Post on 02-Aug-2018
Scott StantonScott StantonTechnical DirectorTechnical Director
Advanced Technology InitiativesAdvanced Technology Initiatives
Scott StantonScott StantonTechnical DirectorTechnical Director
Advanced Technology InitiativesAdvanced Technology Initiatives
Integrated Simulation Integrated Simulation Environment for Electric Environment for Electric Machine Design Machine Design
Integrated Simulation Integrated Simulation Environment for Electric Environment for Electric Machine Design Machine Design
© 2010 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary© 2010 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary
ANSYS Inc.ANSYS Inc.ANSYS Inc.ANSYS Inc.
Design Automation Example:
RMxprt - Maxwell
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UDP: User Defined Primitives
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Thevenin equivalent
(impedance matrix,
source voltages)
2D/3D FEA
External Circuit Coupling:
Maxwell - Simplorer
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Lumped field
parameters
(inductances, induced
Internal voltages)System
Simulator
System/Circuit - FEA Coupling:
Simplorer - Maxwell
Differentiating FeatureExample: Axial-Disk PM Motor Control
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Current Control Loop
Position Control Loop
External Circuit Coupling
Axial Motor – Speed & Torque Profile
3ph Line Current Profile
Flux Linkage ProfileDifferentiating Feature
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Magnetic Flux Density
Axial Motor – Speed & Torque Profile
• Nonlinear lamination is extensively used in low
frequency electromagnetic devices for significant
reduction of eddy current loss.
Nonlinear Lamination and
Nonlinear Anisotropy
Differentiating Feature
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• Nonlinear anisotropy is widely used in magnetic
recording, power transformers and large size electrical
machines. Oriented electrical steels have high induction
but with much lower core loss in the rolling direction.
Nonlinear Lamination and
Nonlinear Anisotropy
Example: Reluctance Motor ApplicationDifferentiating Feature
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
Y
X
The rotor local coordinate system is attached to the
moving rotor
Rotor lamination is defined along r direction in the local
cylindrical coordinate system
PM Characteristic to 2nd & 3rd
Quadrant
• Expand the existing
algorithm to the 3rd
quadrant for demag
computation
Differentiating FeatureB
H
Load line without other
sources
Load line with other
sources
Initial Br
Br after
demag
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
• Base on the actual
user-input B-H
curve in the 3rd
quadrant
H
0
Demagnetization point
Hc after
demagnetization
Generator Fault Example
• 550 W PM generator
• 4 Pole
• 3 Phase, 50HZ AC
• Ceramic 8D PM
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• Ceramic 8D PM
• Rated Speed,
Open-Circuit to
Short-Circuit Fault
Magnet
• 2nd quadrant demagnetization (demag)
• Spatially dependent demag due to fault
Initial Radial Magnetization
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Initial Radial Magnetization
80.00Ansoft LLC Maxwell3DDesign23D_EMF_save_demag ANSOFT
Curve Info
InducedVoltage(PhaseA)Setup1 : Transient
InducedVoltage(PhaseB)Setup1 : Transient
80.00Ansoft LLC Maxwell3DDesign23D_EMF_save_demag ANSOFT
Curve Info
InducedVoltage(PhaseA)Setup1 : Transient
InducedVoltage(PhaseB)Setup1 : Transient
Short-Circuit Analysis
• Short circuit at 15.2ms: Phase A peak
0.35
0.40Ansoft LLC Maxwell3DDesign2BH_Data_Points_Initial_Demag ANSOFT
0.35
0.40Ansoft LLC Maxwell3DDesign2BH_Data_Points_Initial_Demag ANSOFT
Material BH Curve
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0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00Time [ms]
-80.00
-25.00
30.00
Volts [V]
Setup1 : Transient
InducedVoltage(PhaseC)Setup1 : Transient
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00Time [ms]
-80.00
-25.00
30.00
Volts [V]
Setup1 : Transient
InducedVoltage(PhaseC)Setup1 : Transient
Bus short for all phases
-3.00E+005 -2.00E+005 -1.00E+005 0.00E+000H [A/m]
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
B [T]
-3.00E+005 -2.00E+005 -1.00E+005 0.00E+000H [A/m]
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
B [T]
Material BH Curve
Operating Points
Short-Circuit Analysis
• Subsequent use of the magnet results in
reduced performance
80.00Ansoft LLC Maxwell3DDesign33D_EMF_demaged ANSOFT
Curve Info
InducedVoltage(PhaseA)
80.00Ansoft LLC Maxwell3DDesign33D_EMF_demaged ANSOFT
Curve Info
InducedVoltage(PhaseA)
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00Time [ms]
-80.00
-25.00
30.00
Volts [V]
InducedVoltage(PhaseA)Setup1 : Transient
InducedVoltage(PhaseB)Setup1 : Transient
InducedVoltage(PhaseC)Setup1 : Transient
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00Time [ms]
-80.00
-25.00
30.00
Volts [V]
InducedVoltage(PhaseA)Setup1 : Transient
InducedVoltage(PhaseB)Setup1 : Transient
InducedVoltage(PhaseC)Setup1 : Transient
Addt’l short for all phasesWeak Back EMF
-3.00E+005 -2.00E+005 -1.00E+005 0.00E+000H [A/m]
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
B [T]
Ansoft LLC Maxwell3DDesign3BH_Data_Points_Demag ANSOFT
-3.00E+005 -2.00E+005 -1.00E+005 0.00E+000H [A/m]
0.00
0.05
0.10
0.15
0.20
0.25
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0.35
0.40
B [T]
Ansoft LLC Maxwell3DDesign3BH_Data_Points_Demag ANSOFT
Operating Points
Short-Circuit Analysis
• Leading edge is weakened significantly
30.00
80.00
Volts [V]
Ansoft LLC Maxwell3DDesign23D_EMF_save_demag ANSOFT
30.00
80.00
Volts [V]
Ansoft LLC Maxwell3DDesign23D_EMF_save_demag ANSOFT
Original
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0.00 5.00 10.00 15.00Time [ms]
-80.00
-25.00
30.00
80.00
Volts [V]
Ansoft LLC Maxwell3DDesign33D_EMF_demaged ANSOFT
0.00 5.00 10.00 15.00Time [ms]
-80.00
-25.00
30.00
80.00
Volts [V]
Ansoft LLC Maxwell3DDesign33D_EMF_demaged ANSOFT
0.00 5.00 10.00 15.00Time [ms]
-80.00
-25.00
0.00 5.00 10.00 15.00Time [ms]
-80.00
-25.00
Fault
• Mesh a higher percentage
• Higher mesh quality
• Effective on imported geometries
• Matching boundary more robust
• Fewer total elements
• Smoother and more uniform element transition
Robust Mesher
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• Smoother and more uniform element transition
• Automatically healing and repair
High Quality Mesh
Using Minimal Settings
Special Attention given
to Air Gap Region
Induced Eddy Currents in
Magnets
Symmetry
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0 .0 0 2 .0 0 4 .0 0 6 .0 0 8 .0 0 1 0 .0 0 1 2 .0 0T i m e ( m s ) [ s ]
0 .1 0
0 .2 0
0 .3 0
0 .4 0
0 .5 0
0 .6 0
0 .7 0
0 .8 0
0 .9 0
1 .0 0
No
rma
lize
d P
ow
er
Loss [W
]
A n s o ft C o rp o ra t i o n N o S p l i t _ S MN o r m a l i z e d P o w e r L o s s C u r v e In f o
N o r m a liz e d P o w e r L o s s
Im p o r t e d
N o r m a liz e d P o w e r L o s s
End of Rotor
Symmetry
Boundary
PM Loss Reduction
Add cuts:
− Reduce Eddy Currents
− Reduce Loss
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
Up to 32 Magnet Segments
Power Loss in Magnet vs. Number
of Segments
0.70
0.80
0.90
1.00
Normalized Loss with Carrier Harmonics
∑ ∫
=
n mag
dvJ
Lossσ
2
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0.00
0.10
0.20
0.30
0.40
0.50
0.60
1 2 4 8 16 32
PMSM – Core Loss Calculation
echFe PPPP ++=
Core Loss is Expressed as the Sum of:
Hysteresis Ph
Classical Eddy Current Pc
Excess Loss Pe
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
∑∑= =
++−=m
i
n
j
mijiemijicmijihvijech
i
BfkBfkBfkpkkkerror1 1
25.15.1222 )]([),,(
Minimizing the Error:
m: number of loss curves
ni: number of points of the i-th loss curve
Pvij = f(fi , Bmij): two dimensional lookup table for multi-frequency loss curves
5.122 )()( memcmhFe BfkBfkBfkP ++=echFe PPPP ++=
Integrated EM Field and Core
Loss Analysis
Core Loss Effects on Input Power and Force/Torque
d
x
yz
Bz
Je
Eddy current produced by B
d
x
y
z
Bx
Eddy current produced B
Je
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
Eddy current produced by Bn Eddy current produced Bt
Reference: D. Lin, P. Zhou and Q. M. Chen, “The Effects of Steel Lamination Core Losses on Transient Magnetic Fields Using T-Ω Method”,
IEEE VPPC, September 3-5, 2008, Harbin, China
Core Loss
2.50
3.00
3.50
4.00
Ansoft Corporation Test_tranXY Plot 1Curve Info avg
Sinusoidal Excitation, 60Hz Curve 2.2892
4.00
5.00
6.00
Ansoft Corporation Test_tranXY Plot 1Curve Info avg
Sinusoidal Excitation, 60Hz Curve 2.2892
Sine plus 1kHz triangular wave, 60Hz Curve 3.3764
5.00
6.00
7.00
Ansoft Corporation Test_tranXY Plot 1Curve Info avg
Sinusoidal Excitation, 60Hz Curve 2.2892
Sine plus 1kHz triangular wave, 60Hz Curve 3.3764
Sine plus 1kHz triangular wave, multiple CL Curves 3.8978
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00Time [ms]
0.00
0.50
1.00
1.50
2.00
Co
reL
oss [kW
]
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1.00
2.00
3.00
Co
reL
oss [kW
]
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0.00
1.00
2.00
3.00
4.00
Co
reL
oss [kW
]
Core Loss Effect on Torque
5.60
5.70
5.80M
ovin
g1
.To
rqu
e [kN
ew
ton
Me
ter]
Ansoft Corporation Test_MagnetLossXY Plot 3
Curve Info
Torque Not Including CL Effect
5.60
5.70
5.80
5.90M
ovin
g1
.To
rqu
e [kN
ew
ton
Me
ter]
Ansoft Corporation Test_MagnetLossXY Plot 3
Curve Info
Torque Not Including CL Effect
Torque Including CL Effect
0.05
0.10
Ansoft Corporation Test_MagnetLossXY Plot 5
Curve Info
Torque Difference
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00Time [ms]
5.10
5.20
5.30
5.40
5.50
Mo
vin
g1
.To
rqu
e [kN
ew
ton
Me
ter]
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00Time [ms]
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Mo
vin
g1
.To
rqu
e [kN
ew
ton
Me
ter]
16.00 18.00 20.00 22.00 24.00 26.00 28.00 30.00 32.00Time (ms) [s]
-0.05
0.00
To
rqu
e
3 Phase Induction Motor Losses
• Core loss
• Rotor copper loss at no-load condition
– Due to flux pulsations in the air gap
– Difficult to measure
– Are present in every squirrel cage induction
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– Are present in every squirrel cage induction motor
• Two induction motors in the 200 kW range that only differ in the slot design
– Both motors have 48 rotor slots
– Stators have 60 and 36 slot for motors A and B respectively
Reference: J.Germishuizen, S.Stanton “No Load Loss and Component
Separation for Induction Machines”, Proceedings ICEM 2008, Paper ID 1144
No Load Losses
Why the big
difference
between the two
designs?
Input power: 36 Stator slots
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Noticeable difference between input power and copper losses with different
stator slot number.
Input power: 60 Stator slots
Stator Winding Loss
Reference: J.Germishuizen, S.Stanton “No Load Loss and Component
Separation for Induction Machines”, Proceedings ICEM 2008, Paper ID 1144
FEA Rotor Copper Losses
Where:
Jz is the current density
ρr is the resistivity of the rotor bar
l is the stack length
n is the total number of bars
A is the cross-sectional area of a bar
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An is the cross-sectional area of a bar
Reference: J.Germishuizen, S.Stanton “No Load Loss and Component
Separation for Induction Machines”, Proceedings ICEM 2008, Paper ID 1144
Measurement vs. Simulation
Maxwell Transient Results
Measured Results
60 Slots 36 Slots
ULL V 569.3 512.5
Is
A 96.3 123.0
PCuskW 1.0 1.3
PCurkW 0.7 6.5
PFe kW 1.2 1.5
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Motor with its cage removed.
The no load loss without the
cage requires a special
measurement setup to rotate the
rotor with the same speed as the
stator rotating field.
Measured Results
60 slot with cage
36 slot without cage
36 slot with cage
Maxwell Results
Reference: J.Germishuizen, S.Stanton “No Load Loss and Component
Separation for Induction Machines”, Proceedings ICEM 2008, Paper ID 1144
Manufacturing Factor for Iron Loss
• Iron core losses are calculated based on kh, kc and keusing near perfect samples of laminated materials.
Other factors that contribute to core loss include:
– Lamination Punching, Stress and Heat
– Other Losses such as intra-lamination currents
60 Slots 36 Slots
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
60 Slots 36 Slots
Reference: J.Germishuizen, S.Stanton “No Load Loss and Component Separation for Induction
Machines”, Proceedings ICEM 2008, Paper ID 1144
60 Slots 36 Slots
Workflow : Coupled Electromagnetic
and Thermal Analysis for Electric
Machines
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
Geometry
Losses
Maxwell Model
CFD Model
Mapped Losses
TemperatureANSYS Mechanical/
PMDC Motor
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Integrated Design Flow
Customer Requirements
Create Initial Design.
Map of solution domain
Torque
Current
Voltage
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
Customer Requirements Map of solution domain
T, ψd, ψq = f(id, iq,Θ )using Static Solver
Scale
N, L
ScaleN, L
Integrating FEM in an everyday design environment to accurately calculate the performance of IPM motors, J.Germishuizen, S.Stanton and V. Delafosse
ISEF 2009 - XIV International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering Arras, France, September 10-12, 2009
Integrated Solution:
Customer Requirements
Create Initial Design.
Map of solution domain
Torque
Current
Voltage
Verify with Transient
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
Customer Requirements Map of solution domain
T, ψd, ψq = f(id, iq,Θ )using Static Solver
Scale
N, L
ScaleN, L
Integrating FEM in an everyday design environment to accurately calculate the performance of IPM motors, J.Germishuizen, S.Stanton and V. Delafosse
ISEF 2009 - XIV International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering Arras, France, September 10-12, 2009
Cogging Torque Optimization
• Motivation:
– Primary Contributor to:
• Torque Ripple
• Mechanical Vibration
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• Acoustic Noise
• Drive System Instability
– Thus: Lower Efficiency
• Goals:
– Reduce Cogging Torque
– Maintain Machine Performance
Method
• PM Shape Modification
– Pole Embrace
– Pole Arc Offset
– Magnet Thickness
-1.00
0.00
1.00
2.00
3.00
Mo
vin
g1
.To
rque
[N
ew
ton
Me
ter]
Ansoft Corporation Maxwell2DDesign1Torque
Curve Info
Moving1.Torque
Setup1 : Transient
0.40
0.60
0.80
1.00
1.20
Bra
dia
l
Ansoft Corporation PMSM_CTXY Plot 2
Curve Info
Bradial
Setup1 : Trans ient
Time='0ns'
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
– Magnet Thickness
• Transient FEA
• Genetic Optimization Algorithm
– Minimize Peak Cogging Torque
– Maintain Average Air Gap Flux Density
0.00 5.00 10.00 15.00Time [s ]
-3.00
-2.00
0.00 0.20 0.40 0.60 0.80 1.00
Norm alizedDis tance
-0.20
0.00
0.20
Nominal Setup
• PM Geometric Parameters
– Pole Embrace = 0.75
– Pole Arc Offset = 0 mm
– Magnet Thickness = 3.5 mm
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
– Magnet Thickness = 3.5 mm
• Calculations
– Torque: Virtual Work Method
– Average Radial B in Air Gap:
• Brad = Bx*cos(ϕ) + By*sin(ϕ)
-1.00
0.00
1.00
2.00
3.00
Mo
vin
g1
.To
rqu
e [N
ew
ton
Me
ter]
Ansoft Corporation Maxwell2DDesign1Torque
Curve Info
Moving1.Torque
Setup1 : Transient
0.20
0.40
0.60
0.80
1.00
1.20
Bra
dia
l
Ansoft Corporation PMSM_CTXY Plot 2
Curve Info
Bradial
Setup1 : Transient
Time='0ns'
Nominal Solution
2.2 N-m
Avg = 0.76 T
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0.00 5.00 10.00 15.00Time [s]
-3.00
-2.00
0.00 0.20 0.40 0.60 0.80 1.00Norm alizedDis tance
-0.20
0.00
∫ ∫ •Θ
=ΘΘ
= =
v
H
consti dVdHBd
d
d
idWT
0))((|
),(
Virtual Work MethodMagnetic Field Eqn.
Goals
• Cogging Torque Peak Nominal Value = 2.2 N-m
– Optimal Goal = 0.2 N-m
– G1 = 1 + (max(abs(Torque)) – 0.2) * 9 / 5.3– When Cogging Torque = 0.2 N-m, then G1 = 1.0
• Nominal Bavg Value = 0.76 Tesla
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• Nominal Bavg Value = 0.76 Tesla
– Optimal Goal = 0.76 Tesla
– G2 = 1 + (Brad_Avg – 0.5) * 9 / 0.31– When Air Gap Flux Density = 0.76 T, then G2 = 8.55
• Magnet Area Minimize
–G3 = 1 + (Mag_area – 220) * 9 / 290– When Magnet Area = 220 mm2, then G3 = 1.0
Results
-2 .00
-1 .00
0 .00
1 .00
2 .00
3 .00
Y1 [
New
tonM
ete
r]
A ns o f t Co r po ra tion PMSM_CT_V er if yC og g in g Torq u e
0 .1 4 0 2
2 .2 2 7 1
0 .4 3 5 40 .5 8 7 7
Curv e In f o
O p timiz ed Des ign
S e tup1 : Trans ien t
Mov ing1 .To rque
Impor ted
Nomina l Des ign
1.20
Ansof t Corporation PMSM_CT_VerifyAir Gap Flux Density
--- Nominal (0.76 T)
--- Optimized (0.73 T)
© 2009 ANSYS, Inc. All rights reserved. ANSYS, Inc. Proprietary
0 .00 1 .00 2.00 3 .00 4.00 5 .00 6.00 7 .00 8.00Tim e [s ]
-3 .00
-2 .00
M X 2 : 5 .4 0 3 1M X 1 : 0 .6 3 7 9
--- Nominal (2.2 N-m peak)
--- Optimized (0.4 N-m peak)
0.00 0.20 0.40 0.60 0.80 1.00NormalizedDistance
-0.20
0.00
0.20
0.40
0.60
0.80
1.00
1.20
Bra
dia
l
Curve Info
Bradial
Setup1 : Transient
Time='0ns'
Bradial
Imported
Nominal Design
Summary
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