JPS58166B2 - Seishyuudou Kiyotansoutetsushin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in a single-phase core for stationary inductors such as single-phase transformers and reactors, and particularly to a single-phase core suitable for low-noise transformers.

For example, most of the noise from transformers comes from the vibration of an iron core made of laminated magnetic materials. Due to contraction.

The vibration caused by the magnetostrictive phenomenon consists of a fundamental wave with a frequency twice the power supply frequency and harmonic components that are multiples of the fundamental wave, and the vibration of the iron core is transmitted through the oil and the support of the iron core to the transformer. It vibrates the oil tank and radiates noise into the air.

Conventionally, various methods have been used to prevent this type of noise, such as surrounding the entire transformer with a soundproof wall, making the transformer oil tank a double structure, and inserting sound-absorbing materials or air bags into the oil tank. It had been taken.

However, on the other hand, no effective measures had been proposed other than using materials with low magnetostriction or reducing magnetic flux density for the iron core, which is the main source of noise. This method has disadvantages such as being complicated and expensive, and it is difficult to achieve sufficient noise reduction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a single-phase core for a static inductor such as a transformer, which eliminates the drawbacks of the prior art described above and which has a small magnetostrictive phenomenon and can reduce vibration and noise.

The present invention was made by focusing on the fact that the main leg and the yoke, which form a single-phase core, have different contribution methods and ratios to the vibration mode of magnetostriction. The main landing gear has at least two yokes connected above and below the main landing gear to form a magnetic circuit, and when the main landing gear and the yoke are each made of laminated magnetic materials, the yoke has a higher magnetostrictive force than the main landing gear. It is characterized by being formed using a magnetic material with good characteristics, and is also formed by setting the relative cross-sectional area to the main landing gear so that the magnetic flux density of the yoke is smaller than the magnetic flux density of the main landing gear. By doing so, the magnetostriction of the yoke portion is made smaller than that of the main leg portion, thereby achieving the initial objective.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of a single-phase two-leg iron core for a stationary inductor according to the present invention, in which 1a is an upper yoke, 1b
is the lower yoke, 2a is the right main landing gear, and 2b is the left main landing gear.

In addition, Fig. 2 is an explanatory diagram illustrating the vibration characteristics of the single-phase two-leg core shown in Fig. 1. 3 is a characteristic curve showing the vibration displacement at the center of the main landing gear due to magnetostriction of the main landing gear, and 4 is a characteristic curve showing the vibration displacement of the main landing gear center due to magnetostriction of the yoke. This is a curve showing the vibration displacement at the center of the main landing gear.

Next, to explain the state of vibration displacement of the single-phase two-leg core shown in FIG. 1 with reference to FIG. ,
1b and the right and left main landing gears 2a, which are the long sides.

In a single-phase two-leg iron core formed from 2b, the vibration displacement 3 of the main leg center with respect to the vibration frequency when only the main legs 2a and 2b have magnetostriction as shown in Fig.
When only 1b has magnetostriction, the vibration displacement 4 at the center of the main landing gear with respect to the frequency is the one in the window of the so-called iron core surrounded by the main landing gear and the yoke, and the direction toward the outside of the window, which is opposite to each other. The size also differs.

The actual vibration displacement is the sum of both 3 and 4.

Therefore, if the magnitudes of vibration displacements 3 and 4 are equal and opposite in direction, the actual vibration displacement will be approximately zero.

Figure 3 is a vibration characteristic diagram of the single-phase two-legged core of Figure 1 illustrating the calculation results focused on these points, where the lengths of the yokes 1a and 1b are the same as the lengths of the main legs 2a and 2b. one half of
5 shows the calculation results for the case where 5 is the displacement of the center of the main leg when the magnetostriction ε=1×10-6 is the same for both the yoke and the main leg (
solid line), 6 indicates that the magnetostriction ε of the yoke according to the present invention is 0.
32x10-6 This is the displacement (dotted line) at the center of the main landing gear when the magnetostriction ε of the main landing gear is 1x10-6.

That is, according to the present invention, when the magnetic strain of the yoke is reduced to about one third of that of the main landing gear, the vibration displacement is significantly reduced as shown in the figure.

In this way, the vibration noise of the iron core can be reduced by ultimately making the magnetostriction of the yoke smaller than that of the main landing gear.

This tendency is generally true regardless of the presence or absence of side yokes when the length of the yoke is shorter than the length of the main landing gear.

FIG. 4 is a configuration diagram of a single-phase three-leg iron core for a stationary inductor showing another embodiment according to the present invention, in which 7a is an upper yoke, 7b is a lower yoke, 8a is an upper yoke, 8b is a lower yoke, and 9a is an upper yoke.
, sb is a side yoke, and 10 is a main landing gear.

That is, this single-phase three-leg iron core includes the main leg 10, the yoke 7a,
7b, 8a, 8b.

9a and 9b, and half of the magnetic flux of the main landing gear 10 passes through the side yokes 9a and 9b on both sides, so the cross-sectional area is also the same as the main landing gear 10.
yoke 7a, 7b, 8a.

8b, 9a, and 9b are about 1/2.

In this case as well, the vibration of the core can be reduced by changing the magnetostriction of each part of the core in the same manner as in the case of the two-legged core shown in FIG.

Fig. 5 is a vibration characteristic diagram of the single-phase three-legged core in Fig. 4 illustrating the same calculation results as Fig. 3, and 11 is the center of the main leg when the magnetostriction ε of each part of the core is 1 × 10-6. Characteristic curve 12 shows the displacement of the main landing gear according to the present invention, where the magnetostriction ε is 1×1
0-6, and the curve shows the displacement of the center of the main landing gear when the magnetostriction ε of the yoke is 0.39×10-6.

That is, by reducing the magnetostriction of the yoke to about 40% relative to the main landing gear, the vibration and noise of the iron core are significantly reduced, and the peak of resonance is also reduced.

FIG. 6 is a configuration diagram of a single-phase four-leg iron core for a stationary inductor showing still another embodiment of the present invention, 13a.

13b is the main leg; 14a and 14b are upper and lower yokes between the main legs; 15a and 15b are upper yokes; and 15c.

15d is a lower yoke, and 16a and 16b are side yokes forming side legs.

That is, this single-phase four-leg iron core has main leg portions 13a, 13b and a yoke 14a.

14b, 15a, 15b, 15c, 15d, 16a.

16b, and the cross-sectional area of the yoke is approximately one-half that of the main leg.

Figure 7 is a vibration characteristic diagram of this single-phase four-legged core, where 17 is a characteristic curve showing the displacement of the center of the main leg when the magnetostriction ε of each part of the core is 1 x 10-6, and 18 is the characteristic curve of the magnetic field of each part of the core. The curve 19 shows the displacement of the center of the side yoke when the strain ε is 1×10-6, and 19 is the magnetostrictive feeling ε of the main legs 13a and 13b.
is 1×10-6, upper and lower yokes 14a and 14 between the main legs
The magnetostriction ε of the upper and lower yokes 15a, 15b, 15c, 15d and the side yokes 16a, 16b is 0.305×10−6.
6 is a curve showing the displacement of the center of the main leg, and 20 is a curve showing the displacement of the center of the side yoke in the same case.

That is, in this case as well, the vibration of the iron core can be reduced by reducing the magnetostriction of the yoke relative to the main leg.

FIG. 8 is a block diagram 21a of a single-phase five-leg iron core for a stationary inductor showing still another embodiment of the present invention.

21b, 21c are main legs, 22a, 22b are upper yokes between the main legs, 22c, 22d are lower yokes between the main legs, 23a,
23b is an upper yoke, 24a and 24b are lower yokes, 2
5a and 25b are side yokes.

FIG. 9 is a vibration characteristic diagram of this single-phase five-legged core, where 26 is a characteristic curve showing the displacement of the center of the side yoke when the magnetostriction ε of each part of the core is 1×10-6, 27 is the main leg portion 21a, 2
The magnetostriction ε of 1b and 21c is 1×10-6, and the upper and lower yokes 22a, 22b, 22c, and 22d between the main legs
The magnetostriction ε of the upper and lower yokes 23a is 0.0443×10−6.

23b, 24a, 24b and a curve showing the displacement of the center of the side yokes when the magnetostriction ε of the side yokes is 0.23×10 −6 .

In this case as well, by making the magnetostriction of the yoke portion smaller than that of the main leg portion, the vibration of the iron core can be significantly reduced.

Now, in FIGS. 1 to 9, we have explained the case where the relative magnetostriction of each part of the core of the single-phase two-legged to single-phase five-legged core according to the present invention has an optimal value. Even if the magnetostriction does not match that of the main landing gear, it is sufficient to use a value close to them. The effect of reducing vibration and noise can be obtained.

Next, FIG. 10 is a characteristic diagram illustrating the average magnetostriction with respect to the magnetic flux density of various silicon steel plates used for the iron core, 28 is the magnetostriction curve of the non-oriented silicon steel plate, and 29 is the oriented silicon steel plate Z13. ~Z15 (trade name of Nippon Steel Corporation), 30 is the average magnetostriction curve of grain-oriented silicon steel sheets Z10 to Z11 (trade name of Nippon Steel Corporation), 31 is HI-V (HI -B) Steel plate (
This is the magnetostriction curve of Nippon Steel Corporation (product name).

That is, the non-oriented silicon steel plate 28 has a large magnetostriction, and the oriented silicon steel plates Z13 to Z15. Z10~Z
The magnetostriction decreases in the order of No. 11, and the Hi-V steel plate exhibits the characteristic of having a small magnetostriction.

Therefore, in the embodiments of the present invention shown in FIGS. 1 to 9, for example, the following combinations of materials can be used as magnetic materials for each part of the core.

(a) Main landing gear: non-oriented silicon steel plate yoke
...Grain-oriented silicon steel plate Z10~Z11Z13~Z1
5. Hi-V steel plate, etc. (b) Main landing gear: grain-oriented silicon steel plate Z13~Z
15 Yoke・・・・・・Grain-oriented silicon steel plate Z10~Z11
, Hi-V steel plate, etc. (c) Main landing gear: grain-oriented silicon steel plate Z10~Z
11 Yoke: Hi-V steel plate In this manner, in each of the above embodiments, by using a good material with lower magnetostriction than the magnetic material of the main leg as the magnetic material of the yoke, the magnetostriction of the yoke is reduced. It is possible to reduce the vibration and noise of the iron core by making it smaller than the magnetostriction of the main landing gear.

Further, in each of the above embodiments, the cross-sectional area of each part of the core is a normal cross-sectional area where the magnetic flux density of each part is almost the same, and the magnetic material of each part of the core is changed. As is clear from Figure 10, the magnetostriction changes even if the magnetic flux density is changed by appropriately changing the magnetic material of each part of the core and by changing the cross-sectional area of each part of the core. For example, by increasing the cross-sectional area by 10% or more, magnetic flux density to 10
Focusing on the fact that the magnetostriction of various silicon steel plates can be considerably reduced by reducing the magnetostriction by more than %,
By making the cross-sectional area of the yoke smaller than the normal cross-sectional area, preferably by at least 10%, the magnetic flux density of the yoke is made smaller, preferably by at least 10%, relative to the main leg. If the magnetostriction is made smaller than that of the main leg, the vibration and noise of the core can be further reduced.

By forming the yoke of the iron core using a magnetic material with better magnetostriction characteristics than the main leg as in the present invention, if the magnetostriction of the yoke part is made smaller than that of the main leg part, vibration of the iron core can be reduced. It can effectively reduce noise and can be manufactured economically.

In addition, the yoke of the iron core uses a magnetic material with better magnetostrictive characteristics than the main landing gear, and the relative cross-sectional area of the yoke with respect to the main landing gear is set so that the magnetic flux density of the yoke is smaller than that of the main landing gear. If the magnetostriction of the yaw portion is made smaller than the magnetostriction of the main leg portion, vibration and noise of the iron core can be further reduced.

[Brief explanation of the drawing]

1, 2, and 3 are a configuration diagram, a vibration characteristic explanatory diagram, and a vibration characteristic diagram showing an embodiment of a single-phase two-leg iron core for a stationary inductor according to the present invention. FIGS. 6 and 7 are block diagrams and vibration characteristics diagrams showing other embodiments of the single-phase three-leg iron core according to the invention, and FIGS. 6 and 7 are diagrams and vibration characteristics diagrams showing still other embodiments of the single-phase four-leg iron core according to the invention. 8 and 9 are block diagrams and vibration characteristic diagrams showing still other embodiments of the single-phase five-leg iron core according to the present invention, and FIG. 10 is a magnetostriction characteristic diagram of various silicon steel plates. 1a, 1b, 7a, 7b, 8a, 8b, 14a. 14b, 15a, 15b, 15c, 15d, 22a. 22b, 22c, 22a, 23a, 23b, 2
4a. 24b...Yoke, 2a, 2b, 10, 13a
. 13b, 21a, 22b, 21c...Main landing gear, 9a
. 9b, 16a, 16b, 25a, 25b... side yoke.

Claims (1)

[Claims] 1. At least one main leg and at least two yokes that are joined above and below the main leg to form a magnetic circuit, and the main leg and the yokes are each formed by laminating magnetic materials. In the single-phase iron for a stationary inductor, the yoke is formed using a magnetic material having better magnetostriction characteristics than the main leg, so that the magnetostriction of the yoke portion is smaller than that of the main leg portion. heart. 2. A device comprising at least one main leg and at least two yokes joined above and below the main leg to form a magnetic circuit, the main leg and the yokes each being formed by laminating magnetic materials, wherein the yoke is By forming the yoke using a magnetic material with better magnetostrictive properties than the main landing gear, and setting the relative cross-sectional area of the yoke to the main landing gear so that the magnetic flux density of the yoke is smaller than the magnetic flux density of the main landing gear,
A single-phase core for a stationary inductor, characterized in that the magnetostriction of the yoke portion is smaller than that of the main leg portion.