modeling the thermal management of a plug-in hev powertrain€¦ · plug-in hev powertrain martin...

Modeling the Thermal Management of a Plug-In HEV Powertrain

Martin Jäger 1

Jürgen Ogrzewalla 2

Prof. Dr.-Ing. Stefan Pischinger 1

Frankfurt/Main

24th October 2011

1 Institute for Combustion Engines, RWTH Aachen

2 FEV GmbH, Aachen

°C

40.0

34.4

28.8

23.1

17.5

11.9

6.3

0.6

-5.0

© by VKA RWTH Aachen University – all rights reserved. Confidential – no passing on to third partiesVKA/Titel/02.04.20082

Agenda

� Motivation

� Modeling approach

� Thermal modeling of electric drive train components

� Battery

� E-Motor

� Inverter

� Simulation of different cabin heating concepts

� Conclusion and outlook


Heating impact on energy consumption

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120

Velocity / km/h

En

erg

y d

em

an

d a

t co

ns

tan

t sp

ee

d /

kW

h/1

00

km

Art

em

is U

rba

nA

vg. 1

7.7

km

/h

Art

em

is R

oad

Avg

.5

7.5

km

/h

NE

DC

Avg. 3

3.6

km

/h

Art

em

is M

oto

rwa

y 1

30

Avg.9

6.9

km

/h

Driving atconstant speed

+ Heating

Simulation based on FEV Liona electric vehicle, heating demand 3kW

Display analog Beidl et al., 32. Internationales Wiener Motorensymposium 2011


Measures to improve thermal management

Active thermal management

� Waste heat recovery from electric drive train

� Heat pump

� Usage of ICE or fuel cell for heating

� Additional vehicle heater (e.g. ethanol burner)

� Heat storage (e.g. PCM)

� Pre-conditioning at charging station

� Optimized cabin thermal management

� Control of fresh air rate

� Local thermal conditioning (radiation etc.)

Passive thermal management

� Lowering of cabin heating/cooling demand

� Insulation

� Reflective glazing

°C

40.0

34.4

28.8

23.1

17.5

11.9

6.3

0.6

-5.0


Agenda

� Motivation



� Battery

� E-Motor

� Inverter




Modeling approach

Objective: Investigation of energy saving potential for different thermal management concepts for Plug-In HEVs

Vehicle model Cooling system

Variable start and boundary conditions

• Drive cycles• Ambient temperatures• Battery SOC• etc.

Cabinmodel

cabin heating / cooling demand

componentheat

generation


Ele

ctr

ical P

ow

er

/ kW

-20

-10

0

10

20

30

40

Time / s

0 1200 2400 3600 4800 6000 7200

Measurement Simulation

Velo

city /

km

h

0

30

60

90

120

SO

C /

-

0.0

0.2

0.4

0.6

0.8

1.0

SOC

Validation of vehicle model using FEV Liiona EV

6.54Total gear ratio

0.01Rolling resistance factor

2.09 m²Frontal area

0.325Drag coefficient

100 kgPassenger mass

1260 kgVehicle mass

Comparison of vehicle measurement and simulation in NEDC

(Electrical power calculated from current and voltage measurement)

Ele

ctr

ical P

ow

er

/ kW

-20

-10

0

10

20

30

40

Time / s

2500 2700 2900 3100 3300 3500 3700

Measurement Simulation


Possible cooling system layout for a PHEV

ICE

rad

iato

r

Batt

ery

rad

iato

r

E-d

rive r

ad

iato

r

E-motor(s)

BatteryAir Cabin

Cab

in H

X

A/C

co

nd

en

so

r

A/C compressor

A/C

evap

ora

tor

PT

C h

eate

r

Air

HT circuit 90-120°C NT circuit 50-70°C Refrigerant circuit Battery circuit 20-40°C

Powerelectronics

TX

V

Heater

TX

V


Agenda

� Motivation



� Battery

� E-Motor

� Inverter




Temperature sensitivity of Li-ion batteries

Battery Charge Power

Battery Discharge Power

Allowed operating region

Preferred operating region

T

Dis

ch

arg

eP

ow

er

Ch

arg

eP

ow

er

60°C0°C-30°C 45°C-10°C-20°C 15°C 30°C

Discharge Derating

Charge Limitation

Charge Limitation

Discharge Limitation

Source: Aachener Kolloquium

„Fahrzeug- und Motorentechnik“ 2009


Electrical and thermal model of a Li-ion cell

Simple equivalent circuit model

Heat generation model

Extended equivalent circuit model dT

dUITUUIQ 0

0)( −−=

&

Jouleheat

Reversible heat

I

0U

1R

U

C

2R

I

0U iR

U

GT compound

GT compound


Battery Power Prediction in GT-Suite

Max. battery power depending on:

� Max. charge/discharge current

� Max. charge/discharge voltage

IIRUP i ⋅⋅−= )(0

I

0U iR

U

iR

U

4

2

0

-1000

-500

0

500

1000

1500

2000

-400 -200 0 200 400 600 800 1000 1200

Current / A

Po

we

r /

W

max. ch

arg

ecu

rren

t

max. d

isch

arg

ecu

rren

t

max. theoreticalpower

Assumption: U0 = 3.7 V, Ri = 2 mOhm


Heat transfer model for a battery module

Heat transfer model

� Lumped thermal mass for Li-Ion cell and busbar

� Equivalent thermal conductivity from cell to cooling plateto model heat transfer and homogeneous heat generationinside cell active material using lumped model

Li-Ion cell

Top busbar

Bottom busbar

Interface materialflexible, thermally conductive,electrically isolating

Cooling plate

Q&


Battery module simulation results

Top Busbar 1

Top Busbar 2

Cell Top (simulation)

Bottom busbar

Bottom busbar (simulation)

Cooling plate (simulation)

Coolant Inlet

Coolant Outlet

Coolant Outlet (simulation)

Time / s

Tem

pera

ture

/ °C


Thermal model of E-motor

Heat generation

� Calculated from efficiency map

Heat transfer

� Lumped thermal mass

� Heat transfer to coolant throughGT Flow model of coolant jacket

Motor housing

Rotor

Copper windings

Coolant jacket

Heat


Thermal model of inverter

Heat generation

� Calculated from efficiency map

Heat transfer

� Modeling of different materialsand heat transfer propertiesin IGBT module and cooling plate

� GT Flow model of cooling plate

Source: Mitsubishi


Agenda

� Motivation



� Battery

� E-Motor

� Inverter




Simulation of cabin heating during electric drivingmode

Analysis of different cabin heating concepts for compact class vehicle

� Air PTC heater

� Water PTC heater in electric motor + power electronics cooling circuit

� Water PTC heater in independent heating coolant loop

Realistic driving cycles

Velo

city /

km

/h

0

20

40

60

80

100

120

Time / s

0 300 600 900 1200 1500 1800 2100

Artemis Urban Cycle Artemis Road Cycle


Air PTC heater concept

Rad

iato

r

Po

wer

El.

E-M

oto

r

Cab

inH

X

Air

PT

C

CabinAir

Source: Eberspächer

Example of HV PTC air heater

Ele

ctr

ical pow

er

PT

C /

W

2200

2400

2600

2800

3000

3200

Time / s

0 300 600 900 1200 1500 1800 2100

Electric driving at 0°C ambient

Air PTC heating and cabin HXNEDC and different Artemis cycles

without cabin HX (all cycles) NEDC Artemis Road Artemis Urban + Road


Heat

transfe

r cabin

HX

/ W

0

500

1000

1500

2000

2500

3000

3500

Zeit / s

0 120 240 360 480 600

Electric driving at 0°C ambientWater PTC heaterArtemis urban + road cycle

Concept A: Separate cooling circuit for water PTC

Concept B: Water PTC inseries with EM and power el.

4 kW PTC (Concept A) 4 kW PTC (Concept B) 6 kW PTC (Concept B)

Ele

ctr

ical pow

er

PT

C /

W

2000

3000

4000

5000

6000

7000

Time / s

0 300 600 900 1200 1500 1800 2100 Energ

y c

onsum

ption P

TC

/ k

Wh

0.0

0.4

0.8

1.2

1.6

2.0

Energy Consumption

Water PTC heater concepts

Rad

iato

r

Power El.

E-Motor

PT

CC

ab

inH

X

Rad

iato

r

Po

wer

El.

E-M

oto

r

PT

CC

ab

inH

X


Energ

y d

em

and /

kW

h/1

00km

0

5

10

15

20

25

30

35

Without electrical heating Separate 4 kW water PTC 4 kW water PTC in LT cooling circuit 6 kW water PTC in LT cooling circuit Air PTC with cabin HX in LT cooling circuit Air PTC without cabin HX in LT cooling circuit

NEDC

0

5

10

15

20

25

30

35Artemis Road

Energ

y d

em

and /

kW

h/1

00km

0

10

20

30

40

50 Artemis Urban

0

5

10

15

20

25

30

35Artemis Urban + Road

Comparison of heating concepts

- 4,6 %

- 6,4 % - 4,4 %

- 9,7 %


Agenda

� Motivation



� Battery

� E-Motor

� Inverter




Conclusion and outlook

� Cooling and heating can decrease electric range by more than 50%

� Lowering of cabin cooling / heating demand essential for efficient future vehicles

� Waste heat recovery from electric drive train only useful for longer trips

� New concepts like heat pump have to be evaluated

� GT-Suite suitable for holistic thermal management modeling

� Easy coupling of mechanical, electrical and thermal models

� Further cooling system concept studies to be performed

� Usage of both electric drive train and combustion engine for cabin heating

� Optimization of operating strategies


Thank You.

Dipl.-Ing. Martin Jäger

Vehicle Electronics and Integration

Phone +49 241 5689 9760

Fax +49 241 5689 79760

E-Mail [email protected]

Internet www.vka.rwth-aachen.de

Acknowledgement

Parts of the results from this presentationwere achieved during research projects funded by the German Federal Ministryof Economics and Technology (BMWi)

modeling the thermal management of a plug-in hev powertrain€¦ · plug-in hev powertrain martin...

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