JPH0143444B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-phase autotransformer suitable for split transport.

For ultra-high-voltage power transmission of 500 KV or higher, the capacity of a single transformer is large, and transformers for substations installed inland are generally constructed of single-phase transformers due to transportation size and weight constraints. However, due to the difficulty in securing land for these ultra-high voltage substations, transportation conditions are becoming increasingly severe, and it is expected that in the future there will be many cases where it will not be possible to construct a bank with three single-phase transformers. In this case, a method is used in which the single-phase transformer is divided into a plurality of unit transformers, each unit is assembled and transported, and then assembled into a single-phase transformer at the site through an oil-submerged duct or the like.

An example of a divided configuration in this case is shown in FIG. In FIG. 1, series windings 11, 12, 13, shunt windings 21, 22, 23, low voltage windings 31, 32, 3
The three windings of No. 3 are wound around the core legs 41, 42, and 43 in the order of low voltage winding, shunt winding, and series winding from the inside, and are stored in three tanks 51, 52, and 53, respectively. There is. and a separate tank 51,5
The connection between the windings housed in tanks 2 and 53 is connected to tank 5.
This is done through an oil-filled duct that connects 1, 52, and 53. In other words, the high voltage leads are connected to the ducts 61, 6.
2 Medium pressure leads are in ducts 71 and 72, neutral point leads are in ducts 81 and 82, and low pressure leads are in ducts 91 and 72.
92. Electrically, the series windings 11, 12, 13 are connected in parallel, which in turn is connected in series with the shunt windings 21, 22, 23, which are also connected in parallel. Furthermore, the low voltage windings 31, 32, and 33 are also connected in parallel.

In other words, three windings each having one-third the capacity of a single-phase converter are made, each of which is housed in a separate tank, and each winding is connected in parallel. In the figure, U indicates the high-voltage line terminal of the series winding, u and v indicate the medium-voltage line terminal and neutral point terminal of the shunt winding, respectively, and a and b indicate both terminals of the low-voltage winding.

However, in such a configuration, the series windings 11, 12, 13, which all have the potential of the end of the high voltage line, are housed in the three tanks 51, 52, 53.
The insulation dimensions between the series winding and the tank or between the series winding and the shunt winding must be sufficient to withstand the voltage at the end of the high-voltage line for all three units, which is disadvantageous for making the tank more compact.

Therefore, as an example of another division configuration, the method shown in FIG. 2 can be considered. In other words, the series winding 1 divided into three parts
Among 1, 12, and 13, part 1 on the high voltage line end side
1 and 12 are connected in parallel, which is connected in series to the remaining medium-voltage line end portion 13, which is further connected in series to shunt windings 21, 22, and 23 connected in parallel. Of the three unit transformers, the low voltage winding 3 is wound only in the unit on which the series winding 13 on the end side of the medium voltage line is wound. With this configuration, the unit in which the low-voltage winding 3 is not wound can have the series windings 11, 12, the shunt windings 21,
The outer diameter of 22 can be made smaller. In addition, in the unit around which the low voltage winding 3 is wound, the capacity of the low voltage winding 3 is three times that of the case shown in Fig. 1, but in contrast to the increase in the radial dimension due to this increase, in the ultra-super high voltage transformer, series winding is required. Shortening the insulation dimension by reducing the voltage of the line 13 is more effective, and the tank 53 can be made smaller.
At this time, each winding is connected to a duct 61a for passing the high voltage line end leads of the high voltage line ends 11 and 12 of the series windings, to the series windings 11 and 12 on the high voltage line end side, and to the series windings on the medium voltage line end side. Ducts 61b and 62 for passing leads having potentials at 13 connection points and shunt winding 2
1, 22, and 23 are connected in parallel, through ducts 71, 72 through which intermediate voltage leads pass, and ducts 81, 82 through which neutral point leads pass.

Therefore, while the number of ducts for passing high voltage leads higher than the potential at the end of the medium voltage line was four in the configuration of FIG. 1, it is increased to five in the configuration of FIG. Insulation for high voltage leads tends to become more complex as the voltage increases, including the use of multiple barrier structures to increase dielectric strength. Furthermore, since the connections between tanks will be done on-site, sufficient care must be taken to ensure that no foreign matter gets mixed in during the work. From this point of view, it is advantageous in terms of quality and man-hours to have at least one fewer ducts for connecting high voltage leads.

The present invention minimizes the number of ducts connecting the unit transformers when configuring one single-phase transformer with three unit transformers, reduces the size of each unit transformer, and limits transportation. The purpose is to provide a single-phase autotransformer that can expand the

An embodiment of the present invention will be described below based on the drawings. In Figure 3, the series winding 1 is divided into three parts.
1, 12, and 13 are series windings 12 having an intermediate potential between the series winding 11 on the high-voltage line end side and the high-medium voltage line end side.
and a series winding 13 at the end of the medium voltage line are connected in series in sequence, and this is connected in series at the end of the medium voltage line to shunt windings 21, 22, 23 which are also divided into three and all connected in parallel. be done. The series and shunt windings divided into three are stored in three separate tanks 151, 152, 153 for each division unit, and the low voltage winding 3 is housed in the series winding 13 on the end side of the medium voltage line.
Wrap only the unit that is to be wound.

With this configuration, each winding is connected to the high-voltage line end side series winding 11 and the high-medium voltage line end side series winding 11 and the duct 61 through which the lead connecting the series winding 12 having a potential intermediate between the high-medium voltage line end and the high-medium voltage line A series winding 12 having an intermediate potential at the end, and a series winding 13 at the end of the medium voltage line.
duct 62 for passing the leads connecting the shunt windings, and ducts 71, 7 for passing the medium voltage leads connecting the shunt windings in parallel.
2 and the neutral point lead through ducts 81 and 82, and the number of ducts through which the high voltage lead, which is higher than the potential at the end of the medium voltage line, is passed becomes four, which is one less than the configuration shown in Figure 2. . Note that the units that do not wind the low-voltage winding 3 will have the series windings 11 and 1 accordingly.
2 and the outer diameter of the shunt windings 21 and 22 can be made small,
The unit that winds the low-voltage winding 3 has the effect of shortening the insulation dimension due to the voltage reduction of the series winding 13.
It is similar to the configuration shown in FIG. 2 in that it has the advantage of being able to downsize the device. Furthermore, series windings 11, 12, 13
The potential of the leads in the ducts 61 and 62 through which the leads connecting between them are successively lower than the potential at the end of the high voltage line. It also has the advantage of being easier to insulate.

FIG. 4 shows another embodiment in which the low-voltage winding is divided into two parts. This is exactly the same as the unit in which the series winding 11 at the end of the high voltage line is wound, without winding the low voltage winding, and the low voltage windings 32 and 33 wound in other units are connected in parallel.

Even in such a configuration, the number of ducts for passing high voltage leads is naturally only four, as shown in Fig. 4, and in terms of tank miniaturization, the series winding 12, which has an intermediate potential at the end of the high-medium voltage line, is Since the voltage is lower than that at the line end, the voltage is lower than when the low voltage winding is divided into three parts. , it is more effective to shorten the insulation dimensions between the series winding 12 and the tank 152 and between the shunt winding 22, and the tank can also be made smaller. At this time, the winding ratio of the series windings 11, 12, 13, and therefore the capacity ratio of the shunt windings 21, 22, 23 or the capacity ratio of the low voltage windings 32, 33 are the same as those of the tanks 151, 152,
The size of 153 may be distributed so that it is balanced, and there is no need to divide it into equal parts.

Furthermore, as another example, even if the low-voltage winding is divided into three sections as in the example of FIG. 1, if the series winding and shunt winding are configured similarly to the example of FIG. 1
Compared to the configuration shown in the figure, two of the three units (152 and 153) achieved easier insulation of the leads that connect the series windings, and a smaller tank due to the voltage reduction of the series windings 12 and 13. It will be excellent if it has three points.

In each of the above embodiments, the medium voltage bushing and the neutral point terminal may be drawn out from either tank. Furthermore, it goes without saying that the neutral point terminals may be drawn out from each tank and connected externally without using an oil-filled duct.

As explained above, when three unit transformers constitute one single-phase transformer, the present invention connects the unit transformers by connecting all three divided series windings in series. Minimize the number of ducts to
In addition, the tank of each unit transformer can be made smaller and the transportation limit can be expanded.

[Brief explanation of drawings]

1 and 2 are block diagrams of a conventional single-phase auto-transformer, FIG. 3 is a block diagram showing an embodiment of a single-phase auto-transformer according to the present invention, and FIG. 4 is a block diagram of a conventional single-phase auto-transformer. FIG. 3 is a diagram showing the internal structure of a single-phase autotransformer showing another embodiment of the invention. 11, 12, 13...Series winding, 21, 22,
23...Shunt winding, 3,31,32,33...Low voltage winding, 41,42,43...Iron core, 51,5
2,53,151,152,153...Tank,
61, 62, 71, 72, 81, 82, 91, 9
2... Oil-filled duct, U... High voltage line end terminal of series winding, u, v... Medium voltage line end terminal and neutral point terminal of shunt winding, a, b... Both ends of low voltage winding Child.

Claims (1)

[Claims] 1 The series winding and the shunt winding are each divided into three parts, each of which is wound around a core leg in a separate tank, and a low voltage winding is wound around at least one of the core legs to form three units. form a unit transformer,
A single-phase single-turn transformer characterized in that the series windings of these three unit transformers are all connected in series, and the shunt windings and low voltage windings are all connected in parallel.