HEVs as Environmental Friendly Vehicles

Nobuo IWAI　Japan Automobile Research Institute, JARI

The 4th FEALAC Working Group

on Science and Technology29 - 30 June 2006, Bangkok

Battery

Inverter

Generator

Motor/Generator

Engine

What's The Environmental Friendly Vehicles ?

Priority1. Air Pollution Control2. Global Warming (Energy Saving)3. Sustainable Mobility Future Fuel, Energy Diversification, Renewable Energies

EnvironmentEconomy Energy

３E

Regulations on Gasoline Vehicle Exhaust Emissions in Japan

CO: 2.7%@2005/1965

HC: 0.8%@2005/1969

NOｘ : 1.6%@2005/1971

Regulation on Diesel Vehicle Exhaust Emissions in Japan

NOx: 12%@2005/19735%@2009/1973

PM: 3%@2005/19731%@2009/1973

Vehicle Exhaust Emission Problems Could Be Solved Until 2010 in Japan

Next big issues are Energy saving and Energy Diversification

2006 Fuel Economy Guide Lists Top 10 Vehicles

1 Honda Insight 60/66 mpg2 Toyota Prius 60/51 mpg3 Volkswagen New Beetle TDI (manual) (tie)

Volkswagen Golf TDI (manual) (tie)4 Volkswagen J etta TDI(manual) 36/41 mpg5 Ford Escape Hybrid FWD 36/31 mpg6 Volkswagen New BeetleTDI (automatic) (tie)

Volkswagen J etta TDI (automatic) (tie)7 Volkswagen Golf TDI (automatic) 33/44 mpg8 Ford Escape Hybrid AWD (tie)

Mercury Mariner Hybrid AWD (tie)9 Lexus RX 400h 2WD (tie)

Toyota Highlander Hybrid 2WD (tie)10 Toyota Corolla 32/41 mpg

Source: U.S. Environmental Protection Agency

37/44 mpg

35/47 mpg

33/29 mpg

33/28 mpg

http://www.mlit.go.jp/jidosha/nenpi/nenpilist/05-1.pdf

Conv. GasolineHEVLean BurnSIDI2010 Regulation

F.E. km/L

Fuel Economy of Gasoline Vehicles

GVW kg

（年度末）

（台）

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

200,000

H５ H６ H７ H８ H９ H１０ H１１ H１２ H１３ H１４ H１５ H１６

ハイブリッド車保有台数推移

原付自転車( )二輪･四輪軽自動車

特殊車

乗合車

貨物車

乗用車

93 94 95 96 97 98 99 00 01 02 03 04

Years

Vehicle Numbers

HEVs in USE in Japan

Load

Efficiency

Energy Loss ： High Efficient Engine Operation →Generator→ Bat. Storage →Traction Motor 　　　　

Engine Driven３．MotorDriven

Engine Weak Point Is Low Efficiency at Low Load

Principle of HEV Operation

１． Engine Stop at Idling２． Recovered Brake Energy

++

En

erg

yE

ner

gy

Energy supply to Energy supply to make up for shortagemake up for shortage

Engine output energy Engine output energy with maximum efficiency with maximum efficiency

Energy Storage(Battery)Energy Storage(Battery)

Recovery of Recovery of braking energybraking energy

Storage of Storage of excess energyexcess energy

TimeTime

Acceleratio

n

Acceleratio

n

DecelerationDeceleration

Engine turns offEngine turns off

--

0

20

40

60

-120

-80

-40

0

40

80

120

0 20 40 60 80 100 120 140

Dri

vin

g w

he

el p

ow

er

(kW

)

Time sec

Drive work: 1.0

Deceleration work: 0.6

0 20 40 60 80 100 120 140Veh

icle

spe

ed

(km

/h)

Recovery of Deceleration

Energy

0

20

40

60

80

100

0 20 40 60 80 100

Rat

e %

Average vehicle speed km/h

Fuel consumption rate

Time rate during vehicle stop

No engine idling at vehicle stop is effective for energy saving

Vehicle speed

Averagevehicle speed

Veh

icle

V

ehic

le

Sp

eed

Sp

eed

StopStop StartStart AccelerationAcceleration CruisingCruising DecelerationDeceleration StopStop

Motor/Generator

Engine

Battery

Motor/Generator

Generator

Engine

Battery

Motor/Generator

Engine

Battery

Motor/Generator

Generator

Engine

Battery

Motor/Generator

Generator

Engine

Battery

IdlingStop

Motor runMotor +

Engine runEngine run

+ GenerationMotor

regeneration

Operation on HEVs

GeneratorGenerator

Driving Modes

Fuel Economy Improvement Ratio Under the Different Driving Modes

EngineM/G

Inverter

GE

Fuel Tank

Energy

Storage

System

(ESS)

EngineM/G

Inverter

GE

Fuel Tank

ESSHigh Capacity

Low Capacity

Plug-in HEVs for the future Recharge from an electric outlet Daily trip is running as a BEV. Long trip is running as a Conv. HEV.

Non Plug-in HEVsConventional HEVs

Source:US National HighwayTravel Survey 2001

Daily trip distance is not so long

Conv. HEV

Conv. HEV

BEV operation

BEV operation

Using engine at high load

Ｄｉｓｔａｎｃｅ

Power

Ｄｉｓｔａｎｃｅ

Power

Plug-in HEV Operation ModesStarts as a BEV then transition to HEV

Starts like a conventional HEVs・ Drive as a BEV at low load like a commuter・ Drive by engine at high load

Required ultra large batteries large motor and power electronics

Required large batteries to meet daily drive

Source: US National HighwayTravel Survey 2001

Source: EPRI-Car Co’s.-DOE Labs study ”Comparing HEVs options”-Conv. and hybrids P0,P20,P60 for a 1500kg car

Fuel costs, CO2, Fuel economy & Emission of Plug-in HEVs

Energy storage systems are biggest problems

Fuel Cycle Energy, Annual Gasoline Use & Purchase Costs for Midsize 1350kg car

Source: EPRI study

FlywheelBattery

CapacitorLi-ion

BatteryNi-MH

BatteryLead

battery

Charge/discharge mechanism

Flywheel rotation

Electriccharge

Chemical reaction

SOC trackingFlywheel

rpmVoltage (1/2CV2)

Voltage Current integration

Self-discharge

Large Low

Life Semi-permanent 1000-10000 500

Temperature dependency

Low High

Power density High Very high High High Low

Energy density

Low Low High High Medium

Ｃｈａｒａｃｔｅｒｉｓｔｉｃｓ　ｏｆ　Ｃｈａｒａｃｔｅｒｉｓｔｉｃｓ　ｏｆ　Various Energy Storage SystemsVarious Energy Storage Systems

Battery

Engine

PCU

Motor &Generator

Honda Multimatic

INSIGHT (Honda)

Honda IMA System(Integrated Motor Assist)

Production HEVs in Japan

CIVIC（HONDA)

Parallel HEVsParallel HEVs

Engine +Motor Assist

Motor Assist

THSTHS(Toyota Hybrid System)(Toyota Hybrid System)

Gasoline engine

Power split

deviceGenerator

InverterMotor

Battery

PRIUS(TOYOTA)

Series/Parallel HEVsSeries/Parallel HEVs

Production HEVs in Japan

THS-IITHS-II(Toyota Hybrid System)(Toyota Hybrid System)

HARRIER(TOYOTA)

Gasoline engine

Power split

deviceGenerator

InverterMotor

Battery

Front wheel Rear wheel

Rear Mot

KLUGER(TOYOTA)

Series/Parallel HEVsSeries/Parallel HEVs

Production HEVs in Japan

Engine 155kWSystem 200kW

THS-C THS-C (Toyota Hybrid System-CVT)(Toyota Hybrid System-CVT)

BatteryBattery

Inverter RrInverter Rr

RearRearMGMGCVTCVT

Inverter FrInverter Fr

EngineEngine

Fr. MGFr. MG

Front WheelFront Wheel Rear WheelRear Wheel

St. MGSt. MG

ESTIMA(TOYOTA)

ALPHARD(TOYOTA)

Series/Parallel HEVsSeries/Parallel HEVs

Production HEVs in Japan

Series/Parallel HEVsSeries/Parallel HEVs

Production HEVs in JapanLEXUS GS450h (TOYOTA)

Engine 218kWMotor 147kWFront Engine/Rear Drive

Capacitor Hybrid M.D. Diesel TruckCapacitor Hybrid M.D. Diesel Truck

Nissan Diesel EDLC SystemNissan Diesel EDLC System( ( Super Power CapacitorSuper Power Capacitor TM TM ))

Max. 346V,583WhMax. 346V,583WhInverterInverter

Diesel EngineDiesel Engine

Electronic Control Mechanical A/TElectronic Control Mechanical A/T

Electronic Control Brake SystemElectronic Control Brake System

EDLC* SystemEDLC* System(*Electric Double Layer Capacitor)

Motor / Generator x 1Motor / Generator x 1Max. 55kWMax. 55kW

Electronic Control Mechanical ClutchElectronic Control Mechanical Clutch

GearboxGearbox

Production HEVs in JapanParallel HEVsParallel HEVs

(NISSAN DIESEL)

A - BA - B

22×C×C

Incentive for introductionIncentive for introduction

A: Price of a HEV

B: Price of a CV

C: Coefficient of Reduction

0.9 for Light-duty HEVs

0.97 for EVs and the other HEVs

=   

                      

                                                        

Summary

• Vehicle exhaust emission problems could be solved on a next decade.• The next key issue is energy saving.• HEV’s technologies are major keys for vehicle energy saving.• Discussion on Plug-in HEVs due to use clean electricity are just started for the future energy/fuel saving and energy diversification.• Energy Storage systems, such as a battery are major technologies for downsizing and cost down of HEV systems for wide spread introduction.