EVS’27, Barcelona, November 2013

« Energetic Macroscopic Representation and

Inversion-Based control of a CVT-based HEV »

M. Chouhou, F. Grée, C. Jivan, A. Bouscayrol, T. Hofman

(Univ. Lille1, France and Tech. Univ. Eindhoven, The Netherlands)

2 / 15OBJECTIVE AND OUTLINE

1. Studied CVT-based Hybrid Electric Vehicle

2. Energetic Macroscopic Representation of the CVT-based HEV

3. Inversion-based control of the CVT-based HEV

4. Simulation results

Objective: definition of the control scheme of a Hybrid Electric Vehicle

(HEV) using a Continuously Variable Transmission (CVT)

3 / 15CONTINUOUS VARIABLE TRANSMISSION (CVT)

T1

Ω1

T2

Ω2

T1

Ω1

T2

Ω2

T1

Ω1

T2

Ω2

Ω1=Ω2Ω1>Ω2 Ω1<Ω2

CVT = gearbox with continuous evolution of the gear ratio

Different (friction-based) technologies of CVT:

• pulley-based CVT

• roller-based CVT

• cone-based CVT

• etc.

Example of pulley based CVT

4 / 15CVT-BASED HYBRID ELECTIC VEHICLE (HEV)

IC EngineCVT

belt

inverter

Parallel HEV using a CVT

fuel

tank

battery

electrical

machine

(PMSM)

torque

converter

Tice

Ωice

Tem

Ωice

Ttot

Ωice

Ttc

Ωtc

Tcvt

Ωwh

5 / 15

vBat Env

DCM1

DCM2

EP1

EP2

Bat. Fres

ME1

ME2

Energetic

Macroscopic

Representation

(EMR)

Organisation of

control schemes

of complex systems

vref

Strategy

ENERGETIC MACROSCOPIC REPRESENTATION

power control

6 / 15CVT MODEL AND REPRESENTATION

Ttc

Ωcvt Tcvt

Ωwh

CVT = gearbox with continuous evolution of the gear ratio

=

=

whcvtcvt

tcjcvtcvtcvt

k

TkT

ΩΩη

<−=

>=

0 if 1

0 if 1

cvt

cvt

Pj

Pj

)FF(ukdt

dpptccvtcvt 21 −= Ω

Assumptions: constant efficiency and no stiffness and dynamic shift

CVT model: EMR of the CVT

Fp1

Fp2

Ttc Tcvt

ucvt

Ωcvt Ωwh

7 / 15EMR OF THE CVT-BASED HEV

brake

ubatbattery

ICE

electric

drive belt TC chassisCVT wheel

Environ.

ivsi

Tem

Tem-ref

Ωblt

Tice-ref

Tice

Ωice

Ωtc

Tblt Ttc Tcvt Fwh Ftot

Fres

vhev

vhevvhev

vhev

Fbk

Fbk-ref

ucvtktc

Ωcvt Ωwh

distribution of energy

between e-drive and ICE

(when traction)distribution of energy

between electric and mechanical

brake (when deceleration)

8 / 15TUNING PATH

brake

ubatbattery

ICE

electric

drive belt TC chassisCVT wheel

Control?

Environ.

ivsi

Tem

Tem-ref

Ωblt

Tice-ref

Tice

Ωice

Ωtc

Tblt Ttc Tcvt Fwh Ftot

Fres

vhev

vhevvhev

vhev

Fbk

Fbk-ref

vhev-ref

ucvtktc

Ωcvt Ωwh

The control has to define all tuning variables to impose the desire velocity vhev-ref

9 / 15

Tblt-ref Ttc-ref Tcvt-ref

INVERSION-BASED CONTROL OF THE HEV

electric

drive belt TC chassisCVT wheel

vhev-ref

brake

ubatbattery

ICE

Environ.

ivsi

Tem

Tem-ref

Ωblt

Tice-ref

Tice

Ωice

Ωtc

Tblt Ttc Tcvt Fwh Ftot

Fres

vhev

vhevvhev

vhev

Fbk

Fbk-ref

ucvtktc

Ωcvt Ωwh

Ftot-refFwh-ref

kD2

kD1

10 / 15

Tblt-ref Ttc-ref Tcvt-ref

STRATEGY OF ENERGY MANAGEMENT

vhev-ref

brake

ubatbattery

ICE

Environ.

ivsi

Tem

Tem-ref

Ωblt

Tice-ref

Tice

Ωice

Ωtc

Tblt Ttc Tcvt Fwh Ftot

Fres

vhev

vhevvhev

vhev

Fbk

Fbk-ref

ucvtktc

Ωcvt Ωwh

Ftot-refFwh-ref

Strategy

kD2 k

D1

vhevSoC

The strategy aims to reduce the fuel consumption by:

• the energy distribution between e-drive and ICE (kD2)

• the brake distribution between e-brake and m-brake (kD1)

• the choice of the CVT ratio (ucvt)

• the connection of the ICE (ktc)

11 / 15PRINCIPLE OF THE STRATEGY

0.02 0.02 0.020.04 0.04 0.040.06 0.060.06

0.08 0.080.08

0.1 0.1

0.1

0.1

2

0.120.12

0.12

0.1

4

0.140.14

0.14

0.1

6

0.160.16

0.16

0.1

8

0.1

8

0.180.18

0.18

0.2

0.2

0.2

0.2

0.2

0.2

2

0.2

2

0.22

0.22

0.22

0.2

4

0.2

4

0.24

0.24

0.24

0.24

0.2

6

0.26

0.26

0.26

0.2

6

0.26

0.26

0.2

8

0.28

0.28

0.2

8

0.28

0.28

0.3

0.3

0.32

100 200 300 400 5000

20

40

60

80

100

120

140

160

180 torque (Nm)

speed (rad/s)

optimal point wheel power

∆Ω∆Ω∆Ω∆Ω

∆∆∆∆T

The strategy aims to put the ICE in its best consumption area

ICE

12 / 15PRINCIPLE OF THE STRATEGY

0.02 0.02 0.020.04 0.04 0.040.06 0.060.06

0.08 0.080.08

0.1 0.1

0.1

0.1

2

0.120.12

0.12

0.1

4

0.140.14

0.14

0.1

6

0.160.16

0.16

0.1

8

0.1

8

0.180.18

0.18

0.2

0.2

0.2

0.2

0.2

0.2

2

0.2

2

0.22

0.22

0.22

0.2

4

0.2

4

0.24

0.24

0.24

0.24

0.2

6

0.26

0.26

0.26

0.2

6

0.26

0.26

0.2

8

0.28

0.28

0.2

8

0.28

0.28

0.3

0.3

0.32

100 200 300 400 5000

20

40

60

80

100

120

140

160

180 torque (Nm)

speed (rad/s)

optimal point wheel power

∆Ω∆Ω∆Ω∆Ω

∆∆∆∆T

ICE

reftot

opticeD

T

Tk

−

−=2

measwh

opticecvtk

−

−=Ω

Ω

Strategy

kD2

vhevSoC

ktc kcvt

Ktc=1 when traction

(ICE coupled)

KD1=1 when braking

(max of recovery

Energy)

kD1

Ttot-ref

13 / 15SIMULATION USING SIMULINK

800 805 810 8150

5

10

15

20

25

30

0 500 1000 15000

20

40

60

80

100

120

Vhev-ref

Vhev

Vhev (km/h)

t (s)

t (s)

Vhev (km/h)

Matlab-Simulink© + EMR LibaryNew European Drive Cycle

the requested velocity

is wheel achieved

14 / 15FUEL CONSUMPTION

Thermal vehicle

with a 4-speed gearbox

0 5 0 0 1 0 0 0 1 5 0 00

1

2

3

4

kgb

t (s)

0 5 0 0 1 0 0 0 1 5 0 00

0 . 1

0 . 2

0 . 3

0 . 4

0 . 5

0 . 6

fuel (L)

t (s)

4.018 L/100 km

Thermal vehicle

with CVT

Hybrid vehicle

with CVT

4.32 L/100 km5.04 L/100 km

0 500 1000 15000

0.1

0.2

0.3

0.4

0.5

0.6

0 500 1000 15000

1

2

3

4

kcvt

t (s)

fuel (L)

t (s)

0 500 1000 15000

0.1

0.2

0.3

0.4

0.5

0.6

0 500 1000 15000

1

2

3

4kcvt

t (s)

fuel (L)

t (s)

charge at

standstill

but kCVT often limited

and recharge at standstill

15 / 15CONCLUSION

• A CVT-based HEV is a complex vehicle to manage because of the high number of

tuning variable to achieve the velocity by reducing the fuel consumption

• EMR and the deduced inversion-based control is a valuable way to organize the

control of this complex vehicle

• The interest of the CVT has been demonstrated in term of fuel consumption but the

gain between a CVT thermal vehicle and a CVT hybrid vehicle is not relevant using a

rule-based strategy for energy management

A optimal energy management should now be used to develop a more efficient

strategy and to improve the fuel saving for a CVT-based HEV

Coimbra – Portugal

UNESCO Wold Heritage

October 27-30, 2014

http://www.vppc2014.org

IEEE Vehicle Power and Propulsion Conference“Spreading E-Mobility Everywhere”

Organization:

Supported by:

Digests deadline: 31th March 2014

Notification deadline:18th May 2014

Final paper deadline: 01th July 2014

Conference in a Carbon Care Philosophy

We will be pleased to Welcome you in We will be pleased to Welcome you in We will be pleased to Welcome you in We will be pleased to Welcome you in

Coimbra!Coimbra!Coimbra!Coimbra!

EVS’27, Barcelona, November 2013

« Energetic Macroscopic Representation and

Inversion-Based control of a CVT-based HEV »

M. Chouhou, F. Grée, C. Jivan, A. Bouscayrol, T. Hofman

(Univ. Lille1, France and Tech. Univ. Einhoven, The Netherlands)

18 / 15STRATEGY FOR A CVT-BASED THERMAL VEHIC.

100 200 300 4000

50

100

150

torque (Nm)

speed (rad/s)

optimal operation line

maximal torque

wheel power

constant power

As a CVT can only act on torque ratio OR speed ratio,

the optimal operation line is the preferable operation line

=

=

whcvtcvt

tcjcvtcvtcvt

k

TkT

ΩΩη