JPS598317A - On-single-phase load tap changing transformer - Google Patents

Abstract

PURPOSE:To enable a rational division, and to obtain the compact transformer by collecting neutral-point side terminal drawn out of the main windings of unit transformers in three pairs and connecting the pairs to three sectors of an on- load tap changer for changing over three phases. CONSTITUTION:The neutral point sides of the main windings 2 received in each unit transformer 1 are collected in three blocks in the numbers of three, three and two, collected at every block, and connected to each tap winding 4-1-4-3 of an on-single-phase load voltage regulator 3 through connecting ducts 7. On the other hand, these tap windings 4-1-4-3 are connected to each sector 6-1-6-3 of the on-load tap changer 5 for changing over three phases. Accordingly, the number of a main transformer proper divided can be optimized judging from an aspect of the size of transport, and the transformer is manufactured economically and compacted.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a single-phase on-load tap-changing transformer. In particular, the present invention relates to a single-phase on-load tap-changing transformer. In particular, the present invention relates to a UHV ultra-large transformer that constitutes a three-phase bank with a single-phase transformer in which the main body and windings are divided into multiple parts. The present invention relates to a single-phase load tap-changing transformer suitable for a capacitive load tap-changing transformer.

[Technical background of the invention]

In recent years, power systems have become larger in capacity and higher in voltage, and it is planned that UHV power systems will be installed in the future.

Accordingly, it is planned that the on-load tag switching transformers installed in the UHV system will also be ultra-high capacity transformers with a puncture capacity of 300 MVA class.

By the way, due to transportation constraints, large-capacity transformers are not suitable for single-phase transformers.
In many cases, a single-phase load voltage regulator is installed separately for each phase, and this is installed inside a single-phase main transformer that does not have a tap winding. A method has been adopted in which an on-load tap-changing transformer is constructed by connecting to the power point side.

However, in the case of a 3000 MVA class ultra-large capacity transformer, the above construction method cannot keep the transport dimensions within limits, and it is necessary to further divide the single-phase transformer into a plurality of unit transformers.

On the other hand, a load tag switch is usually connected to the neutral point of a three-phase star connection, and a three-set neutral point type in which three sets of contacts are integrated is common.

Therefore, even when a single-phase transformer is further divided into multiple units, the neutral point of each divided unit transformer is connected to the three sectors of the on-load tag switch for three-phase switching provided in the single-phase load special voltage regulator. Conventionally, the single-phase transformer was divided into multiples of 3, which is the number of sectors, to construct a single-phase load tap change transformer.

[Problems with background technology]

However, according to the above-mentioned conventional configuration, an intermediate number of divisions cannot be obtained.
If the product is divided, it may not fit within the transport size limit, but if it is divided into 6 parts as shown in Figure 2, it will be far below the transport size limit and the cost will be high. There was a problem that something reasonable could not be obtained.

1 and 2, 1 is a divided unit transformer, 2 is a main winding contained in the unit transformer 1, and 3 is a divided unit transformer.
is a single-phase load special voltage regulator, 4 is a tag winding, 5 is a negative Wi tag switch for three-phase switching, 6 is a sector, and 7 is a connection duct. Further, the connection between the excitation winding of the on-load voltage regulator and the winding on the main transformer side connected in parallel with the excitation winding is omitted in the figure.

[Purpose of the invention]

The present invention solves the above problems and provides an economical and compact single-phase load tag Kirimata transformer by rationally dividing the single-phase transformer from the viewpoint of transportation dimensions. With the goal.

[Summary of the invention]

Therefore, when dividing the single-phase transformer main body and winding, the present invention determines the number of divisions by considering only the transport limit dimensions, without worrying about the number of sectors of the on-load tap changer for three-phase switching, and further The neutral points of the divided main windings of each transformer are grouped into three approximately equal blocks, and each block is batched for tap switching from each tap winding of the single-phase load special voltage regulator during load for three-phase switching. It is characterized by being connected to each sector of the device.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows the configuration of a single-phase load tap-changing transformer according to an embodiment of the present invention. 4
This is an example in which the transformer is divided and each unit transformer 1 is configured with two sets of main windings 2. In the figure, the same reference numerals as in FIG. 1 indicate the same or equivalent parts, and a total of 8
On the neutral point side of the main winding 2, there are 3 windings, 3 windings, and 2 windings as shown in the figure.
Group each block into 3 blocks, group each block together,
It is connected to each tag winding 4-1 to 4-3 of the single-phase load special voltage regulator 3 via the connection duct 7. On the other hand, these tap windings 4-1 to 4-3 are connected to a three-phase switching load tap changer 5.
It is connected to each sector 6-1 to 6-3. Therefore, if the capacity of the single-phase converter is 1000 MVA, the capacity of each sector of the tap changer 5 is 375 MVA.
, 375 MVA.

250 MVA and unbalanced, but the switching capacity of each sector 6 of the on-load tap changer 5 is 50 MVA in terms of transformer capacity.
0 MVA, so there is no problem with switching ability.

FIG. 4 shows a configuration diagram of a single-phase load tag switching transformer according to another embodiment of the present invention, in which the single-phase main transformer main body is divided into five parts, and each unit transformer 1 has a This is an example in which one main winding 2 is accommodated. In the figure, the same symbols as in Figure 2 are the same.
The neutral point side of a total of five main windings 2 housed in each unit transformer 1 is grouped into 2, 2, and 1 windings, respectively, and is connected individually via a connecting duct 7. It is connected to the tap windings 4-1 to 4-3 of the phase load special voltage regulator 3. In this case, if the single-phase transformer capacity is the same (100 OMVA), the capacity of each sector of the on-load tap changer 5 is 400 OMVA.
MVA, 400 MVA, and 200 MVA, but there is no problem with the switching ability as described above.

The above example shows how a single-phase transformer body is divided into 4 or 5 parts, but in order to cope with the transportation size restrictions of transformers, when dividing a single-phase transformer body and windings + In each sector 6 of the on-load tap changer 5, the transformer main winding is divided into 3N+1 or 3N+2 (N is an integer), taking into account only transportation constraints, regardless of the multiple of 3, which is the number of sectors. Each N+1. N,
N pieces or N+1. By connecting N-1-1, N pieces, a rational divided structure of the on-load tap-changing transformer can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the number of divisions of the main transformer main body can be set to the optimum number from the viewpoint of transportation dimensions, so an economical, compact, and rational on-load tap-changing transformer can be obtained. You will be able to do it.

[Brief explanation of the drawing]

FIGS. 1 and 2 are block diagrams of conventional single-phase load tap-changing transformers, and FIGS. 3 and 4 are block diagrams of single-phase load tap-changing transformers according to embodiments of the present invention. be. 1...Unit transformer, 2...Main winding, 3...Single-phase load special voltage regulator, 4.4-1 to 4-3...Tag coiling, 5...3-phase Load tag switch for switching, 6.6-1
~6-3...Sector, 7...Connection duct. Figure 7 Figure 2 Figure 3

Claims (1)

[Claims] The main body of the single-phase transformer is divided into multiple unit transformers taking into account the transport limit dimensions, and the neutral point side terminals drawn out from all the main windings housed in each of these unit transformers are divided into approximately equal numbers. It is characterized in that it is assembled into three sets, and each set is collectively connected to the three sectors of the on-load tag switch for switching the three sets from the three sets of tap windings of the single-phase load special voltage regulator. Single phase load tap changing transformer.