Jens Otto CADFEM GmbH

Transcription

1 Titelmasterformat Simulation of Electric durch Machines Klicken with bearbeiten ANSYS Jens Otto CADFEM GmbH 1

2 Why Simulation with ANSYS? Challenges for electric machines Electromagnetic Design: Rated power/ Power-Volume-Ratio Material consumption Losses/Efficiency Torque ripple Circuit interaction Structural Design: Housing integrity Active steel integrity Winding-end design Cooling Design Air/Fluid flow Coupled Analyses: Temperature prediction Vibroacoustics - 2 -

3 Simulation Driven Product Development Customer Workflow Marc Brück EM-motive a Bosch + Daimler Company 3

4 Virtual Prototype: Simulation is Everywhere! Electromagnetic is just one aspect of design EADT also part of Workbench environment Thermal Fluid-flow Structural Coupled Simulation 4

5 Electromagnetic FEM Solution in ANYS Maxwell Maxwell: Static Time-Dependent Time domain (Transient) Frequency domain (Harmonic) Motion (Linear, Rotational) Source: CADFEM Advanced physics capability 2D; 2.5D; 3D Materials Circuit coupling - 5 -

6 Maxwell s Approach: Finite Element Method Translate differential equation to algebraic equations Split one big task into a finite number of simple subtasks Discretize space by tetrahedrons/triangles Solution only at element s nodes Quantities are interpolated between nodes Solution computed on nodes Source:CADFEM - 6 -

7 Automatic Adaptive Meshing Generate efficient mesh without expert mesh know-how Start Generate Initial Mesh Find a compromise accuracy vs simulation time Solve fields using the Finite Element Method User defined convergence criteria Global energy error (default) Torque Force Inductance Adaptive meshing available for all non-transient solvers Calculate local Solution error End criteria reached? yes no Refine Mesh Calculate Outputs (Force, Inductance, etc.) - 7 -

8 Automatic Adaptive Meshing Example Source ANSYS Inc

9 Mesh Operations Can be combined with adaptive approach Fewer iterations Faster solution times Mesh refinement for transient simulations Manual mesh refinement Import mesh from static/harmonic Source CADFEM - 9 -

10 True Motion in Electromagnetic Simulation User friendly configuration Velocity dependent effects Eddy currents (effect on field) PMs Squirrel cage Conducting slot wedges/ mechanical parts External particles 10

11 3D Vector Hysteresis Modeling Lamination support Optimization to minimize total error of major & minor loop Non-zero initial condition support footer 11

12 Material properties Nonlinear and/or anisotropic permeability Anisotropic conductivity Core loss model Steinmetz approach electrical steel power ferrite Solid or lamination model Scaling of B-H curve Temperature dependent

13 User Friendly Extraction of Steinmetz Coefficients Select Electrical Steel or Power Ferrite Select extraction method Core loss versus frequency Core loss at one frequency Iron s conductivity needed Lamination thickness needed Input datasheet data from supplier Manual csv, txt import Sheet scan Automatic calculation of coefficients Automatic update in material properties

14 Simulation Dimensionality 2D Simulation Planar B-field General machine sizing 2.5D for skewing approximation Stepwise approximation 3D Full flexibility Detailed eddy current paths End effects (Stray fields) Non planar flux 14

15 Since R17: Time Decomposition Method HPC-Method for transient magnetic designs T1 Tk Simultaneous calculation of k time steps N-Tasks containing k-time steps each N-Tasks can be distibuted in DMP mode Matrix Size X k T1 T2 k Time Steps n Parallel Distribued Tasks T3 T(k-2) T(k-1) T(k) Source: ANSYS Inc.

16 Periodic TDM enhancement R18 Periodic TDM is only solved for 1 period Torque Currents

17 Periodic TDM enhancement R18: Example Synchronous generator 350,000 elements, 2nd order elements Eddy current in bars 20ms 3 Simulation cases: 8 cores HPC (no-tdm) over 10 electrical periods 112 cores HPC (TDM general transient) over 10 electrical periods 112 cores HPC (TDM periodic) solving just 1 electrical period # of cores HPC Method Used Simulation time Speed up 8 No-TDM 151h45min General Transient TDM Periodic TDM 22h53min 6.6 7h33 20

18 Coupled Circuit-Motor Analysis in ANSYS Maxwell Maxwell includes circuit editor Sources Passive elements (R-L-C) Diodes Switches Couple EM-field to Circuit Dedicated elements Winding Source CADFEM

19 System Analysis of Electric Machines Why SIMPLORER? Detailed switch models (Semiconductor) Control Loops Terminal coupling to other domains System simulation using ANSYS Simplorer Embedded motor model PE-Circuit Control Co-simulation with Simulink and Maxwell Other Domains Mechanical Thermal Source CADFEM

20 Simplorer: Electric Powertrain System with Thermal Simulation Heat-Sink + Fan Model Extraction from CFD Power Transistor Electrothermal Characterisation Motor Magnetic FEM Co-simulation

21 Virtual Prototype: Simulation is Everywhere! Electromagnetic is just one aspect of design Mechanical Thermal / Stress EADT also part of Workbench environment Thermal Fluid-flow Structural Coupled Simulation CFD Fluid Flow / Thermal 21

22 Stress & Fatigue Life Centrifugal and magnetic forces Nonlinear contact between magnet and steel Definition of rotor shape according to Deformation Stresses Fatigue life

23 Thermal Efficient Fluid Models Components often cooled by fluid flow Oil flow channels Fluid flow by detailed CFD requires computing power ANSYS heat pipe model with semianalytical approach Objective: Reduce simulation time maintaining global result accuracy Restriction: Exact knowledge of fluid flow not of interest Axial T- gradient Axial air flow Source: CADFEM GmbH

24 Application Case: Thermal Integrity Simulation Losses from EM-Simulation used as realistic loads Thermal analysis in Mechanical Thermal analysis in Fluent Automatic Mesh interpolation 2D-3D interpolation capability Energy preserving 25

25 Dynamic Temperature Dependent Coupled Demagnetization Maxwell Transient 3A current pulse First thermal iteration on original curve 1st thermal iteration 2nd thermal iteration Second iteration on lower level 26

26 Coupling: Magnetostriction Analyses Applications: Vibration and noise analysis Transformers Electrical machines Actuators Control devices Sensors and transducers Smart materials Magnetic characteristic changes under mechanical stress Electro-magnetic Solution Magnetic Force + Magnetostriction Force Inverse Magnetostriction Magnetostriction Displacement Vector + Strain & Stress Tensor Mechanical Structure Solution Physical dimension changes due to magnetic field

27 Example: Magnetostriction Analyses effecting forces of machines Force Calculation on a Tooth Tip Suitable for NVH simulation Strain = f(h) EM Force EM Force + Magnetostriction

28 Application Case: Vibroacoustic Calculation 29

29 Parametric Simulation What is the benefit of a single simulation? Material ± 5-10% Boundary Conditions ± 1-20% Variation gives most understanding Geometric shape Material Current Windings Circuits Controller Geometry ± % Manufacturing ± 5-30% Loads, Signals ± % Result ±??% DoE, Optimization, Robust Design 30

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31 Thank you! Questions? (please use the chat) footer 32

32 Germany CADFEM GmbH HQ Grafing Marktplatz Grafing b. München T +49 (0) info@cadfem.de Office Berlin Breite Straße 2a Berlin T +49 (0) Office Chemnitz Cervantesstraße Chemnitz T +49 (0) Office Dortmund Hafenpromenade Dortmund T +49 (0) Office Frankfurt Im Kohlruß Liederbach am Taunus T +49 (0) Office Hanover Pelikanstraße Hannover T +49 (0) Office Stuttgart Leinfelder Straße Leinfelden-Echterdingen T +49 (0) Österreich Austria CADFEM (Austria) GmbH HQ Vienna Wagenseilgasse Wien T +43 (0) info@cadfem.at Office Innsbruck Grabenweg 68 (SOHO 2.0) 6020 Innsbruck T +43 (0) Schweiz Switzerland CADFEM (Suisse) AG HQ Aadorf (Zurich) Wittenwilerstrasse Aadorf T +41 (0) info@cadfem.ch Office Lausanne Avenue de la Poste Renens T +41 (0)