RU1786520C - Method of magnetic flow concentration in some place of ferromagnetic magnetic circuit cross section - Google Patents

Abstract

A method for concentrating a magnetic flux at a cross-section of a magnetic core made of a ferromagnetic material at any place. The invention relates to the field of electrical engineering - more specifically, to methods for exposing ferromagnetic objects to a magnetic field. The essence of the proposal: permanent magnets are applied to the base of the toroidal magnetic core so that the angle between the line connecting the middle of the permanent magnets and the middle line of the magnetic core is 20-89 °. 4 ill.

Description

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The invention relates to the field of electrical engineering, in particular to a method for forming the properties of toroidal magnetic cores. The invention can be used for the manufacture of chokes and other electrical devices with adjustable magnetic permeability. capacities.

In electrical engineering, in order to obtain a lower value of the magnetic permeability necessary for the normal operation of the throttle, an air gap is introduced into the core (magnetic core). By changing the length of the air gap, magnetic is permeable. Capability can vary widely. A known method for adjusting the air gap in power induction converters by introducing magneto. conductive material in the form of plates, proleshka or grains.

The disadvantages of the above methods are:

1) the great technical difficulty of creating gaps of the required length in toroidal magnetic cores:

2) the inability of the manufactured magnetic cores to regulate the magnetic permeability even if not within wide limits.

There is also known a method for extracting current pulses of one polarity using the method of magnetic displacement generated by a permanent magnet in contact with the core (magnetic wire) and creating a radial magnetic flux near one surface thereof.

However, this method has significant drawbacks, since the regulatory action of a permanent magnet in contact with

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one surface of the core and creating a magnetic flux near this surface; a rather laborious method of magnetizing a permanent magnet in the radial direction; it is necessary to ensure the gap between the layers of the tape if its thickness is less than 50 microns, which increases the complexity of manufacturing the core (magnetic core); the coefficient of filling the magnet with soft material decreases, which will lead to an increase in the diameter of MarHHTonpo bA a W fecTj6Hl (imeieea.:

The closest technical solution, allowing to control the magnetic permeability over a wider range, is a method of concentration of the magnetic flux at the desired location in the cross section of the magnetic circuit. The magnitude of the magnetic magnitude depends on the degree of magnetization of the magnetic circuit Мз and remains unchanged when this magnetic circuit is saturated:

However, the known method has significant drawbacks, since the properties of ferromagnetic materials to change their domain structure and reduce the mobility of domains under the influence of external magnetic fields are insufficiently used to expand the range of control of magnetic permeability. Here, we used only the influence of an external magnetic flux acting at an angle of 90 ° to the direction of the main magnetic flux, perpendicular to the plane of the ferromagnetic material and did not use the influence of magnetic flux other than those indicated in the known method.

The aim of the proposed method is to expand the magnetic capabilities of the magnetic circuit by increasing the range of permeability changes and obtaining a magnetic hysteresis loop offset.

This goal is achieved by the fact that in some area a toroidal magnetic core of ferromagnetic material is magnetized with the help of permanent magnets at any angle to its midline. Based on the sizes of the magnetic conductors for a standard series of their standard ratings, the most appropriate range of angles of action of the magnetizing flux created by permanent magnets is from 20 ° to 89 °. The direction of the magnetizing flux coincides with the plane of the tape twisted into a magnetic circuit. Thus, two magnetic fluxes act in the plane of the tape during the operation of the magneto-law:

(working) —in the direction of the length of the tape and transverse (magnetization flux) —in the direction of its width at an angle to its midline. The magnetic permeability of the magnetic circuit changes not only when the magnitude of the magnetization flux changes, but also the angle of application of this magnetizing magnetic flux with respect to the main magnetic flux. In this case, the magnetic permeability also varies depending on the sign of unipolar current pulses, which indicates the presence of a magnetic displacement of the hysteresis loop of the magnetic circuit, which can be used to isolate current pulses or voltage of any one polarity. As the angle of action of the magnetizing flux decreases, the magnetic permeability gradually decreases, which allows insignificant adjustment of the magnetic permeability of the magnetic circuit during its operation, if it is possible to insignificantly change the angle of the magnetizing flux in the manufacture of a product with a magnetic circuit. When a magnetization flux is applied, the domains are reoriented in the magnetic circuit in the region where it is affected, their mobility decreases when the main magnetic flux of the magnetic circuit is exposed to them, which will lead to a decrease in magnetic permeability, since domain rotation is difficult when the magnetic circuit is magnetized by the main magnetic flux. The magnetizing magnetic field can be created by both opposite and the same poles of permanent magnets. The prototype provides a method for concentrating magnetic flux in a cross section perpendicular to the main magnetic flux of a magnetic circuit, in which a gap is created for introducing an additional magnetic circuit M3 (Fig. 2). The proposed method involves the use of a toroidal magnetic circuit without a gap. The research results showed that the effect of the transverse magnetic flux acting in the plane of the tape in the direction of its width will be most effective compared to the magnetic flux acting perpendicular to the plane of the tape.

The use of magnetizing fluxes acting at different angles to the main magnetic flux created by the poles of permanent magnets.

The magnitude of the magnetic permeability and the efficiency of the extraction of current or voltage pulses are controlled not only by changing the magnitude of the magnetization flux but also by changing the direction of action of this flux.

Fig. 1 illustrates a method for creating magnetization fields; Fig. 2 shows the magnetic permeability of a magnetic circuit made of 24KSR and AMAG-183 materials as a function of the angle between the direction of the magnetization flux and the middle line of the magnetic circuit; in Fig. 3 - dependence of the magnetic permeability of the magnetic circuit of the material 81 NMD on the angle between the direction of the magnetization flux created by the application of the same poles of magnets and the middle line of the magnetic wire; Fig. 4 shows the dependence of the magnetic induction increment of materials 24KSR (curve 1) and AMAG-183 (curve 2) on the magnitude of the main magnetic field of the magnetic circuit when applying unipolar pulses of the same sign.

The method of magnetic flux concentration at any place in the cross-section of the magnetic circuit is implemented on magnet wires OL 30 / 40-6 from amorphous material 24KSR TU 14-1-3730-84 and OL 30 / 40-5 from material AMAG-183 YaEO. 021.180.TU. The magnetization flux has the greatest effect on materials with a cobalt base (AMAG-183) in comparison with materials based on iron (24KSR). By applying permanent magnets from the alloy KS-37 BLS 777.002.TU of a rectangular shape with dimensions 6, magnetization fluxes are created (Fig. 1). By shifting the permanent magnets (Fig. 1 a) in contact with the upper end surface of the magnetic circuit, relatively in contact with the lower surface of the magnetic circuit of permanent magnets of opposite polarity, a decrease in magnetic permeability is created (figure 2), moreover, different materials respond differently to inclined magnetization currents. The magnetic permeability of the magnetic core from 24KSR material is reduced by 3 times, and the permeability of the magnetic core from AMAG-183 material is reduced by 35 times. The application of the same poles of magnets to the magnetic circuit (Fig. 15) leads to a decrease in magnetic permeability by 20 times

(for a magnetic circuit made of AMAG-83 material) and 40 times (for a magnetic circuit made of 24KSR material). By shifting the permanent magnets in contact with the upper end face 5 of the magnetic circuit, relatively in contact with the lower surface of the magnetic circuit of permanent magnets of the same polarity, a smooth increase in the magnetic permeability occurs (Fig. 3). Figure 4 shows the graphs of the increment of the magnetic induction of the magnetic cores with changes in the magnetic field of both directions in the magnetic wire. The graphs show that for

5 of the magnetic core of 24KSR material, the increment of magnetic induction changes by 1.3 times, and for a magnetic core of AMAG-183 material by 3.5 times when magnetic fields of opposite directions are applied. Permanent magnets can be replaced with electromagnets; .

Using the proposed method of concentration of the magnetic flux at any place in the magnetic circuit for

5 regulation of the magnetic permeability of the toroidal magnetic cores will provide: ..., ......

1) reducing the complexity of manufacturing magnetic cores with a low value of 0 magnetic permeability, since there is no need to create an air gap;

2) reducing the weight of electrical products, in which it is not necessary to reduce the inductance to increase the length of the middle line of the magnetic circuit operating with the magnetization field (e.g., a smoothing filter inductor).

Claims (1)

The claims 0 A method of magnetic flux concentration at some point in the cross-section of a magnetic circuit made of ferromagnetic material, carried out by magnetizing a part of the magnetic circuit by intensity 5 an applied magnetic field, characterized in that, in order to expand the magnetic capabilities of the magnetic drive by increasing the range of magnetic permeability changes and to obtain a displacement of the magnetic hysteresis loop, permanent magnets are applied to the base of the toroidal magnetic core so that the angle between the line connecting the middle permanent magnets, and medium 5 the line of the magnetic circuit was 20-89 °,