CN100406759C

CN100406759C - A Design Method for Radial Hybrid Magnetic Bearing with Permanent Magnet Bias Outer Rotor

Info

Publication number: CN100406759C
Application number: CNB2006101142683A
Authority: CN
Inventors: 孙津济; 房建成; 王曦; 韩邦成
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2006-11-03
Filing date: 2006-11-03
Publication date: 2008-07-30
Anticipated expiration: 2026-11-03
Also published as: CN1945035A

Abstract

A design method for radial hybrid magnetic bearing with permanent magnet bias outer rotor. This method takes the displacement stiffness of the magnetic bearing as the starting point, and conducts the design of the magnetic bearing with the constraints of maximum bearing capacity, saturation magnetic density, and slot fullness. Compared with some radial hybrid magnetic bearing design methods that aim at the best working point of the permanent magnet, this method is more conducive to the control of the magnetic bearing, and the size of the obtained permanent magnet is more reasonable. This method is highly accurate, simple and feasible, Its design idea can be used in the design of various types of permanent magnetic bias external rotor radial hybrid magnetic bearings.

Description

A Design Method for Radial Hybrid Magnetic Bearing with Permanent Magnet Bias Outer Rotor

技术领域 technical field

本发明涉及一种非接触磁悬浮轴承的设计方法，特别是一种磁悬浮飞轮、磁悬浮控制力矩陀螺等需要磁悬浮支承的装置用永磁偏置外转子径向混合磁轴承的设计方法，其设计思想可作为各类永磁偏置外转子径向混合磁轴承的设计。The invention relates to a design method of a non-contact magnetic suspension bearing, in particular to a design method of a magnetic suspension flywheel, a magnetic suspension control moment gyroscope, and other devices that require magnetic suspension support. As a design for various types of permanent magnet bias outer rotor radial hybrid magnetic bearings.

背景技术 Background technique

磁悬浮轴承分纯电磁式和永磁偏置加电磁控制的混合式磁悬浮轴承，前者使用电流大、功耗大，永磁偏置加电磁控制的混合式磁悬浮轴承，永磁体产生的磁场承担主要的承载力，电磁磁场提供辅助的调节承载力，因而这种轴承可大大减小控制电流，降低损耗。常用的磁轴承控制方式采用的是传统的PID控制方式，实现该种方式的控制器参数由轴承刚度与阻尼来确定，经过大量实践证明，为使得磁轴承具有优良的特性，应使轴承刚度与其位移刚度在同一个数量级上。因此磁轴承的位移刚度对于磁轴承的控制而言至关重要。现有的磁轴承设计方法均利用永磁体最佳工作点进行设计，目的是使永磁体体积最小，但是通过这种方法计算得到的永磁体尺寸往往不太合理，而且加工困难，由于没有考虑位移刚度对控制系统的影响，因而现有设计方法存在准确度差且难于控制的缺陷。Magnetic suspension bearings are divided into pure electromagnetic bearings and hybrid magnetic suspension bearings with permanent magnetic bias and electromagnetic control. The former uses large current and consumes a lot of power, and the hybrid magnetic suspension bearings with permanent magnetic bias and electromagnetic control. The magnetic field generated by the permanent magnet bears the main load. Bearing capacity, the electromagnetic field provides auxiliary adjustment bearing capacity, so this kind of bearing can greatly reduce the control current and reduce the loss. The commonly used magnetic bearing control method adopts the traditional PID control method. The controller parameters to realize this method are determined by the bearing stiffness and damping. After a lot of practice, it has been proved that in order to make the magnetic bearing have excellent characteristics, the bearing stiffness should be matched with the Displacement stiffness is on the same order of magnitude. Therefore, the displacement stiffness of the magnetic bearing is very important for the control of the magnetic bearing. The existing magnetic bearing design methods all use the best working point of the permanent magnet to design, the purpose is to minimize the volume of the permanent magnet, but the size of the permanent magnet calculated by this method is often unreasonable, and it is difficult to process, because the displacement is not considered The influence of stiffness on the control system, so the existing design methods have the defects of poor accuracy and difficult control.

发明内容 Contents of the invention

本发明的技术解决问题是：克服现有技术的不足，提供一种永磁偏置外转子径向混合磁轴承的设计方法。The technical problem of the present invention is to overcome the deficiencies of the prior art and provide a design method for radial hybrid magnetic bearings with permanent magnetic bias outer rotors.

本发明的技术解决方案是：一种永磁偏置外转子径向混合磁轴承的设计方法，需要确定：永磁体内径D_pm2、永磁体外径D_pm1(即定子铁心内径D_s2)、永磁体轴向长度h_pm、定子齿内径D_st，定子铁心外径D_s1、定子铁心宽度b_s、定子铁心轴向长度L_sfe、转子铁心内径D_r2、转子铁心外径D_r1(即外导磁环内径D_dao2)、转子铁心轴向长度为L_rfe、外导磁环外径D_dao1、槽口宽度L_c以及线圈匝数N。The technical solution _of the present invention is: _a design method of a radial hybrid magnetic bearing with a permanent magnet bias outer rotor _. Magnet axial length h _pm , stator tooth inner diameter D _st , stator core outer diameter D _s1 , stator core width b _s , stator core axial length L _sfe , rotor core inner diameter D _r2 , rotor core outer diameter D _r1 (namely outer guide The inner diameter of the magnetic ring D _dao2 ), the axial length of the rotor core is L _rfe , the outer diameter of the outer magnetic ring D _dao1 , the slot width L _c and the number of coil turns N.

其特征在于：该方法基于磁轴承的位移刚度，其具体步骤如下：It is characterized in that: the method is based on the displacement stiffness of the magnetic bearing, and its specific steps are as follows:

(1)根据所需磁悬浮支承的装置的指标要求设定转子转速n和最大承载力F_max、根据功耗要求设定静态悬浮电流i，根据现有加工水平设定气隙长度δ以及叠片系数K_fe、根据现有磁轴承控制器的要求设定磁轴承的位移刚度K_x、根据磁场分析设定漏磁系数σ、根据所选铁心材料的磁化特性设定铁心的饱和磁密B_S；(1) Set the rotor speed n and the maximum bearing capacity F _max according to the index requirements of the required magnetic suspension support device, set the static levitation current i according to the power consumption requirements, and set the air gap length δ and laminations according to the existing processing level Coefficient K _fe , set the displacement stiffness K _x of the magnetic bearing according to the requirements of the existing magnetic bearing controller, set the magnetic leakage coefficient σ according to the magnetic field analysis, and set the saturation flux density B _S of the core according to the magnetization characteristics of the selected core material ;

(2)根据定子的强度及模态要求确定永磁体内径D_pm2；(2) Determine the inner diameter D _pm2 of the permanent magnet according to the strength and modal requirements of the stator;

(3)根据最大承载力F_max、饱和磁密B_s以及叠片系数K_fe确定定子铁心截面积A；(3) Determine the cross-sectional area A of the stator core according to the maximum bearing capacity F _max , the saturation magnetic density B _s and the lamination coefficient K _fe ;

(4)根据实际需求确定定子铁心宽度b_s与定子铁心轴向长度L_sfe的比例关系，进而确定定子铁心宽度b_s和定子铁心轴向长度L_sfe以及转子铁心轴向长度L_rfe；(4) Determine the proportional relationship between the width b _s of the stator core and the axial length L _sfe of the stator core according to actual needs, and then determine the width b _s of the stator core, the axial length L _sfe of the stator core, and the axial length L _{rfe of} the rotor core;

(5)由磁路分析，合理分配定、转子铁心各部分磁密，确定定子铁心轭部厚度h_sfe以及转子铁心轭部厚度h_rfe；(5) According to the analysis of the magnetic circuit, the magnetic density of each part of the stator and rotor cores is reasonably distributed, and the thickness of the yoke part of the stator core h _sfe and the thickness of the yoke part of the rotor core h _rfe are determined;

(6)根据气隙长度δ确定永磁体轴向长度h_pm和定子槽口宽度L_c；(6) Determine the axial length h _pm of the permanent magnet and the slot width L _c of the stator according to the air gap length δ;

(7) 根据位移刚度K_x计算永磁体外径D_pm1(即定子铁心内径D_s2)，再结合转子重力G计算电流刚度K_i，由静态悬浮电流i以及电流密度J确定线圈导线的直径d_c；(7) Calculate the outer diameter of the permanent magnet D _pm1 (that is, the inner diameter of the stator core D _s2 ) according to the displacement stiffness K _x , and then calculate the current stiffness K _i in combination with the rotor gravity G, and determine the diameter d of the coil wire by the static levitation current i and the current density J _c ;

(8)由定子铁心轭部厚度h_sfe确定定子齿内径D_st，根据槽满率确定定子铁心外径D_s1；(8) The stator tooth inner diameter D _st is determined by the stator core yoke thickness h _sfe , and the stator core outer diameter D _s1 is determined according to the slot fullness;

(9)由气隙长度δ确定出转子铁心内径D_r2，由转子铁心轭部厚度h_rfe确定转子铁心外径D_r1(即外导磁环内径D_dao2)，由磁路各部分磁密相等原则确定外导磁环外径D_dao1，由电流刚度K_i确定线圈匝数N。(9) The inner diameter D _r2 of the rotor core is determined by the air gap length δ, the outer diameter D _r1 of the rotor core is determined by the thickness h _rfe of the yoke of the rotor core (that is, the inner diameter D _dao2 of the outer magnetic ring), and the magnetic density of each part of the magnetic circuit is equal The outer diameter D _dao1 of the outer magnetic ring is determined in principle, and the number of coil turns N is determined by the current stiffness K _i .

所述的位移刚度取值范围由控制器决定，为-0.5N/um～-3N/um；所述的气隙长度δ为0.15～0.35mm；所述的漏磁系数σ为1.1～3；所述的叠片系数K_fe是通过实际定子或转子铁心重量与其理论计算值的比值得到，为0.75～0.95；所述的定子铁心宽度b_s与定子铁心轴向长度L_sfe的比例关系由实际要求确定，若磁轴承要求轴向长度短，则该比例值取为4～6，否则该比例值取为1～3；所述的槽满率一般取为40％～60％。The value range of the displacement stiffness is determined by the controller, which is -0.5N/um～-3N/um; the air gap length δ is 0.15～0.35mm; the magnetic leakage coefficient σ is 1.1～3; The lamination coefficient K _fe is obtained by the ratio of the actual stator or rotor core weight to its theoretically calculated value, and is 0.75 to 0.95; the proportional relationship between the stator core width b _s and the axial length L _sfe of the stator core is determined by the actual Requirements are determined. If the magnetic bearing requires a short axial length, the ratio is 4-6; otherwise, the ratio is 1-3; the slot fullness rate is generally 40%-60%.

本发明的原理是：本发明以径向混合磁轴承的位移刚度入手进行设计，根据要求设定各个参数，通过该种磁轴承的磁路分析与计算，即可得到磁轴承的其它结构尺寸。根据定子的强度及模态要求确定永磁体内径D_pm2，根据最大承载力F_max、饱和磁密B_s以及叠片系数K_fe由下式确定定子铁心截面积A。The principle of the present invention is: the present invention starts with the displacement stiffness of the radial hybrid magnetic bearing for design, sets various parameters according to requirements, and through the magnetic circuit analysis and calculation of this type of magnetic bearing, other structural dimensions of the magnetic bearing can be obtained. Determine the permanent magnet inner diameter D _pm2 according to the strength and modal requirements of the stator, and determine the cross-sectional area A of the stator core according to the following formula according to the maximum bearing capacity F _max , saturation flux density B _s and lamination coefficient K _fe .

$A A = = \frac{{F f}_{max max} \cdot &Center Dot; {μ μ}_{00}}{{B B}_{s the s}^{22} \cdot &Center Dot; {K K}_{fe fe}} - - - - - - ((11))$

式中μ₀＝4π×10^-7H/m，为空气的磁导率。In the formula, μ ₀ =4π×10 ^-7 H/m, which is the magnetic permeability of air.

设定子铁心宽度b_s与定子铁心轴向长度L_sfe的比值为C，则定子铁心宽度b_s和定子铁心轴向长度L_sfe为：Set the ratio of the width b _s of the stator core to the axial length L _{sfe of} the stator core as C, then the width b _{s of} the stator core and the axial length L _sfe of the stator core are:

${L L}_{sfe sfe} = = \sqrt{\frac{A A}{C C}} - - - - - - ((22))$

b_s＝C·L_sfe (3)b _s ＝C·L _sfe (3)

为了避免由于定、转子铁心轴线不对中引起的磁拉力，可取转子铁心轴向长度为：In order to avoid the magnetic pull caused by the misalignment of the stator and rotor core axes, the axial length of the rotor core can be taken as:

L_rfe＝1.2·L_sfe (4)L _rfe =1.2·L _sfe (4)

根据磁路分析，分配定、转子铁心各部分磁密，可得到定子铁心轭部厚度h_sfe以及转子铁心轭部厚度h_rfe为：According to the analysis of the magnetic circuit, the magnetic density of each part of the stator and rotor cores is distributed, and the thickness of the yoke part of the stator core h _sfe and the thickness of the yoke part of the rotor core h _rfe can be obtained as:

${h h}_{sfe sfe} = = \frac{A A}{22 \cdot &Center Dot; {L L}_{sfe sfe}} / / 33 - - - - - - ((55))$

式中系数3是考虑到定子铁心轭部主要通过电励磁磁通，不通过永磁磁通，在磁轴承承受最大承载力时，电励磁磁通一般为永磁磁通的1/3。The coefficient 3 in the formula is to consider that the yoke of the stator core mainly passes through the electric excitation flux and does not pass through the permanent magnet flux. When the magnetic bearing bears the maximum bearing capacity, the electric excitation flux is generally 1/3 of the permanent magnet flux.

${h h}_{rfe rfe} = = \frac{{h h}_{sfe sfe} \cdot &Center Dot; {L L}_{sfe sfe}}{{L L}_{rfe rfe}} - - - - - - ((66))$

根据设定的定转子之间的磁气隙长度δ，可以得到永磁体轴向长度h_pm以及槽口宽度L_c为：According to the set magnetic air gap length δ between the stator and rotor, the axial length h _pm of the permanent magnet and the slot width L _c can be obtained as:

h_pm＝K₁·δ (7)h _pm =K ₁ ·δ (7)

L_c＝K₂·h_pm(8)L _c =K ₂ ·h _pm (8)

式中K₁、K₂为常数，根据经验取值。In the formula, K ₁ and K ₂ are constants, whose values are taken according to experience.

根据位移刚度K_x可得到永磁体外径D_pm1(即定子铁心内径D_s2)为：According to the displacement stiffness K _x , the outer diameter D _pm1 of the permanent magnet (that is, the inner diameter D _s2 of the stator core) can be obtained as:

${D D.}_{pm pm 11} = = \sqrt{\frac{{44 h h}_{pm pm}}{{C C}_{11} \cdot &Center Dot; {μ μ}_{pm pm} \cdot &Center Dot; {μ μ}_{00} \cdot &Center Dot; π π} + + {D D.}_{}^{pm pm 22}} - - - - - - ((99))$

式中： $C_{1} = \frac{\sqrt{- \frac{F_{pm}^{2} \cdot μ_{0} \cdot A}{K_{x} \cdot σ^{2} \cdot δ} - δ}}{2 \cdot μ_{0} \cdot A} - - - (10)$ In the formula: $C_{1} = \frac{\sqrt{- \frac{f_{pm}^{} \cdot μ_{0} \cdot A}{K_{x} \cdot σ^{2} &Center Dot; δ} - δ}}{2 &Center Dot; μ_{0} &Center Dot; A} - - - (10)$

其中F_pm＝H_pm·h_pm为永磁体的磁动势，H_pm为永磁体的矫顽力，一般取为760kA/m～790kA/m；μ_pm为永磁体的相对磁导率，一般取为1.03～1.05。Where F _pm = H _pm h _pm is the magnetomotive force of the permanent magnet, H _pm is the coercive force of the permanent magnet, generally taken as 760kA/m～790kA/m; μ _pm is the relative permeability of the permanent magnet, generally Take it as 1.03-1.05.

结合转子重力G可得电流刚度K_i：Combined with the rotor gravity G, the current stiffness K _i can be obtained:

${K K}_{i i} = = \frac{G G / / 22 - - {K K}_{x x} \cdot &Center Dot; x x}{i i} - - - - - - ((1111))$

式中x为静态悬浮时转子中心距离磁中心的偏移量。In the formula, x is the offset between the rotor center and the magnetic center during static levitation.

由电流密度J以及静态悬浮电流i确定线圈导线的直径d_c为：The diameter d _c of the coil wire is determined by the current density J and the static levitation current i as:

${d d}_{c c} = = \sqrt{\frac{44 \cdot \cdot i i}{π π \cdot \cdot J J}} - - - - - - ((1212))$

然后根据国家标准取值。Then take the value according to the national standard.

由定子铁心轭部厚度h_sfe确定定子齿内径D_st为：The stator tooth inner diameter D _st is determined by the thickness of the yoke of the stator core h _sfe as:

D_st＝D_s2+2·h_sfe (13)D _st =D _s2 +2·h _sfe (13)

根据槽满率要求确定定子铁心外径D_s1，再由气隙长度可确定出转子铁心内径D_r2为：Determine the outer diameter D _s1 of the stator core according to the slot fullness requirement, and then determine the inner diameter D _r2 of the rotor core by the length of the air gap as:

D_r2＝D_s1+2·δ(14)D _r2 =D _s1 +2·δ(14)

由转子铁心轭部厚度h_rfe可得转子铁心外径D_r1(即外导磁环内径D_dao2)为：From the thickness h _rfe of the yoke of the rotor core, the outer diameter D _r1 of the rotor core (that is, the inner diameter D _dao2 of the outer magnetic ring) can be obtained as:

D_r1＝D_r2+2·h_rfe (15)D _r1 =D _r2 +2·h _rfe (15)

根据磁路各部分磁密基本相等原则可得外导磁环外径D_dao1为：According to the principle that the magnetic density of each part of the magnetic circuit is basically equal, the outer diameter D _dao1 of the outer magnetic ring can be obtained as:

${D D.}_{dao dao 11} = = \sqrt{\frac{44}{π π} \cdot \cdot A A + + {D D.}_{}^{dao dao 22}} - - - - - - ((1616))$

根据电流刚度K_i可以求得线圈匝数N为：According to the current stiffness K _i , the number of coil turns N can be obtained as:

$N N = = \frac{{K K}_{i i} \cdot \cdot σ σ \cdot &Center Dot; δ δ \cdot &Center Dot; ((22 \cdot &Center Dot; {R R}_{pm pm} \cdot &Center Dot; {μ μ}_{00} \cdot \cdot A A + + δ δ))}{22 \cdot \cdot {F f}_{pm pm} \cdot &Center Dot; {μ μ}_{00} \cdot \cdot A A} - - - - - - ((1717))$

式中：R_pm为永磁体磁阻， $R_{pm} = \frac{h_{pm}}{μ_{0} \cdot μ_{pm} \cdot \frac{π}{4} \cdot (D_{pm 1}^{2} - D_{pm 2}^{2})}$ In the formula: R _pm is the reluctance of the permanent magnet, $R_{pm} = \frac{h_{pm}}{μ_{0} &Center Dot; μ_{pm} &Center Dot; \frac{π}{4} \cdot ({D.}_{pm 1}^{2} - {D.}_{pm}^{2})}$

至此，整个磁轴承设计完毕。So far, the design of the entire magnetic bearing is completed.

本发明与现有技术相比的优点在于：本发明由于采用以径向混合磁轴承位移刚度为出发点的设计方法，与现有外转子径向混合磁轴承设计以永磁体最佳工作点为出发点的设计方法相比，更加利于控制，得到的参数更加合理。Compared with the prior art, the present invention has the advantages that: because the present invention adopts the design method based on the displacement stiffness of the radial hybrid magnetic bearing, it is different from the design of the existing outer rotor radial hybrid magnetic bearing based on the optimum working point of the permanent magnet. Compared with the design method, it is more conducive to control and the obtained parameters are more reasonable.

附图说明 Description of drawings

图1为本发明针对的永磁偏置外转子径向混合磁轴承的结构图；Fig. 1 is the structural diagram of the permanent magnet bias outer rotor radial hybrid magnetic bearing aimed at by the present invention;

图2为本发明的设计流程图；Fig. 2 is the design flowchart of the present invention;

具体实施方式 Detailed ways

如图1所示，本发明的设计对象为一种磁悬浮飞轮用永磁偏置外转子径向混合磁轴承，图中1为永磁体，2为内导磁环，3为线圈，4为定子铁心，5为定、转子间的磁气隙，6为转子铁心，7为外导磁环。根据现有磁轴承控制器的要求设定磁轴承的位移刚度K_x为-1N/um，根据定子强度及模态的要求给定的永磁体内径D_pm2为37mm，根据现有加工水平设定气隙长度δ取为0.2mm，叠片系数K_fe为0.85，根据该磁轴承的磁场分析设定漏磁系数σ为1.3，根据磁悬浮飞轮的指标要求设定最大承载力F_max为178N，根据磁悬浮飞轮的功耗要求设定静态悬浮电流i为0.2A，静态悬浮电流密度J为3A/mm²，该实施例中磁轴承的定、转子铁心选用铁镍系软磁合金0.1mm厚的1J50，根据1J50的磁化曲线设定饱和磁密B_s为1.2T，根据现有线圈的下线水平设定定子槽满率为40％。As shown in Figure 1, the design object of the present invention is a radial hybrid magnetic bearing with a permanent magnetic bias outer rotor for a magnetic levitation flywheel, in which 1 is a permanent magnet, 2 is an inner magnetic ring, 3 is a coil, and 4 is a stator Iron core, 5 is the magnetic air gap between the stator and the rotor, 6 is the rotor core, and 7 is the outer magnetic ring. According to the requirements of the existing magnetic bearing controller, the displacement stiffness K _x of the magnetic bearing is set to -1N/um, and the inner diameter of the permanent magnet D _pm2 given according to the requirements of the stator strength and modal is 37mm, which is set according to the existing processing level The air gap length δ is taken as 0.2mm, the lamination coefficient K _fe is 0.85, the magnetic leakage coefficient σ is set to 1.3 according to the magnetic field analysis of the magnetic bearing, and the maximum bearing capacity F _max is set to 178N according to the index requirements of the magnetic levitation flywheel. The power consumption requirement of the magnetic levitation flywheel is to set the static levitation current i as 0.2A, and the static levitation current density J as 3A/mm ² . According to the magnetization curve of 1J50, the saturation magnetic density B _s is set to be 1.2T, and the stator slot full rate is set to 40% according to the off-line level of the existing coil.

根据以上条件，由(1)式可以计算出定子铁心截面积A＝182.8mm²，设定子铁心宽度b_s与定子铁心轴向长度L_sfe的比值C＝8，则由式(2)和(3)可以得出定子铁心宽度b_s＝32mm，定子铁心轴向长度L_sfe＝4mm，为了避免由于定、转子铁心轴线不对中引起的磁拉力，由式(4)可得转子铁心轴向长度为L_rfe＝4.8mm，由式(5)可得定子铁心轭部厚度h_sfe＝7.6mm，由式(6)可得转子铁心轭部厚度h_rfe＝6.3mm，由式(7)和(8)令K₁＝16，K₂＝3，可以得到永磁体轴向长度h_pm＝3.2mm，槽口宽度L_c＝9.6mm，实际中可取L_c＝10mm，由式(9)和(10)可通过位移刚度计算得到永磁体外径D_pm1＝46mm，考虑到一般磁轴承静态悬浮后的转子偏移量x＝0.1mm，由(11)可得电流刚度K_i＝412.6N/A，由式(12)可得线圈导线的直径d_c＝0.291mm，取为0.29mm，由式(13)可得定子齿内径D_st＝61.2mm，根据设定的槽满率通过程序循环后可得定子铁心外径D_s1＝79.2mm，由式(14)可得转子铁心内径D_r2＝79.6mm，由式(15)可得转子铁心外径D_r1＝92.3mm，由式(16)可得外导磁环外径D_dao1＝93.6mm，考虑到现有加工水平以及外导磁环的强度，取D_dao1＝96mm。由式(17)可得线圈匝数N＝192.5匝，取为193匝。至此，该永磁偏置外转子径向混合磁轴承设计完毕。According to the above conditions, the cross-sectional area of the stator core A = 182.8mm ² can be calculated from the formula (1), and the ratio of the width b _s of the stator core to the axial length L _{sfe of} the stator core is set to C = 8, then the formula (2) and (3) It can be obtained that the width of the stator core b _s = 32mm, and the axial length of the stator core L _sfe = 4mm. In order to avoid the magnetic pull caused by the misalignment of the axes of the stator and rotor cores, the axial length of the rotor core can be obtained from formula (4): The length is L _rfe = 4.8mm, the thickness of the yoke of the stator core h _sfe = 7.6mm can be obtained from the formula (5), the thickness of the yoke of the rotor core h _rfe = 6.3mm can be obtained from the formula (6), and the thickness of the yoke of the rotor core can be obtained from the formula (7) and (8) Let K ₁ =16, K ₂ =3, the permanent magnet axial length h _pm =3.2mm, the notch width L _c =9.6mm can be obtained, in practice L _c =10mm is desirable, from formula (9) and (10) The outer diameter of the permanent magnet D _pm1 = 46mm can be obtained by calculating the displacement stiffness. Considering the rotor offset x = 0.1mm after the general magnetic bearing is statically suspended, the current stiffness K _i = 412.6N/ A. The diameter of the coil wire d _c = 0.291mm can be obtained from the formula (12), which is taken as 0.29mm. The stator tooth inner diameter D _st = 61.2mm can be obtained from the formula (13), and the program cycle is passed according to the set slot fullness rate After that, the outer diameter of the stator core D _s1 = 79.2mm can be obtained, the inner diameter of the rotor core D _r2 = 79.6mm can be obtained from the formula (14), the outer diameter of the rotor core D _r1 = 92.3mm can be obtained from the formula (15), and the outer diameter of the rotor core can be obtained from the formula (16 ) can obtain the outer diameter of the outer magnetic ring D _dao1 = 93.6mm, considering the existing processing level and the strength of the outer magnetic ring, take D _dao1 = 96mm. From formula (17), the number of coil turns N=192.5 turns can be obtained, which is taken as 193 turns. So far, the design of the permanent magnetic bias outer rotor radial hybrid magnetic bearing is completed.

本发明说明书中未作详细描述的内容属于本领域专业技术人员公知的现有技术。The contents not described in detail in the description of the present invention belong to the prior art known to those skilled in the art.

Claims

1. the design method of a permanent magnet bias outer rotor radial mixed magnetic bearing, it is characterized in that: this method is based on the displacement rigidity of magnetic bearing, and its concrete steps are as follows:

(1) the displacement rigidity K of setting magnetic bearing _x, gap length δ, leakage coefficient σ, lamination COEFFICIENT K _Fe, maximum load capacity F _Max, static suspension current i and saturation magnetic induction B unshakable in one's determination _s

(2) intensity and the mode according to stator requires to determine the permanent magnet inside diameter D _Pm2

(3) according to maximum load capacity F _Max, saturation magnetic induction B _sAnd lamination COEFFICIENT K _FeDetermine stator core sectional area A;

(4) determine stator core width b according to the actual requirements _sWith the stator core axial length L _SfeProportionate relationship, and then definite stator core width b _sWith the stator core axial length L _SfeAnd rotor core axial length L _Rfe

(5) by the magnetic circuit analysis, distribute stator and rotor each several part magnetic unshakable in one's determination close, determine stator core yoke portion thickness h _SfeAnd rotor core yoke portion thickness h _Rfe

(6) determine permanent magnet axial length h according to gap length δ _PmWith stator rabbet width L _c

(7) according to displacement rigidity K _xCalculate the permanent magnet outer diameter D _Pm1, calculate current stiffness K in conjunction with rotor gravity G again _i, determine the diameter d of winding wire by static suspension current i and current density, J _c

(8) by stator core yoke portion thickness h _SfeDetermine the stator tooth inside diameter D _St, determine frame diameter D according to copper factor _S1

(9) determine the rotor core inside diameter D by gap length δ _R2, by rotor core yoke portion thickness h _RfeDetermine the rotor core outer diameter D _R1, determine outer magnetic guiding loop outer diameter D by the close equal principle of magnetic circuit each several part magnetic _Dao1, by current stiffness K _iDetermine turn number N.

2. the design method of a kind of permanent magnet bias outer rotor radial mixed magnetic bearing according to claim 1 is characterized in that; Described displacement rigidity span determines by controller, for-0.5N/um～-3N/um.

3. the design method of a kind of permanent magnet bias outer rotor radial mixed magnetic bearing according to claim 1, it is characterized in that: described gap length δ is 0.15～0.35mm.

4. the design method of a kind of permanent magnet bias outer rotor radial mixed magnetic bearing according to claim 1, it is characterized in that: described leakage coefficient σ is 1.1～3.

5. the design method of a kind of permanent magnet bias outer rotor radial mixed magnetic bearing according to claim 1 is characterized in that: described lamination COEFFICIENT K _FeBeing that ratio by actual stator or rotor core weight and its calculated value obtains, is 0.75～0.95.

6. the design method of a kind of permanent magnet bias outer rotor radial mixed magnetic bearing according to claim 1 is characterized in that: described stator core width b _sWith the stator core axial length L _SfeProportionate relationship require to determine that by reality if magnetic bearing requires axial length short, then this ratio value is taken as 4～6, otherwise this ratio value is taken as 1～3.

7. the design method of a kind of permanent magnet bias outer rotor radial mixed magnetic bearing according to claim 1, it is characterized in that: described copper factor generally is taken as 40%～60%.