JPH10256020A - Iron core with small variation in iron loss characteristics - Google Patents

Abstract

(57) [Problem] To provide an iron core suitable for transformers and reactors, which has a small variation in iron loss characteristics. SOLUTION: In an iron core in which soft magnetic thin plates having a thickness of 0.05 mm or more and less than 0.1 mm are laminated, the insulation resistance per lamination between layers is 1.0 Ω · cm ² or more. In an iron core in which soft magnetic thin plates having a thickness of 0.1 mm or more are laminated, the insulation resistance per lamination between layers is 0.3 Ω · cm ^2.
Each of the above is characterized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron core suitable for transformers and reactors and having a small variation in iron loss characteristics.

[0002]

2. Description of the Related Art As an iron core for a transformer or a reactor, an iron core using a soft magnetic thin plate has been widely used mainly in the field of electric power. As the frequency of the equipment has been increased, the requirements for iron loss characteristics of iron cores for transformers and reactors have increased. Conventionally, the iron loss characteristics of an iron core using a soft magnetic thin plate have large fluctuations and variations compared to the core loss gain of the material thin plate itself. Measures are taken for all products.

[0003]

However, the variation in iron loss characteristics of an iron core using a soft magnetic thin plate tends to increase at higher frequencies. However, the frequency of use has increased with the recent increase in the use of high-frequency applications, and as a result, there has been a problem that the production cost increases and the delivery date is delayed. Therefore, an object of the present invention is to provide an iron core that has a small variation in iron loss characteristics and is suitable for transformers and reactors.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, in an iron core on which soft magnetic thin plates are laminated, one core per lamination according to the thickness of the thin plates. It has been found that by setting the insulation resistance value to a specific value or more, variation in iron loss characteristics can be extremely reduced. The present invention has been made based on such findings, and the features thereof are as follows.

[1] In an iron core in which soft magnetic thin plates having a thickness of 0.05 mm or more and less than 0.1 mm are laminated, the insulation resistance per lamination between layers is 1.0 Ω · cm ² or more. Iron core with small variation in iron loss characteristics. [2] In an iron core formed by laminating soft magnetic thin plates having a thickness of 0.1 mm or more, the insulation resistance per lamination between layers is 0.3Ω · c.
An iron core having a small variation in iron loss characteristics, characterized in that the core has an m ² or more.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION With respect to an iron core laminated with a soft magnetic thin plate having a thickness of 0.05 mm, an iron loss W1 / 10k at a frequency of 10 kHz and a magnetic flux density of 0.1 T and an insulation resistance value per one layer between the iron cores are shown. Is shown in FIG. Here, the insulation resistance per lamination between the cores is a value obtained from the resistance between the outermost thin plates of the core by the following equation (1). The outermost thin sheet of the core is defined as the outermost and innermost thin sheets as shown in FIG. 2 for a wound core, and the uppermost layer and the outermost sheet as shown in FIG. 3 for a stacked iron core. The lowermost thin plate, and the resistance value between the outermost thin plates is a resistance value measured between these two thin plates. (Insulation resistance value per laminated layer) = (resistance value between outermost thin plates) x {(average area of outermost thin plates) / (number of laminated iron cores)} ... (1)

[0007] In an iron core in which soft magnetic thin plates are laminated, it is inevitable that the insulation resistance per lamination between layers varies to some extent. According to FIG. 1, in an iron core in which soft magnetic thin plates having a thickness of 0.05 mm are laminated, if the insulation resistance per lamination between layers is less than 1.0 Ω · cm ² , the insulation resistance is somewhat increased. If it varies, the iron loss value fluctuates greatly and varies. On the other hand, if the insulation resistance per lamination between layers is 1.0 Ω · cm ² or more, the dependence of the iron loss W1 / 10k on the insulation resistance is less than 1.0 Ω · cm ^2. It can be seen that the variation in iron loss characteristics can be made extremely small even if the insulation resistance varies to some extent, and the absolute value of iron loss is stable at a low value. FIG. 4 shows the relationship between the core loss W10 / 400 at a frequency of 400 Hz and a magnetic flux density of 1.0 T and the insulation resistance per one layer between the iron cores. Is exactly the same as above.

[0008] Next, a core having laminated thereon a soft magnetic thin plate having a thickness of 0.1 mm has a frequency of 10 kHz and a magnetic flux density of 0.1.
FIG. 5 shows the relationship between the iron loss W1 / 10k at T and the insulation resistance per layer between the laminations. In the case where the insulation resistance per lamination between layers is less than 0.3 Ω · cm ² , the iron loss value fluctuates greatly if the insulation resistance varies to some extent in an iron core in which soft magnetic thin plates having a thickness of 0.1 mm are laminated. , It will vary.
On the other hand, the insulation resistance per lamination between layers is 0.3Ω · cm.
If it is ² or more, the dependence of the iron loss W1 / 10k on the insulation resistance value is extremely small as compared with a case of less than 0.3Ω · cm ² , so that even if the insulation resistance value varies to some extent, the iron loss characteristics It can be seen that the variation can be made extremely small and the absolute value of iron loss is stable at a low value.

From the results shown in FIGS. 1 and 5, it can be seen that the greater the thickness of the thin plate, the smaller the variation in iron loss characteristics and the lower the insulation resistance per lamination between layers. For this reason, in the present invention, the sheet thickness is 0.05 mm or more,
In an iron core in which soft magnetic thin plates having a thickness of less than 1 mm are laminated, the insulation resistance per lamination between layers is 1.0 Ω · cm ² or more,
In an iron core in which soft magnetic thin plates having a thickness of 0.1 mm or more are laminated, the insulation resistance per lamination between layers is 0.3 Ω · cm.
^The condition is ² or more.

The method of obtaining the insulation resistance per lamination between the iron cores specified by the present invention is not particularly limited. For example, in the case of a wound iron core, the tension at the time of winding around a mold is controlled. In the case of a stacked iron core in which cut plates are stacked, a method of controlling the caulking pressure of a bolt fixing the iron core is possible. The iron core targeted by the present invention includes a cut core,
Includes wound cores and stacked cores such as toroidal cores.

[0011]

【Example】

[Example 1] At a plate thickness of 0.05 mm, Si was substantially 6.
Ten cut cores of CS32 size of the Japan Wind Iron and Steel Industry Association standard using Fe-Si alloy thin plates containing 5 wt% were prepared. The primary and secondary coils were subjected to 40 turns on the iron core, and were excited under the excitation conditions of a frequency of 10 kHz and a magnetic flux density of 0.1 T, and the iron loss W1 / 10k was measured. On the other hand, the resistance value between the outermost thin plates of the iron core was measured by the method shown in FIG. 6, and the insulation resistance value per layer between the laminations was obtained by the above equation (1).

FIG. 1 shows the relationship between the iron loss W1 / 10k and the insulation resistance per layer between the laminations. According to this, if the insulation resistance per lamination between the layers is in the range of 1.0 Ω · cm ² or more, the dependency of the iron loss W1 / 10k on the insulation resistance is 1.0 Ω · cm ^2. It was confirmed that the value was extremely small as compared with the case where the value was less than the above, the variation in the iron loss characteristics was extremely small, and the absolute value of the iron loss was stable at a low value.

[Example 2] Nine CS20 size cut cores of CS20 standard using a Fe-Si alloy thin plate having a thickness of 0.1 mm and substantially containing 6.5 wt% of Si, CS200 5 size cut cores, CS32
Five cut cores of size 0 were prepared. 1 in this iron core
Next and secondary coil, CS20 size 32 turns, CS2
The sample was subjected to 42 turns of 00 size and 42 turns of CS320 size, and was excited under the excitation conditions of a frequency of 10 kHz and a magnetic flux density of 0.1 T, and the iron loss W1 / 10k was measured. On the other hand, the resistance value between the outermost thin plates of the iron core was measured by the method shown in FIG. 6, and the insulation resistance value per layer between the laminations was obtained by the above equation (1).

FIG. 5 shows the relationship between the iron loss W1 / 10k and the insulation resistance per layer between the laminations. According to this, iron loss W1 / 10
There is a high degree of correspondence between k and the insulation resistance per layer between the outermost thin plates of the iron core, and the correspondence is constant regardless of the size of the iron core. When the insulation resistance per lamination between layers is in the range of 0.3 Ω · cm ² or more, the dependency of the iron loss W1 / 10k on the insulation resistance is less than 0.3 Ω · cm ^2. It was confirmed that the iron loss characteristics were extremely small, the variation in iron loss characteristics was extremely small, and the absolute value of iron loss was stable at a low value.

[0015]

As described above, the iron core of the present invention has an extremely small variation in iron loss characteristics, and is an extremely suitable iron core for transformers and reactors.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between an insulation resistance value per lamination between iron cores in which soft magnetic thin plates having a thickness of 0.05 mm are laminated and an iron loss W1 / 10k.

FIG. 2 is an explanatory view showing an outermost thin plate in a wound iron core;

FIG. 3 is an explanatory view showing an outermost thin plate in the piled core.

FIG. 4 is a graph showing a relationship between an insulation resistance value per lamination between iron cores laminated with a soft magnetic thin plate having a thickness of 0.05 mm and iron loss W10 / 400.

FIG. 5 is a graph showing the relationship between the insulation resistance per lamination between iron cores in which soft magnetic thin plates having a thickness of 0.1 mm are laminated and the core loss W1 / 10k.

FIG. 6 is an explanatory diagram showing a method of measuring a resistance value between outermost thin plates of an iron core performed in an example.

Claims (2)

[Claims] 1. An iron core formed by laminating soft magnetic thin plates having a thickness of 0.05 mm or more and less than 0.1 mm, wherein the insulation resistance per layer between the laminations is 1.0 Ω · cm ² or more. Iron core with small variation in iron loss characteristics. 2. Variations in iron loss characteristics of an iron core in which soft magnetic thin plates having a thickness of 0.1 mm or more are laminated, wherein an insulation resistance per lamination between layers is 0.3 Ω · cm ² or more. Is a small iron core.