connecting duct is also φ80 due to the structural strength of the tank.
It is limited to about 0 mm to 900 mm. Also, the AC test voltage is a high voltage of 1100 kV, and insulation must be performed within this limit. Therefore, when the lead support is placed in the high-voltage lead connection duct to support the high-voltage lead as in the case of the conventional 500 kV lead, since the inner diameter of the connection duct is small, the creeping part of the lead support becomes an insulating weak point. It is necessary to support the leads by the supports fixed to the bushing oil terminal and the transformer body.

On the other hand, the high-voltage lead connection duct must be disassembled from the tank of each unit transformer and reassembled on site for transportation reasons. Therefore, how much it is possible to simplify the connection work and insulation work between the high-voltage line end of the winding wire and the multi-barrier high-voltage lead in the field, and also in the field assembly work, to insulate a large amount of the high-voltage bushing duct and each unit transformer. Moisture absorption and prevention of foreign matter are the most important issues in ensuring the reliability of UHV transformers.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to use a rigid member for a 1000 kV high voltage line end lead in a UHV transformer. To prevent deformation due to its own weight, do not install the lead support in the high-voltage lead connection duct with the minimum diameter, and do the lead support at two places: the high-voltage bushing oil terminal and the support fixed to the transformer body. To strengthen the insulation of the high-voltage bushing lead, improve the accuracy of the connection position between the high-voltage line end lead and the high-voltage lead, and minimize the on-site assembly parts such as connection and insulation work to improve the moisture and dust proof quality. To provide a lead connecting device for a transformer.

[0008]

In order to achieve the above object, according to claim 1 of the present invention, two unit transformers having a plurality of windings connected in parallel are arranged such that the long sides of the tanks face each other. In the lead connection device for the transformers connected in parallel, the high voltage line end bushing is arranged between the two unit transformers, and the oil terminal of the bushing and the high voltage line end outlet of the winding of each unit transformer are exposed. A high voltage lead connecting
The transformer main body is arranged substantially linearly between adjacent windings, and the high-voltage lead is arranged in the vicinity of the winding in the tank that exits the connecting duct between the oil terminal portion of the bushing and the high-voltage lead. It is characterized in that it is configured to be supported by a lead support fixed to the contents.

[0009]

According to the present invention, since the UHV 1000 kV line end leads are linearly arranged, the multi-barrier structure to be mounted around the leads is simplified, and the UHV 1000 kV line end lead support is provided with the bushing oil terminal part and the transformer. Since the lead support is fixed to the main body, the 1000 kV line end lead support part in the high-voltage lead connection duct with a small diameter is not required, and it is possible to eliminate the creeping part of the lead support, which is an insulating weak point, and improve the insulation characteristics. Becomes

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a connection between two unit transformers connected in parallel according to an embodiment of the present invention and a 1000 kV high voltage bushing, and FIG. 2 is a side view of the high voltage lead connecting portion.

As shown in FIGS. 1 and 2, 1000 k
V high pressure bushing duct 1 for housing the high pressure bushing 6
3 is branched to the left and right at the bushing electric field shield 6a portion and is connected to the tank 1 of each unit transformer 1A, 1B.
The high-voltage lead connection duct 5 is arranged at a tank facing portion between two windings 2 connected in parallel. Further, the height of the high-voltage lead connection duct 5 is set near the height of the line end lead-out 9 of the high-voltage winding 2 having the same potential.

The high voltage lead 4 connecting the high voltage bushing terminal 8 and the line end lead 9 is arranged in a straight line, and the periphery thereof is insulated by the multiple barrier 12. A rigid member is used for the high voltage lead 4, which is arranged near the high voltage bushing terminal 8 and the in-tank winding 2, and is supported by a lead support 11 fixed to the contents of the transformer body. In addition, each unit transformer 1A, 1B
The winding 2 of is divided into three or more due to restrictions from the transportation limit.

When assembling and transporting the high-voltage bushing connecting duct 13 on-site, as shown in FIG. 3, a 1000 kV bushing 6 and a high-voltage lead 4 are mounted in the duct 13, and a multiple barrier 12 is provided around the high-voltage lead 4. The position around the multiple barrier 12 is fixed by the temporary lead support 10 to ensure the proper assembly state in the factory, and the portion of the high-voltage lead 4 protruding left and right from the connection duct 5 is sealed with the airtight film material 15. Attach the transportation cover 17 to protect and transport it locally.

The high voltage lead 4 whose periphery is insulated by the multiple barrier 12 is supported by a lead support 11 fixed to the inside of the transformer main body as shown in FIG. The fixed part is fixed not by the entire circumference of the high voltage lead 4 by the lead support 11a that is cut out in an arc shape, but by fixing the upper and lower fixed parts. When disassembling and transporting, it is sufficient to remove only the upper lead support 11a and reassemble at the site. The configuration is easy.

FIG. 5 is a side view showing a situation where the high-pressure bushing connecting duct 13 is collectively transported in the state shown in FIG. 3 and is reassembled on site. As shown in the figure, the opening of the connection duct 5 of the unit transformers 1A and 1B connected to the high-voltage bushing connection duct 13 has a high-voltage lead 4
Is sealed in advance with a bag-like airtight film 16 capable of accommodating the inside and the protruding portion of the tank 1 before factory shipment, and after the assembly work of the high voltage bushing connection duct 13 and the unit transformers 1A and 1B on site. To remove. Further, the high voltage lead 4 is supported by a lead support 11 fixed to the contents of the transformer main body, the temporary lead support 10 is removed during transportation of the high voltage lead 4, and insulation work for connecting the high voltage lead 4 and the line end lead 9 is performed.

Next, the operation of this embodiment will be described.
The 1000 kV high-voltage bushing 6 arranged between the two unit transformers 1A and 1B connected in parallel and the line end outlet 9 are connected to each other by a horizontal duct branched left and right from a high-voltage bushing duct 13 accommodating the high-voltage bushing 6, respectively. It is linearly extended and connected to the side surface of the tank 1 facing between the two windings 2 connected in parallel in the unit transformers 1A and 1B. Therefore, the structure of the multiple barrier 12 around the high voltage lead 4 can also be a simple linear structure, and the defect in insulation can be eliminated.

If there is a lead supporting portion in the high-pressure lead connecting duct 5 having a small diameter of about φ800 mm to φ900 mm, the creeping surface of the support, which is inferior in pressure resistance to a simple oil gap, becomes a weak point in insulation. By using a rigid member for the high voltage lead 4, deformation of the high voltage lead 4 due to its own weight and the weight of the multiple barrier 12 is prevented, and the position is stabilized even if the supporting portion of the high voltage lead 4 is eliminated in the connection duct 5. This makes it possible to improve the insulation characteristics by eliminating the lead support in the connection duct 5 where the electric field is severe.

On the other hand, the high voltage bushing 6 and the high voltage lead 4
Assembling the multiple barriers 12 around it and fixing the position of one end of the high voltage lead 4 with the temporary lead support 10 as shown in FIG. The projecting portion is sealed with the airtight film material 15, and the transportation cover 17 is attached and protected to transport. Further, as shown in FIG. 5, the lead support 11 supports from the outside of the multiple barrier 12 arranged around the high voltage lead 4, and the support range is divided into upper and lower parts, not the entire circumference, and a high voltage lead support part is provided at a certain portion. It is fixed by a method of sandwiching it by a support 11a that is cut out in an arc shape. Thereby, the multiple barrier 1 arranged around the high voltage lead 4
It is possible to attach the two without dividing them, and it is possible to prevent deterioration of the insulation characteristics. Further, by fixing the lead support 11 to the contents of the transformer main body, the connection position accuracy of the high voltage lead 4 and the line end lead 9 at the time of on-site reassembly is improved, and the lead support 11 fixing the high voltage leads 4 to the contents of the transformer main body is improved. The line end lead 9 and the high-voltage lead 4 can be easily connected by adjusting the above.

Further, the assembling work of the multiple barrier 12 is eliminated, and the assembling work of the high voltage line end at the site is only to connect the high voltage lead 4 and the line end lead 9 and to insulate and fix the high voltage lead 4 to the lead support 11. Simplify and complete in a short time. Furthermore, by performing the airtight film attached to the opening of each of the connection ducts 5 of the tank 1 and the high-pressure bushing connection duct 13 after the completion of the duct connection, it is possible to prevent moisture absorption and foreign matter from entering and to prevent deterioration of insulation quality.

As described above, according to this embodiment, the most important UHV is achieved by eliminating the support portion of the high voltage lead 4 from the inside of the connection duct 5 and minimizing the on-site reassembly location.
It is possible to improve the insulation reliability of the high voltage lead.

Although the high-voltage bushing duct and the lead duct have a horizontal T-branch structure in the above-described embodiment, the UHV high-voltage lead insulation reliability is improved even if the high-voltage bushing is inclined or arranged vertically. It becomes possible.

[0022]

As described above, according to the present invention, the following effects can be obtained. (1) The 1000 kV high-voltage lead duct that connects between unit transformers and each unit transformer tank is connected near the high-voltage winding outlet height at the portion facing between the parallel-connected windings of each unit transformer. The insulation can be simplified by arranging the high-voltage leads connecting the high-voltage bushing terminal and the line end lead in a straight line, and the surrounding multiple barrier structure can also have a simple straight-line structure, thus eliminating insulation defects. it can. Also, support the high-voltage lead that connects the high-voltage line end bushing oil terminal and the high-voltage line end outlet of the winding of each unit transformer near the winding in the tank where the high-voltage bushing oil terminal and high-voltage lead connection duct exit. By using the lead support fixed to the contents of the transformer body located at the position, the connection position accuracy of the high voltage lead and the line end lead is improved, and the high voltage lead is aligned with the lead support fixed to the contents of the transformer body during on-site reassembly. This makes it possible to easily connect to the end of the track.

(2) Bushing at the end of the high-voltage line The high-voltage lead connecting the terminal in oil and the outlet of the high-voltage line end of the winding of each unit transformer is made of a rigid member, so that the weight of the high-voltage lead and the multiple barrier are increased. It is possible to prevent the deformation due to the weight of, and to stabilize the position even without removing the support portion of the high voltage lead from the inside of the connection duct, and the diameter is φ800 mm to φ9.
By removing the creeping surface such as the lead support from the inside of the connection duct, which is as small as about 00 mm and has a severe insulation condition due to the structure, it is possible to eliminate a weak point in the insulation and improve the insulation characteristics.

(3) A 1000 kV bushing and a high-voltage lead are installed in the high-voltage bushing duct, the positions of the high-voltage lead and the multiple barrier are fixed with temporary lead supports, and the condition of assembling in the factory is maintained. And the high-voltage leads are separated, then the parts are assembled normally, and the parts protruding left and right from the connection duct of the high-voltage leads are sealed with an airtight film material. To do. For the assembly work of the high-voltage line end in the field, fix the position of the high-voltage lead in the connection duct with a temporary lead support, and transport it while maintaining the regular assembled state in the factory. The disassembly and reassembly of multiple barriers is not required, and the quality during the assembly test in the factory can be maintained as it is. Furthermore, since the connection, insulation and fixing of the high voltage lead to the lead end of the high voltage lead are simplified, the on-site reassembly work can be completed in a short time. Further, by removing the airtight films attached to the connection duct openings of the tank and the high-pressure bushing connection duct after completion of the duct connection, it is possible to prevent moisture absorption and foreign matter from entering and to prevent deterioration of insulation quality.

(4) The lead support fixed near the windings in the tank at the exit of the high-voltage lead connection duct and fixed from the transformer body is supported from the outside of the multiple barrier arranged around the high-voltage lead, In addition, the support range is divided into upper and lower parts instead of the entire circumference, and the high-voltage lead support part is fixed by a method of sandwiching the high-voltage lead support part with an arc-shaped notched support. As a result, the multiple barriers arranged around the high-voltage lead can be mounted with a simple structure without being divided, and the work of assembling the multiple barriers at the time of on-site reassembly can be eliminated to prevent the deterioration of the insulation characteristics. In addition, the support range of the high-voltage lead is divided into upper and lower parts instead of the entire circumference, and a fixed part is supported and fixed by a support that is cut out in an arc shape to facilitate the attachment work of the high-voltage lead to the support. As the assembly work of the high voltage line end at the site is simplified and the on-site reassembly work is completed in a short time, it is possible to prevent moisture absorption and foreign matter mixture and prevent deterioration of insulation quality.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a plan view showing an on-site transportation and assembly state of the high-pressure bushing connecting duct of FIG.

FIG. 4 is a plan view in which the high voltage lead of FIG. 1 is supported by a support fixed to the inside of the converter.

5 is a side view showing the on-site high voltage lead connection state of the transformer of FIG. 1. FIG.

[Explanation of symbols]

1A, 1B ... Unit transformer, 1 ... Tank, 2 ... Winding, 3 ...
Iron core, 4 ... High voltage lead, 5 ... High voltage lead connecting duct, 6
... High voltage line end bushing, 6a ... Electric field shield, 7 ... High pressure gas bus bar, 8 ... Bushing oil terminal, 9 ... High voltage line end opening, 10 ... Temporary lead support, 11 ... Lead support, 11
a ... upper lead support, 12 ... multi-barrier, 13 ... high pressure bushing duct, 14 ... tank reinforcement beam, 15,1
6 ... Airtight film, 17 ... Transport cover.

Claims (1)

[Claims] 1. A lead connecting device for a transformer, wherein two unit transformers each having a plurality of windings connected in parallel are arranged in parallel so that the tank long sides face each other. A high voltage lead, which is arranged between the unit transformers of the stand and connects the in-oil terminal of the bushing and the high voltage line end of the winding of each unit transformer, is arranged substantially linearly between the adjacent windings. The high-voltage lead is arranged in the vicinity of the in-tank winding that has exited from the connecting terminal of the bushing in oil and the high-voltage lead, and is supported by a lead support fixed to the contents of the transformer body. A transformer lead connecting device characterized in that