JPH0461211A - Magnetic iron core - Google Patents

Abstract

PURPOSE:To reduce the noise and the vibration of an electric apparatus such as a simple inverter or the like which is operated by nonsinusoidal waves by a method wherein ordinary electric iron sheets are laminated on an iron core and specific iron sheets are laminated, at arbitrary intervals, on both end parts and between laminated parts. CONSTITUTION:Low-silicon steel sheets 1 are laminated on a magnetic iron core 2. Electric iron sheets 5 whose permeability at a high frequency is larger than that of said low-silicon steel sheets, which are provided with a reduced strain characteristic and which contain 6.5% of silicon are laminated, at arbitary intervals, on both iron-core end parts 3 at the outside and between iron-core laminated parts 4. A high-frequency magnetic flux is nearly passed through parts arranged at arbitrary intervals at both end parts 3 and the laminated intermediate parts 4 which are constituted of the electric iron sheets 5 of 6.5%-silicon steel sheets 6. A carrier frequency flows at the outer circumferential parts by the skin effect of the magnetic flux, and is passed through the electric iron sheets 5 as reduced-strain materials of both end parts 3 of the magnetic iron core 2. Since the 6.5%-silicon steel sheets as materials generating small electrostriction are used in this part, it is possible to form an electric apparatus whose noise and vibration by electrostriction by the high-frequency magnetic flux are small.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a magnetic core for electrical equipment used in motors, transformers, reactors, etc., particularly in high frequency power sources and power sources containing harmonics.

(Prior Art) Conventionally, this type of magnetic core has been used in combination with a silicon steel plate or a pure iron electric iron plate with a low carbon content to reduce iron loss. (Japanese Unexamined Patent Publication No. 51-136108) (Problem to be solved by the invention) In recent years, inverters have become widespread, and high-frequency power sources are now available in cylinders, and electrical equipment is increasingly driven by inverter power sources.

In particular, a non-sine wave power source such as a PWM inverter contains many harmonic components in addition to the fundamental frequency.

Therefore, the magnetic flux flowing through the magnetic core of electrical equipment also contains a large amount of harmonic magnetic flux, which generates magnetic flux in the magnetic core, resulting in an extreme increase in vibration and noise.

For this reason, we use high-silicon steel plates with low magnetostriction, and
Yado's method used filters to remove harmonics.

The above-mentioned high-silicon steel plate is expensive, and the method using a filter requires space to be installed separately, which also increases the cost.

An object of the present invention is to reduce the noise and vibration of electrical equipment such as inverters that are operated using non-sinusoidal radio waves with a simple configuration.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in the present invention, general low silicon steel plates are used for the laminated core, and arbitrary intervals are provided at both ends and between the laminated layers. It is characterized by being laminated with electric iron plates (for example, iron containing 6.5% silicon) that have low magnetostriction properties and allow harmonic magnetic flux to pass through them more easily than low-silicon steel plates (having high magnetic permeability properties against harmonics) and have low magnetostriction properties. That is.

(Function) In the device configured in this way, the magnetic flux flowing through the magnetic core is permeable to the magnetic material forming the core.

The magnetic flux of the harmonic component that is introduced into the non-sinusoidal power supply is made of a magnetic material that easily passes the harmonic magnetic flux. It passes through a part of the core. In addition, since the main magnetic flux of the basic component has a high magnetic flux density, low silicon steel plate (3,596
(hereinafter referred to as silikoshi-containing iron) will flow in 1, before:
Self-harmonic magnetic flux normally flows at both ends of the outer side of the iron core due to the skin effect, and it may be possible to use an electric iron plate (e.g. 6.5% silicon-containing lighted iron) where the harmonic magnetic flux flows easily and also produces less magnetostriction. By flowing, magnetostriction is reduced, and harmonic components are made to flow more easily, resulting in a power of 1 liJ, making it possible to obtain electrical equipment with low noise and low vibration.

In addition, if the laminated width of the core is long, it will be difficult to pass the harmonic magnetic flux at the middle part of the core through the electrical iron plates that are laminated at both ends and have a magnetic permeability of ρj. By stacking electric iron plates with high magnetic permeability and low magnetostriction at intervals of Furthermore, it is possible to make the harmonic components flow more easily, which makes it possible to obtain electrical equipment with low noise and low vibration.

(Embodiment) An embodiment of the present invention will now be described with reference to FIG.

Figure 1 shows the laminated structure of thin electrical steel sheets in the magnetic core that constitutes the magnetic circuit of electrical equipment.
5% or less silicon-containing iron plates or pure iron iron plates) are laminated on the magnetic core 2, and markings are made at arbitrary intervals of 1° on both ends 3 of the outer core and the core laminated portion 4 to have a magnetic permeability at higher frequencies than that of a low-silicon steel plate. An electric iron plate 5 that is large in size and has low magnetostriction characteristics (example).

The material is laminated with 6.5% silicon-containing iron.

In such a configuration, when driven by a non-sinusoidal power source such as an inverter, the magnetic core 2 contains magnetic flux of many harmonic components in addition to the fundamental wave component (for example, 50 Hz, 60 Hz) magnetic flux. It is often included as harmonics of 1 kHz or 2 kHz or as 4-Yaya frequencies.

Here, the magnetic permeability at high frequencies is large.

A 6.5% silicon steel plate will be explained as an electric iron plate having low magnetostriction characteristics. The magnetic flux at the fundamental wave frequency is 14 magnetic flux, which is a high magnetic flux density of 1.3 T or higher, so as shown in Figure 2, at a magnetic flux density of 13-13 T, the magnetic permeability at high frequencies is difficult for humans. The magnetomotive force of 6,59o silicon steel plate 6, which is a serious iron plate with low magnetostriction characteristics, is 24x.
102 (A/m), whereas each of the low silicon steel plates 7 has a smaller H-3°3 x 1.0' (A/m),
For the fundamental magnetic flux, C is (24/3, 3 =)
7, -. 3 times 1. Moreover, at B-1.4T or higher, it becomes several tens of times easier to pass through, and most of it flows through the low-silicon steel plate 7. Also, 1kHz.

The magnetic flux due to a carrier frequency of several kHz is 1/1 of the frequency of the fundamental wave (magnetic flux Φ-E/f)
So, for the fundamental wave (for example, 50Hz), at 51kHz it is 50/1000 - 1/20.2kHz is 50/20
00-1/40, and the magnetizing force is also small, for example, λ is ]/20 to 1/40 of the fundamental wave, and the magnetizing force is o, 5x10
2 (AT/m) or less, which is 6.5 as shown in Figure 3.
As can be seen from the non-permeability characteristics of the silicon steel plate 6,
．． Comparing the non-permeability μS of the 5% iXI silicon steel plate 6 and the non-permeability of the low silicon steel plate 7, at 1kHz it is more than 20 times,
At 2kHz, it is about 10 times the harmonic magnetic flux, or 6°5%.
It passes through portions arranged at arbitrary intervals between both ends 3 and the laminated intermediate portion 4 of the magnetic core 2, which is made up of electrical iron plates 5 made of silicon steel plates 6. Also, if the fundamental frequency of the power supply is higher than 50Hz or 60Hz, for example, if the fundamental frequency is 400Hz or higher, this may occur.

The carrier frequency is 8 kHz or higher, and due to the skin effect of the magnetic flux, it flows around the outer periphery and passes through the electric iron plates 5, which are low magnetostrictive materials, at both ends 3 of the magnetic core 2. Therefore, since a material with low magnetostriction (6.5% silicon steel plate) is used in this part, it is possible to use an electric device with low noise and vibration caused by the magnetic flux caused by this harmonic magnetic flux.

In addition, when the lamination width of the core is long, it becomes difficult to pass the harmonic magnetic flux at the core lamination intermediate portion 4 through the electric iron plate 5, which is a low magnetostrictive material, in the high permeability magnetic flux laminated at both end portions 3. Therefore, by laminating electrical iron plates 5 made of high magnetic permeability and low magnetostriction material at arbitrary intervals in the core laminated portion 4, the harmonic magnetic flux in the core laminated portion 4 can be effectively reduced by this high permeability and low magnetostriction material. It becomes possible to pass it through the electric iron plate 5 which is a magnetostrictive material. [By using a material with less magnetostriction (6°5% silicon steel plate) for this part, it is possible to create an electrical device with less noise and vibration due to magnetostriction caused by this harmonic magnetic flux.

When the power source includes a high frequency like this, by using a material with less magnetostriction 11 especially in the part where the high frequency magnetic flux passes through and generates magnetostriction, it is possible to make an electrical device with less vibration and noise.

(Other Embodiments) In the embodiments of the present invention, two blocks of electric iron plates 5 having high magnetic permeability and low magnetostriction are laminated at an arbitrary interval in the core interlayer portion 4, and will be explained. However, the number of core blocks is not limited to two, and as shown in FIGS. 4 to 6, one, three, fourteen, etc. may be selected according to the width of the laminated core. .

As yet another embodiment of the present invention, as shown in the schematic diagram of the magnetic core in FIG. An electric iron plate 5 (e.g. 6.5 silicon-containing iron plate or pure iron iron plate) which has high magnetic permeability at high frequencies and low magnetostriction characteristics with a thickness thinner than that of the low-silicon steel plate ), at high frequency, due to the skin effect of the magnetic flux, C has difficulty passing through a thick iron plate, but instead flows around the outer periphery of a thin iron plate.
The electric iron plate 5, which is made of a low magnetostrictive material, is passed through.

5 Therefore, since feed with low magnetostriction is used in this part, the sound due to magnetostriction due to this harmonic magnetic flux,
It can be used as an electrical device with low vibration.

FIG. 8 shows a schematic diagram of a magnetic core according to another embodiment of the present invention. In an electric iron plate 5 having high magnetic permeability and low magnetostriction characteristics, the stacking width L1 of the electric iron plates 5a laminated at both end portions 3 is shown in FIG. By making the lamination width L2 or more of the electric iron plate 5b laminated on the intermediate part 4, it becomes possible to pass the harmonic magnetic flux at both ends 3 to the electric iron plate 5 with high magnetic permeability and low magnetostriction. Low noise and low gestational movements are 61 times more effective.

Of course, the combination ratio of the low silicon steel plate and the material having low magnetostriction characteristics varies depending on the harmonic content of the power source.

In addition, in this example, a 6.5% silicon steel plate is used as a low silicon steel plate and a high magnetic permeability, low magnetostriction electric iron plate. However, the present invention is not limited to this. Any combination of materials having different high-frequency magnetic permeability and magnetostriction coefficient is included in the present invention, regardless of the nitrogen content.

[Effects of the Invention] As is clear from the above description, the present invention can be used as a magnetic core for general electrical equipment, with high magnetic permeability and low magnetostriction at arbitrary intervals at both ends of the magnetic core and between laminated layers. By providing an electric iron plate, electrical equipment driven by a power source containing high-frequency alternating current, such as an inverter power source, can be made to have low magnetostriction, low noise, and low vibration.

Furthermore, this effect is enhanced by using an electric iron plate with high magnetic permeability and low magnetostriction, which is thinner than a low-silicon steel plate.

[Brief explanation of the drawing]

Fig. 2 is a schematic diagram of a magnetic core structure of an electrical equipment showing an embodiment of the present invention; Fig. 2 is a magnetic characteristic diagram of an electric iron plate; Fig. 3 is a relative magnetic permeability characteristic diagram of an electric iron plate; Fig. 4 8 to 8 correspond to FIG. 1 and FIG. 8, respectively, showing other embodiments of the present invention. 1.7...Low silicon steel plate, 2...Magnetic core 13
...Both ends of the core, 4...Between the core laminations. 5.5a, 51>...Low magnetostrictive electric iron plate. 6...6.5% silicon steel plate. Agent Patent Attorney Noriyuki ChikaFigure 3Figure 6Figure 7

Claims (3)

[Claims] (1) In a magnetic core made by laminating two or more thin electric iron plates made of different materials, ordinary electric iron plates are laminated on the core, and a higher frequency than the above ordinary electric iron plates is placed at arbitrary intervals at both ends and between the laminations. A magnetic iron core characterized by laminating electric iron plates containing 6.5% silicon, which have high magnetic permeability and low magnetostriction characteristics. (2) The above-mentioned ordinary electric iron plate is a relatively thick one, and the plate thickness is 6.5 mm, which is thinner than the ordinary electric iron plate.
% silicon-containing electric iron plate according to claim (1). (3) The magnetic iron core according to claims (1) and (2), in which the width of the electrical iron plate containing 6.5% silicon is such that the width of the lamination at both ends is greater than the width of the lamination between the laminations.