EV POWERTRAIN AND THERMAL MODELING IN CROSS DOMAIN SIMULATION
GT INDIA CONFERENCE 202027TH JANUARY 2020, PUNE, INDIA
AUROBBINDO LINGEGOWDADIBAKAR MAHALANABISH
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
EV Powertrain and Thermal Modeling in Cross Domain SimulationMotivation & Challenge
Innovation
from
xDomain functions
New business models
with
faster time to market
Mobility providers
with
change in sourcing
ElectrifiedConnectedAutomated
BBM*
Provide system solutions
Understand interaction of systems & engineering on vehicle level
Handle increased complexity
A good response to these challenges opens opportunity to offer new competitive solutions & services
New Mobility
*BOSCH Business Sector Mobility Solutions
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Approach: System Development on Vehicle Level
Mobility
Vehicle
xDomain
Domains
Components
Transportation
Scope
System development on vehicle level organization founded @ BBM*
xDomain Projects
Optimized Cross Domain Systems
Requirements
Effect ChainsHolistic View
Specific View
xDomain Engineering Enabler
*BOSCH Business Sector Mobility Solutions
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.4
Body
Powernet
Powertrain
Controls
Traffic
Environment
Thermo
Body
Powernet
Powertrain
Controls
Traffic
Environment
Thermo
Co-
Simulation
Cross Domain simulationDomain Specific simulation
Shifting from Standalone to Cross Domain
Modeling beyond the
boundary of typical
subsystem
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Model Library
Powertrain
Infotainment
Environment
Body
Controls
Thermo
Powernet
Chassis
+
Simulation Platform
…
Co-Simulation Model Repo
EV Energy Flow
Vehicle Dynamics
Virtual Demonstr.
Further standard vehicles
=
Domain Experts
from Bosch
divisions
Central Simulation Team
ECU SW
Info Hub
Cont.Test.
Architect.
Model users in
Bosch
divisions
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.6
Model Library
Powertrain
Infotainment
Environment
Body
Controls
Thermo
Powernet
Chassis
…
EV Powertrain & Thermal Model using GT SUITE
Components built as GT compounds
Used standard GT libraries components
for thermal system modeling
Parameters defined as gto’s
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.7
Comprehensive Powertrain Model
✓ Powertrain model for xdomain
simulator is developed as a
compound template.
✓ This compound is a combination of
the e-machine and the inverter
compounds.
✓ The rotor and stator temperature,
desired torque, mean junction and
mean cooling temperature are
inputs to the e-machine and inverter
compounds from thermal models.
e-machine
compound Inverter
compound
Auxiliary
Consumer
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.8
Comprehensive Thermal System Model
The comprehensive thermal system compound
combines the 4 Physical Thermal Models in GT:
✓ Coolant Circuit
✓ Refrigerant Circuit
✓ Underhood Air Path
✓ Air Conditioning Unit Air Path
The thermal controller model is in Matlab and is
connected via co-simulation middleware.
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.9
Coolant Circuit
Components that are modelled as *.gtc :
✓ Heat sources: Inverter, E-Axle, PTC-Heater, On-
Board-Charger,
✓ Heat exchangers: NT-Radiator (Coolant/Air HX),
Chiller
Components that are analyzed within the
cooling circuit:
✓ The pumps: Main pump, PTC pump
✓ The Valves: 2 switch-over-valves
PTC Pump
Heater
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.10
Refrigerant Circuit
Components that are modelled as *.gtc :
✓ Heat exchangers: The Front HX, the Chiller, the
HVAC condenser, the HVAC evaporator
Components that are analyzed within the
cooling circuit:
✓ The switch valves
✓ The expansion valves
✓ The accumulator
Compressor
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.11
Underhood Air Path Base Line Break Down
Interfaces
✓ Fan control signal (Control Model Out)
✓ The coolant radiator (physical Interface to
cooling circuit)
✓ The refrigerant front HX (physical Interface to
refrigerant circuit)
✓ Vehicle Speed
✓ Ambient pressure and temperature
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.12
Air Conditioning Unit Air Path
Components that are modelled as *.gtc :
✓ Heat exchangers: the two cabin refrigerant air heat
exchangers
Effects that are analyzed within the air
conditioning unit air path:
✓ Blower characteristic
✓ Heat exchanger pressure losses
✓ Flap characteristic
HVAC Blower
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.13
Powertrain Model Validation: Measurement to SimulationEV Powertrain and Thermal Modeling in Cross Domain Simulation
e-m
achin
e S
pe
ed (
RP
M)
e-d
rive T
orq
ue
(N
m)
Drive Cycle: WLTC
Standard Environment Conditions
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.14
Powertrain Model Validation: Measurement to SimulationEV Powertrain and Thermal Modeling in Cross Domain Simulation
Ba
tte
ry P
ow
er
(W)
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.15
Coolant Outlet Temperature Comparison: Measurement to Simulation
✓ Measurement: 15°C environment temperature at CADC cycle (2017_11_28_8a) (verification test case)
✓ +/- 0.5K measurement tolerance
Test Case Environment
Temperature
[°C]
Driving
Cycle / use
case
HVAC
operation
Preconditioning
2017_11_28_8a 15 CADC automatic and
max heating
1st measurement
after
preconditioning
Axle coolant outlet temperatures:
TDriveOut_Meas: Measured temperature
TDriveOut_Sim: Simulated temperature
Inverter coolant outlet temperatures:
TInvOut_Meas: Measured temperature
TInvOut_Sim: Simulated temperature
Chiller coolant outlet temperatures:
T Chiller Out_Meas: Measured temperature
T Chiller Out_Sim: Simulated temperature
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.16
Coolant Outlet Temperature Comparison: Measurement to Simulation
✓ Measurement: 15°C environment temperature at maximum and medium stationary load (2017_11_28_7ab) (verification test case)
✓ +/- 0.5K measurement tolerance
Axle coolant outlet temperatures:
TDriveOut_Meas: Measured temperature
TDriveOut_Sim: Simulated temperature
Inverter coolant outlet temperatures:
TInvOut_Meas: Measured temperature
TInvOut_Sim: Simulated temperature
Chiller coolant outlet temperatures:
T Chiller Out_Meas: Measured temperature
T Chiller Out_Sim: Simulated temperature
Test Case Environment
Temperature
[°C]
Driving
Cycle / use
case
HVAC
operation
Preconditioning
2017_11_28_7ab1 15 stationary
max and
medium
automatic and
max heating
1st measurement
of the day
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.
Summary• The domain specific models have been first validated at component and subsystem level and then in
the complete vehicle co-simulation environment
• Parameters required for calibrating the model are taken from actual component measurements
• Powertrain and thermal system models calculate the necessary interface quantities for vehicle level
simulation
• Validation results show that powertrain and thermal model simulation results match well with actual
data
• The validated powertrain and thermal models provide a strong basis for building the vehicle
environment model in analyzing complete vehicle interactions
• Thermal models are extensively dependent on thermal controls as well as power losses from
powertrain models.
• Further improvement in thermal modeling is ongoing to fine tune the results.
EV Powertrain and Thermal Modeling in Cross Domain Simulation
Internal | RBEI/EHV-EP2 | 2019-12-17
© Robert Bosch Engineering and Business Solutions Private Limited 2019. All rights reserved, also regarding any disposal, exploitation, reproduction, editing, distribution, as well as in the event of applications for industrial property rights.18
Thank you
EV Powertrain and Thermal Modeling in Cross Domain Simulation