JPH043093B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a transformer winding employing a helical winding, which is often used as a low voltage, high current winding of a transformer.

[Technical background of the invention and its problems]

The low-voltage winding of a transformer has fewer turns than the high-voltage winding, and a large current flows through it, so so-called helical winding, in which a large number of rectangular conductors are connected in parallel to form a spiral, is often used. has been done. In this case, in order to improve the shunt imbalance between the parallel conductors, it is necessary to balance the impedance between each parallel conductor and the opposing winding, and for this purpose, the relative positions of the parallel conductors are swapped. and
This is called dislocation.

FIG. 1 shows the most commonly performed transposition method in the case of eight parallel conductors.
A helical winding 12 is shown concentrically wound around the core leg 11, and a winding 13 facing the outside thereof is wound concentrically. One standard transposition that flips all parallel conductor positions in the center of the total height H of the helical winding 12 (referred to as the winding stack), and also 1/4H and 3/4H of the stack.
At two locations, special transposition is performed to swap between two groups of four inner parallel conductors. The concept of this dislocation is shown in Figure 2, where the parallel conductors of the low-voltage helical winding 12 are
The positions occupied by each group in the stack direction are shown in B. If such a transposition is performed, the impedance between each parallel conductor and the opposing winding 13 becomes approximately equal, and as a result, an equal load current is shunted to each parallel conductor.

On the other hand, with the recent rise in energy saving ideas, there has been a strong demand for reducing the total loss generated in transformers, and for this reason, it has become increasingly necessary to make transformers more compact. As a means of making transformers more compact, improvements in the space factor of the conductors are important as well as reductions in insulation dimensions due to advances in insulation technology.In helical windings, the insulation covering of each parallel conductor is minimized. This is extremely effective.

For this purpose, the parallel conductors are covered with ultra-thin insulating paper, or with insulation films such as formal. Since helical winding originally involves winding conductors of the same potential in parallel, it was thought that there was no need for much insulation between the conductors. however,
As the conductor insulation continues to be miniaturized, there is a concern that the conductor insulation may be locally broken due to minute foreign matter attached to the conductor, resulting in conduction between the conductors.

In this way, each parallel conductor is originally a conductor that should have the same potential, so some degree of conduction between conductors may be tolerated, but if you examine it in detail,
Helical winding 1 as shown in Figures 1 and 2
In No. 2, it can be seen that an induced voltage on the order of about 100 V is generated inside the winding between the parallel conductor groups A and B when the load current is applied. Therefore, if unexpected electrical conduction occurs between groups A and B inside the winding, an excessive current may flow through this portion and burn out the winding.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a transformer winding that can improve the conductor space factor, make the transformer more compact and reduce loss, and prevent breakdown of the conductor insulation due to adhesion of foreign matter.

[Summary of the invention]

The transformer winding according to the present invention is characterized in that a plurality of parallel conductors are wound with additional insulation separate from general conductor insulation between each transposed parallel conductor group.

[Embodiments of the invention]

The present invention will be described below with reference to an embodiment shown in FIG. The embodiment shown in FIG. 3 also shows a helical winding 12 in which eight parallel conductors 1 to 8 are wound. As before, the helical winding 1
The total height of the stack is H, and each 1/4H of the stack is wound in units of 1T, 2T, 3T, and 4T from the bottom, and the inner four of the parallel conductors are 1 to 4 and 5 to 8.
Rearrangements are carried out as groups A and B. In other words, from winding unit 2T to winding unit 3T, which is the center of helical height H, all parallel conductor positions are 1, 2,
3, 4 to 4, 3, 2, 1 and 5, 6, 7, 8
A standard transition such as flipping from 8 to 7 to 6 to 5 is carried out once, and in parallel at two locations: between 1T and 2T and between 3T and 4T. A special transposition is performed in the same way as in FIG. 2, in which two groups A and B of four conductors are swapped inside and outside.

Helical winding 1 wound in such a transposed manner
In No. 2, an induced voltage on the order of 100V is generated between the parallel conductor groups A and B when the load current is applied. The present invention is characterized in that an insulator 14 is additionally inserted over the entire length of the winding between group A of conductor groups 1 to 4 and group B of conductor groups 5 to 8 to be transposed. With this configuration, even if the insulation coating of each conductor is minimized, another insulator 14 is placed between the parallel conductor groups A and B, so There is no risk of unexpected conduction, and the conductor space factor of the helical winding 12 can be improved, and the transformer as a whole can be made more compact and have lower losses.

In addition, although FIG. 3 shows the insertion of an insulator 14 separate from the conductor insulation, instead of this, conductors 1, 4, 5, and 8 located adjacent to each group A and B are inserted with a general conductor. It may be reinforced with additional insulation.

Furthermore, in Fig. 3, the insulation between each group A and B is inserted over the entire length of the winding stack, but strictly speaking, conductors 1 to 8 are bundled at both ends, so
Actually, the problem of conduction inside the winding is the part where conductor 1 and conductor 8 are adjacent, that is, the unit of winding 2T.
Since it is a 1/2H section of 3T, this winding unit
Insulator 14 only between winding groups A and B of 2T and 3T parts
Alternatively, conductors 1 and 8 may be additionally insulated from other conductors. Furthermore, when the number of parallel conductors increases and they are divided into four parallel conductor groups A to D as shown in Figure 4 and transposed, an insulator 14 can be inserted between each group to achieve exactly the same result. effect can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, by providing additional insulation separate from general conductor insulation between each transposed parallel conductor group of a plurality of parallel conductors,
By minimizing the conductor insulation coating, it is possible to obtain a helical winding that improves the conductor space factor, and it can be manufactured without worrying about unexpected conduction problems due to foreign objects, making the transformer more compact. It is possible to reduce the loss and reduce the loss.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing a conventional helical winding and its transposition state, Fig. 2 is a conceptual diagram for explaining its conductor transposition, and Fig. 3 shows a transposition state of a transformer winding according to the present invention. The schematic configuration diagram, FIG. 4, is a conceptual diagram for explaining conductor transposition according to another embodiment of the transformer winding of the present invention. 1, 2...8...Conductor number, 11...Iron core leg,
12...Helical winding, 13...Opposed winding, 14
...Insulator inserted between conductors.

Claims (1)

[Claims] 1 A plurality of insulated conductors are arranged in parallel and formed into a spiral shape, these parallel conductors are divided into a plurality of conductor groups, and the relative positions of these conductor groups in the winding radial direction are swapped to cause transfer. A transformer winding characterized in that additional insulation is provided between groups of conductors that are transferred.