thermal and mechanical system simulation
TRANSCRIPT
Thermal and Mechanical
System Simulation
ANSYS CONFERENCE & 27. CADFEM USERS’ MEETING
18 – 20 November 2009, Congress Center Leipzig
Evgenii Rudnyi, CADFEM GmbH
Outline
System level simulation
Simplorer
Coupling Workbench and
Simplorer
Model Order Reduction
Thermal simulation
Electrothermal
Mechanical simulation
Control
Other papers at ACUM
1
Mechatronics: mechanical + electrical + computer sciences
2
3
Simplorer: http://www.ansoft.com/
Circuits
Block Diagrams
State Machines
Equation Blocks
VHDL-AMS
Example of VHDL-AMS
4
Compact Modeling: Transistor Compact Model
Figure from J. Lienemann, E. B. Rudnyi and J. G. Korvink. MST MEMS model
order reduction: Requirements and Benchmarks. Linear Algebra and its
Applications, v. 415, N 2-3, p. 469-498, 2006.
From Finite Elements to System Simulation
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Electrothermal Simulation with power MOSFET:
From ANSYS Workbench to Simplorer
7
Model Order Reduction
Relatively new technology
Solid mathematical background:
Approximation of large scale
dynamic systems
Dynamic simulation:
Harmonic or transient simulation
Industry application level:
Linear dynamic systems
8
Model Reduction as Projection
Projection onto low-
dimensional subspace
How to find subspace?
Mode superposition is not the best way to do it.
zx V
x V
z
=
uxx BKE
uzz BVKVVEVV TTT
E
Er
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Implicit Moment Matching
Padé approximation
Matching first moments for the
transfer function
Implicit Moment Matching:
via Krylov Subspace
0
0 )( i
i ssmH
mi mi,red, i 0, ,r
BKsEsH1
)(
0
0, )( i
redired ssmH
s0 0
V span{(K1E,K1b)}
uxx BKE
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MOR for ANSYS: http://ModelReduction.com
FULL files
Linear Dynamic
System, ODEsCxy
BuKxxExM
MOR Algorithm
Small dimensional
matrices
Current version 2.5
ANSYS Model
Simulink,
Simplorer, VerilogA,
…
MOR for ANSYS Timing: MOR as Fast Solver
Reduced model of dimension 30
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Dimension,
DoFs
nnz MOR Time
/ANSYS
static
4 267 20 861 1.4
11 445 93 781 1.8
20 360 265 113 1.7
79 171 2 215 638 1.5
152 943 5 887 290 2.2
180 597 7 004 750 1.9
375 801 15 039 875 1.7
System Thermal Simulation in Simplorer
Current : Heat Flow
Voltage : Temperature
Resistor : Thermal
resistance
Capacitor : Thermal
capacitor
Voltage source :
Temperature source
Current source :
Heat Flow source
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Compact Thermal Models
Looks understandable – but how to do it in practice?
Figure from the book “Fast Simulation of Electro-Thermal MEMS: Efficient Dynamic
Compact Models.” Springer, 2006.13
Electrical vs. Thermal
Thermal phenomena are much more distributed, it is hard to lump
them.
Figure from the book “Fast Simulation of Electro-Thermal MEMS: Efficient Dynamic
Compact Models.” Springer, 2006.14
Electrical flow
cond /ins 108
Heat flow
cond /ins 102
Conductor
Insulator
Freescale Multi-channel Power Devices
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PCBLeadframe
heavy gauge
wires
control
chippower
chipMOR for ANSYS at
Therminic 2009
More information: Thursday 09:20 - 09:40 Thermoelectric System
simulation: Compact Model Simulation with ANSYS Workbench, Freescale
Chip and its Model in Workbench
Two power MOSFET transistors
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Interface to call MOR for ANSYS in Workbench
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Import Reduced Model in Simplorer
Simplorer supports state space model
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Test Thermal Circuit in Simplorer
Conservative thermal subsystem in Simplorer
Voltage – Temperature
Current – Heat flow
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Thermal Impedance and Comparison with ANSYS
ANSYS: about 300 000 DoFs, Reduced model: 30 DoFs
The difference is less than 1%
Timing: 60 timesteps is about 30 min in ANSYS
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Thermal Runaway
Transistor is considered as temperature dependent RDSon
The VHDL-AMS model
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Thermal Runaway Model
Conservative coupling between electrical and thermal part
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Transient Turn-on of an Automotive Light-Bulb
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Transient Turn-on of an Automotive Light-Bulb
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0.00 10.00 20.00 30.00 40.00 50.00Time [ms]
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
E2
.I [A
]
Curve Info
SL1='1' SL2='0' SL3='0'
SL1='1' SL2='1' SL3='0'
SL1='1' SL2='1' SL3='1'
Ansoft LLC FET_Light_Bulb_P21W_2Lamp Currents at turn-on
1 lamp
2 lamps
3 lamps
0.00 10.00 20.00 30.00 40.00 50.00Time [ms]
250.00
300.00
350.00
400.00
450.00
500.00
550.00
TH
M1
.T [ke
l]
Curve Info
THM1.TSL1='1' SL2='0' SL3='0'
THM1.TSL1='1' SL2='1' SL3='0'
THM1.TSL1='1' SL2='1' SL3='1'
Ansoft LLC FET_Light_Bulb_P21W_2Junction Temperature at turn-on
3 lamps
2 lamps
1 lamp
Example of Mechanical System
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System Level Simulation
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Hard Disk Drive Actuator/Suspension System
Michael R Hatch, Vibration Simulation Using MATLAB and ANSYS
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Model Reduction
3352 elements
7344 nodes
21227 equation
400 frequencies takes about 12
min
MOR takes only 3 s
Comparison for head
ANSYS
MOR 30
MOR 80
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Comparison
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Comparison
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Velocity Control: Device as a Black Box
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Velocity Control: Multiphysics Modeling
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Model Reduction for the FEM Model
13 347 elements
11 765 nodes
55 481 equations to
solve
200 frequencies
takes about 20 min
Model reduction
takes 8 second
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Comparison
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Efficient Simulation of Acoustic FSI
Wednesday 17:00 - 17:20, CADFEM + Simetris
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System Level Battery Thermal Behavior Study
Thursday, 12:20 - 12:40, CADFEM
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Battery thermal model
Electrical cell model(cell1)
0 0
EQU
FML1
CONST
Heating
RLoad
RT_LRT_S
CT_LCT_S
IBatt
Ccapacity
Rseries
VOC
CONST
TempRptc
1
2
REF
H
HeatConfig10
H
HeatConfig01
TCell2
TCell1
Q
Tref
Elektrothermische Simulation eines IGBT Wechselrichters
Thursday 11:40 – 12:20, CADFEM + ANSOFT
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Thermal Domain
Electrical Domain MechanicalDomain
0
R1 R2 R3
MASS_ROT1
DR1
SINE2
SINE1
A
A
A
IN_A
IN_B
IN_C
OUT_A
OUT_B
OUT_C
I_motSimplorer4
A
B
C
N
ROT1
ROT2
Induction_Motor_20kW
Q
Ambient
P1
P2
P3
P4
P5
P6
P7
P8 P
9
P1
0
P1
1
P1
2
P_
RE
F
z_um z_vm z_wm
z_wpz_vpz_up
+
V
VM311 R6 R5 R4
E1
RZM
DR1
RZM
0.00 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00Time [ms]
-500.00
-250.00
0.00
250.00
500.00
Y1 [
V]
Curve Info rms
R1.VTR 230.9405
R4.VTR 313.3812
0.00 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00Time [ms]
1475.00
1485.00
1495.00
1500.00
MA
SS
_R
OT
1.O
ME
GA
[rp
m]
0.00
50.00
100.00
150.00
180.00
MA
SS
_R
OT
1.P
HI
[deg]
Curve Info
MASS_ROT1.OMEGATR
MASS_ROT1.PHITR
Extraction of Thermal Properties of Thin Films
Thursday, 12:20 - 12:40, T. Bechtold, NXP
Parametric Model Reduction
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Also on Thursday
16:20 - 16:40, Export von modal reduzierten Körpern aus ANSYS
und deren Echtzeitberechnung, P. Sekler, A. Dadalau
17:00 - 17:20 Application of MOR for ANSYS to Hydro Turbine
Runner Dynamics, F. Lippold (Voith Hydro Holding GmbH & Co. KG,
Heidenheim)
17:00 - 17:20 Zustandsraumbeschreibung von piezo-mechanischen
Systemen auf Grundlage einer Finite-Elemente-Diskretisierung, B.
Kranz (Fraunhofer-Institut IWU, Dresden)
17:20 - 17:40 Parametric Reduction of Multiphysics Models, J.
Mohring (Fraunhofer-Institut ITWM, Kaiserslautern)
17:40 - 18:00 Novel Model Reduction Techniques for Control of
Machine Tools, P. Benner (Technische Universität Chemnitz)39
Conclusion
ANSYS – device level model
Simplorer – system level simulation
MOR for ANSYS – model reduction for ANSYS models
40