JP7768026B2 - Iron core structure and static winding equipment - Google Patents

Description

The present invention relates to technology for static winding devices such as transformers and reactors, and relates to transformers and reactors having an iron core made of multiple stacked block cores such as ferrite.

The core of a large-capacity transformer generally has a structure in which plate-shaped magnetic bodies, such as ferrite cores, are arranged in a frame-like configuration and stacked in one direction (Patent Documents 1 and 2).

Patent Application No. 12915/1983 Japanese Patent Application Publication No. 5-326289

The iron core 1 shown in Figure 4 is made by stacking block cores 10, and when gaps 13 are secured between the block cores 10, the width of the gaps 13 is set uniformly across the cross section. This ensures uniform magnetic resistance in each magnetic path at the front and rear center in the depth direction of the leg portion 11, as shown in Figure 2(a). Furthermore, even when gaps 13 are not secured, the magnetic resistance of these magnetic paths is uniform, so the magnetic flux density in the leg portion 11 is uniform.

However, as shown in Figure 3(a), the temperature near the center of the leg portion 11, which is disadvantageous for air cooling, becomes high, resulting in hot spots.

In consideration of the above circumstances, the present invention aims to reduce the magnetic flux density in areas of the leg portion of the iron core that are unfavorable for cooling, thereby reducing the maximum temperature rise of the iron core.

One aspect of the present invention is an iron core structure that has three or more block cores stacked in the depth direction of the leg portion of the iron core, the gaps between the block cores vary in length in the depth direction of the leg portion, and the gap between the block cores in the center in the depth direction is longer than the gaps between the block cores at the front and rear in the depth direction.

One aspect of the present invention is a static winding device having the above-mentioned core structure.

According to the present invention, the magnetic flux density in the leg portion of the core, which is unfavorable for cooling, is reduced, thereby reducing the maximum temperature rise of the core.

(a) Front view of an iron core according to one embodiment of the present invention, (b) top view of the iron core, (c) side view of the iron core, (d) cross-sectional views A and C of the iron core, and (e) cross-sectional view B of the iron core. (a) Magnetic flux density distribution of a conventional iron core, (b) Magnetic flux density distribution of an iron core of the present invention. (a) Temperature distribution of a conventional iron core, (b) Temperature distribution of an iron core of the present invention. 1A is a front view of a conventional iron core, FIG. 1B is a top view of the iron core, and FIG. 1C is a side view of the iron core.

Embodiments of the present invention will be described below with reference to the drawings.

The core 1 shown in Figure 1, which is one embodiment of the core structure of the present invention, is applied to static winding devices such as core-type or shell-type transformers and reactors.

The core 1 has a leg portion 11 around which windings such as the primary winding and secondary winding are wound, and a yoke portion 12 around which the windings are not wound.

The core 1 consists of three or more block cores 10 stacked in the depth direction. Gaps 13 are maintained between the block cores 10 in the leg portion 11 of the core 1.

The gap 13 is ensured to have different lengths in the depth direction of the leg portion 11. In particular, the gap 13 is ensured in the center of the depth direction of the leg portion 11 of the iron core 1, which is prone to hot spots as shown in Figure 3(a).

That is, as shown in Figure 1, the gap 13 at the center of the depth direction of the leg portion 11 is set to be longer than the gaps 13 at the front and rear of the depth direction. However, if the difference in length between the gaps 13 at the center of the depth direction and the front and rear of the depth direction becomes too large, the magnetic flux density at the front and rear of the depth direction becomes too high, resulting in increased heat generation, and the effect of reducing magnetic flux density and temperature cannot be obtained.

With the above-described core 1 structure, the length of the gap 13 at the depth center of the leg portion 11 is set to be longer than the length of the gap 13 at the front and rear ends in the depth direction, thereby reducing the magnetic flux density of the block core 10 at the depth center of the leg portion 11. This also reduces the loss density of the block core 10 at the depth center of the leg portion 11. Furthermore, although the cooling conditions for the block core 10 at the depth center of the leg portion 11 are stricter than those for the block cores 10 at the front and rear ends in the depth direction, the maximum temperature can be reduced by the above-described operation.

The specific effects of iron core 1 will be explained with reference to Figures 2 and 3.

Figure 2(a) shows the magnetic flux density distribution of a conventional iron core 1, and Figure 2(b) shows the magnetic flux density distribution of an iron core 1 of the present invention. As is clear from comparing the magnetic flux density distributions of the two, the structure of the iron core 1 of the present invention makes it possible to reduce the magnetic flux density of the block core 10 at the center in the depth direction of the iron core 1 compared to the conventional iron core 1, and it was also shown that the loss density of this central block core 10 can be reduced.

Figure 3(a) shows the temperature distribution of a conventional core 1, and Figure 3(b) shows the temperature distribution of an iron core 1 of the present invention. As is clear from comparing the two temperature distributions, the structure of the iron core 1 of the present invention can reduce the temperature in the center of the leg portion 11, which is less favorable for cooling than the conventional core 1. In particular, it was shown that there is a temperature reduction effect when three or more block cores 10 are arranged in the depth direction of the core 1 and gaps 13 are secured near the heat spots of the leg portion 11.

1...Iron core, 10...Block core, 11...Leg section, 12...Yoke section, 13...Gap

Claims (2)

a leg portion around which the winding is wound;
a yoke portion on which the winding is not wound;
and
Gaps are secured between the leg portion and the yoke portion and between the block cores of the leg portion,
Three or more block cores of the leg portion and the yoke portion are stacked in the depth direction of the leg portion and the yoke portion,
the gap between the block cores has a different length in the depth direction of the leg portion;
An iron core structure characterized in that the gap between the block cores at the center in the depth direction is longer than the gaps between the block cores at the front and rear in the depth direction. A static winding device having the core structure described in claim 1.