幻灯片 1

Size: px

Start display at page:

Download "幻灯片 1"

毽彭
5 years ago
Views:

1 考虑剩磁影响的作动器多物理域仿真和系统设计方法 Advancements in Actuator Simulation 李时伟 ANSYS 中国高级应用工程师

2 主要内容作动器设计流程介绍 - 作动器设计方法 - 磁扩散 - 耦合仿真衔铁偏心和侧向力基于矢量磁滞建模功能的剩磁力计算总结

3 作动器设计流程 Optimization 2D Magnetic FEA Co-simulation Equivalent circuits System Simulation 3D Magnetic FEA Co-simulation Thermal, CFD 完整的集成化的设计流程

4 涡流效应 : 磁扩散磁扩散电导率不为 0 的导磁性材料置于时变磁场时会产生涡流, 感应涡流延缓磁场建立, 造成磁场穿过材料厚度的时间扩散磁扩散时间在施加外部激励后, 材料内部每一点的磁通密度基波分量从 0 上升至其最终值的 63% 所需的时间磁流入线圈通入电流时的向内扩散磁流出线圈开路时的向外扩散

5 涡流效应 : 磁扩散介绍假定电导率 = 0 S/m 无磁扩散现象假定电导率 = 2E6 S/m 产生磁扩散 Steel Coil Coil Coil Flux Density, B (Tesla) vs Time Flux Density, B (Tesla) vs Time <- Coil Current -> <- Flux Density ->

6 涡流效应扩散对于静止的线性材料, 磁扩散时间推导为 slabs of width w: τ m = µσ (w/π) 2 and cylinders of radius r: τ m = µ σr 2 / (2.4048) 2 对于饱和的非线性 BH 材料, 磁扩散时间简化计算公式为 slabs of width w : τ m = σ w 2 B m / (8H o ) and cylinders: τ m = σr 2 B m / (4H o ). 对于形状复杂的结构和非线性 BH 曲线, 推荐采用有限元计算 Maxwell 在仿真的同时考虑了衔铁运动造成的涡流效应的影响 1 Magnetic Actuators and Sensors, 2 nd Edition, John Brauer, Wiley, IEEE Press

7 电流斩波控制下的磁密云图 Working Gap Coil Armature 磁通密度 vs 时间 Includes Magnetic Diffusion

8 基于有限元法的材料研究硬磁和软磁材料可用 BH 曲线定义材料特性对材料特性的参数化扫略可以快速评估其对力和电感等参数的影响 Closed Open

9 基于有限元法的线圈设计通常, 多匝绕组采用等效集总模型建模在有限元模型中, 线圈参数可直接基于变量和公式定义在参数化和优化设计时, 当绕组参数发生变化, 线圈参数会自动更新和计算 Parameter Design #1 Design #2 Coil Height (mm) Coil Radius (mm) AWG Turns Resistance (Ohms) Inductance (mh) Steady State Current (ma) Time Constant (L/R)

10 耦合仿真气动力耦合机械参数活塞上的磁力, 电磁场暂态仿真气动力, 流体仿真机械力采用集总参数建模弹簧质量阻尼仿真可以提供 : 精确的闭合时间控制动态范围摆动, 涡穴作用作为扰动 Per time step 2 Multi-Physics Simulation and Multi-Domain System Approach for Solenoid Design, 2013 ANSYS User Group Meeting, L. Voss, M. Rosu

案例 : 耦合仿真气动力耦合 S1 Maxwell Cosimulation SM_TRB1 S + smpl_lift CTRL=S1 R1 T1 T4 F E1 D1

V0=0m_per_sec S0=0.5mm M=1gram Ideal STOP LOWER_LIM=0.01mm UPPER_LIM=0.

00 Current Current Plunger Force Plunger Force 15.00 Position w.

11 案例 : 耦合仿真气动力耦合 S1 Maxwell Cosimulation SM_TRB1 S + smpl_lift CTRL=S1 R1 T1 T4 F E1 D1 F_mag F_Plunger F F_spring F F_TRB2 F cfd_force 0 Simplorer Schematic T3 T2 0 MASS_TRB1 V0=0m_per_sec S0=0.5mm M=1gram Ideal STOP LOWER_LIM=0.01mm UPPER_LIM=0.195mm F_TRB1 F 0 0 S + SPRING_TRB1 C=333 S_TRB1 VALUE=0.185mm 0 FLUENT Cosimulation Transient Switching with CFD Curve Info Y Axis 02_CoSim_MAgnetic_CFD Current Current Plunger Force Plunger Force Position w. CFD Y3 Position w/o CFD Y ANSOFT Position [um] Coil Current [A] Plunger Force [newton] Time [ms]

12 偏心造成的侧向力

13 偏心造成的侧向力衔铁偏离中心, 会导致侧向电磁力, 并造成轴承表面过度摩擦

14 模型介绍 Frame 骨架 Endstop 固定挡块 Coil Plunger 活塞 Flange 法兰

15 模型介绍 - 偏心整体偏移 X Offset 轴向倾斜

16 ANSYS 核心技术自动自适应网格剖分每个设计的模型均不同自动自适应网格可快速输出收敛结果分布式计算选项每个 CPU 求解一个设计, 在采用优化模块计算时, 以近乎线性的方式加快仿真速度 Measured

17 侧向电磁力计算了衔铁上偏心造成的侧向力力或转矩可显示成矢量力密度或幅值通过云图可以看出在任一给定位置电流下的力密度分布

003 inch Gap = 0.15 inch Armature Center X Offset = 0.

18 在不同偏移程度下的侧向力密度 Magnitude Armature Force Density Field Plot (N/m^2) vs X Offset Armature Left X Offset = inch Gap = 0.15 inch Armature Center X Offset = 0.0 inch Gap = 0.15 inch Armature Right X Offset = inch Gap = 0.15 inch

19 侧向力与偏移程度的关系曲线 Note: Nearly zero force at zero XOffset indicates the radial forces are balanced, as expected.

在不同衔铁间隙下的侧向力密度 Magnitude Armature Force Density Field Plot (N/m^2) vs Armature Gap Armature Left X Offset = +0.

20 在不同衔铁间隙下的侧向力密度 Magnitude Armature Force Density Field Plot (N/m^2) vs Armature Gap Armature Left X Offset = inch Gap = 0.10 inch Armature Left X Offset = inch Gap = 0.15 inch Armature Left X Offset = inch Gap = 0.20 inch

21 侧向力与偏移大小和衔铁间隙的关系曲线 Different axial Gap positions can yield different side load forces

22 扭矩与偏移大小的关系曲线 Note: Torque can be calculated on the armature using any desired co-ordinate system. This is calculated about the y-axis at an axial point mid-length along the armature

23 在不同衔铁倾斜角度下的侧向力密度 Magnitude Armature Force Density Field Plot (N/m^2) vs Armature Gap Armature Tilt Top Tilt Angle = -0.5 deg Armature No Tilt Tilt Angle = 0 deg Armature Tilt Bottom Tilt Angle = +0.5 deg

24 衔铁扭矩与衔铁倾斜角度的关系曲线

25 基于 Workbench 的电磁力映射流程 Forces in Maxwell Geometry Mapped Forces in Mechanical Deformation in Mechanical

26 作动器的温度场计算 Maxwell Losses Mapped Coil Losses Coil Temperature

27 剩磁

28 磁性材料的 BH 曲线 Hard Magnetic Material Permanent Magnet, large Hc Soft Magnetic Material Permeable Steel, small Hc M.A. Juds, Notes on Electromagnetics, Eaton Corporation

29 基于矢量磁滞建模功能的剩磁分析绝大多数电磁部件采用软磁材料作为导磁路径软磁材料 BH 回线较窄, 矫顽力较小在计算电磁性能时, 通常采用初始磁化曲线计算 BH 工作点但是在某些场合, 例如作动器设计, 当线圈断电后, 磁场不会降为 0, 出现剩磁现象 Several papers and patents etc. on the topic: Brake Failure from Residual magnetism in the Mars Exploration Rover Lander Petal Actuator, Louise Jandura, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA Proceedings of the 37 th Aerospace mechanisms Symposium, Johnson space Center, May 19-20, Patent 6,820,856: Manually-Opened and Latchable with Only Residual Magnetism, Two-Way Two-Position Fluid Control Valve Assembly and Methods of Operation

30 作动器统磁路模型 R = l / µ a R SYS = R f + R t + R sg1 +R sg2 + R a + R wg +R b P SYS = 1/ R SYS NI = φ * R SYS R a R sg2 NI R t R f P SYS = 1/ R SYS = µ a / l 系统磁导主要用气隙决定衔铁闭合时, 系统磁导仍主要由气隙决定在模型含有永磁体或剩磁现象时, 系统磁导在确定工作点时非常重要 R wg φ R R b sg1

31 负载线永磁体工作点 Small Air Gaps P SYS is large B is Large Large Air Gaps P SYS is Small B is Small

32 Maxwell 3D - Bessho Actuator Model Model is held in closed position, and current is ramped up, then down to zero. Point1 in Armature Vector Hysteresis Model shows that residual or remanent force remains due to remanent flux in the steel. Point objects can be used to evaluate B and H. Small 0.2mm shim is also installed in the airgap in an attempt to reduce the Remanent force. Coil

33 模型介绍和设置材料设置 : 初始磁化曲线, 另外铁耗计算 : 磁滞模型 Intrinsic Coercivity = A/m Remanence Br = 0.5 Tesla 激励设置 : Current source half sin wave of varying Peak currents

34 仿真 BH 工作点 vs 电流幅值 Evaluated at Point in Armature, shown in 1st and 2nd quadrant of the operating loop. Minor loops are represented and the impact of different peak currents are seen.

35 磁密 vs 垫块

36 剩磁力和磁通密度 vs 垫块 Comparison of flux density, B d operating point at zero current with and without Shim at different peak currents Comparison of remanent Armature force at zero current with and without Shim and different peak currents The Shim helps to reduce the remanent flux density operating point as well as the remanent force.

37 总结 ANSYS 先进的仿真技术可实现作动器的全面设计磁扩散现象在作动器设计中是一个重要的考虑因素耦合仿真技术可实现电磁和流体的耦合仿真 Maxwell 自动自适应网格剖分可便捷的实现偏心电磁力的准确计算基于矢量磁滞建模功能, 可准确计算剩磁和电磁力

Material

东磁 MnZn 铁氧体材料主要应用 Application Area Frequency Range Material Main Features μi Bs Bs 1 Pcv Pcv 1 Tc( ) 28