RU2257630C2 - Method for varying shape of reactor magnetization curve - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: proposed method can be used not only for low-power devices in pulse engineering and control circuits but also for power circuits of automatic-control systems to ensure operation of electromagnetic components during step-by-step regulation of electrical energy supplied to load, as well as in converter engineering, ferroresonance circuits and regulators to vary magnetization curve shape of reactor that has coil with split core made of electric steel strips. This method includes additional treatment of butt-ends of core halves. Prior to joining split core halves together their butt ends are covered with nonmagnetic insulating material in the form of films or plates of various shapes and sizes. Then their surfaces are tightly fitted to one another.

EFFECT: enhanced nonlinearity of magnetization curves.

1 cl, 6 dwg

Description

The invention relates to electrical engineering, in particular to methods for manufacturing chokes, transformers, electromagnetic switches.

It is known that the shape of the magnetization curve can change due to the inclusion of various impurities in the composition of the magnetic material, mechanical stresses arising from various internal deformations in the steel sheets during the manufacturing of the magnetic circuit, as a result of special machining of the magnetic material, for example, its cold rolling [ 1].

Known methods for changing the shape of the magnetization curve by introducing into the magnetic circuit of the throttle air gap [2].

Closest to the proposed method is a method of changing the shape of the magnetization curve by additional processing (refinement) of the surface of the ends of the split tape magnetic circuits [3] (prototype).

The disadvantage of this method is to obtain unambiguous characteristics B (H) due to the non-essential non-linearity of the magnetization curves of the inductor [4].

The objective of the invention is to obtain significant non-linearity of the magnetization curves, and accordingly their ambiguity, which contributes to the appearance in these devices of fundamentally new phenomena and effects used in the conversion technique.

The problem is achieved in that in the method of changing the shape of the magnetization curve of the inductor containing a coil with an iron core made of tape electrical steel, by additional processing of the ends of the core, non-magnetic dielectric material is applied in various places in the form of films or plates of various shapes and sizes.

The dielectric material is applied to the surface of the pretreated ends of the split tape magnetic cores in the form of thin films or small plates or by spraying. To apply a dielectric to the ends, you can use the method of spraying or applying electrical varnish with a roller or brush in the form of a thin film on a stencil. The plates can be held at the ends due to the forces of the magnetic field when connecting two halves of the magnetic circuit.

The change in the shape of the magnetization curve here occurs due to the formation of local internal stresses, due to the dielectric permittivity gradient at the junction of two media - a dielectric and an electrical material. With surfaces “densely” attached to each other — the upper and lower ends, a sharp decrease in the magnetic permeability occurs at the locations of the dielectric. The main magnetic flux, which closes along the magnetic circuit, will encounter local magnetic resistance in its path to a greater or lesser extent depending on the dielectric constant of the dielectric material, its location on the end surfaces, shape and size. The dielectric applied to the surface of the ends of the magnetic circuit can be considered as a tough program, since this or that characteristic can be obtained only for a dielectric plate of a certain size, configuration, and its location on the surface of the ends.

Below is the data on the experimental study of a choke with a coil wound with a PEL wire of 0.8 mm diameter, 180 turns and a PL type magnetic tape made of cold-rolled textured steel grade 3405, 0.35 mm thick, window height 80 mm, end section (25 × 40) mm ² . As dielectric material tracing paper, electrical varnish, electrical paper and mica were used. For comparison, in all the graphs presented below, the magnetization curve (1) is a characteristic of a choke without dielectric plates. The thickness of the used plates (0.05-0.1) mm.

Figure 1. Dependences B (H) are presented for chokes with plates in the form of squares of the same size (1.3 × 1.3) mm ² deposited on the surface of the ends of the magnetic circuit in the same places (Fig. 5), but with different magnetic permeabilities: curve (2) - a plate of mica, (3) - of tracing paper, (4) - paper, (5) - a substrate from magnetic tape.

Figure 2. Curves B (H) are presented for chokes with plates in the form of squares of the same size (3 × 3) mm ² , deposited on the surface of the ends of the magnetic circuit in various places (Fig.6). The location of the plates on the ends of the magnetic circuit made of the same material are indicated by numbers in accordance with the designation of the curves B (H) of FIG. 2.

Figure 3. Curves B (H) for chokes with plates in the form of squares from tracing paper of various sizes: for characteristic (2) the size of the plates is (2 × 2) mm ² , for curve (3) it is (1.3 × 1.3) mm ² , for the curve (4) - (3 × 3) mm ² equally spaced along the surface of the ends of the magnetic circuit (Fig. 5).

Figure 4. Curves B (H) for chokes with plates of electrical paper located on the ends of the magnetic circuit in the same place (Fig. 5), but in a different configuration: for characteristic (2) in the form of a corner measuring (3 × 3) mm, width 1.5 mm and in the form of a square measuring (3 × 3) mm ² .

By the polysemy of a nonlinear function is meant that, for a certain value of one variable, another variable can take several values. In our case, the functions are multi-valued - the curve (3) in Fig. 1, where induction B can take different values from 0.8 to 1.2 T at the same tension value N = 0.8 A / m, also curve (3) in FIG. 3, where induction B can have three values (0.8; 1.12; and 1.4) T at a tension of H = 0.92 A / m.

The phenomenon of the ambiguity of the obtained characteristics of the chokes makes it possible to use them in various apparatuses and devices without complicating the electrical circuits and structures, as well as without including additional linear and nonlinear electromagnetic and semiconductor elements necessary to obtain such characteristics. For example, such devices may be power ferroresonant stabilizers. The effect of "negative" resistance in characteristic (3) of Fig. 3 makes it possible to use the chokes in question in a number of devices: as oscillation generators, multipliers and frequency dividers, pulse transformers, magnetic amplifiers, in power automation devices with parametric oscillatory circuits [L. 5].

Thus, the results of the study confirm that by applying dielectric plates to the surface of the ends of the magnetic circuit, it is possible to obtain chokes with various forms of magnetization curves B (H) - from single to multi-valued.

Bibliographic sources

1. Rainbot G. Magnetic materials and their application. Per. with him. Ed. A.A. Preobrazhensky. - L .: Energy, 1974.- 384 p.

2. Borisov Yu.M., Lipatov D.N., Zorin Yu.N. Electrical Engineering - M .: Energoatomizdat, 1985 .-- 552 p.

3. Kosenko V.L., Kosenko A.I., Shevchenko V.N. The effect of cutting and end processing on the electromagnetic parameters of tape magnetic circuits // Electronic Engineering, series 5, Radio components and radio components. Issue 1 (62). 1986.

4. Kosenko V.L., Kosenko A.I. Analysis of electromagnetic parameters of a coil with a cut magnetic circuit. Sat - M .: International conference “Actual problems of fundamental sciences”, Russia, 1994.

5. Filippov E. Nonlinear electrical engineering. - M .: Energy, 1968, - 504 s.

Claims (1)

A method of changing the shape of the magnetization curve of chokes containing a coil with a split core made of tape electrical steel by additional processing of its ends, characterized in that non-magnetic dielectric material is applied to said ends of the specified split core in the form of films or plates of various shapes and sizes and densely fit their surfaces to each other.

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