ev powertrain and thermal modeling in cross domain …€¦ · • the validated powertrain and...

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



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


© 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




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




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




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




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.




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




Refrigerant Circuit


✓ 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




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




Air Conditioning Unit Air Path


✓ 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




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



Powertrain Model Validation: Measurement to SimulationEV Powertrain and Thermal Modeling in Cross Domain Simulation

Ba

tte

ry P

ow

er

(W)



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




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




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.




Thank you


ev powertrain and thermal modeling in cross domain …€¦ · • the validated powertrain and...

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