JPH0451462Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an oil-immersed transformer in which an oil-immersed arrester is attached to the upper part of the transformer tank.

[Prior Art] In recent oil-immersed transformers, the high-voltage terminals and the conductors that connect the high-voltage terminals to the line are placed inside the gas pipeline and isolated from the outside, making it difficult to conduct dielectric strength tests at the installation site. In this case, the test voltage cannot be applied to the winding from the high voltage terminal side. Therefore, for transformers with an arrester attached to the top of the transformer tank and a neutral point lead connected to the arrester, during testing, the arrester is removed and a test bushing is attached, and the test bushing and neutral lead are connected. A test voltage is applied between the neutral point of the winding and the tank (ground) through.

Conventional transformers of this type are shown in FIGS. 4-6. FIGS. 4 and 5 show the conditions when conducting a dielectric strength test of the transformer, and FIG. 6 shows the condition during steady operation. In these figures, 1 is a transformer tank, and the transformer body is housed in this tank 1 together with insulating oil. A short tubular pocket 2 whose axis is vertically oriented is provided at the top of the tank 1, and one end of an L-shaped duct 3 is connected to this pocket 2. A cylindrical arrester container 4 is connected to the other end of the duct 3, and this arrester container is supported by a support frame 5 provided to project diagonally upward from the upper side of the tank 1. A test bushing connection part 4a is provided at the lower side of the arrester container 4, and the lower end of a substantially dogleg-shaped bushing support tube 6 extending obliquely upward is connected to this connection part 4a. Bushing support pipe 6
A test bushing 7 is attached to the upper end of the test tube.

As shown in FIG. 5, the duct 3 includes an L-shaped pipe 3A whose one end is connected to the pocket 2, and the L-shaped pipe 3A.
A short pipe 3B whose one end is connected to the other end of A, and the short pipe 3
The other end of the long tube 3C is connected to a duct connection portion 4b provided on the lower end side of the arrester container 4.

A partition part 8 is provided between the short pipe 3B and the long pipe 3C of the duct 3 to partition the inside of the arrester container 4 and the inside of the transformer tank 1. A through bushing 9 is attached. Tank 1 of center conductor of bushing 9
A neutral point lead 10 connected to the neutral point of the winding of the transformer main body (not shown) is connected to one end of the side.
The other end of the center conductor of the bushing 9 is connected to a lead wire 11.
It is connected to a terminal connected to the center conductor of the test bushing 7 through the test bushing 7.

The arrester container 4 has an opening 4c in its upper part, through which an oil-immersed arrester can be attached; however, when performing a dielectric strength test of a transformer, this arrester must be removed. Then, the opening 4c is closed with the lid 12.

The insides of the duct 3, arrester container 4, and bushing support tube 6 are filled with insulating oil.

In FIG. 4, reference numeral 13' denotes a soundproof building, which covers the entire transformer, thereby suppressing noise generated from the transformer from leaking to the surroundings.

Leads connected to terminals other than the neutral point of the winding of the transformer body are led out to the outside of the soundproof building through a gas insulated conduit (not shown) connected to tank 1 via a gas-oil classification bushing. .

FIG. 6 shows the state during steady operation. In this state, the test bushing 7 is removed together with the bushing support tube 6, and the bushing connection portion 4a is closed with the lid 13. and arrester container 4
The oil immersion type arrester 14 is passed through the opening 4c at the upper end of the
is installed. Most of this arrester is immersed in insulating oil within the arrester container, and its non-grounded terminal is connected to the center conductor of the through bushing 9 through a lead wire 15. The ground terminal of the arrester is connected to a ground wire (not shown) outside the arrester container.

[Problems to be solved by the invention] In the conventional oil-immersed transformer described above, the arrester container 4 was attached to the transformer tank 1 via the duct 3, so that the arrester container 4 protruded largely to the side of the tank 1. The problem was that the transformer as a whole became large. In addition, since the arrester container 4 is disposed protruding from the side of the tank, it is necessary to provide a large supporting member 5 to support the arrester container 4, which increases the number of parts and increases the cost. I couldn't avoid it.

Furthermore, a partition wall 8 that partitions the inside of the arrester container and the inside of the transformer tank is provided in the conduit extending in the horizontal direction of the doubt 3, and the through bushing 9 is installed horizontally by passing through the partition wall 8, so that the duct It was unavoidable that a bent portion 10a was formed in the neutral point lead 10 near the corner of No. 3. This bent part 10a
Nearby, the neutral point lead is unstable and its position is difficult to determine, and there is a risk that the neutral point lead may come close to the corner of the duct due to vibration, etc., and the neutral point lead may come into contact with the duct. Otherwise, there was a risk that dielectric breakdown would occur between the neutral point lead and the duct during a dielectric strength test. In order to avoid this, the neutral point lead 10 should be
It is necessary to support and position the neutral point lead near a, but since the space inside the duct 3 is narrow, it is not easy to provide means for supporting the neutral point lead inside the duct 3.

The purpose of the present invention is to provide an oil-immersed transformer in which an arrester container can be attached to a transformer tank without increasing the size of the transformer, and in which bends are prevented from forming in the neutral point lead. It is in.

[Means for Solving the Problems] The present invention consists of a transformer tank that houses a transformer body, and a short tubular pocket that is protruded from the top of the transformer tank with its axis oriented vertically. an oil-immersed arrester housed in the arrester container, and a through bushing installed through a partition wall provided to partition the inside of the arrester container and the inside of a transformer tank. In oil-immersed transformers where the neutral point lead connected to the neutral point of the winding of the transformer body is connected to the arrester through a through bushing, the arrester container can be installed without protruding significantly to the side of the transformer tank. At the same time, the neutral point lead is not bent near the connection part with the through bushing.

Therefore, in the present invention, the arrester container has a cylindrical arrester storage head whose axis is vertically oriented, and a tubular neck lower part coaxially provided below the head. The lower end of the lower neck of the arrester container is connected to a pocket provided in the upper part of the transformer tank.

A partition wall separating the inside of the arrester container and the inside of the transformer tank is provided inside the pocket. The through bushing is attached to the partition wall with its axis oriented vertically, and the neutral wire lead is raised vertically upward and connected to the through bushing.

[Function] As described above, connect the arrester container with its axis vertically oriented to the pocket provided at the top of the transformer tank, and attach the through bushing to the partition wall provided inside the pocket with its axis oriented vertically. This allows the arrester container to be installed without protruding laterally from the transformer tank to a large extent or at all, which prevents the transformer from increasing in size due to the installation of the arrester container. , it is possible to prevent an increase in the installation area and an increase in the size of the building housing the transformer.

Further, when the through bushing is installed vertically as described above, the neutral point lead does not bend, so there is no need to provide means for supporting the neutral point lead, and the structure can be simplified.

[Embodiments] Examples of the present invention will be described below with reference to the accompanying drawings.

Figures 1 to 3 show an embodiment of the present invention. Figures 1 and 2 show the state when conducting a dielectric strength test, and Figure 3 shows the state during steady operation. There is.

In these figures, one transformer tank is shown, and the transformer main body (not shown) is housed in the transformer tank 1 together with insulating oil. On the ceiling of tank 1 is a short tubular pocket 2 with a flange at the upper end.
is provided with its axis oriented vertically, and the arrester container 20 is directly connected to this pocket.

The arrester container 20 is made up of a cylindrical arrester storage head 21 whose axis is vertically oriented, and a tubular neck lower part 22 provided below the head 21 and coaxially with the head. A flange provided at the lower end of the lower part of the neck is oil-tightly connected to a flange at the upper end of the pocket 2. Lower neck 2 of arrester container 20
A short tubular bushing connection pocket (test bushing connection part) 23 having a flange at the tip is provided on the side surface of the test piece 2 with its axis oriented in the horizontal direction. When performing a dielectric strength test, the flange at the lower end of the bushing support pipe 6 is oil-tightly connected to the flange of the test bushing connection part 23, and the test bushing 7 is attached to the flange at the upper end of the bushing support pipe 6. It will be done. An opening 21a is provided at the upper end of the head 21 of the arrester container 20, through which the oil-immersion arrester 14 can be attached. When testing, the arrester is removed and the opening 21a is closed with the lid 24.

In order to partition the inside of the arrester container 20 and the inside of the transformer tank 1, a partition part 25 is provided inside the pocket 2, and a through bushing 9 whose axis is vertically oriented is inserted through the partition part 25 in an oil-tight manner. is installed.

A neutral point lead 10 is connected to the lower end of the center conductor of the through bushing 9, which is pulled out laterally from the neutral point of the winding of the transformer body in the transformer tank and then raised vertically upward. The upper end of the center conductor of the bushing 9 is connected to the center conductor of the test bushing 7 through a lead wire 15.

A support frame mounting bracket 26 is attached to the upper side surface of the transformer tank 1, and the lower end of a support frame 27 that stands diagonally upward and supports the lower part of the bushing support pipe 6 is fixed to this bracket with bolts 28. ing.

The inside of the transformer tank 1, the arrester container 20, and the bushing support tube 6 are filled with insulating oil.

During steady operation, as shown in FIG.
Closed oil-tightly. and arrester container 2
The oil immersion type arrester 14 is installed through the opening 21a at the upper end of the head 21 of 0. Most of this arrester is immersed in insulating oil within the arrester container 20, and its non-grounded terminal is connected to the upper end of the center conductor of the through bushing 9 through a lead wire 31 extending in the vertical direction. Oil immersion arrester 14
The ground side terminal is connected to a ground wire (not shown) outside the container 20.

In this example, the entire transformer is placed within a soundproof building 13, which prevents noise from leaking.

Although not shown, a gas insulated conduit is connected to the transformer tank 1 via an oil and gas through bushing.
Terminals other than the neutral point of the winding of the transformer are connected to an external circuit such as a railroad line through a conductor in the gas-insulated conduit.

As described above, in the oil-immersed transformer of the present invention, the arrester container 20 can be installed with little or no protrusion from the transformer tank 1 laterally. Therefore, the transformer can be made smaller and its ground area can be reduced. Furthermore, the building that houses the transformer can be made smaller.

Further, the neutral point lead 10 is supported in a stable state hanging from the through bushing 9, and its position does not change significantly even when vibration is applied, so there is no need to provide any special means for supporting the neutral point lead.

In the above embodiment, the transformer is placed in a soundproof building, but it goes without saying that the present invention can also be applied to a case where the transformer is placed in a normal building.

Further, in the above embodiment, the test bushing connection part 23 was provided on the side surface of the neck lower part 22 of the arrester container 20, and the test bushing 7 was connected to this connection part via the bushing support pipe 6.
If space can be secured above the transformer, a test bushing may be attached through the upper end opening 21a of the head 21 of the arrester container 20. In this case, the opening 21a serves as both the arrester mounting part and the bushing connection part, so the bushing connection part 23 provided in the above embodiment may be omitted, and it can also be used as a hand hole. You may.

[Effects of the invention] As described above, according to the invention, an arrester container whose axis is vertically oriented is connected to a pocket provided at the top of a transformer tank, and a through-button is attached to a partition wall provided inside the pocket. Since the arrester container is installed vertically, the arrester container can be installed without protruding laterally from the transformer tank, or at all. can be prevented. Therefore, it is possible to prevent an increase in the installation area and an increase in the size of the building that houses the transformer.

Further, in the present invention, since the through bushing is installed vertically, the neutral point lead will not be bent. Therefore, there is no need to take measures to support the neutral point lead, and the structure can be simplified.

[Brief explanation of the drawing]

Figures 1 to 3 show examples of the present invention. Figure 1 is a configuration diagram of the main parts, Figure 2 is a sectional view of the main parts during dielectric strength testing, and Figure 3 is during steady operation. It is a sectional view of the main part at the time. Figures 4 to 6 show conventional transformers. Figure 4 is a configuration diagram of the main parts, Figure 5 is a sectional view of the main parts during a dielectric strength test, and Figure 6 is during steady operation. FIG. 1...Transformer tank, 2...Pocket, 6...
Bushing support tube, 7... Test bushing, 9
...Through bushing, 10...Neutral point lead, 1
4...Oil immersion arrester, 15, 31...Lead wire, 20...Arrester container, 21...Head, 22
...Lower part of the neck.

Claims (1)

[Scope of Claim for Utility Model Registration] A transformer tank housing a transformer body, and an arrester container connected to a short tubular pocket protruding from the top of the transformer tank with its axis oriented vertically. , comprising: an oil-immersion arrester housed in the arrester container; and a through bushing installed through a partition wall provided to partition the arrester container and the transformer tank;
In an oil-immersed transformer in which a neutral point lead connected to a neutral point of a winding of the transformer body is connected to the arrester through the through bushing, the arrester container is a cylindrical arrester with an axis oriented in a vertical direction. It consists of a storage head and a tubular lower neck provided below the head coaxially with the head, the lower end of the neck lower being connected to the pocket, and the partition wall is located inside the pocket. , the through bushing is attached to the partition wall with its axis oriented vertically, and the neutral wire lead is raised vertically upward and connected to the through bushing. Oil-immersed transformer.