Split micro-Hybrid breathing for Highly Diluted CombustionAnna Stefanopoulou (PI), University of Michigan

Jason Siegel (co-PI, UM), Swami Subramanian (EATON),Robert Middleton, Shima Nazari, Rani Kiwan,

Bryan Maldonado and Chuck Solbrig (UM)

Monya Bransky (EATON), Scott Hotz (SWRI)

Enable a 20% increase in fuel efficiency through

highly diluted combustion at half the cost of a full

hybrid targeting $60/%FE

Project Goal

Fed. funding: $1.9M

Length 36 mo.

Shown 37% fuel economy improvement (52 mpg)

on the FTP75 cycle with 0.6s tip-ins.

Current Technical Status

2015 Open

U.S. DoE Award Number:

DE-AR0000659

Cost Effectiveness -- Target

1

Friction reduction

Variable valve timing

Variable valve lift

Gasoline direct injection

Turbocharging

& downsizing

Diesel

HEV

xEV MPGe

(estimated)80% of full

hybridization benefit

with 50% of the cost

fast as

naturally aspirated

Anna Stefanopoulou, black symbols-NRC data, red symbols -NHTSA

Perc

en

t R

ed

ucti

on

in

Fu

el C

on

su

mp

tio

n (

%)

Technology Cost ($)

100% of full

hybridization benefit

with 50% of the cost

when eco-driving

Pulley

BrakeCarrier

Sun

Ring

Bypass

Valve

Motor

Engine

Supercharger

Battery

+ −

Electrically Assisted Variable Speed

(EAVS) Supercharger (from EATON)

Power Split Supercharger

• Mild hybridization (48V)

• Start-stop

• Limited regenerative braking/torque assist

• Boosted engine

• Down sized/right sized engine

2

Hardware (Open 2015)

+ −

Baseline

Turbocharged

1.6L EcoBoost

+ −

+ −

Dual Motor

(eSC+ SGM)

(Big Motor)

Full HEV

Hybrid Powertrains

Power Split

Supercharger

with cEGR

+ −

3

Architectures Considered

(Single Small Motor)

Power Split

Supercharger

+ −

Turbocharged 1.6L

EcoBoost (Baseline)

Engine + PSS

2 s

0.6 s

Time [s]

Torq

ue [

N.m

]

Coordinating actuators

nine air +spark+VVT

Highlights:

Power-Split Supercharger Performance

5

Maximum torque with

supercharging

SC

only

SC or TA

Highlights:

Power Split Supercharger Optimization

Maximum torque with

naturally aspirated

Maximum

torque with

torque assist

Crank

torqueEngine

speed

𝜏 𝑐𝑟

Simple rule: Use the supercharger

only when you MUST!

35

40

45

50

55

Baseline EAVS -TA only EAVS+EGR EAVS+EGR +Start/Stop

FE [mpg]

6%17%

37%

FE Increase

FTP75

6

Experimental Fuel Economy Verification

800 825 850 875 900 925 950 975 1000 1025 1050recorder_time [s ]

TO

RQ

UE

.pro

c [N

m]

-80

-40

0

40

80

120

160

Ped

& T

hr [

%]

0

25

50

75

100

Veh

Spd

[km

/h]

0

50

100

EG

R [

%]

0

10

20

30

40

19_0117_FTP75_SCad.1156.mf4 TransRec[1]

Shaft Torque Target Shaft Torque Feedback

800 825 850 875 900 925 950 975 1000 1025 1050recorder_time [s ]

TO

RQ

UE

.pro

c [N

m]

-80

-40

0

40

80

120

160

Ped

& T

hr [

%]

0

25

50

75

100

Veh

Spd

[km

/h]

0

50

100

EG

R [

%]

0

10

20

30

40

19_0117_FTP75_SCad.1156.mf4 TransRec[1]

+− Motor

SC

Battery

Engine

Gearbox

ECMS

Shaft Torque Motor Torque

Pedal

Shaft Speed

Model

Dynamometer

PSS Mode

Hardware Engine

PSS

7Motor peak power in hybrid system

Turbocharged

Engine with PSS

Full HEV

NEXTCAR:

Comparison with Full HEV with Traffic PreviewLevel of hybridization with Eco-driving?

Velocity Profile Optimization: LA92

With velocity profile

optimization the mild hybrid

can be as efficient as a full

hybrid

On-Going:

+ −

Single motor or dual motors

+ −

0

10

20

30

40

FTP75 HWFET US06

EAVS eSC+SGM

FE

Incre

ase [

%]

Operation constrained to

boosting or torque assist

Cheaper

Boosting and torque

assist simultaneously

More expensive

1% more FE gain

on US06 cycle

8

PSS + cEGR has best cost effectiveness

Components PSS+cEGR Full Hybrid

60kW Motor

300V, 1.2KWh

EAVS / Electric Motor 1020 720

Battery / Alternator 340 1680

cEGR 212 --

Turbocharger -580 --

TOTAL $992 $2400

%FE improvement 24 28

Cost Effectiveness $41/%FE $83/%FE

CO2 Effectiveness $47/%CO2 $110/%CO2

Target

$1200

20

$60/%

$72/% CO2

+ −

9

Tech to Market: System Cost Effectiveness

+ −

Thank you!