battery simulation - cadfem€¦ · multi-level physics in battery simulation ... channel can be...
TRANSCRIPT
Evgeny Rudnyi
Lucas Kostetzer
Sreekanth Nallabolu
Funded by
Battery Simulation CADFEM GmbH
Marktplatz 2
85567 Grafing
Germany
gefördert vom: funded by
BMBF Project
„Zentrales Innovationsprogramm
Mittelstand (ZIM)
A project for 2 years
CADFEM
ZSW
Zentrum für Sonnenenergie- und
Wasserstoff-Forschung (ZSW)
Baden-Württemberg
LionSmart
- 1-
gefördert vom: funded by
Multi-Level Physics in Battery simulation
1D System Level: Battery pack and power train Analyze individual systems and integrated performance
Tool used: ANSYS Simplorer & MOR
3D Component level: Battery pack Charge/discharge cycle design, life, safety, cost, thermal
management
Tool used: ANSYS Mechanical & CFD
1D Component level: Battery Cell I-V characteristics, Electro-chemistry analysis
Tool used: ANSYS Simplorer
Model
Extraction
Physic solvers
Me
ch
an
ica
l
Component level
System level
Coupled physics +
Control system
- 2-
gefördert vom: funded by
Content
Vehicle Dynamic Simulation
Electrochemical Modeling of Li-
ion Battery
Thermal Model of Battery (1D
CFD)
Compact Thermal Models via
Model Order Reduction
Battery Pack Electrothermal
Simulation at System Level
- 3-
gefördert vom: funded by
Complex interdependency of subsystems in HEV
Electric
Machine
(EM)
GearboxEngine
(ICE)
Control
Strategy
Maximum and mean
electric powerPower
Electronics
Peak and mean
power demand
over time
Downsizing due to EM
Power and Torque
Distribution of load to
EM and ICE
Torque capability
Battery
• Power
• Voltage
• Energy
- 4-
gefördert vom: funded by
Drive cycle
Backward quasistatic simulation
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0 200 400 600 800 1000 1200 1400 1600 1800 2000
FTP
Time (sec)
Sp
ee
d (
m/s
)
Speed request
- 5-
gefördert vom: funded by
Hybrid Electric Vehicle Simulation @ CADFEM
Series HEV model
Model to check the integrity of our semi-physical battery model
Model useful for component sizing
Model useful to test energy management startegies
- 6-
gefördert vom: funded by
Vehicle Dynamics and Wheel
mv·g
vFaero
Ftrac
Fgrad
Frolla
a
Linear acceleration Force
Gravitational Force
Rolling Resistance force
Aerodynamic drag force
v
Rwheel
vreq , Freq
ωreq , Treq
Treq
ωreq
Treq = FTR * Rwheel
ωreq = Vreq / Rwheel
Freq
vreq
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gefördert vom: funded by
Software for System Level Simulation: Simplorer
8
+
-
B11A11 C11
A12 A2
B12 B2
C12 C2
ROT 2ROT 1
ASMS
3~M
J
STF
M(t)
GN
D
m
STF
F(t)
GN
D
Magnetics
JA
MMF
Mechanics
L
HQ
Simplorer Simulation Data Bus / Simulator Coupling Technology
Block DiagramsState-space
Models
Digital/
VHDL
JK-Flip flop with Active-low Preset and Clear
CLK
INV
CLK
CLK
J Q
QB
CLR
PST
Flip flop
K
CLK
CLK
INV
0 0 0 0 1 1 1 1 1 1X-Axis
Curve Data
ffjkcpal1.clk:TR
ffjkcpal1.j:TR
ffjkcpal1.k:TR
ffjkcpal1.clr:TR
ffjkcpal1.pst:TR
ffjkcpal1.q:TR
ffjkcpal1.qb:TR
MX1: 0.1000
PROCESS (CLK,PST,CLR)
BEGIN
IF (PST = '0') THEN
state <= '1';
ELSIF (CLR = '0') THEN
state <= '0';
ENDIF;
statetransition
AUS
SET: TSV1:=0SET: TSV2:=1SET: TSV3:=1SET: TSV4:=0
(R_LAST.I <= I_UGR)
(R_LAST.I >= I_OGR)
EIN
SET: TSV1:=1SET: TSV2:=0SET: TSV3:=0SET: TSV4:=1
State Graphs
Cxy
BuAxx
Electrical circuits Hydraulics, Thermal,
...
gefördert vom: funded by
Battery Model
Three possibilities in Simplorer
Block Diagrams Equivalent circuit
Analog modeling (Physics based)
- 9-
gefördert vom: funded by
Content
Vehicle Dynamic Simulation
Electrochemical Modeling of Li-
ion Battery
Thermal Model of Battery (1D
CFD)
Compact Thermal Models via
Model Order Reduction
Battery Pack Electrothermal
Simulation at System Level
- 10-
gefördert vom: funded by
HEV / EV
Battery requirements
Safety
Performance
AvailabilityLife
Costs
Source: li-Tec
No Overheating
internal shortcut, overcharge
or abuse
Long life time, 10
years
High energy
density
Fast charging
Low self discharge
Functionality over
wide temperature
range
THERMAL
THERMAL
THERMAL
- 11-
gefördert vom: funded by
Thermal model of a cell
Thermal simulation coupling:
Heat generation phenomena:
Reaction heat
Ohmic heat from contact resistance
Ohmic heat from solid phase
Ohmic heat from electrolyte phase
Reversible heat (usually ignored)
Cell model Battery pack
Heat
Temperature
elejsjcrTotal qqqqq ,,
K. Smith, C. Wang, J. Power Sources 160 (2006) 662 – 673
- 12-
gefördert vom: funded by
Battery principle
(Rosario, 2007)
- 13-
gefördert vom: funded by
Ideal vs. Real Battery
Voltage
SOC
Capacity
Current
Constant voltage during
discharge/charge
Constant capacity for all
discharge/charge
currents
Voltage
SOC
i2
i1
i1>i2Capacity
Current
Voltage drops during
discharge
The higher the
current lower the
Capacity decreases for
higher currents
- 14-
gefördert vom: funded bygefördert vom: funded by
Impedance model: This model comes from those
who measure the impedance
spectrum (Z=V/I) of a battery.
The model allows to describe
high frequency effects well
Reference: Jochen Bernhard Gerschler, Julia
Kowal, Magnus Sander, Dirk Uwe Sauer ,High-
spatial impedance-based modeling of electrical and
thermal behavior of lithium-ion batteries
In Simplorer, Resistor, capacitor
etc. can be combined to create
Impedance model
1-D semi-physical
model: The model is based on
electrochemistry equations.
– The Nernst equation,
– The Buttler-Volmer equation,
– The 1D diffusion,
– The 1D migration of ions.
– Some parameters are
necessary to be adjusted
through testing
CADFEM has implemented Semi-
physical model in Simplorer
1-D physical model: The model is based on
electrochemistry equations. The
best well known model is the
Newman model (Software Dualfoil)
ANSYS has implemented
Newman model in Simplorer
Newman Research Group
CADFEM uses Newman model as
reference model(dualfoil)
Different cell physics Simulation models
- 15-
gefördert vom: funded by
Physical based models
DUAL FOIL, Fuller and Newman
(1993)
Open source Fortran code
Li-ion battery
Detailed model
6 non linear, coupled PDE’s
Over than 50 parameters
Very high accuracy
Model used to evaluate other battery
models
Implemented in Simplorer
K. Smith, C. Wang, J. Power Sources 160 (2006) 662 – 673
- 16-
gefördert vom: funded bygefördert vom: funded by
Newman Model vs. Semi-Physical model
Newman model
Semi-physical model
Note:
The Semi-physical model uses an
equivalent method to treat the
porous media
- 17-
gefördert vom: funded by
Material parameters by optimization with optiSLang
Optimization: 11 parameters to fit the SOC Curve
Reference signal
Signal of best design after
40 generations
- 18-
gefördert vom: funded by
Content
Vehicle Dynamic Simulation
Electrochemical Modeling of Li-
ion Battery
Thermal Model of Battery (1D
CFD)
Compact Thermal Models via
Model Order Reduction
Battery Pack Electrothermal
Simulation at System Level
- 19-
gefördert vom: funded bygefördert vom: funded by
Battery pack Thermal management
Liquid cooled:
more complex
silent
very efficient
isolation difficult
additional cooling system
necessary
Air cooled:
simple
noisy
less efficient
Source: Prof. Dr.-Ing. Andreas Jossen , TUM- 20-
gefördert vom: funded by
3D thermal model - example
Pouch cells
Cooling by Air
Rectangular channels
Battery cell Fluid channel
Cutting detail
Simplified CFD domain
- 21-
gefördert vom: funded bygefördert vom: funded by
ANSYS Thermal model
FEM mesh
Automatic, one
push button,
HEX mesh
CFD 1D CFD + Thermal simulation
FLUID116
Average film coefficient is calculated in the CFD problem
- 22-
gefördert vom: funded by
ANSYS Thermal model - transient
Step response of 1W/cell
HOW to use this in the system level?
- 23-
gefördert vom: funded by
Content
Vehicle Dynamic Simulation
Electrochemical Modeling of Li-
ion Battery
Thermal Model of Battery (1D
CFD)
Compact Thermal Models via
Model Order Reduction
Battery Pack Electrothermal
Simulation at System Level
ANSYS
matricesReduced
Model
MOR
- 24-
gefördert vom: funded by
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
Tamb=f(time)
Cooling by natural convection
Tamb=t1
heat=f(time)
Cooling by natural convection
- 25-
gefördert vom: funded by
Different 3D pack cooling Simulation models
3D Thermal model
•3D thermal model is very
efficient for flat cooling
channel, in which the cooling
channel can be modeled as
1D flow.
ANSYS
matrices
Complete FEM model
Reduced
Model
Reduced dimension
(State Space Model)
MOR
From 3D model to state space model
Note:For efficient system simulation, the model reduction is
necessary, the 3D thermal model can be easily reduced to a
compact model with MOR method
3D CFD model
•3D CFD model can be used as a
general purpose simulate method
for very complicated 3D cooling
channel.
From 3D model to Foster network • The response of the Foster network under step
input is a sum of several exponentially decaying terms.
Note:For efficient system simulation, the model reduction is
necessary, 3D CFD model can be reduced to a compact
model with LTI(Foster network) method
- 26-
gefördert vom: funded by
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, Spice,
…
- 27-
gefördert vom: funded bygefördert vom: funded by
ANSYS Workbench
Steady State model
Extract system
matrices
Checking
Transient model
Run transient case
Extract temperature results for
comparison with reduced model
(optional)
- 28-
gefördert vom: funded bygefördert vom: funded by
Get System matrices
APDL script
Edx
dt Kx f
f
K
E
- 29-
gefördert vom: funded bygefördert vom: funded by
Reducing the order of the model
mor_for_ansys Cell1.full -K fstatic.full -N 40 -l -C output.txt -m
Cell2.full Cell3.full Cell4.full > mor.out
r
T
rr
rrrr
xcy
ubxAx
State Space format
- 30-
gefördert vom: funded bygefördert vom: funded by
Comparison
Accuracy 1% - 10 dofs
per input
Model reduction time
is comparable with
several static solves
0.00 1000.00 2000.00 3000.00 4000.00Time [s]
0.00
0.50
1.00
Tem
pera
ture
[cel]
Curve Info
TCell1.TTR
ansys_Cell1Imported
System level Device level (FEM)
Simulation time [s] 4000 4000 (100 timesteps)
Dimension 40 (10 x Input) 48500 elements
CPU time [s] <1 ~20 min
- 31-
gefördert vom: funded by
Content
Vehicle Dynamic Simulation
Electrochemical Modeling of Li-
ion Battery
Thermal Model of Battery (1D
CFD)
Compact Thermal Models via
Model Order Reduction
Battery Pack Electrothermal
Simulation at System Level
- 32-
gefördert vom: funded bygefördert vom: funded by
Multiphysics Coupling in Simplorer
Ohmic loss of a power transistor:
Resistance as a function of temperature
Ohmic loss as a function of current and
temperature
Thermal dissipation modeled as a
thermal reservoir (C) and a thermal
resistance (R) to the environment
oo TTkRR
oo TTkIRIRIP 222
Ohmic loss
of transistor Temperature
of transistor
Conservative nodes
Temperature
Heat flow
Across Current Heat Flow
Through Voltage Temperature
- 33-
gefördert vom: funded bygefördert vom: funded by
ANSYS Simplorer
3D cooling model
3D Thermal model
3D CFD model
Electrochemistry cell model
Impedance model
1D Semi-Physical model
Heat
Temperature
MOR
LTI
Reduced cooling model
A B
C DState - Space
Coupling between cell models and 3D pack cooling model
- 34-
gefördert vom: funded by
Simplorer integration
Import Matrices of State Space model
4 conservative
thermal pins
Temperature
reference pin
- 35-
gefördert vom: funded by
Thermal System Level Simulation
0000
Cell1
Cell2
Cell3
Cell4 T_Ref
H
VALUE=0
H
VALUE=0
H
VALUE=0
Q
VALUE=20H
VALUE=10
0.00 1000.00 2000.00 3000.00 4000.00 5000.00Time [s]
293.00
294.25
295.50
296.75
297.50
Y1
[ke
l]
Curve Info
THM1.TTR
THM2.TTR
THM3.TTR
THM4.TTR
Thermometers
Heat flow sources
- 36-
gefördert vom: funded by
Electro-Thermal System Level Simulation
SOC definition
0
I1
A
+
V
EQU
ICA:
Q
VALUE=20
Cell1
Cell2
Cell3
Cell4 T_Ref
H
tfm1
H
tfm2
H
tfm3
H
tfm4
H
tfm5
th
p m
th
p m
th
p m
th
p m
0.00 2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00Time [s]
-375.00
25.00
375.00
14.895
14.900
14.904
0.488
0.500
Curve Info
AM1.ITR
VM1.VTR
SOCoutTR
CONST
const1
- 37-
gefördert vom: funded by
Electro-Thermal System Level Simulation
Current(prescribed)
Voltage
SOC
Cell
Temperature
- 38-
gefördert vom: funded bygefördert vom: funded by
Less Pollution, A better way to live
1
2
3
Ele
ctr
oche
mis
try
Th
erm
al
Po
wer
Te
mp
era
ture
batt
ery
syste
m s
imu
lati
on
Inductive battery charging system
- 39-