JP4081831B2 - Inspection method for iron loss characteristics of iron core - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, in order to obtain a core small variations of the preferred iron loss as transformers and reactors, it relates to a method for inspecting the iron loss characteristics of the core.
[0002]
[Prior art]
As cores for transformers and reactors, cores using soft magnetic thin plates are widely used mainly in the electric power field. Recently, however, the frequency of equipment for the purpose of miniaturization and higher efficiency of power supply equipment has been increased. Along with this, the demand for iron loss characteristics of iron cores for transformers and reactors has increased.
Conventionally, the iron loss characteristics of iron cores using soft magnetic thin plates vary and vary more than the iron loss performance of the thin sheet itself, so the iron loss characteristics are inspected by actually exciting the iron core before shipment. Measures are taken to apply the method to all products.
[0003]
[Problems to be solved by the invention]
However, since the variation in iron loss characteristics of iron cores using soft magnetic thin plates tends to increase as the frequency increases, the frequency at which iron cores are manufactured but rejected as a result of iron loss characteristic inspections As a result, it has increased, resulting in problems such as an increase in manufacturing cost and a delay in delivery.
Accordingly, an object of the present invention is to provide a method for inspecting the iron loss characteristic of an iron core in order to obtain an iron core suitable for a transformer or a reactor with little variation in iron loss characteristics .
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have determined that the insulation resistance value per one layer between the stacks is a specific value or more according to the thickness of the thin plate in the iron core laminated with the soft magnetic thin plate. By doing so, it was found that the variation in the iron loss characteristics can be extremely reduced.
The present invention has been made based on such knowledge, and the features thereof are as follows.
[0005]
[1] In the method of inspecting the iron loss characteristics of an iron core laminated with soft magnetic thin plates, the resistance value between the outermost layer thin plates of the iron core is measured, and the insulation per layer is obtained from the resistance value according to the following equation (1) In determining the resistance value, and inspecting the iron loss characteristics of the iron core based on the insulation resistance value ,
When the iron core is a laminate of soft magnetic thin plates having a thickness of 0.05 mm or more and less than 0.1 mm, the standard of the insulation resistance value in the inspection is 1.0 Ω · cm ² or more,
When the iron core is a laminate of soft magnetic thin plates having a thickness of 0.1 mm or more, the insulation resistance value standard in the inspection is 0.3 Ω · cm ² or more. Inspection method of characteristics.
(Insulation resistance value per layer between layers) = (resistance value between outermost thin plates) × {(average value of outermost thin plate area) / (number of laminated iron cores)} (1)
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the relationship between the core loss W1 / 10k at a frequency of 10 kHz and a magnetic flux density of 0.1 T, and the insulation resistance value per layer between the cores for an iron core laminated with a soft magnetic thin plate having a thickness of 0.05 mm. . Here, the insulation resistance value per layer between the laminated cores is a value obtained by the following equation (1) from the resistance value between the outermost thin plates of the iron core. In the case of a wound core, the outermost layer thin plate of the iron core is a thin plate on the outermost and innermost sides as shown in FIG. 2, and in the case of a stacked iron core, the outermost layer and the outermost layer are as shown in FIG. It is a lower layer thin plate, and the resistance value between the outermost layer thin plates is a resistance value measured between these two thin plates.
(Insulation resistance value per layer between laminations ) = (resistance value between outermost thin sheets) × {(average value of outermost thin sheet area) / (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 value per layer between the laminations 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, when the insulation resistance value per layer between laminations is less than 1.0 Ω · cm ² , the insulation resistance value is somewhat If it fluctuates, the iron loss value fluctuates greatly and varies. On the other hand, if the insulation resistance value per layer between layers is 1.0 Ω · cm ² or more, the dependence of the iron loss W1 / 10k on the insulation resistance value is less than 1.0 Ω · cm ² As a result, it can be seen that even if the insulation resistance value varies to some extent, the variation in the iron loss characteristic can be made extremely small, and the absolute value of the iron loss is stable at a low value. Also, FIG. 4 shows the relationship between the iron loss W10 / 400 at a frequency of 400 Hz and a magnetic flux density of 1.0 T and the insulation resistance value per layer between the laminated cores. It can be seen that the relationship is exactly the same as above.
[0008]
Next, FIG. 5 shows the relationship between the iron loss W1 / 10k at a frequency of 10 kHz and a magnetic flux density of 0.1 T, and the insulation resistance value per layer between the layers of an iron core in which soft magnetic thin plates having a thickness of 0.1 mm are laminated. Show. In an iron core in which soft magnetic thin plates with a thickness of 0.1 mm are laminated, if the insulation resistance value per layer between laminations is less than 0.3 Ω · cm ² , the iron loss value fluctuates greatly if the insulation resistance value varies to some extent. , Will vary. On the other hand, if the insulation resistance value per layer between the layers is 0.3 Ω · cm ² or more, the dependence of the iron loss W1 / 10k on the insulation resistance value is extremely less than the case of less than 0.3 Ω · cm ^2. Therefore, even if the insulation resistance value varies to some extent, it can be seen that the variation of the iron loss characteristic can be made extremely small, and the absolute value of the iron loss is stable at a low value.
[0009]
From the results shown in FIG. 1 and FIG. 5, it can be seen that the insulation resistance value per layer between layers may be lower as the plate thickness of the thin plate is larger and the variation in iron loss characteristics is reduced. Here, 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, an insulation resistance value per layer between laminations is 1.0 Ω · cm ² or more and a plate thickness of 0.1 mm or more. For iron cores laminated with soft magnetic thin plates, if the insulation resistance value per layer between layers is 0.3 Ω · cm ² or more, variation in iron loss characteristics is extremely small, and the absolute value of iron loss is also low. Can stabilize.
[0010]
In addition , although the method for obtaining the insulation resistance value per one layer between the laminations of the iron cores is not particularly limited, for example, in the case of a wound iron core, the tension of the wound iron cores for laminating the cut plates is controlled. In some cases, a method such as controlling the caulking pressure of the bolt fixed to the iron core is possible.
The iron cores targeted by the present invention include wound cores such as cut cores and toroidal cores, and stacked iron cores.
[0011]
【Example】
[Example 1]
Ten cut cores having a plate thickness of 0.05 mm and using a Fe-Si alloy thin plate containing substantially 6.5 wt% of Si and having a CS32 size of Japanese winding core industry association were prepared. The iron core was subjected to 40 turns for both the primary and secondary coils, 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 layers was determined by the above equation (1).
[0012]
FIG. 1 shows the relationship between the iron loss W1 / 10k and the insulation resistance value per layer between layers. According to this, when the insulation resistance value per layer 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 value is 1.0Ω · cm ^2. It was confirmed that the iron loss characteristic was extremely small compared with the case of less than the value, the variation of the iron loss characteristic was extremely small, and the absolute value of the iron loss was stable at a low value.
[0013]
[Example 2]
Nine Japanese roll iron core industry standard CS20 size cut cores, five CS200 size cut cores using a Fe-Si alloy thin plate with a thickness of 0.1 mm and substantially containing 6.5 wt% Si, Five cut cores of CS320 size were prepared. The iron core was subjected to CS20 size 32 turns, CS200 size 42 turns, CS320 size 42 turns for both the primary and secondary coils, 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 layers was determined by the above equation (1).
[0014]
FIG. 5 shows the relationship between the iron loss W1 / 10k and the insulation resistance value per layer between layers. According to this, there is a high degree of correspondence between the iron loss W1 / 10k and the insulation resistance value per layer between the outermost thin sheets of the core, and the correspondence is constant regardless of the size of the core. is there. If the insulation resistance value per layer between layers is in the range of 0.3 Ω · cm ² or more, the dependence of the iron loss W1 / 10k on the insulation resistance value is less than 0.3 Ω · cm ² It was confirmed that the variation in iron loss characteristics was extremely small, and the absolute value of iron loss was stable at a low value.
[0015]
【The invention's effect】
As described above, according to the inspection method of the present invention, the iron loss characteristic variation is extremely small, and an iron core that is extremely suitable for a transformer or a reactor can be easily selected.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the insulation resistance value per layer of iron cores laminated with a soft magnetic thin plate having a thickness of 0.05 mm and iron loss W1 / 10k. FIG. 2 shows the outermost thin plate in a wound core. FIG. 3 is an explanatory view showing an outermost layer thin plate in a stacked iron core. FIG. 4 is an insulation resistance value per one layer between cores laminated with a soft magnetic thin plate having a thickness of 0.05 mm and iron loss W10 / 400. [Fig. 5] Graph showing the relationship between the insulation resistance per layer of iron cores laminated with soft magnetic thin plates with a thickness of 0.1 mm and iron loss W1 / 10k [Fig. 6] Explanatory drawing which shows the measuring method of the resistance value between the outermost layer thin plates of the iron core performed in the example

Claims (1)

In the inspection method of iron loss characteristics of iron cores laminated with soft magnetic thin plates, the resistance value between the outermost thin plates of the iron core is measured, and the insulation resistance value per layer between the layers is calculated from the resistance value by the following equation (1). In determining the iron loss characteristics of the iron core based on the insulation resistance value ,
When the iron core is a laminate of soft magnetic thin plates having a thickness of 0.05 mm or more and less than 0.1 mm, the standard of the insulation resistance value in the inspection is 1.0 Ω · cm ² or more,
When the iron core is a laminate of soft magnetic thin plates having a thickness of 0.1 mm or more, the insulation resistance value standard in the inspection is 0.3 Ω · cm ² or more. Inspection method of characteristics.
(Insulation resistance value per layer between layers) = (resistance value between outermost thin plates) × {(average value of outermost thin plate area) / (number of laminated iron cores)} (1)

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