© 2009 ANSYS, Inc. All rights reserved.
1
ANSYS, Inc. Proprietary
Coupled Electromagnetic
and Thermal Solution for
Electric Machine Design
Xiao HU
Zed (Zhangjun) TANG
ANSYS, INC.
© 2009 ANSYS, Inc. All rights reserved.
2
ANSYS, Inc. Proprietary
Introduction
• Electric machine design is a multi-physics problem
– Electromagnetic
– Fluid and thermal
– Mechanical (Stress, Vibration)
– Power electronics/control
• Electromagnetic, thermal and mechanical designs are
interrelated
– Losses from electromagnetic design affect temperature
– Temperature rise will change material properties
– Thermal induced mechanical stress
• A design environment that accommodates all physics
and their interaction is highly desired
– ANSYS Workbench environment
© 2009 ANSYS, Inc. All rights reserved.
3
ANSYS, Inc. Proprietary
Simulation Driven Product Development
- Electric Machine Design Methodology
Much better solution with
ANSYS CFD/Mechanical
© 2009 ANSYS, Inc. All rights reserved.
4
ANSYS, Inc. Proprietary
Maxwell2D for Electromagnetic
• Majority of Electromagnetic Designs are Done
in 2D for Electric Machine
– >80%
– Faster
– Enough accuracy
• Maxwell2D Transient Solver
– Transient excitation
– Transient motion
– Motion induced transient effects
• Coupling between Maxwell3D and ANSYS is
possible and follows the same design flow
© 2009 ANSYS, Inc. All rights reserved.
5
ANSYS, Inc. Proprietary
Design Flow
Geometry
Losses
Centroids
Mapped Losses
Temperature
Workbench DM
Maxwell UDP
Maxwell
Workbench Mesher
ANSYS Mechanical (automated)
ANSYS CFD (Scripted)
© 2009 ANSYS, Inc. All rights reserved.
6
ANSYS, Inc. Proprietary
Accurate Loss Coupling
• Most Losses are Distributed
– Eddy loss (PMs)
– Core loss (Stator & Rotor)
• Time Averaged Spatial Losses
– Time constants are very different for electrical
and thermal
© 2009 ANSYS, Inc. All rights reserved.
7
ANSYS, Inc. Proprietary
Export Thermal Data to
ANSYS Mechanical
© 2009 ANSYS, Inc. All rights reserved.
8
ANSYS, Inc. Proprietary
Import Maxwell Loads to
ANSYS Mechanical
© 2