JPS6038013B2 - single phase transformer - Google Patents

Description

Detailed Description of the Invention The present invention reduces the impedance change due to each tap of a single-phase transformer or a multi-phase transformer divided into a plurality of single-phase transformers, and changes the impedance change tendency of each tap. The present invention relates to a fist-phase transformer with an improved structure that can be used.

The capacity of transformers is also increasing as the voltage of electricity transmission becomes higher, but transport by rail is subject to weight restrictions due to tunnels, station buildings, etc., especially when the base is located in a mountainous area. Dimensional restrictions are often placed in the height and width directions. For this reason, various ideas have been devised for transformer winding configurations. Figure 1a Figures 2 and 3 show the winding configuration of a conventional single-phase transformer, and Figure 3 shows the most common conventional single-phase transformer (using a single-phase four-legged core). In the configuration example of a transformer, the two main legs 5A and 5B of the iron core are
Tertiary winding unit 11A, 11B, low voltage winding unit 2 respectively
A, 2B are then wound with high voltage windings 10A, 10B, and the side leg 6 is wound with a tertiary winding 38 and a tap winding 4. FIG. 1a is a configuration diagram of a follower which is an improved version of the single-phase transformer shown in FIG. 3, and FIG. 2 is an example of a configuration using a single-phase five-legged core. FIG. 1a and FIG. 2 differ only in the number of core main legs, but are completely the same in explaining the intent of the present invention, so FIG. 1a will be briefly described. In a single-phase four-leg iron core having two main legs and two side legs, the first main leg 5A is sequentially wound with a low-voltage winding unit 2A from the core side, and then with a high-voltage winding unit IA on the track side. Then, the tertiary winding unit 3A, the low voltage winding unit 2B, and the high voltage winding unit IB on the neutral point side are sequentially wound on the main leg 5B from the iron core side, and on one side leg 6 of the iron core. The tertiary winding unit 3B and the high-voltage tap winding 4 are sequentially wound from the iron core side, and the low-voltage winding units 2A and 2B of the first main adjacent 5A and the 0th main breast 5B are connected in parallel, and the The main leg 5B and the tertiary windings 3A and 3B wound on the one side leg 6 are connected in parallel, and
high-voltage winding units IA and IB on the line side and neutral point side, respectively, wound on the main leg 5A and the 0th main neighbor 5B, and the high-voltage tap winding 4 wound on the one side leg 6. This is a single-phase three-winding transformer with two wires connected in series.

According to the winding configuration shown in Figure 1a, compared to a transformer with a general winding configuration such as the slave in Figure 3, insulation is required because there is only one high-voltage winding with a line end. By reducing the size and winding the tertiary windings together on the 0th main leg 5B, a reasonable increase in the impedance between the low-voltage and tertiary windings can be achieved, resulting in small and medium size reductions in weight and dimensions. It can be achieved.

However, the winding configurations shown in FIGS. 1a and 2 have the following drawbacks. That is, although the increase in the impedance change between the high voltage and low voltage windings due to each tap was even larger in the case of the conventional winding configuration shown in FIG. There is a tendency for the range of change to become even larger in a direction that promotes this, which conflicts with the requirements for power system operation. In terms of power system operation, it is undesirable for the impedance change to be too large, and it is sometimes desired that the change trend be the opposite of that of the subordinate. In view of the above circumstances, the present invention makes it possible to reduce the range of change in the impedance between the high voltage and low voltage windings due to each tap, and to change the tendency of the change, while maintaining the advantages of the conventional Figures 1 and 2. The purpose is to provide a single-phase transformer that enables

An embodiment of the present invention will now be described with reference to FIG. 4a.

The impedance of a large capacity transformer is approximately equal to the reactance. That is, impedance is proportional to the magnetic energy stored in the winding and in the main gap and is expressed by the following equation. % main % IX wide group dV where %P...% impedance %...% reactance B...magnetic flux density V at each part of the winding and main gap...
...As can be seen from the volumetric equations for each part of the winding and main gap, in order to change the impedance, JB2dV must be changed, but this is generally done by mainly changing the magnetic flux density B. ing.

Figure 1b shows the leakage magnetic flux distribution between the high voltage and low voltage windings corresponding to the winding configuration shown in Figure 1a.
9 are the magnetic flux distributions at the lowest tap, center tap, and highest tap, respectively.

As can be seen from the figure, at the highest tap, the magnetic flux distribution is minimum for both the first main landing gear 5A and the zeroth main landing gear 5B, and on the contrary, at the lowest tap, the first main landing gear 5A and the zeroth main landing gear 5
In both cases B, the magnetic flux distribution is maximum. As a result, the impedance between the high-voltage and low-voltage windings changes due to each tap as shown by curve A in FIG. 5, and varies greatly depending on the tap position. On the other hand, the leakage magnetic flux distribution between the high voltage and low voltage windings in the winding configuration shown in FIG. 4a, which is an embodiment of the present invention, is shown in FIG. 4b.
As shown in the figure, at the highest tap, the magnetic flux distribution of the G-1 main leg 5A is the minimum, whereas the D-1 main leg 5B has the smallest magnetic flux distribution.
Also, at the lowest tap, the magnetic flux distribution of the first main landing gear 5A is the maximum, while that of the second main landing gear 5B is the minimum, and the changes are canceled out by each other. We are happy. As a result, the impedance change between the high-voltage and low-voltage windings due to each tap becomes flat, as shown by curve B in FIG. The present invention described above can be applied not only to the case of a single-phase four-legged core but also to the m-th main landing gear 5B in the case of a single-phase five-legged core, and similar effects can be obtained. is obvious.

If a more minute impedance change is required, it is also possible to arrange the windings as shown in FIG. 6a. FIG. 6a shows the winding configuration of FIG. 4a, in which a part of the neutral point side low voltage winding IB wound around the 0th main leg 5B is replaced by a part of the side leg around which the high voltage tap winding is wound. This has been moved to 6. According to the winding configuration shown in FIG. 6a, the magnetic flux distribution becomes as shown in FIG. By changing it as shown in Figure a, the direction of impedance change of each tap can be changed arbitrarily. Further, by practicing the present invention, FIG.
This has the advantage of further promoting the characteristic of increasing the impedance between the low-voltage primary and tertiary windings, which is an advantage of the conventional embodiment shown in FIG.

As described above, according to the present invention, it is possible to obtain a single-phase transformer in which the change in impedance at each tap can be made much smaller than that of a conventional structure, and the tendency of impedance change at each tap can be arbitrarily changed. be able to.

[Brief explanation of the drawing]

Figure 1a is a schematic diagram showing the arrangement and connection of the windings of a conventional single-phase transformer, and Figure 1b is a diagram showing the leakage distribution between the high-voltage and low-voltage windings corresponding to the winding configuration of Figure 1a. 2 and 3 are schematic diagrams showing the winding arrangement and connection of a conventional single-phase transformer according to other embodiments, and FIG. 4a explains an embodiment of the present invention. Fig. 4b is a schematic diagram showing the arrangement and connection of the windings of a single-phase transformer, and Fig. 5 is a conceptual diagram showing the leakage magnetic flux distribution between high voltage and low voltage windings corresponding to the winding configuration of Fig. is the change in the leakage impedance between the high voltage and low voltage windings at each tap due to the conventional winding configuration, and
Conceptual diagram for explaining the difference according to the present invention, No. 6
Figure a is a schematic diagram showing the winding arrangement and connection of a single-phase transformer illustrating another embodiment of the present invention, and Figure 6b is a high-voltage-low-voltage winding corresponding to the winding configuration of Figure 6a. A conceptual diagram showing the leakage magnetic flux distribution between the wires, FIG. 7a is a partial modification example of FIG. 6, and FIG. 7b is a conceptual diagram showing the magnetic flux distribution corresponding to the winding configuration of FIG. 7a. It is. IA, IB, IA', 10A, 10B, IC...
・High voltage winding unit, 2A, 28, 2A'...Low voltage winding unit, 3A, 3B, 11A, 11B...Tertiary winding unit, 4...High voltage tap Winding wire, 5A, 5
8, 5A'... Core main leg, 6... Core side leg, 7, 8, 9... Leakage flux between windings at the lowest tap, center tap, and highest tap. distribution. Figure 1a Figure 1b Figure 2Figure 3Figure 4a Figure 4b Figure 5Figure 6a Figure 6b Figure 7

Claims (1)

[Scope of Claims] 1. An iron core having at least two main legs and two side legs, a low-voltage winding unit wound around each of the main legs of the iron core and connected in parallel, and one main leg of the iron core. a line-side high-voltage winding unit wound on the other main leg of the iron core and connected in series with the line-side high-voltage winding unit; Connected in series to high voltage winding units,
A tap winding is wound around one side leg of the iron core, a main leg of the iron core around which the neutral point side high voltage winding unit is wound, and a side leg of the iron core around which the tap winding is wound, respectively. In a single-phase transformer configured with a tertiary winding unit and a tertiary winding unit connected in parallel, one main leg of the iron core is wound in order from the iron core side, a low voltage winding unit, and then a high voltage winding unit on the track side. A single-phase transformer characterized in that the other main leg of the transformer is wound with a tertiary winding unit, a neutral point side high voltage winding unit, and then a low voltage winding unit, in this order from the iron core side. 2 A part of the high voltage winding unit on the neutral point side is wound around the side leg, and a part of this high voltage winding is wrapped around the high voltage winding unit wound around the main landing gear, and the tap winding unit is wound around the side leg. A single-phase transformer according to claim 1, characterized in that the single-phase transformer is connected in series with a line. 3. The single-phase transformer according to claim 1 or 2, wherein the iron core is a five-legged iron core having three main legs and two side legs.