3.1 (version 1.1)

APEC 2007 - System Design 28 February 2007 – Anaheim

Evolution of Hybrid Vehicle Electric System and its Support

Technologies

Kimimori Hamada TOYOTA MOTOR CORPORATION


Contents1. Toyota Hybrid System1. Toyota Hybrid System--II (THSII (THS--II)II)2. Electric Components in Hybrid system 2. Electric Components in Hybrid system 3. 3. HV Inverter SimulationHV Inverter Simulation4. IGBT development4. IGBT development5. Conclusion5. Conclusion


1. Toyota Hybrid System1. Toyota Hybrid System--IIII(THS(THS--II)II)


Toyota Hybrid System IIToyota Hybrid System II

Power split

GeneratorBattery

Motor

Mechanical power path

Electrical power path

Hybrid transmission

Engine

Power control unit

Inverter Boostconverter

device


Toyota Hybrid System IIToyota Hybrid System IIWith two-stage motor speed reduction device

Mechanical power path

Electrical power pathPower control unit

Power split device

Generator

Inverter

BatteryMotor

Hybrid transmission

Engine

Boost

Two-stage motor speed reduction device

Speed

Torq

ue

Output in high gear position

Output in low gear position

converter


Motor EfficiencyMotor Efficiency

Highefficiency area

Motor speed

Mot

or to

rque

Fixed motor speed reduction device

Motor speedM

otor

torq

ue

Two-stage motor speed reduction device


Fuel Efficiency & Fuel Efficiency & Acceleration PerformanceAcceleration Performance

20.0

22.5

25.0

27.5

30.0

32.5

35.0

2.5 3 3.5 4 4.5 530-50 mph (sec)

US

mod

e fu

el e

ffici

ency

(MP

G)

GS430

GS350

RX400hGToyota(2.4L)

E

B

DA

F(2.4L)

C

GoodGS450h（FR-HV)


2. Electric Components 2. Electric Components in Hybrid Systemin Hybrid System


Electric Circuits and Energy Flow in THSElectric Circuits and Energy Flow in THS--IIII

Filtercapacitor

Maincapacitor Inductor 288V

650V

PCU (power control unit)

Battery

Boost Converter

Inverterfor generator

Inverterfor motor

Generator

Motor

30kW

50kW

20kW




Reactor

Water-cooled heat sink

Smoothing capacitor

Boost power module

MG-ECUConverter

Inverter

& filter capacitor

Inverter power module

Internal Structure of PCU for GS450h

- Cooling units- Electric/electronic circuits- Power semiconductors- Simulation


3. HV Inverter Simulation3. HV Inverter Simulation


Inverter

Motor

ControllerTimeVe

hicl

e Sp

eed

TimeTem

pera

ture

Accelerator signal

Aims of Simulation TechnologyAims of Simulation Technology

Battery

INPUT

- Chip temperature- Current balance- Voltage surge- Power dissipationetc.

OUTPUT


Overall Structure of HV Inverter SimulationOverall Structure of HV Inverter Simulation

IGBT module

Electrical modelElectrical model

Heatsink

Controlsystem

Thermal modelThermal model

System modelSystem model

MotorTemp.

Smoothing capacitor

INVERTER

Accelerator signal

Current

Voltage

Voltage

Current

Loss

Vehicle specificationsCurrent

Frequency

Torque

(Weight, tire-diameter)

Diagram of electro-thermal-mechanical simulationfor HV inverter system


E2

VVP1GVVP1E

RuLu

RvLv

RwLw

VVN1E

VWP1GVWP1E

VWN1G

VUP1GVUP1E

VUN1G

VWN1E

VVN1G

IGBT_WP1

IGBT_WN1 IGBT_VN1

IGBT_VP1

IGBT_UN1

IGBT_UP1

DWP1

DWN1

DVP1

DVN1

DUP1

DUN1

L1

R1

C1

L2

R2

C2

Lu2

Lu3

IGBT_WP2

DWP2

IGBT_WN2

DWN2VWN2GVWN2E

VWP2GVWP2E

VUN1E

DUN2

DUP2

DVN2

DVP2

IGBT_UN2

IGBT_UP2

IGBT_VN2

IGBT_VP2

VUP2GVUP2E

VUN2GVUN2E

VVN2G

VVN2E

VVP2GVVP2E

Lu9 Lu4

Lu10 Lu5

Busbar parasitic inductance matrix

Motor

Capacitors

Diodes

IGBTs

Gate drive circuits

U V W

Electrical model in HV inverter system

(1) Electrical modelMajor Parts of Inverter SimulationMajor Parts of Inverter Simulation


IGBT power loss

Temperature of IGBT

Bottom of heatsink

Thermalinterference part

Silicon (IGBT)SolderCopper (DBC)AlN (DBC)Copper (DBC)SolderCopper (base plate)GreaseAluminum alloy(heatsink)

Heat transfer

Diode power lossTemperature of diode

(2) Thermal model

Compact thermal model (CTM) for IGBT moduleincluding water-cooling system


Prediction of IGBT temperature at full-throttle acceleration

0

25

50

75

100

0 1 2 3 4Time [s]

Tem

pera

ture

rise

[deg

ree

C]

SimulationMeasurement

Verification of HV Inverter SimulationVerification of HV Inverter Simulation


4. IGBT Development4. IGBT Development


Battery

Boostconverter

Inverter

Generator

Motor

HighHigh--Voltage Electrical SystemVoltage Electrical System

PriusPrius 500VDC 200VDC650VDCRX400hRX400h 288VDC

970V1200V

Bus line voltage Battery voltageIGBT VBD


Electric field (V/m）

Increase of resistivity

Improvement of IGBT Breakdown VoltageImprovement of IGBT Breakdown Voltage

N- drift layer

N+

P-

VB=area

Ecrit

600

800

1000

1200

1400

50 100 150 200Thickness of drift layer (um)

Bre

akdo

wn

volta

ge (V

)

50

150

250

350

450

On-

stat

e lo

sses

(W)

d

Increase of thicknessN+ buffer layer

(A)

(B)

P+ substrate

●

Increase of on-state losses accompanied with improvement in breakdown voltage

General ways to improve breakdown voltage of IGBT


Introduction of Introduction of EElectric lectric FField ield DDispersion (EFD) Layerispersion (EFD) LayerConventionalstructure(trench IGBT)

Conventionalstructure(trench IGBT)

Novelstructure(EFD IGBT)

N- drift layer

N+

P-

N+ buffer layerP+ substrate

N- drift layer

N+

P-


N- drift layer

N+

P-


EFD layer

Electricfield (V/m)

Electric fielddispersionprincipal

(Low BV)(High BV)(High BV)


Design and Effect of EFD LayerDesign and Effect of EFD Layer

1180

1190

1200

1210

Doping concentration of EFD layer (arb. unit)

Bre

akdo

wn

volta

ge (V

)

Thinner -10%

1000

1100

1200

1300

Without EFD layer

Bre

akdo

wn

volta

ge (V

)

230

250

270

290

On-

stat

e lo

sses

(W)

WithEFD layer

Thicker

Effect of EFD layerBreakdown voltage dependence on EFD layer conditions


Benchmark of Toyota InBenchmark of Toyota In--House IGBTsHouse IGBTs

180

220

260

300

340

500 750 1000 1250 1500Breakdown voltage (V)

On-

stat

e lo

sses

(W/c

m2 )

‘06 GS‘05 RX

Competitors

Good Toyota


Evolution of InEvolution of In--House IGBTsHouse IGBTs

Chip appearance

Chip size (mm2)

Chip thickness (um)

Breakdown voltage (V)

On-state losses(W/cm2)

Item ’03 Prius ’05 RX

13.7×9.7 12.75×9.39

380 375970 1200

265 242

’06 GS

300

232

12.75×9.39

1200

Device structure Planar IGBT EFD IGBT EFD IGBT


5. Conclusion5. Conclusion-

-

-

-

THS-II realizes dual requirements of fuel efficiency and acceleration performance by employing boost converter and two-stage motor speed reduction device.The electrical components of the THS-II are contributing to making the system more compact, and lightweight, and to increasing its power density.An HV inverter simulation has been developed as a powerful tool for HV system development.Low loss high-breakdown voltage novel IGBTs ,named EFD IGBTs, have been successfully developed for the THS-II.


Thank you!Thank you!

Documents

3.1 (version 1.1)