hybrid drive systems for vehicles - iea - lund university ht19/lectures/ehs_l8_2019... ·...

Hybrid Drive Systems for Vehicles

The Series Hybrid

The Complex Hybrid

EHS

© Mats Alaküla

Study Tour October 9th

• Borg Warner

– 09:00 ... 15:00

– Possibly w lunch

© Mats Alaküla EHS

The Parallel Hybrid

• The EM provides the dynamics

that the ICE cannot

• Stationary solution:


IC E EM

PEBatt

GEARClutch

D

DIFF

*

*

*

ice

r

wheel

em Tg

TT

ice

icesocauxtractiveice PSOCSOCkPP

dt

dP

** )*(

ech

batt

soc

Wk

arg

max,

400

auxtractiveice PPP *

Efficiency limitation

• Turn off the ICE if the efficiency

is not high enough ...

– leads to pure electric drive and

battery depletion .... which ...

– leads to increased charge power

requirement ... meaning ...

– that the ICE efficiency increases and

it is restarted


Charge sustaining / depleting mode


Control of the Parallell Hybrid Vehicle


Gear select

”Throttle”*

iceT

*

ice

- +

*

emT

Wheel radius

&

Gear ratio

Speed

+ -

Dynamics

Limitation

Efficiency

Limitation

+ X

ICEOffOn /

*

iceP*

iceP*

chargeP

*

tractionP

*SOC SOC

RPMNm

RPMNm

RPMNm

*Speed

+

-X

*

tractiveF *

shaftinputgearboxT

D

Energy

Storage

+ -

El.

machDiesel Engine

Power

Electronics

Gearbox

Benefits of the Parallel hybrid

• Minimum of energy conversions

• Minimim of electrical machines


Design of a Parallel hybrid

• Philosophy:

1: Big ICE & small EM. Since EM and

battery are expensive and ICE is

getting better by itself.

2: Small ICE & big EM. ”Plug in

Hybrid”. Commuter car using mostly

electric energy from the PowerGrid.


Philosophy 1 – Big ICE

• Select 80 kW ICE and 20 kW EM

• Big ICE for safety in case SOC low

• 20 kW Em enough to take off and to run silently and emission free at low speed– In residential area nighttime

– In garage

– ...

• Make a Sensitivity Study !


Conclusion on the parallel hybrid

• Competitive design

– Simple, cheap and safe

• Can be either a charge

sustaining hybrid or an charge

depleting hybrid


Control of the Series Hybrid Vehicle


”Throttle”*

iceT

*

ice

*

emTWheel radius

&

Gear ratio

Speed Contr+

-

ice

*

genT

Speed

+ -

Dynamics

Limitation

Efficiency

Limitation

+ X

ICEOffOn /

*

iceP*

iceP*

chargeP

*

tractionP

*SOC SOC

RPMNm

RPMNm

RPMNm

*Speed

+

-X

*

tractiveF

Diesel EngineEl.

mach

Power

Electronics

>30%

95 %

95 %

D

Energy

Storage

+ -

El.

mach

Power

Electronics

95 %

95 %

98 %

System design of a series hybrid

• 100 kW in total installed power ...

• Split 60 kW traction, 20+20 kW

ICE+gen

• Traction motor torque and

speed?

– Assume 0...100 km/h in 10 seconds

– Max torque 200 Nm EM with gr2=5.0

– Max speed vmax/rw* gr2 *30/pi=8800

rpm


NmrFT

NamF

wheelwheel 10003.0*3600

360010/)6.3/100(1300

The Traction motor


0200

400600

800

0

50

100

150

200

0

0.5

1

Speed [rad/s]

Electrical machine efficiency

Torque [Nm]

System design of a series hybrid

• ICE and Generator?

– 20 kW each

– Tgen_max=1.2*Tice_max. Margin for

speed control of ICE+generator.

– wgen_max=wice_max


To Simulink


Series hybrid modelv* & v

-K-

m/s -> km/h

Tice

Tem1

Tem2

Tbroms

Fv äg

v

Tdriv

Wf riktion

Wbroms

w_genset

Transmission

wem2

T*em2

T_em2

Pel_em2

Traction Motor (EM2)

Wbränsle

HastighetFC

SOC

v Froad

Modell av vägen

T*ice

wice

Fuel energyTicePice

EtaICE

ICE-model

wem1

T*em1

T_em1

Pel_em1

Generator (em1)

v bus *

v busTtot*

Förare

Twheel*

v

SOC

w_genset

Tice*

w_genset

Tem1*

Tem2*

w_em2

Drivlinans

styrsystem

Paux

Bränsleförbruking

T*em2

Tem2

T_broms

Broms

P elm1

P elm2

P aux

SOC

Ploss

Pcharge

Batteri

Driv ing cy cle

Rethink ...

• ICE and Generator?

– 25 kW each

– Tgen_max=1.2*Tice_max. Margin for

speed control of ICE+generator.

– wgen_max=wice_max


Conclusions on the Series Hybrid

• Highest possible ICE dynamics

should be utilized

• The high number of energy

conversions is a drawback

• Mostly for city traffic


The Complex Hybrid Vehicle


Advantage:

- CVT function

- Simple mechanical gearbox

Drawbacks:

- Two el. drives

- Not flexible for alternative ICE’s

- Maximum output torque limited by solar wheel motor

DEnergy

Storage

+ -

Power

Electronics

El.

mac

h

El.

mac

h

Diesel Engine

Power

Electronics

The Complex Hybrid


Complex transmission power flow

• Some energy the ”series”

way, some the ”parallell”

• The ”series” way means 4

conversions !


IC E

D

DIFFEM1

rc

Ring wheel (em2)

Sola

r wheel (em

1)

Car

rier w

heel

(ICE)

Pla

net wheel

EM2

KEKE

BattBattBatt

Tem1<0

em1 <>0Tem2<>0

em2 >0

Complex transmission animation


2009/Simulering/Complex/Planetväxel.swf

Complex transmission Control

• Strategy:

– Select ICE speed and torque for

optimum efficiency

– Set ICE torque to reference

– Use EM1 for speed control of ICE

– Use EM2 for transmission torque

levelling

• Almost like Series for ICE speed

control

• Almost like Parallel for

tranmission torque levelling


Control of the Complex Hybrid Vehicle


”Throttle”

*

iceT

*

ice

*

emT

Wheel radius

& final gear

Speed Contr+

-

ice

*

genT

Speed

+ -

Dynamics

Limitation

Efficiency

Limitation

+ X

ICEOffOn /

*

iceP*

iceP*

chargeP

*

tractionP

*SOC SOC

RPMNm

RPMNm

RPMNm

*Speed

+

-X

*

tractiveF

DEnergy

Storage

+ -

Power

Electronics

El.

mac

h

El.

mac

h

Diesel Engine

Power

Electronics

- + *

shaftinputgearboxT

Torque relation: Solar/Carrier


Torque relation: Ring/Carrier


Torque relation: Ring/Solar


Speed relations


Hybrid Definitions


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