JPH07220954A - Three-phase on-load tap switching transformer - Google Patents

Abstract

PURPOSE:To enable transportation without increasing the number of tank divisions even if a three-phase on-load tap switching transformer in a tank five-division method exceeds an adaptable maximum capacity value. CONSTITUTION:A unit three-phase on-load voltage adjuster 5 is connected to one terminal side of a unit three-phase transformer 4 and three unit single phase transformers 1 are connected to the other terminal side through a duct 6 to be disassembled freely. A low voltage winding 7, a low voltage winding 10 of corresponding phase and a low voltage winding 13 of corresponding phase are connected parallel through the duct 6. A line side high voltage winding 8, a high voltage winding 18 of corresponding phase and an intermediate point side high voltage winding 19 of corresponding phase are connected in series through the duct 6. Weight ratio between the unit single phase transformer 1, the unit three phase transformer 4 and a unit three-phase on-load voltage adjuster 5 can be changed by changing the ratio of the number of the windings. Therefore, a maximum capacity value can be improved without changing the number of tank division by making all the weights of the unit single- phase transformer 1, the unit three-phase transformer 4 and the unit three-phase on-load voltage adjuster 5 equal and a least upper bound of a transportation limitation weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase load tap change transformer, and more particularly to a three-phase load tap change transformer which is dividable during transportation.

[0002]

2. Description of the Related Art Generally, a transformer installed in a mountainous area such as a hydroelectric power plant is severely constrained to be transported to the installation site. Therefore, the transformer is divided into several units and transported. Are connected using a duct to form a three-phase transformer with a specified rating. However, if the number of divisions is increased, the number of ducts that should be used also increases. This will increase the transformer installation space in the field, so it is desirable to reduce the number of divisions as much as possible.

Now, a conventional three-phase load tap switching transformer having a five-part split tank configuration will be described with reference to FIG. One unit three-phase transformer 4 has one terminal side connected to one unit three-phase load voltage regulator 5 so as to be able to conduct electricity, and the other unit side of the unit three-phase transformer 4 has three unit single-phase units. The transformers 1 are connected so that they can be energized. Further, the unit single-phase transformers 1 are also connected so as to be able to conduct electricity. A duct 6 is used to connect these unit devices, and both units can be connected to and separated from each other. The unit single-phase transformer 1 is composed of an iron core (not shown), a low-voltage winding 7 and a line-side high-voltage winding 8 wound around the iron core, and each is housed in a tank 9. The unit three-phase transformer 4 is constituted by an iron core (not shown), a low-voltage winding 10 for each phase wound around the iron core, and a neutral-point-side high-voltage winding 11 for each phase, and is housed in a tank 12. . The unit three-phase load voltage regulator 5 is composed of an iron core (not shown), a low-voltage winding 13 of each phase wound around the core, a high-voltage tap winding 14 of each phase, and a tap changer 15 under load, and a tank 16 It is stored in.
The neutral point end of the high voltage tap winding 14 and the neutral point side high voltage winding 11 is
It is connected to the tap switch 15 under load via a tap lead 17. Furthermore, the line-side high-voltage winding 8 in each unit single-phase transformer 1 and the neutral-point-side high-voltage winding 11 of the corresponding phase in the unit three-phase transformer 4 are connected in series via a duct to make an arbitrary winding adjustment. In addition, the low-voltage winding 7 in each unit single-phase transformer 1, the low-voltage winding 10 of the corresponding phase in the unit three-phase transformer 4, and the corresponding phase in the unit three-phase load voltage regulator 5 Is connected in parallel via the duct 6.

When transporting the three-phase load tap change transformer having the above-mentioned structure, first, the duct 6 for connecting a plurality of unit devices constituting the three-phase load transformer is removed and disassembled. Then, after transporting the disassembled unit devices or ducts 6, these are connected locally and the three-phase load tap switching transformer is constructed again.

Here, the weight of the unit three-phase load voltage regulator 5 is approximately equal to the weight of the high-voltage tap winding 14, and is generally 10% or less of the weight of the three-phase load tap switching transformer. Also, the weight of the unit three-phase load voltage regulator 5 is lighter than the weight of the unit single-phase transformer 1 or the unit three-phase transformer 4 because it comprises the low-voltage winding 13 and the high-voltage tap winding 14. . Further, the weight of the unit single-phase transformer 1 becomes equal to the weight of the line side high voltage winding 8, and becomes equal to the weight of the neutral point side high voltage winding 11 rather than the unit three phase transformer 4. Therefore, the weight ratio of the unit three-phase transformer 4 to the unit single-phase transformer 1 can be changed by changing the winding number ratio of the line side high voltage winding 8 and the neutral point side high voltage winding 11. Therefore, the maximum capacity value that can be transported without changing the number of divided tanks of the tap switching transformer at the time of three-phase load is that the unit single-phase transformer 1 and the unit three-phase transformer 4 have the same weight and the transport limit weight. It will be within the upper limit of.

[0006]

When a three-phase load tap switching transformer having a capacity exceeding the maximum capacity that can be adopted in the above-mentioned tank five-division system is adopted, the number of divisions is further increased than five-divisions per unit device. Must be less than the transportation limit weight value. However, if the number of divisions is increased, the installation space of the equipment is increased due to the increase in the number of ducts described above, and the amount of insulating oil filled inside is also greatly increased. By the way, as described above, the line-side high-voltage winding 8 and the neutral-point-side high-voltage winding 11 connected in series via the duct 6
By changing the winding number ratio with
The weight ratio of the unit three-phase transformer 4 to the unit can be changed. By adjusting these weight values, it is possible to facilitate transportation and to increase the maximum transportable capacity value in the three-phase load tap switching transformer. However, the weight value of the unit three-phase load voltage regulator 5 which is lighter than the unit single-phase transformer 1 or the unit three-phase transformer 4 cannot be changed.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a three-phase load tap having an improved maximum transportable value without increasing the number of divided tanks. It is to provide a switching transformer.

[0008]

To achieve the above object, the present invention provides three unit single-phase transformers each having a low-voltage winding and a line-side high-voltage winding wound around an iron core, One unit three-phase transformer equipped with low-voltage winding of each phase and high-voltage winding of each phase wound on the iron core, low-voltage winding of each phase wound on the iron core, and neutral point side of each phase A unit unit comprising a high-voltage winding, a high-voltage tap winding of each phase, and a load tap changer, and connecting the neutral-point-side high-voltage winding and the high-voltage tap winding to the load tap-changer. A voltage regulator during phase load is connected in a freely connectable / detachable manner, and the line-side high-voltage winding, the high-voltage winding, and the neutral-point-side high-voltage winding are connected in series so that the number of turns can be arbitrarily adjusted And connecting the low-voltage winding of the unit single-phase transformer and the low-voltage winding of the corresponding phase of the unit three-phase transformer with the unit three-phase. Providing a three-phase load tap changing transformer, characterized in that connected in parallel to each other and the low-voltage winding of the corresponding phase in the load voltage regulator.

[0009]

With the above configuration, not only the winding number ratio between the line side high voltage winding in the unit single-phase transformer and the high voltage winding in the unit three-phase transformer, which are connected in series via the duct, By changing the ratio of the number of turns to the neutral-point side high-voltage winding in the unit three-phase load voltage regulator, the weight of each unit device that constitutes the three-phase load tap switching transformer can be reduced. It is possible to increase the maximum capacity value while keeping within the upper limit value of.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention described in claim 1 will be described below with reference to FIG. The same parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. One unit three-phase transformer 4 has one terminal side connected to one unit three-phase load voltage regulator 5 so as to be able to conduct electricity, and the other unit side of the unit three-phase transformer 4 has three unit single-phase units. The transformers 1 are connected so that they can be energized. Further, the unit single-phase transformers 1 are also connected so as to be able to conduct electricity. Duct 6 is used to connect these unit devices.
Is used, and both can be disassembled. The unit single-phase transformer 1 is composed of an iron core (not shown), a low-voltage winding 7 and a line-side high-voltage winding 8 wound around the iron core, and each is housed in a tank 9. Also, the unit three-phase transformer 4 is
An iron core (not shown), a low-voltage winding 10 of each phase wound around the core, and a high-voltage winding 18 of each phase wound around the iron core are housed in a tank 12. The unit three-phase load voltage regulator 5 includes an iron core (not shown), low-voltage windings 13 of each phase wound around the core, high-voltage neutral point winding 19 of each phase, and high-voltage tap winding 14 of each phase. And the tap changer 15 at the time of load and are housed in the tank 16. The neutral point end of the high-voltage tap winding 14 and the neutral-point-side high-voltage winding 19 is connected to the tap changer 15 under load via the tap lead 17.
It is connected to the. Further, the line-side high-voltage winding 8 in each unit single-phase transformer 1, the corresponding high-voltage winding 18 in the unit three-phase transformer 4, and the corresponding phase in the unit three-phase load voltage regulator 5 The point-side high-voltage winding 19 is connected in series via the duct 6 so that the winding can be adjusted arbitrarily, and the low-voltage winding 7 in each unit single-phase transformer 1 and the unit three-phase transformer 4 can be handled. The low-voltage winding 10 of the corresponding phase and the low-voltage winding 13 of the corresponding phase in the unit three-phase load voltage regulator 5 are connected in parallel via the duct 6.

In the three-phase load tap switching transformer having the above-mentioned structure, not only the winding number ratio between the line-side high-voltage winding 8 and the high-voltage winding 18 connected in series via the duct 6 but also the neutral point. Since the winding number ratio with the side high-voltage winding 19 can also be changed, the weight ratios of these five unit devices are changed so that the weights of the unit devices forming the three-phase load tap switching transformer are all equal and It is possible to set the weight value to the upper limit of the transportation weight limit. Therefore, it becomes possible to further increase the maximum transportable capacity value in the three-phase load tap switching transformer.

[0012]

As described above, according to the present invention, the weight division values of all the unit devices constituting the three-phase load tap change transformer are set within the transportable upper limit value, thereby changing the number of divided tanks. It is possible to improve the maximum capacity value without doing so.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a three-phase load tap switching transformer according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional three-phase load tap switching transformer.

[Explanation of symbols]

1 ... Unit single-phase transformer 1, 4 ... Unit three-phase transformer, 5 ... Unit three-phase load voltage regulator, 6 ... Duct, 7, 10, 13 ... Low voltage winding, 8 ... Line side high voltage winding, 9, 12, 16 ... Tank, 11,
19 ... Neutral point side high voltage winding, 14 ... High voltage tap winding, 15 ... Load tap changer, 17 ... Tap lead, 18 ... High voltage winding.

Claims (1)

[Claims] 1. Three unit single-phase transformers each equipped with a low-voltage winding and a line-side high-voltage winding wound on an iron core, a low-voltage winding of each phase wound on the iron core, and One unit three-phase transformer equipped with high-voltage winding, low-voltage winding of each phase wound around the iron core, high-voltage neutral point side winding of each phase, high-voltage tap winding of each phase, and one load A unit three-phase load voltage regulator, comprising a tap changer, the neutral-point-side high-voltage winding and the high-voltage tap winding are connected to the load-time tap changer, and are connected to and detachable from each other, The line-side high-voltage winding, the high-voltage winding, and the neutral-point-side high-voltage winding for each corresponding phase are connected in series so that the number of turns can be adjusted arbitrarily, and the low-voltage winding and the unit in the unit single-phase transformer are connected. The low-voltage winding of the corresponding phase in the three-phase transformer and the low-voltage winding of the corresponding phase in the unit three-phase load voltage regulator are connected. A three-phase load tap switching transformer that is connected in parallel with each other.