CN105871257A - Torque current distribution method for moving coil type magnetic suspension permanent magnet planar motor - Google Patents

Abstract

The invention discloses a torque current distribution method for a moving coil type magnetic suspension permanent magnet planar motor and belongs to the field of magnetic suspension permanent magnet planar motors. A global coordinate system OXYZ and a local coordinate system oxyz are established, the current iA1 of a rectangular coil A1, the current iA2 of a rectangular coil A2 and the current iA3 of a rectangular coil A3, the current iC1 of C1, the current iC2 of C2 and the current iC3 of C3 are distributed, and only torque around the axis z is generated through an A coil group and a C coil group; the current iB1 of a rectangular coil B1, the current iB2 of a rectangular coil B2, the current iB3 of a rectangular coil B3 and the current iD1 of D1, the current iD2 of D2 and the current iD3 of D3 are distributed, and only torque around the axis z is generated through a B coil group and a D coil group; decoupling between the torque and between the torque and thrust is achieved, operation is simple, convenient and rapid, the requirement for motion control real-time performance can be completely met, the coupling problem is fundamentally solved on the physical level, and a good foundation and an engineering method are provided for motion control and precise positioning of the magnetic suspension permanent magnet planar motor.

Description

A kind of torque current distribution method of moving-coil type magnetic suspension permanent magnet planar motor

Technical field

The present invention relates to magnetic suspension permanent magnet planar motor control field, be specifically related to a kind of moving-coil type magnetic suspension permanent magnet plane The current distribution method of motor.

Background technology

Magnetic suspension permanent magnet planar motor directly uses magnetic suspension to realize plane motion, it is not necessary to supporting mechanism, belongs to a class , there is coupling in multiple-input and multiple-output motor system, the Long travel motion of the single degree of freedom between multiple degree of freedom, will impact The positioning precision of other degree of freedom.For improving this motor motion control and positioning precision, it is necessary to realize between motor thrust/torque Decoupling.But, currently for the design of this kind of motor, it is that the control algolithm to its degree of freedom improves mostly, not Inherently solving the coupled problem between each degree of freedom, the coupled problem of permanent-magnet planar motor is intended to motor thrust/torque Between decouple, including the decoupling between the decoupling between thrust and torque.

Moving-coil type magnetic suspension permanent magnet planar motor be mover be coil array, stator be the planar motor of permanent magnet array, its Structure sees shown in Fig. 1 and Fig. 2, and stator is arranged in Halbach permanent magnet array 1 by the permanent magnet that two kinds of volumes are different and forms, and two Planting permanent magnet thickness equal, big permanent magnet magnetization intensity is identical with little permanent magnet magnetization intensity, but the direction of magnetization is orthogonal；So shape The magnetic field magnetic induction side become is very strong, and opposite side is the most weak, and mover is placed in the strong side of magnetic field magnetic induction；Mover does not has There is iron core, be the coil array 2 of 12 coil compositions.Coil array 2 comprises these 4 coil groups of A, B, C, D, 4 coil groups in " ten " font is placed centrally, A coil groups and C coil groups arranged opposite, B coil groups and D coil groups arranged opposite.Each coil groups All being made up of three square coils, A coil groups is made up of A1, A2, A3 these three square coil, B coil groups by B1, B2, B3 this Three square coil compositions, C coil groups is made up of C1, C2, C3 these three square coil, and D coil groups is by D1, D2, D3 these three Square coil forms.Take pole span τ_nFor the half of the centre-to-centre spacing of the identical adjacent two blocks of big magnet steel of the direction of magnetization, each rectangular lines Circle length L is all even-multiple pole span τ_n, at a distance of 4/3 times of pole between the axis of adjacent two square coils in same coil groups Away from τ_n.When to coil distribution electric current, thrust/torque will be produced with the magnetic field phase separation in stator.

Document: a kind of moving-coil type magnetic suspension permanent magnet planar motor real-time current allocation strategy (Proceedings of the CSEE, 2013,33 (6): 144-152. open Xinhua, Sun Yukun, Xiang Qianwen, etc.), it is proposed that moving-coil type magnetic suspension permanent magnet planar motor produces Raw horizontal thrust and the Current Assignment Strategy of suspending power, determine each line in coil array according to desired suspending power and horizontal thrust The electric current of circle, but, document content does not determine the torque current of each coil in coil array, and Current Assignment Strategy is also It is not related to torque, does not produce torque, therefore, be only capable of the decoupling realized between thrust or between thrust and torque, but cannot Realize the decoupling between torque and between torque and thrust.

Summary of the invention

The present invention seeks to overcome what above-mentioned existing moving-coil type magnetic suspension permanent magnet planar motor Current Assignment Strategy existed to ask Topic, proposes the torque current distribution method of a kind of moving-coil type magnetic suspension permanent magnet planar motor, by carrying out 4 coil groups rationally Electric current distribution, it is achieved the decoupling between torque and between torque and thrust.

The torque current distribution method of the present invention a kind of moving-coil type magnetic suspension permanent magnet planar motor the technical scheme is that The stator of described moving-coil type magnetic suspension permanent magnet planar motor is made up of Halbach permanent magnet array, and mover is made up of 12 coils Coil array, coil array comprises these 4 coil groups of A, B, C, D, A, C coil groups arranged opposite, B, D coil groups arranged opposite, A Coil groups is made up of A1, A2, A3 these three square coil, and B coil groups is made up of B1, B2, B3 these three square coil, C coil Group is made up of C1, C2, C3 these three square coil, and D coil groups is made up of D1, D2, D3 these three square coil, including following step Rapid:

1) setting up global coordinate system OXYZ and local coordinate system oxyz, zero O is Halbach permanent magnet array upper surface Magnet steel center, N pole, zero o is the center of coil array, and X, x-axis are to all long with each square coil in B, D coil groups Degree direction is consistent, Y, y-axis to all consistent with each square coil length direction in A, C coil groups, Z-axis direction, z-axis to all with The short transverse of Halbach permanent magnet array is consistent, and in global coordinate system OXYZ, the center point coordinate of mover is (X_C, Y_C, Z_C)；

2) the electric current i of square coil A1, A2, A3_A1、i_A2、i_A3And the i of C1, C2, C3_C1、i_C2、i_C3Electric current is assigned asThe torque around z-axis is only produced by A, C coil groups；

3) the electric current i of square coil B1, B2, B3_B1、i_B2、i_B3And the electric current i of D1, D2, D3_D1、i_D2、i_D3It is assigned asThe torque around z-axis is only produced by B, D coil groups:

Im is the current amplitude of coil, α=π X_C/τ_n, β=π Y_C/τ_n, τ_n-permanent magnet array magnetic field pole span.

Further, in A, C coil groups, the electric current of each square coil is The torque around x-axis is only produced by A, C coil groups；In B, D coil groups, the electric current of each square coil isThe torque around y-axis is only produced by B, D coil groups.

Compared with prior art, the invention has the beneficial effects as follows: the present invention according to the stress equation of maglev planar motor, According to the electromagnetic push/torque mathematical model of moving-coil type magnetic suspension permanent magnet planar motor, can determine in coil groups each easily The torque current of coil, carries out reasonable distribution to the electrical current of multiple coils, it is achieved between torque and torque and thrust it Between decoupling.Computing is simple, convenient, can meet the needs of motor control real-time completely, solve from physical layer at all Coupled problem；Motor control for magnetic suspension permanent magnet planar motor provides good basis and engineering with being accurately positioned simultaneously Change method.

Accompanying drawing explanation

Fig. 1 is heretofore described moving-coil type magnetic suspension permanent magnet planar motor structural representation；

In Fig. 1: 1-Halbach permanent magnet array；2-coil array；Three square coils in A1, A2, A3-A coil groups； Three square coils in B1, B2, B3-B coil groups；Three square coils in C1, C2, C3-C coil groups；D1、D2、D3-D Three square coils in coil groups；τ_n-permanent magnet array magnetic field pole span；L-loop length；OXYZ-global coordinate system；Oxyz-office Portion's coordinate system.

Fig. 2 is A-A profile in Fig. 1；

In Fig. 2: h_m-magnet steel height；OXYZ-global coordinate system；Oxyz-local coordinate system.

Fig. 3 is that the A coil groups in moving-coil type magnetic suspension permanent magnet planar motor shown in Fig. 1 only produces x-axis and works when thrust Situation schematic diagram

In Fig. 3: i_A1、i_A2、i_A3-A1, the electric current of A2, A3 coil；F_AxThe x-axis that-A coil groups produces is to thrust；T_Az-A line Circle group produce around z-axis torque；T_Ay-A coil groups produce around y-axis torque；OXYZ-global coordinate system；Oxyz-local coordinate System.

Fig. 4 is that the A coil groups in moving-coil type magnetic suspension permanent magnet planar motor shown in Fig. 1 only produces z-axis and works when thrust Situation schematic diagram

In Fig. 4: i_A1、i_A2、i_A3-A1, the electric current of A2, A3 coil；F_AzThe z-axis that-A coil groups produces is to thrust；T_Ax-A line Circle group produce around x-axis torque；T_Ay-A coil groups produce around y-axis torque；OXYZ-global coordinate system；Oxyz-local coordinate System.

Detailed description of the invention

See Fig. 1 and Fig. 2, moving-coil type magnetic suspension permanent magnet planar motor structure is set up global coordinate system OXYZ and local is sat Mark system oxyz, and the zero O of global coordinate system OXYZ is defined on the N pole of Halbach permanent magnet array 1 upper surface of stator Magnet steel center, is defined on the center of the coil array 2 of mover by the zero o of local coordinate system oxyz.X axis, x-axis are to all Consistent with the direction of each square coil length L in B, D coil groups, Y-axis, y-axis to all with each rectangular lines in A, C coil groups The direction of circle length L is consistent, Z-axis direction, z-axis to all with magnet steel height h_mDirection consistent, i.e. the height of Halbach permanent magnet array 1 Degree direction is consistent.

The space three-dimensional fundamental wave magnetic field magnetic induction expression formula that then Halbach permanent magnet array 1 produces is as follows:

$\left\{\begin{array}{c}{B}_X=K_m{e}^{-\frac{\mathrm{\π}Z}{{\mathrm{\τ}}_n}}sin\left(\frac{\mathrm{\π}X}{{\mathrm{\τ}}_n}\right)\\ B_Y=K_m{e}^{-\frac{\mathrm{\π}Z}{{\mathrm{\τ}}_n}}sin\left(\frac{\mathrm{\π}Y}{{\mathrm{\τ}}_n}\right),\\ B_Z=K_m{e}^{-\frac{\mathrm{\π}Z}{{\mathrm{\τ}}_n}}\[cos\left(\frac{\mathrm{\π}X}{{\mathrm{\τ}}_n}\right)+cos\left(\frac{\mathrm{\π}Y}{{\mathrm{\τ}}_n}\right)\]\end{array}\right.,$

In formula, τ_nFor the pole span in permanent magnet array magnetic field, K_mStrong for magnetic field magnetic induction at Halbach permanent magnet array 1 upper surface Degree amplitude.B_X、B_YAnd B_ZFor three-dimensional fundamental wave magnetic field magnetic induction X-component, Y-component and Z-component.B_XWith X in Sinusoidal variations, unrelated with Y；B_YIt is sinusoidal variations with Y, unrelated with X；B_ZIt is varies with cosine with X, but the size of superposition thereon is with Y DC component in varies with cosine, or B_ZIt is varies with cosine with Y, but the size of superposition thereon is the straight of varies with cosine with X Flow component；The amplitude of each component all with Z increase and exponentially rule reduce.

In global coordinate system OXYZ, the center point coordinate of mover is (XC, YC, ZC), defined parameters α=π X_C/τ_n, β=π Y_C/τ_n, the current amplitude of each square coil is Im, it is stipulated that be counterclockwise coil current reference direction.

A coil groups only produce x-axis when thrust working condition schematic diagram as it is shown on figure 3, in Fig. 3 the direction of each physical quantity equal For reference direction, the electric current in tri-square coils of A1, A2 and A3 is identical with reference direction, and i_A1、i_A2And i_A3Value is as follows

$\left\{\begin{array}{c}{i}_{A1}=I_{m}sin(\mathrm{\α}-4\mathrm{\π}/3)\\ i_{A2}=I_{m}sin\left(\mathrm{\α}\right)\\ i_{A3}=I_{m}sin(\mathrm{\α}+4\mathrm{\π}/3)\end{array}\right.,$

The x-axis that then A coil groups produces is to thrust F_AxBeing not zero, the y-axis of generation is to thrust F_AyWith z-axis to thrust F_AzIt is Zero；The torque T around y-axis that distributed force suffered by A coil groups produces_AyWith the torque T around z-axis_AzAll be not zero, generation around x-axis Torque T_AxIt is zero.

A coil groups only produce z-axis when thrust working condition schematic diagram as shown in Figure 4, in Fig. 4, the direction of each physical quantity is equal For reference direction, the electric current in tri-square coils of A1, A2 and A3 is identical with reference direction, and i_A1、i_A2And i_A3Value is as follows

$\left\{\begin{array}{c}{i}_{A1}=I_{m}cos(\mathrm{\α}-4\mathrm{\π}/3)\\ i_{A2}=I_{m}cos\left(\mathrm{\α}\right)\\ i_{A3}=I_{m}cos(\mathrm{\α}+4\mathrm{\π}/3)\end{array}\right.$

The z-axis that then A coil groups produces is to thrust F_AzBeing not zero, the x-axis of generation is to thrust F_AxWith y-axis to thrust F_AyIt is Zero；The torque T around x-axis that distributed force suffered by A coil groups produces_AxWith the torque T around y-axis_AyAll be not zero, generation around z-axis Torque T_AzIt is zero.

In like manner, tri-square coil groups of remaining C, B, D only produce x-axis to thrust or z-axis to the working condition of thrust Similar with the operation principle of A coil groups, here is omitted.Therefore, only can be produced around z by A, C coil groups or B, D coil groups The torque of axle, only produces the torque around x-axis by A, C coil groups, and B, D coil groups only produces the torque around y-axis, each group coil Torque current distribution method is as follows:

1) only produce the torque around z-axis by A, C coil groups: the electric current in each coil is identical with reference direction and value such as Under

$\left\{\begin{array}{c}{i}_{A1}=-i_{C1}=I_{m}sin(\mathrm{\α}-4\mathrm{\π}/3)\\ i_{A2}=-i_{C2}=I_{m}sin\left(\mathrm{\α}\right)\\ i_{A3}=-i_{C3}=I_{m}sin(\mathrm{\α}+4\mathrm{\π}/3)\end{array}\right.,$

In formula, i_C1、i_C2And i_C3It is respectively the electric current in three square coils C1, C2, C3 in C coil groups.A, C coil groups Produced y-axis is zero to z-axis to thrust, and x-axis is equal in magnitude to thrust, in opposite direction, cancels out each other；Two groups of coil groups institutes Producing the torque around x-axis is zero, the most equal in magnitude around the torque of y-axis, in opposite direction, cancels out each other, identical around the torque of z-axis, It is overlapped mutually；Now mover only produces the torque around z-axis, and the torque around x-axis, around y-axis is zero, is also respectively zero to thrust.

The torque around z-axis is only produced: the electric current in each coil is identical with reference direction and value is as follows by B, D coil groups

$\left\{\begin{array}{c}{i}_{B1}=-i_{D1}=I_{m}sin(\mathrm{\β}-4\mathrm{\π}/3)\\ i_{B2}=-i_{D2}=I_{m}sin\left(\mathrm{\β}\right)\\ i_{B3}=-i_{D3}=I_{m}sin(\mathrm{\β}+4\mathrm{\π}/3)\end{array}\right.,$

In formula, i_B1、i_B2And i_B3It is respectively the electric current in square coil B1, B2 and B3, i_D1、i_D2And i_D3It is respectively rectangular lines Electric current in circle D1, D2 and D3.The produced x-axis of B, D the two coil groups is zero to z-axis to thrust, and y-axis is to thrust size Equal, in opposite direction, cancel out each other；The torque that two coil groups are produced around y-axis is zero, the most equal in magnitude around the torque of x-axis, In opposite direction, cancel out each other, identical around the torque of z-axis, it is overlapped mutually；Now mover only produces the torque around z-axis, around x-axis, around The torque of y-axis is zero, is also respectively zero to thrust.

2) only produce the torque around x-axis by A, C coil groups: the electric current in each coil is identical with reference direction and value such as Under

$\left\{\begin{array}{c}{i}_{A1}=-i_{C1}=I_m\cos (\mathrm{\α}-4\mathrm{\π}/3)\\ i_{A2}=-i_{C2}=I_m\cos \left(\mathrm{\α}\right)\\ i_{A3}=-i_{C3}=I_m\cos (\mathrm{\α}+4\mathrm{\π}/3)\end{array}\right.,$

The produced x-axis of A, C coil groups is to being zero with y-axis to thrust, and z-axis is equal in magnitude to thrust, in opposite direction, mutually supports Disappear；It is zero that two coil groups are produced the torque around z-axis, the most equal in magnitude around the torque of y-axis, in opposite direction, cancels out each other, around x The torque of axle is identical, is overlapped mutually；Now mover only produces the torque around x-axis, and the torque around z-axis, around y-axis is zero, respectively to Thrust is also zero.

3) only produce the torque around y-axis by B, D coil groups: the electric current in each coil is identical with reference direction and value such as Under

$\left\{\begin{array}{c}{i}_{B1}=-i_{D1}=I_m\cos (\mathrm{\β}-4\mathrm{\π}/3)\\ i_{B2}=-i_{D2}=I_m\cos \left(\mathrm{\β}\right)\\ i_{B3}=-i_{D3}=I_m\cos (\mathrm{\β}+4\mathrm{\π}/3)\end{array}\right.,$

Two produced x-axis of coil groups are to being zero with y-axis to thrust, and z-axis is equal in magnitude to thrust, in opposite direction, mutually Offset；It is zero that two coil groups are produced the torque around z-axis, the most equal in magnitude around the torque of x-axis, in opposite direction, cancels out each other, around The torque of y-axis is identical, is overlapped mutually；Now mover only produces the torque around y-axis, and the torque around z-axis, around x-axis is zero, respectively to Thrust is also zero.

Claims (3)

1. a torque current distribution method for moving-coil type magnetic suspension permanent magnet planar motor, described moving-coil type magnetic suspension permanent magnet plane The coil array that the stator of motor is made up of Halbach permanent magnet array, mover is made up of 12 coils, coil array comprise A, These 4 coil groups of B, C, D, A, C coil groups arranged opposite, B, D coil groups arranged opposite, A coil groups is by A1, A2, A3 these three Square coil forms, and B coil groups is made up of B1, B2, B3 these three square coil, and C coil groups is by C1, C2, C3 these three rectangle Coil forms, and D coil groups is made up of D1, D2, D3 these three square coil, it is characterized in that comprising the following steps:

1) setting up global coordinate system OXYZ and local coordinate system oxyz, initial point O is the N pole magnetic of Halbach permanent magnet array upper surface Steel center, initial point o is the center of coil array, X, x-axis to all consistent with each square coil length direction in B, D coil groups, Y, y-axis to all consistent with each square coil length direction in A, C coil groups, Z, z-axis to all with the height of Halbach permanent magnet array Degree direction is consistent, and in global coordinate system OXYZ, the center point coordinate of mover is (X_C, Y_C, Z_C)；

2) the electric current i of square coil A1, A2, A3_A1、i_A2、i_A3And the i of C1, C2, C3_C1、i_C2、i_C3Electric current is assigned asThe torque around z-axis is only produced by A, C coil groups；

3) the electric current i of square coil B1, B2, B3_B1、i_B2、i_B3And the electric current i of D1, D2, D3_D1、i_D2、i_D3It is assigned asThe torque around z-axis is only produced by B, D coil groups:

I_mIt is the current amplitude of coil, α=π X_C/τ_n, β=π Y_C/τ_n, τ_n-permanent magnet array magnetic field pole span.

A kind of torque current distribution method of moving-coil type magnetic suspension permanent magnet planar motor, its feature It is: in A, C coil groups, the electric current of each square coil is assigned asBy A, C coil groups only Produce the torque around x-axis.

A kind of torque current distribution method of moving-coil type magnetic suspension permanent magnet planar motor, its feature It is: in B, D coil groups, the electric current of each square coil is assigned asBy B, D coil groups only Produce the torque around y-axis.