JPS6013287B2 - split winding transformer - Google Patents

Description

[Detailed description of the invention] The present invention relates to improvements in split-winding transformers.

In general, in a split winding transformer, for example, when the inner coil arranged in the same shape on the iron core is used as a low voltage coil and the outer coil arranged in the same manner as a high voltage coil, conventionally, as shown in FIG. Two low voltage coils 11 and i2 were arranged concentrically. And these low voltage coils 11,1
The high-voltage coils hl and h2 are arranged so as to face the high-voltage coils hl and h2, respectively, and the tap coil section 2 connected to the on-load tap switching device (not shown) is located on the neutral point side of the high-voltage coils hl and h2, which have a lower insulation class. It is provided in N. L is the line side of the high voltage coils hl and h2. In this arrangement of coils, in the case of a large-capacity transformer, these coils will be constructed of parallel conductors in order to satisfy the current capacity.

However, in order to prevent circulating current due to dislocation, the magnetic flux distribution is symmetrical between the low voltage coil 11 and the high voltage coil hl and between the low voltage coil 12 and the high voltage coil h2, as shown in Figure 2 A and 2, respectively. Even if the ampere turns are adjusted so that
The magnetic flux distribution in the coil is not always symmetrical. Therefore, it is not possible to prevent circulating current flowing through the parallel conductors, resulting in an increase in stray load loss and a rise in coil temperature. SUMMARY OF THE INVENTION An object of the present invention is to provide a split-winding transformer in which the magnetic flux distribution in each coil is symmetrical under any operating conditions, thereby preventing circulating currents flowing in parallel conductors.

In the present invention, even when only the low voltage coils 11 or 12 are used, if the tap coil portions 2 of the high voltage coils bl and h2 are arranged symmetrically, the magnetic flux distribution in each coil can be maintained in any state of use. In order to take advantage of the symmetry and the ability to prevent circulating current flowing in the parallel conductors, the low voltage coils 11, 12 and the high voltage coils hl, h2
When arranging them concentrically around the iron core, one of the low-voltage coils is placed inside the high-voltage coil and the other one is placed outside the high-voltage coil so that they are symmetrical in the axial direction of the iron core. . An embodiment of a split winding transformer according to the present invention will be described below with reference to FIG.

The high voltage coils hl and h2 are arranged coaxially and connected in parallel, and the tap coil section 2 connected to the on-load tap switching transformer (not shown) is on the neutral point side of the high voltage coils hl and h2, which has a lower insulation class. It is provided in N. High voltage coil hl,h
A low voltage coil 11 is placed inside the 2, and a low voltage coil 12 is placed outside. With the above coil arrangement configuration, the low voltage coil 11 and the low voltage coils hl and h
2 and between the low voltage coil 12 and the high voltage coils hl and h2
For example, if only the low voltage coil 11 or 12 is used, or if the low voltage coils 11 and 12 are used simultaneously, if the ampere-turn distribution is made symmetrical between them, as shown in FIG. When viewed from above, the low voltage coils 11, ]2 are vertically symmetrical.

Further, since the high voltage coils hl and b2 are connected in parallel, if the overall configuration is considered as the high voltage coil hl+h2, even if the ampere turns of the tap coil section 2 changes due to tap switching, the magnetic flux distribution will be vertically symmetrical. Therefore, even if each coil is composed of parallel conductors, the circulating current flowing in the parallel conductors can be prevented by performing the transposition. Since the transformer of this embodiment is constructed in this manner, the magnetic flux distribution of each coil is vertically symmetrical in any state of use, so that circulating current flowing in the ordinary conductor can be prevented by dislocation.

Therefore, the stray load loss of each coil of the transformer can be reduced, and the temperature rise can be kept low. As described above, according to the split winding transformer of the present invention, the magnetic flux distribution in each coil is symmetrical in any usage state such as when changing taps, thereby reducing the circulating current flowing in the parallel conductors. This has the effect of preventing the above.

[Brief explanation of the drawing]

Figure 1 is a winding arrangement diagram of a secondary winding transformer, Figure 2 A is a magnetic flux distribution diagram when a pair of opposing coils are used at the maximum tap of the transformer in Figure 1, respectively. FIG. 3 is a winding layout diagram showing an embodiment of the split winding transformer of the present invention. 1... Iron'0, 2... Tap coil part, hl, h2...
...High voltage coil, 11,12...Low voltage coil, L...Line side, N...Neutral point side. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. An iron core, a plurality of low-voltage coils arranged concentrically on the iron core and connected to a load or a power source, and a plurality of low-voltage coils formed from the same number of low-voltage coils as the above-mentioned low-voltage coils, arranged concentrically and connected in parallel to the power source or load. and high-voltage coils each having a tap coil section connected to the load tap switching device on the neutral point side, each of the low-voltage coils having an inner periphery so as to sandwich each high-voltage coil having the tap coil section. A split winding transformer characterized by being arranged on the side and the outer circumferential side.