JPH05135953A - Transformer - Google Patents

Abstract

PURPOSE:To obtain a reliable transformer by mounting the flexible part of a gas insulating bus not in the middle of the gas bus but in its end in a connector of a duct from the transformer, a bushing, and a gas insulating bus. CONSTITUTION:A duct 31 from a transformer is mounted on a bushing 32, and the flexible part 35 of a gas insulating bus 37 on the bushing 32; further, the gas insulating bus 37 is connected to its other end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to transformers, and in particular
A lead wire having an electric potential is taken out from the winding wire, accommodated in a duct and then connected to a bushing, and the other end of the bushing relates to a duct structure of a transformer connected to a gas-insulated duct.

[0002]

2. Description of the Related Art In recent years, due to rising prices of land in cities,
Power supply sites such as power plants are often constructed in parts away from power demand sites. UHV power transmission has recently been studied as a power transmission from such a remote distance. UHV
The substation for power transmission is located in the mountains. The transformers used in such substations are also manufactured within the strict transportation restrictions, as before. However, since the voltage is high and the capacity is large, a three-phase transformer divided into six is being considered. An example of one phase of such a transformer is shown in FIG.

In FIG. 2, the unit transformers 1A and 1B constituting the single-phase transformer are juxtaposed in parallel so that their longitudinal tanks 23 face each other and are covered with a soundproof wall 4. . Each unit transformer 1A, 1B is a tank
23, an iron core 24 installed in the tank 23, and a winding wire 25 wound around the main leg of the iron core 24.
The high-voltage lead 14 and the medium-voltage lead 15 of each unit transformer 1A, 1B are connected to the tanks 23 of each unit transformer 1A, 1B from the positions of substantially the same height on the side surfaces facing each other through a T-shaped duct. High pressure bushing 16, medium pressure bushing
It is connected to one end of 17.

The load voltage regulators 3A and 3B attached to the unit transformers 1A and 1B are arranged in the lateral direction of the tank 23 of the unit transformers 1A and 1B, respectively.
2B, respectively.

FIG. 3 is a diagram showing a case where the three single-phase transformers shown in FIG. 2 are arranged to form a three-phase transformer. The single-phase transformer U composed of the two unit transformers 1A and 1B, and similarly, the single-phase transformers V and W composed of the single-phase transformers 1C, 1D, 1E, and 1F each have the longitudinal length of the tank 23. High pressure bushing 16 and medium pressure bushing 17 with their sides facing each other
Are arranged side by side in the same direction in opposite directions to each other and arranged in parallel to form a three-phase transformer. The high-voltage line, the medium-voltage line, and the transformer are connected by gas-insulated busbars 26 and 27.The high-voltage bushing 16 and the high-voltage gas-insulated busbar 26, and the medium-voltage bushing 17 and the medium-pressure gas-insulated busbar 27 are connected. ing. These gas-insulated buses 26 and 27 are connected to other substation equipment at the ends opposite to the transformers. Meanwhile, the conventional split type three-phase transformer configured as described above has the following problems.

[0006]

As described above, the duct from the transformer and the gas-insulated busbar are connected via the bushing. The gas-insulated bus bar is connected to the substation equipment. In such a connection device, when the gas insulated busbar is in the UHV class, the distance between the transformer and the gas insulated device tends to be long, and in order to cope with temperature changes in the part of the gas insulated device and to A flexible tank is used as part of the gas-insulated equipment in order to increase the seismic strength of the gas-insulated equipment. In other words, with a transformer,
For example, in the event of an earthquake or the like, the gas insulating device is not connected directly to the transformer, and the flexible gas tank is used to suppress the vibration. However, in the UHV class, the electric field on the ground side of the gas insulated busbar becomes high. In particular, with respect to the flexible tank surface, the grounded tank has a bellows shape, and the electric field on the grounded side tends to be higher than that of the portion other than the flexible tank. To deal with this, for example, as shown in FIG.
A shield 113 is attached to a portion of the flexible tank 111 corresponding to the high voltage conductor 112. But this method
For example, the electric field on the tank side of a gas duct that does not have flexibility and the shield on the part where flexibility is attached.
Flexible tank 111 to equalize the electric field of 113
The outer diameter of the tank must be larger than that of the general tank. Therefore, as shown in FIG. 4, the flange diameter 114 of the tank in the general portion is increased. Therefore, the mechanical strength of the flange portion may decrease. Furthermore, since the tank diameter of the general part is made smaller and the same as the shield diameter of the flexible tank part, there is a step between the shield end part and the flange corner part 115 of the tank of the general part and the end part of the shield 113 is Even when rolled, electric field concentration occurs at the end portion 115 on the flange side. It is a well-known fact that, when electric field concentration occurs, breakdown occurs at a low voltage.

The present invention has been made in view of the above points, and an object thereof is to connect a duct from a transformer, a bushing, and a gas-insulated bus bar, in which a flexible portion of the gas-insulated bus bar is attached in the middle of the gas bus bar. To provide a reliable split-type transformer that can be attached to the end of the gas busbar.

[0008]

In the present invention, a duct from a transformer is attached to a bushing, a flexible portion of the bushing gas-insulated busbar is attached, and a gas-insulated busbar is connected to the other end.

[0009]

In the present invention thus constructed, the following actions occur.

In the present invention, the flexible portion of the gas insulated bus bar is attached to the bushing. As is well known, the bushing is constructed by winding insulating paper around the center conductor, and an equalizer for controlling the potential is attached between the insulating paper coaxially with the center conductor. There is. The outermost (outer diameter side) equalizer is configured to be substantially at ground potential. Therefore, almost no electric field is applied to the gas duct portion facing it. Therefore, conventionally required
The shield of the flexible tank part is not necessary.
Furthermore, the tank diameter of the flexible portion can be made smaller than before, and the flange diameter of the end portion can be matched with the general portion of the gas-insulated busbar.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same parts as those of the conventional one are designated by the same reference numerals, and the description thereof will be omitted. FIG. 1 shows an outline of a duct from a transformer, a bushing connected to the duct, a flexible tank of a gas-insulated bus bar, and a general portion of a gas-insulated bus bar as one embodiment of the present invention. In FIG. 1, reference numeral 31 is a duct from a transformer, and a high voltage lead or a medium voltage lead connected to the divided transformer is connected to the inside of the duct.

Further, 32 is a high pressure or medium pressure bushing, and flanges 33 and 34 are attached to the bushing 32. Further, 35 is a flexible tank of a gas-insulated busbar, which is fixed between the flexible tank and a flange 34 attached to the bushing 32. The other end is connected to the gas-insulated bus bar 37. The grounding side flange of the bushing is longer on the gas insulated bus side than on the transformer side, and the flexible tank 35 is attached to the grounding side flange of the bushing.

In one embodiment of the present invention thus constructed, the following operational effects occur. That is, the bushing 32 is constructed by winding insulating paper around the central conductor as is well known, and an equalizer for controlling the potential coaxially with the central conductor is attached between the insulating papers.
The outermost (outer diameter side) equalizer is configured to be substantially at ground potential. Therefore, almost no electric field is applied to the gas duct portion facing it. Therefore, it is not necessary to shield the flexible tank portion, which was required in the past. In particular, in one embodiment of the present invention, as described above, the bushing 32
The ground side flanges 33, 34 of the gas insulated busbar 37 side are made longer than the oil side, and the flexible tank 35 is attached to that part.Since the electric field is hardly applied to the flexible tank 35, the shield of the flexible part is Even if it does not exist, it does not cause any problem in terms of insulation. Furthermore, the tank diameter of the flexible part can be made smaller than before,
Since the flange diameter of the end portion can be matched with the general portion of the gas-insulated bus bar 37, a local electric field concentration can be prevented even at the tank connection portion without a step. Therefore, it is possible to provide a reliable transformer having a high breakdown voltage.

Further, since the flexible tank 35 is directly attached to the bushing portion, the reliability is improved even against an earthquake. Especially in the 32 parts of the bushing,
Since the flexible tank 35 is directly attached, the effect is great when the transformer and the gas-insulated busbar are installed on different mounts. Furthermore, since the flexible tank 35 is attached directly to the bushing 32 even when the duct or the like is contracted due to a temperature rise during the operation of the transformer,
Since the displacement of contraction is not transmitted to the gas bus side, a reliable split type transformer can be provided.

[0015]

As described above, according to the present invention, the bushing connected to the duct has a grounding flange portion on the gas duct side longer than the oil side, and a flexible gas duct is attached to that portion, thereby improving reliability. , A transformer with excellent seismic strength can be obtained.

Although a split type transformer has been described as one embodiment of the present invention, the configuration is not limited to the split type transformer, and the transformer may be connected to an oil duct, a bushing, and a gas insulated busbar. It goes without saying that it can also be applied to a transformer. Furthermore, although the transformer has been described as an oil-filled transformer, it goes without saying that it can be applied to a gas-insulated transformer as well, in a configuration in which a bushing is attached between the transformer and the gas-insulated bus bar.

[Brief description of drawings]

FIG. 1 is a duct from a transformer showing one embodiment of the present invention,
Schematic which shows a bushing and a gas-insulated busbar.

FIG. 2 is a plan view showing a split transformer.

FIG. 3 is a diagram of a three-phase transformer in which three divided single-phase transformers are grouped together for one bank.

FIG. 4 is a schematic view showing a situation in which a conventional flexible tank is attached to a gas-insulated bus bar.

[Explanation of symbols]

 35 ... Flexible tank 33, 34 ... Flange 32 ... Bushing 37 ... Gas-insulated busbar 39 ... Duct

Claims (1)

[Claims] 1. A tank, an iron core arranged in the tank, a plurality of high-voltage windings wound in parallel around the iron core, connected in parallel, a high-voltage winding of a transformer having an intermediate-voltage winding, and an intermediate-voltage winding. At least one of which is drawn out of the tank into the high-pressure duct and the medium-pressure duct by a high-pressure lead and a medium-pressure lead, respectively, and connected to a bushing, and the other end of the bushing is a lead wire inside the gas-insulated duct. In the transformer adapted to be connected to the transformer, the duct from the transformer and the gas insulated duct are separated by the bushing portion, and the gas duct of the portion attached to the bushing is a flexible gas tank.