Titelmasterformat durch Klicken bearbeiten Vibration and Acoustics for Electric Drive Development Presenter: Jens Otto, CADFEM GmbH Developer: Dr. Jürgen Wibbeler, Dr. Martin Hanke, CADFEM GmbH 4th CADFEM ANSYS Simulation Conference Ireland & UK 12th and 13th October, Engineers Ireland, Dublin 1
1. Business of CADFEM GmbH 2. Electrical Drives as Noise Sources 3. Concept of FEM-based Noise Computation 4. Computation of Magnetic Excitation Loads 5. Structural Dynamics and Noise using Electric Drive Acoustics inside ANSYS 6. Summary and Additional Topics Numerical Prediction of Motor Noise in a Continuous Speed Range 2
1. Business of CADFEM GmbH CADFEM in Germany, Austria, Switzerland: Founded in 1985 2,300 customers 11 locations 220 employees ( 130 of them technical experts) Dortmund Hannover Frankfurt Darmstadt Berlin Chemnitz Stuttgart Lausanne Aadorf Zürich Grafing Otterfing Innsbruck Wien Numerical Prediction of Motor Noise in a Continuous Speed Range 3
1. Business of CADFEM GmbH CADFEM Simulation is more than Software: ANSYS Elite Channel Partner PRODUCTS Software und IT Solutions SERVICES Advice, Support, Engineering KNOW-HOW Transfer of Knowledge Numerical Prediction of Motor Noise in a Continuous Speed Range 4
1. Business of CADFEM GmbH CADFEM ANSYS Extensions: Numerical Prediction of Motor Noise in a Continuous Speed Range 6
1. Business of CADFEM GmbH 2. Electrical Drives as Noise Sources 3. Concept of FEM-based Noise Computation 4. Computation of Magnetic Excitation Loads 5. Structural Dynamics and Noise using Electric Drive Acoustics inside ANSYS 6. Summary and Additional Topics Numerical Prediction of Motor Noise in a Continuous Speed Range 7
2. Electrical Drives as Noise Sources Wikipedia E-mobility Railway traction Wikipedia Marine Propulsion Energy Sector Industrial Drives Home Appliances Universal Motors, Schottel Numerical Prediction of Motor Noise in a Continuous Speed Range 8
2. Electrical Drives as Noise Sources Origin of Noise by Electrical Drives: Magnetic Circuit Fluidics Drive Side Reluctance, Geometry Cooling Gearbox etc. Magnetic Saturation Electric Drive Acoustics inside ANSYS Current Waveform, Inverters Gap forces Courtesy of Elektromotorenwerk Grünhain GmbH Numerical Prediction of Motor Noise in a Continuous Speed Range 9
1. Business of CADFEM GmbH 2. Electrical Drives as Noise Sources 3. Concept of FEM-based Noise Computation 4. Computation of Magnetic Excitation Loads 5. Structural Dynamics and Noise using Electric Drive Acoustics inside ANSYS 6. Summary and Additional Topics Numerical Prediction of Motor Noise in a Continuous Speed Range 10
3. Concept of FEM-based Noise Computation Positioning Noise Analysis (NVH) in a Motor Design Process: Motor-CAD Efficient Motor Design Toolkit Maxwell 2D/3D Advanced Magnetics Modeling Mechanical, CFD NVH, Cooling System Validation Control Logic, Software Lab Lab Thermal Emag Design Analysis Operation Numerical Prediction of Motor Noise in a Continuous Speed Range 11
3. Concept of FEM-based Noise Computation Analysis Workflow: External computation of excitation loads Electromagnetic Analysis DFT Excitation Loads Harmonic Vibration Analysis Oscillation, ERP, Waterfall Plot Numerical Prediction of Motor Noise in a Continuous Speed Range 12
3. Concept of FEM-based Noise Computation Waterfall Diagram by Measurement: Equipment: Accelerometers Microphones Spectrum analyser Anechoic room Easy to record at controlled run-up of a motor Example traction drive (www.vem-group.com) Numerical Prediction of Motor Noise in a Continuous Speed Range 13
3. Concept of FEM-based Noise Computation Computational Effort for a Waterfall Diagram Produced by Simulation: Example: 40 rotational speed points 30 spectral lines One simulation point per rotational speed and spectral index! = 1200 simulation points! FEM-methods with minimized computational effort required for electromagnetics structural dynamics Numerical Prediction of Motor Noise in a Continuous Speed Range 14
3. Concept of FEM-based Noise Computation Equivalent Radiated Power (ERP): Obtained from structural velocity at the vibrating surface (surface normal component v n ) P ERP 1 c vˆ 2 2 n da Natural deviation from true radiation by σ 1: P acoustic = σ P ERP Advantage of ERP vs. air-born acoustics: No meshing of fluid space computationally less expensive Returns a fast figure of produced noise Indicates critical operating points efficient comparison of designs Numerical Prediction of Motor Noise in a Continuous Speed Range 15
3. Concept of FEM-based Noise Computation Utilization of Results: Identify critical OPs ERP [db] Get vibration shapes for critical OPs only Analyse true radiation by acoustic field simulation n f (optional; by dedicated tools for air-borne acoustics) Numerical Prediction of Motor Noise in a Continuous Speed Range 16
1. Business of CADFEM GmbH 2. Electrical Drives as Noise Sources 3. Concept of FEM-based Noise Computation 4. Computation of Magnetic Excitation Loads 5. Structural Dynamics and Noise using Electric Drive Acoustics inside ANSYS 6. Summary and Additional Topics Numerical Prediction of Motor Noise in a Continuous Speed Range 17
4. Computation of Magnetic Excitation Loads Excitation Loads at Stator (Time Domain): Maxwell 2D or 3D Load centroid M z F rad F tan Goal: Forces/moments acting at stator teeth (2D: F rad, F tan, M z ; 3D: + F z, M rad, M tan ) Load as function of time: To be condensed to load centroids Numerical Prediction of Motor Noise in a Continuous Speed Range 18
4. Computation of Magnetic Excitation Loads Reducing Electromagnetic Simulation Runs: Loads vary continuously in characteristic sections of the operating range. A few OPs are sufficient to capture load variation. Reduce EM-Simulations to selected OPs Interpolate loads at intermediate OPs later at structural simulation. Internally done by E.D.A. inside ANSYS Applicable to synchronous motors and synchronous pulsed inverters (required f i ~ n) Interpolation of excitation loads n 3 n 2 n 1 OP = operating point Numerical Prediction of Motor Noise in a Continuous Speed Range 19
4. Computation of Magnetic Excitation Loads Data Transfer to Structural Dynamics by Files: Export load sets for centroids of faces or face segments into csv-file: (e.g. for 2D load sets: Time, F rad1, F tan1, M z1, F rad2, F tan2, M z2, ) Numerical Prediction of Motor Noise in a Continuous Speed Range 20
1. Business of CADFEM GmbH 2. Electrical Drives as Noise Sources 3. Concept of FEM-based Noise Computation 4. Computation of Magnetic Excitation Loads 5. Structural Dynamics and Noise using Electric Drive Acoustics inside ANSYS 6. Summary and Additional Topics Numerical Prediction of Motor Noise in a Continuous Speed Range 21
5. Structural Dynamics and Noise Using Electric Drive Acoustics inside ANSYS Workbench Project: Harmonic Analysis Based on Mode Superposition (MSUP) Eigenmodes and Eigenfrequencies as intermediate result ANSYS Project Structure: Mode 1 Mode 3 Mode 6 610 Hz 1456 Hz 2654 Hz Modal Analysis Harmon. Analysis Faster than full harmonic analysis Excitations as input to harmonic analysis Excitations Numerical Prediction of Motor Noise in a Continuous Speed Range 22
5. Structural Dynamics and Noise Using Electric Drive Acoustics inside ANSYS Speed-up at ERP-computation Based on MSUP Harmonic Analysis: Full Harmonic Analysis MSUP Harmonic Analysis Method used by E.D.A. inside ANSYS Complex modal displacements ("modal coordinates") ERP Vibration of structural nodes Expansion Pass Vibration of structural nodes Time and memory saving! ERP Computationally expensive! ERP P ERP 1 c vˆ 2 2 n da Numerical Prediction of Motor Noise in a Continuous Speed Range 23
5. Structural Dynamics and Noise Using Electric Drive Acoustics inside ANSYS Electric Drive Acoustics inside ANSYS: ACT-based Extension for ANSYS Mechanical Appears as a toolbar in the GUI Numerical Prediction of Motor Noise in a Continuous Speed Range 24
5. Structural Dynamics and Noise Using Electric Drive Acoustics inside ANSYS Support of Load Import and Application: Text based import interface, flexible formats DFT at import Graphical check Load application always at Remote Points (= load centroides) Load file table Remote Points attached to faces Excitation loads Import preview Numerical Prediction of Motor Noise in a Continuous Speed Range 25
5. Structural Dynamics and Noise Using Electric Drive Acoustics inside ANSYS Treatment of Non-skewed and Skewed Motors: Non-skewed Skewed Single point per stator tooth Axial discretization of loads Numerical Prediction of Motor Noise in a Continuous Speed Range 26
5. Structural Dynamics and Noise Using Electric Drive Acoustics inside ANSYS Support of Solution and ERP-postprocessing: Definition of sweep parameters ERP-waterfall diagram across speed range ERP-spectrum at selected speed point Extraction of vibration shape at selected OP Numerical Prediction of Motor Noise in a Continuous Speed Range 27
1. Business of CADFEM GmbH 2. Electrical Drives as Noise Sources 3. Concept of FEM-based Noise Computation 4. Computation of Magnetic Excitation Loads 5. Structural Dynamics and Noise using Electric Drive Acoustics inside ANSYS 6. Summary and Additional Topics Numerical Prediction of Motor Noise in a Continuous Speed Range 28
6. Summary and Additional Topics Summary: ANSYS-based tool for efficient assessment of noise induced by magnetics ERP Waterfall diagram Continuous workflow with easy-to-use functions First release in July 2017 www.cadfem.de Numerical Prediction of Motor Noise in a Continuous Speed Range 29
6. Summary and Additional Topics Selection of Additional Topics: Lamination and coil modeling Induction motors, Inverters 1 0.1 0.01 0.001 0 4 8 12 16 20 24 28 32 36 40 44 48 Circular force pattern analysis r0 r8 r0 r4 r8 r12 Connection to parametrics and optimization Numerical Prediction of Motor Noise in a Continuous Speed Range 30
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