RU2092922C1 - Method controlling magnetic flux and device for its implementation - Google Patents

Abstract

FIELD: conversion of magnetic energy of permanent magnets to various forms of energy (mechanical, electrical, thermal, light, etc). SUBSTANCE: method proposes principle of control over magnetic flux by controlling magnetic resistance of magnetic shunt in circuit of permanent magnet. This principle determines operation of device implementing given method as amplifier of magnetic flux. EFFECT: expanded range of adjustment of value of magnetic flux depending on preset adjustment law, simplified design and adjustment process. 7 cl, 6 dwg

Description

 The invention relates to techniques using various types of devices that convert the magnetic energy of permanent magnets into various types of energy (mechanical, electrical, thermal, light and others).

 Known methods for controlling the magnetic flux when converting the magnetic energy of a permanent magnet into mechanical energy, which consist in directly controlling the working magnetic flux using an additional source of magnetomotive force (MDS) in the form of an electromagnet having a common magnetic circuit with a permanent magnet and controlled by a regulating device.

 The closest in technical essence to this is the well-known method of controlling the magnetic flux generated by a permanent magnet, which consists in the fact that the opposite poles of the permanent magnet are shorted to each other by means of a magnetic shunt.

 The shunting element is usually the steel poles of the adapter, which when turned on are located strictly opposite the poles of the permanent magnet, and when disconnected they close (shunt) its opposite poles. A known device for implementing this method contains a permanent magnet, the opposite poles of which are short-circuited by a magnetic shunt, and a control unit for the magnitude of the control action intended for compensatory control.

 The known methods with direct regulation of the working magnetic flux using an additional source of magnetomotive force in the form of an electromagnet have the following disadvantage: high energy costs associated with the conversion of magnetic energy stored in a permanent magnet, which is a battery of magnetic energy, into other types of energy, for example, mechanical .

 With the direct control method, the permanent magnet is affected by the external magnetic field, which is usually longitudinal in nature, for example, in magnetic flux density, the permanent magnet begins to demagnetize as the magnetic field increases.

 Upon reaching the control magnetic flux intensity equal to the coercive force of the permanent magnet, the working magnetic flux becomes equal to zero.

 In the case of using high-energy permanent magnets, for example, rare-earth magnets as magnetic energy batteries, the application of the known method under conditions associated with the conversion of magnetic energy to other types of energy becomes problematic primarily due to the low efficiency.

 The technical result of the claimed method and device for its implementation is to expand the range of regulation of the magnitude of the magnetic flux depending on a given regulation law, providing the possibility of creating controlled magnetic energy batteries based on the design of devices for implementing this method with specified parameters, ease of regulation and simplification of the design of the device, exception Permanent magnet demagnetization using this control method.

 The technical result of the claimed method of controlling the magnetic flux generated by a permanent magnet is achieved by the fact that in the method consisting in that the opposite poles of the permanent magnet are shorted together by means of a shunt and form a control magnetic flux whose density vector is perpendicular to the magnetic flux density vector generated in a magnetic shunt by the indicated permanent magnet, the magnetic shunt is made of isotropic in magnetoelectric parameters, for example, in magnetic permeability, saturation magnetic flux density and resistivity, material and flux control is achieved by regulating magnetic resistance of the magnetic shunt, changing the value of the generated control magnetic flux.

 In addition, the magnetic core of the permanent magnet is performed with a working non-magnetic gap in which the magnitude of the working magnetic flux is measured, it is converted into a control signal according to a given law, in accordance with which the magnitude of the generated control magnetic flux is changed.

где μ магнитная проницаемость,
H_c коэрцитивная сила,
B_s магнитная индукция насыщения,
r удельное электрическое сопротивление.The magnetic shunt is made of an iron-nickel alloy, for example, permalloy, grade 45 H or 50 H, having the following characteristics:

where μ is the magnetic permeability,
H _c coercive force,
B _s magnetic induction of saturation,
r electrical resistivity.

 A device for implementing the method comprises a permanent magnet, the opposite poles of which are short-circuited by means of a magnetic shunt, a control value adjuster, a magnetic shunt resistance control element, a magnetic shunt made of isotropic magnetic-electric parameters, for example, magnetic permeability, magnetic saturation induction and specific electric resistance, material, the output of the control unit magnitude of the control action is connected to the control input of the magnet control element shunt resistance, established with the possibility of forming the resulting vector of the magnetic field density through a magnetic shunt according to a given law.

где μ магнитная проницаемость,
H_c коэрцитивная сила,
B_s магнитная индукция насыщения,
r удельное электрическое сопротивление.The magnetic shunt is made of an iron-nickel alloy, for example, permalloy, grade 45 H or 50 H, having the following characteristics:

where μ is the magnetic permeability,
H _c coercive force,
B _s magnetic induction of saturation,
r electrical resistivity.

 The control element of the magnetic resistance of the shunt is made in the form of a choke, on one side of the magnetic circuit of which there is a control winding, the terminals of which are the control input of the element, and the other side is the magnetic shunt of the device.

 The magnetic core of the permanent magnet is made with a working non-magnetic gap, in which a meter of magnetic flux is located, the output of which is connected to the information input of the setpoint of the magnitude of the control action.

 In FIG. 1 shows an example of an equivalent equivalent circuit according to the proposed method according to claim 1 of the formula; in FIG. 2 is an example of an equivalent equivalent circuit according to the known method of direct control of the magnetic flux by introducing an additional source of magnetomotive force, the direction of the magnetic flux of which has a longitudinal character (excluding the scattering magnetic flux); in FIG. 3 an example of an equivalent circuit equivalent to PP. 2 and 7 in the case of a magnetic circuit with a working non-magnetic gap; in FIG. 4 an example of the implementation of the device for implementing the inventive method in the case of execution of the control element of the magnetic resistance of the shunt in the form of a choke according to claims 4 and 6; in FIG. 5, section AA in FIG. 4; in FIG. 6 adjusting characteristics of different parameters depending on the control current or the intensity of the control magnetic flux.

In FIG. 2 shows an equivalent circuit of one of the devices implemented by the known method of direct control of the working magnetic flux (Φ _P ) of a permanent magnet 1 with magnetic circuits 2 and 3 by introducing an additional source 4 of magnetomotive force (F _y ), whose magnetic flux (Φ _Y ) has longitudinal character.

In FIG. 2, the magnetic resistances of the magnetic cores 2 and 3, respectively, are designated R _Fe1 and R _Fe2 , where the control value is 5.

In this equivalent circuit, the permanent magnet 1 is a magnetic energy accumulator having a magnetomotive force
F _PM = (- H _C ) • l _M ,
where H _{C is the} coercive force of the permanent magnet, taken into account the sign “-” from the demagnetization curve;
l _{M is the} length of the permanent magnet 1 in the direction of its magnetization.

где
μ_М магнитная проницаемость вещества постоянного магнита;
S_М площадь поперечного сечения постоянного магнита в его нейтральной плоскости.The internal magnetic resistance (R _i ) is equal to the magnetic resistance of the permanent magnet

Where
μ _M magnetic permeability of a permanent magnet substance;
S _{M is} the cross-sectional area of a permanent magnet in its neutral plane.

(3)
где

магнитное сопротивление рабочего немагнитного зазора в месте сопряжения ферромагнитной детали (R_ДЕТ) с магнитопроводом 2 и 3.When placing a ferromagnetic part 6 (R _DET ) with a working non-magnetic gap of the magnetic circuit made in accordance with FIG. 2, the load magnetic resistance (R _NG ) of the battery 1 is determined as follows:

(3)
Where

the magnetic resistance of the working non-magnetic gap at the interface of the ferromagnetic part (R _DET ) with the magnetic circuit 2 and 3.

Under the resistance (R _DET ) understand the magnetic resistance provided by the substance of the part 6 flowing through it working magnetic flux (Φ _P ) from the battery 1.

где

магнитная индукция в рабочем зазоре (δ_p);

площадь поперечного сечения двух рабочих немагнитных зазоров (δ_p);
магнитная проницаемость рабочего немагнитного зазора, приблизительно равная магнитной проницаемости вакуума μ_o = 4•π•10^-7 Гн/м.
Для регулирования силы притяжения детали (на чертеже не показана) (F_М) служит электромагнит 4, по обмотке которого пропускают управляющий ток (I_у) со стороны задатчика 5 величины управляющего воздействия, связанного с электрической сетью и работающего в соответствии с вводимыми в него задающим сигналом (U_ЗС).As a result of the transfer of magnetic energy from the side of the battery 1 to the working non-magnetic gap (not shown in the drawing), the ferromagnetic component to be machined (for example, grinding) begins to be attracted to the magnetic cores 2 and 3 with a force

Where

magnetic induction in the working gap (δ _p );

cross-sectional area of two working non-magnetic gaps (δ _p );
the magnetic permeability of the working non-magnetic gap, approximately equal to the magnetic permeability of the vacuum μ _o = 4 • π • 10 ^-7 GN / m.
To control the force of attraction of the part (not shown in the drawing) (F _M ), an electromagnet 4 is used, along the winding of which a control current (I _y ) is passed from the side of the setter 5 to the magnitude of the control action associated with the electric network and operating in accordance with the input signal (U _ЗС ).

When passing through the winding of an electromagnet 4 having a common magnetic circuit with a source of MDS (F _PM ) (permanent magnet), direct current (I _y ) in a magnetic circuit, an external source of MDS (F _y ) is created, directed in the opposite direction to MDS (F _PM ) direction, as a result of which the magnitude of the working magnetic flux (Φ _P ) in the workpiece can be reduced from the maximum value (Φ _Pmax ) at which it was machined (F _M = F _Mmax ) to a zero value at which, in the case lack of residual magnet The strength of the part is F _M 0 and the part can be removed from the working surface of the magnetic plate at the end of machining.

Такой способ управления требует больших затрат энергии при низком к.п.д.The expression for the working magnetic flux has the form:

This control method requires high energy consumption at low efficiency.

 The essence of the claimed invention is illustrated in FIG. 1, which presents an equivalent equivalent circuit according to p. 1 and p. 4 of the claimed method and device for its implementation.

In FIG. 1 shows a permanent magnet 1 (magnetic energy accumulator) as a source of magnetomotive force (F _PM ), having an internal resistance (R _i ) equal to the magnetic resistance of a permanent magnet (R _M ), determined by the formula (2), (N) and (S ) opposite poles of the permanent magnet 1, U _UPR signal of the magnitude of the control action of the magnitude of the control action coming from the setter 5, the control element of the magnetic resistance of the shunt 7, the magnetic shunt 8 with the magnetic resistance of the shunt (R _W ).

 In FIG. 3 presents an equivalent equivalent circuit for the case of a magnetic circuit with a working non-magnetic gap, in which a meter 9 of the magnitude of the working magnetic flux is installed, made, for example, in the form of a Hall sensor.

An example embodiment of the device shown in FIG. 4 and 5, and its cross section contains a permanent magnet 1, the magnetic circuit of which contains a working non-magnetic gap 10 in which the ferromagnetic part 6 is placed, a Hall sensor 9 is installed in the non-magnetic working gap 10 and measures the magnitude of the magnetic flux in the gap. The control element 7 of the magnetic resistance of the shunt 8 is made in the form of a throttle, on one side of which is placed a control winding (W _y ), the terminals of which are the control input of the control element 7, the other side of the magnetic circuit of the throttle is a magnetic shunt 8.

 The device operates as follows.

где

магнитные сопротивления рабочего немагнитного зазора 10,
δ_p рабочий немагнитный зазор в месте сопряжения обрабатываемой детали 6 с магнитопроводами 2, 3;
R_ДЕТ магнитные сопротивления детали, и далее по магнитопроводу 3, имеющему магнитное сопротивление

к южному полюсу (S) (или к клемме "-" по аналогии с аккумулятором электрической энергии).The working magnetic flux (Φ _P ) to be regulated flows through the magnetic circuit 2, which has magnetic resistance (R _{Fe 1} ) from the north pole (N) (or the “+” terminal, by analogy with the electric energy storage battery) of the magnetic energy storage battery 1 (permanent magnet) to the fastening zone of the ferromagnetic part 6, the magnetic resistance of which (i.e., the zone) in the diagram is indicated in the form of the load resistance of the battery 1 (R _NG ) equal to

Where

the magnetic resistance of the working non-magnetic gap 10,
δ _{p the} working non-magnetic gap at the interface of the workpiece 6 with the magnetic circuits 2, 3;
R _{DET is the} magnetic resistance of the part, and further along the magnetic circuit 3 having a magnetic resistance

to the south pole (S) (or to the “-” terminal by analogy with an electric energy storage battery).

To control the working magnetic flux (Φ _P ) in order to change the magnitude of the force (F _M ) applied to the workpiece 6, the north (N (+)) and south (S (-)) poles of the battery 1 of magnetic energy (permanent magnet), having a source of magnetomotive force (MDS) (F _PM ) and internal magnetic resistance (R _i ), equal to the magnetic resistance of a permanent magnet (R _M ) through which the magnetic flux (Φ _M ) flows inside the permanent magnet, they are shorted between each other by the shortest path controlled by magnetic shunt 8 made of isotropic mate a region having increased values of the magnetic permeability μ of saturation induction (B _s ), electrical resistivity r and a reduced value of coercive force (H _C ), the magnetic resistance (R _W ) of which is regulated by an additional source of magnetomotive force (F _y ) creating in the magnetic shunt 8, which is electrically connected with the setpoint, the magnitude of the control action 5 is transverse with respect to the magnetic flux (Φ _Ш ) from the side of the permanent magnet (accumulator of magnetic energy) 1 magnetic control flux (Φ _Y ) and change the magnitude of the working magnetic flux (Φ _P ) and the force proportional to it (F _M ) (not shown in the drawing) applied to the workpiece 6.

The range of regulation of the working magnetic flux (Φ _P ) and force (F _M ) is limited by two extreme operating modes of the magnetic energy accumulator (permanent magnet) 1:
one). At the lowest possible value of the magnetic resistance (R _Ш ) of the shunt 8, when the maximum flux (Φ _Ш ) flows approximately equal to the magnetic flux (Φ _M (k)) with a short circuit of the magnetic energy accumulator 1 (R _Ш <R _НГ ; Φ _Ш ≈ Φ _M (k); Φ _P ≈ 0 F _M ≈0).

2). At the maximum possible value of the magnetic resistance (R _Ш ) of shunt 8, when the minimum flux (Φ _Ш ) flows close to zero (R _Ш > R _НГ , Φ _Ш ≈ 0; Φ _P ≈ Φ _M ; F _M F _Mmax ).

To stabilize the selected working magnetic flux nominal value (Φ _PH ) and to enter this value using the driving signal (U _ЗС ) into the setter 5, the device is covered by signal feedback (U _ОБ ) by means of a meter located in the fastening zone of the ferromagnetic part 6 magnetic flux 9, for example, by a Hall sensor.

The behavior of the electromagnetic system according to the equivalent circuit shown in FIG. 3, and the implementation of the device shown in FIG. 4, when changing the control current (I _i ) within the above control range, FIG. 6, where the adjustment characteristics are presented in the coordinate system (0 '), which are the dependences (in relative units) of the magnetic induction B $\genfrac{}{}{0ex}{}{\text{*}}{\text{W}}$ permeability μ $\genfrac{}{}{0ex}{}{\text{*}}{\text{W}}$ magnetic resistance R $\genfrac{}{}{0ex}{}{\text{*}}{\text{W}}$ magnetic flux Φ $\genfrac{}{}{0ex}{}{\text{*}}{\text{W}}$ working magnetic flux Φ $\genfrac{}{}{0ex}{}{\text{*}}{\text{P}}$ magnetic flux Φ $\genfrac{}{}{0ex}{}{\text{*}}{\text{M}}$ and forces F $\genfrac{}{}{0ex}{}{\text{*}}{\text{M}}$ acting on the workpiece, from the control current (I $\genfrac{}{}{0ex}{}{\text{*}}{\text{At}}$ I _U / I _Umax ) or control transverse magnetic flux intensity (H $\genfrac{}{}{0ex}{}{\text{*}}{\text{At}}$ H _U / H _Umax ). The basic values of the listed characteristics are taken to be their values at zero control current (I $\genfrac{}{}{0ex}{}{\text{*}}{\text{At}}$ )
From the graphs of the dependence μ _W = f ₁ (H _W ) and B _W f ₂ (H _W ) in the coordinate system (0) it can be seen that in the absence of a control signal (I _Y 0; H _Y 0) to the magnetic shunt 8 from the constant side magnet 1 is affected by an external source of MDS (mixing) F _Ш (cm), which creates a longitudinal magnetic field in the shunt, the intensity of which is equal to (H _Ш (cm)).

The proposed method and device that implements it allows to increase the efficiency of conversion of magnetic energy of permanent magnets 1 (magnetic energy accumulators) into other types of energy, including mechanical energy due to the relatively small power spent on controlling the work flow (Φ _P ) demagnetization of a permanent magnet both during its operation and in an idle state, since when using the proposed method the condition for the absence of demagnetization of a permanent magnet is fulfilled annoe for its poles (Figure 3.) in the following form:
Φ _M ≈ Φ _W + Φ _P = const. (6) and

Claims (7)

 1. A method of controlling a magnetic flux generated by a permanent magnet, in which the opposite poles of the permanent magnet are shorted together by means of a magnetic shunt and form a control magnetic flux, characterized in that the control magnetic flux is formed so that its density vector is perpendicular to the magnetic flux density vector created in the magnetic shunt by a permanent magnet, the magnetic shunt is made of isotropic in magnetoelectric parameters, for example, magnetic permeability The current, magnetic induction of saturation and the electrical resistivity of the material, and by changing the magnitude of the control magnetic flux by adjusting the magnetic resistance of the magnetic shunt, control the magnetic flux.  2. The method according to claim 1, characterized in that the magnitude of the generated control magnetic flux is changed according to the control action, for which the magnitude of the working magnetic flux is measured in the working non-magnetic gap in the permanent magnet core and converted into a signal of the specified control action according to a given law. 3. The method according to claim 1, characterized in that the magnetic shunt is made of a nickel-iron alloy, for example permalloy, grade 45H or 50H, having
μ _max = 25 • 10 ^-3 T. M / A, H _c = 24 A / m, B _s = 1.5 T,
ρ = 0.45 Ohm • mm ² / m,
where μ is the magnetic permeability;
N _with coercive force;
In _s magnetic induction of saturation;
ρ is the electrical resistivity.  4. A control device for the magnetic flux generated by a permanent magnet, containing a permanent magnet, the opposite poles of which are short-circuited by means of a magnetic shunt, and a control value adjuster, characterized in that a magnetic resistance control element of the shunt is introduced into the device and the magnetic shunt is isotropic by magnetoelectric parameters, for example, magnetic permeability, saturation magnetic induction and electrical resistivity, material, setpoint output the magnitude of the control action is connected to the control input of the control element of the magnetic resistance of the shunt, installed with the possibility of forming the resulting vector of the density of the magnetic field through the magnetic shunt according to a given law. 5. The device according to claim 4, characterized in that the magnetic shunt is made of a nickel-iron alloy, for example permalloy, grade 45H or 50H, having
μ _max = 25 • 10 ^-3 T. M / A, H _c = 24 A / m, B _s = 1.5 T,
ρ = 0.45 Ohm • mm ² / m,
where μ is the magnetic permeability;
N _with coercive forces;
In _s magnetic induction of saturation;
ρ is the electrical resistivity.  6. The device according to claim 4, characterized in that the control element of the magnetic resistance of the shunt is made in the form of a choke, on one side of the magnetic circuit of which there is a control winding, the terminals of which are the control input of the element, and the other side of the magnetic circuit is the magnetic shunt of the device.  7. The device according to claim 4, characterized in that the magnetic core of the permanent magnet is made with a working non-magnetic gap, in which there is a meter for the magnitude of the working stream, the output of which is connected to the information input of the setpoint magnitude of the control action.

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