JPS6232602B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a single-phase three-winding transformer having a tertiary winding used in an ultra-high voltage power transmission circuit, and in particular to a single-phase three-winding transformer having a tertiary winding, which increases the impedance between the tertiary winding and the medium voltage winding. Regarding phase 3 winding transformers.

The transformers used in ultra-super high voltage power transmission circuits have large capacities and are large, so due to transportation constraints, three single-phase transformers are connected in three-phase banks on-site.
It is generally used as a three-phase transformer.

On the other hand, in transformers with a tertiary winding installed in substations, etc., the purpose is to reduce the tertiary circuit's rupture capacity, and to reduce the mechanical force acting on the tertiary winding when the tertiary circuit is short-circuited. Therefore, it is desired to increase the impedance between the tertiary winding, the high voltage winding, and the medium voltage winding (particularly the medium voltage winding).

Based on the above background, in single-phase three-winding transformers with a tertiary winding used in ultra-super high voltage power transmission circuits, in order to increase the impedance between the tertiary winding and the medium voltage winding, conventional Alternatively, a winding configuration as shown in FIG. 2 has been proposed.

Figure 1 shows that the first main leg 5A of a single-phase four-leg iron core is wound with a medium-voltage winding unit 2A and a track-side high-voltage winding unit 1A sequentially from the core side, and the second main leg 5B is wound with a medium-voltage winding unit 2A and a high-voltage winding unit 1A from the core side. In order, tertiary winding unit 3B, medium voltage winding unit 2B,
The neutral point side high voltage winding unit 1B and the tap winding unit 4B are respectively wound, and the medium voltage winding unit 2A of the first main leg 5A and the medium voltage winding unit 2B of the second main leg 5B are connected in parallel. The line side high voltage winding unit 1A of the first main leg 5A is connected in series with the neutral point side high voltage winding unit 1B and tap winding unit 4B of the second main leg 5B. According to this configuration,
Since the tertiary winding 3B is wound only on the second main landing gear 5B, the impedance between the medium voltage winding and the tertiary winding is as follows:
This is approximately twice as large as the conventional most common winding arrangement in which the wire is divided into B and wound.

However, in the above winding arrangement, the tap winding 4B is placed outside the high-voltage winding 1B, which has a high voltage, so it is necessary to keep a large insulation distance between the windings. There is also a drawback that the diameter of the winding becomes large, and the entire transformer becomes large so that it no longer fits within the transport limit dimensions. In addition, if a higher value is required for the impedance between the medium voltage winding and the tertiary winding,
This has to be overcome by making the dimensions between the tertiary windings larger than those determined by the insulation, resulting in a disadvantage that the space factor of the windings deteriorates and the overall size and weight of the transformer increases.

On the other hand, Fig. 2 shows the first main leg 5A of the single-phase four-leg iron core.
A medium voltage winding unit 2A and a track side high voltage winding unit 1A are wound sequentially from the iron core side, and the second main landing gear 5B
The medium voltage winding unit 2B, the neutral point side high voltage winding unit 1B, the tertiary winding unit 3B, and the tap winding unit 4B are wound in order from the iron core side to the first main landing gear 5A. The medium voltage winding unit 2A wound on the second main landing gear 5B and the medium voltage winding unit 2B wound on the second main landing gear 5B are connected in parallel;
In this configuration, a line side high voltage winding unit 1A wound around the main leg 5A of the main leg 5B, a neutral point side high voltage winding unit 1B wound around the second main leg 5B, and a tap winding unit 4B are connected in series.

According to this configuration, medium voltage winding 2B-tertiary winding 3B
There is an advantage that the impedance between the tertiary winding and the medium voltage winding becomes larger than in the example shown in FIG. Therefore, it is necessary to provide a core grounding shield to protect the edges of the core legs, which increases the number of manufacturing steps. In addition, since the tertiary winding 3B and tap winding 4B are arranged outside the high voltage winding 1B of the second core main leg 5B, the insulation distance between the high voltage winding 1B and the tertiary winding 3B is increased. This has the same disadvantage as the example shown in FIG. 1, in that the diameter of the winding of the second main leg becomes large due to the fact that the winding diameter of the second main leg has to be increased, making the entire transformer larger.

The present invention has been developed in view of the above-mentioned drawbacks of the conventional structure.
A compact, single-phase three-winding design that allows the impedance between the tertiary windings to be significantly increased, thereby reducing the short-circuit capacity of the tertiary circuit, and at the same time providing high reliability against tertiary circuit short-circuits. The purpose is to supply line transformers.

The present invention will be described below with reference to an embodiment shown in FIG.

In Fig. 3, a medium voltage winding unit 2A and a track side high voltage winding unit 1A are wound sequentially from the iron core side onto the first iron core main leg 5A, and a second iron core main leg 5B is wound sequentially from the iron core side. , a tertiary winding unit 3B, a tap winding unit 4B, a medium voltage winding unit 2B, a neutral point side high voltage winding unit 1B, and a medium voltage winding 1B of the first main landing gear 5A.
and the medium voltage winding 2B of the second main landing gear 5B in parallel,
The line-side high-voltage winding unit 1A of the main leg 5A, the neutral point-side high-voltage winding unit 1B and the tap winding unit 4B of the second main leg 5B are connected in series, respectively.
Configure a wire-wound transformer.

With the above configuration, in the second main landing gear 5B, the tap winding 4B is arranged between the tertiary winding 3B and the medium voltage winding 2B, so compared to the conventional configuration shown in FIG. Since the distance between the secondary winding and the medium voltage winding increases, the magnetic energy stored between the tertiary winding and the medium voltage winding also increases by this increased distance.
The impedance between the tertiary winding and the medium voltage winding also increases. Further, since the winding facing the second core main leg 5B is the tertiary winding 3B having a relatively low voltage, a ground shield for protecting the edge of the core leg is not required. Further, since no other winding is wound outside the high-voltage winding 1B, the diameter of the second main leg winding is small, and the dimensions of the entire transformer can also be reduced.

As shown in Fig. 4, in the embodiment of Fig. 3,
If the configuration is such that the neutral point side high voltage winding 1B of the second main landing gear 5B and the intermediate voltage winding 2B are replaced, the high voltage winding 1
Since the medium voltage winding 2B is placed outside B, the second
Although the outer diameter of the main landing gear winding becomes larger, the distance between the tertiary winding 3B and the medium voltage winding 2B becomes even larger than in the example shown in Figure 3, so the impedance between the medium voltage winding and the tertiary winding is It can be made even larger, and there is no need for a ground shield to protect the edges of the iron core.

Furthermore, it is clear that substantially the same effect as in the example of FIG. 4 can be obtained by replacing the tap winding 4B and the tertiary winding 3B in the example of FIG. 4 as shown in FIG.

As explained above, according to the present invention, the tertiary winding can be removed without increasing the winding diameter or installing a grounding shield to protect the core edge.
To obtain a compact single-phase three-winding transformer that can significantly increase the impedance between medium-voltage windings, thereby reducing the short-circuit capacity of the tertiary circuit, and that is highly reliable against short-circuits in the tertiary circuit, and that is compact and satisfies transportation restrictions. I can do it.

[Brief explanation of the drawing]

1 and 2 are block diagrams of a conventional single-phase three-winding transformer, FIG. 3 is a block diagram of a single-phase three-winding transformer showing an embodiment of the present invention, and FIGS. FIG. 5 is a block diagram of a single-phase three-winding transformer showing other embodiments of the present invention. 1A... Line side high voltage winding unit, 1B... Neutral point side high voltage winding unit, 2A, 2B... Medium voltage winding unit,
3A, 3B... Tertiary winding unit, 4A, 4B... Tap winding unit, 5A... First main landing gear, 5B... Second main landing gear.

Claims (1)

[Claims] 1. A medium voltage winding unit and a track side high voltage winding unit are wound around the first iron core main leg in order from the iron core side, and a tertiary winding is wound in the second iron core main leg in order from the iron core side. A tap winding, a medium voltage winding, and a high voltage winding unit on the neutral side are wound, and the medium voltage winding units are connected in parallel, and the high voltage winding on the neutral side and the high voltage winding on the line side are connected in parallel. 1. A single-phase three-winding transformer, characterized in that the transformers are connected in series, and the high-voltage winding on the neutral point side is connected in series with a tap winding. 2 A medium voltage winding unit and a track side high voltage winding unit are wound on the first iron core main leg in order from the iron core side, and a tertiary winding, a tap winding, and a neutral winding are wound in order from the iron core side on the second iron core main leg. Winding the point side high voltage winding unit and medium voltage winding unit,
The medium voltage winding units are connected in parallel, and the neutral point side high voltage winding and the line side high voltage winding are connected in series,
A single-phase three-winding transformer characterized in that a tap winding is connected in series to the high-voltage winding on the neutral point side. 3 The first iron core main leg is wound with a medium voltage winding unit and the track side high voltage winding unit in order from the iron core side, and the second iron core main leg is wound with a tap winding, a tertiary winding, and a neutral winding in order from the iron core side. A high voltage winding on the point side and a medium voltage winding unit are wound, and the medium voltage winding units are connected in parallel, and the high voltage winding on the neutral point side and the high voltage winding on the line side are connected in series, and A single-phase three-winding transformer comprising a tap winding connected in series to the high-voltage winding on the neutral point side.