1. HEVs as Environmental Friendly Vehicles The 4th FEALAC Working Group
Battery
Inverter
Generator
Motor/ Generator
Engine
The 4th FEALAC Working Group
on Science and Technology
June 2006, Bangkok
Nobuo IWAI　
Japan Automobile Research Institute, JARI

2. ３E Environment Economy Energy
What's The Environmental Friendly Vehicles ?
Priority
1. Air Pollution Control
2. Global Warming (Energy Saving)
3. Sustainable Mobility
Future Fuel, Energy Diversification, Renewable Energies
Environment
Economy
Energy ３E

3. Regulations on Gasoline Vehicle Exhaust Emissions in Japan
CO:
HC:
NOｘ:

4. Regulation on Diesel Vehicle Exhaust Emissions in Japan
NOx:
Vehicle Exhaust Emission Problems Could Be Solved Until 2010 in Japan
PM:
Next big issues are Energy saving and Energy Diversification

6. Fuel Economy of Gasoline Vehicles
F.E. km/L
Conv. Gasoline
HEV
Lean Burn
SIDI
2010 Regulation
GVW kg

7. HEVs in USE in Japan Vehicle Numbers 94 95 96 97 98 99 00 01 02 03 04
（台）
（年度末）
Years

8. Engine Weak Point Is Low Efficiency at Low Load
Principle of HEV Operation
Efficiency
１．Engine Stop at Idling
２．Recovered Brake Energy
Engine Driven
３．Motor
Driven
Energy Loss ：High Efficient Engine Operation →Generator→ Bat. Storage →Traction Motor
Load
Engine Weak Point Is Low Efficiency at Low Load

9. Recovery of Deceleration Energy20 40 60
-120
-80
-40 80
120
100
140
Driving wheel power (kW)
Time sec
Drive work: 1.0
Deceleration work: 0.6
Vehicle speed (km/h)
Recovery of Deceleration Energy

10. No engine idling at vehicle stop is effective for energy saving
Vehicle speed
Average
vehicle speed

11. Operation on HEVs Stop Start Acceleration Cruising Deceleration Stop
Idling
Stop
Motor run
Motor +
Engine run
Engine run
+ Generation
Motor regeneration
Vehicle Speed
Motor/ Generator
Engine
Battery
Motor/ Generator
Generator
Engine
Battery
Motor/ Generator
Engine
Battery
Motor/ Generator
Generator
Engine
Battery
Motor
/Generator
Generator
Engine
Battery
Generator
Generator

12. Driving Modes

13. Fuel Economy Improvement Ratio Under the Different Driving Modes

14. 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.
Low Capacity
Energy
Storage
System
(ESS)
High Capacity
ESS
Fuel Tank
Inverter
Inverter
Fuel Tank
M/G GE
Engine
Non Plug-in HEVs
Conventional HEVs
M/G GE
Engine
Daily trip distance
is not so long
Source:
US National Highway
Travel Survey 2001

15. Plug-in HEV Operation Modes
Starts as a BEV then transition to HEV
Conv. HEV
Power
Required
ultra large batteries
large motor and
power electronics
BEV
operation
Ｄｉｓｔａｎｃｅ
Starts like a conventional HEVs
・Drive as a BEV at low load like a commuter
・Drive by engine at high load
Power
Using engine at high load
BEV
operation
Conv. HEV
Ｄｉｓｔａｎｃｅ
Required
large batteries to meet daily drive
Source: US National Highway
Travel Survey 2001

16. Fuel costs, CO2, Fuel economy & Emission of Plug-in HEVs
Source: EPRI-Car Co’s.-DOE Labs study ”Comparing HEVs options”-Conv. and hybrids P0,P20,P60 for a 1500kg car

17. Fuel Cycle Energy, Annual Gasoline Use & Purchase Costs for Midsize 1350kg car
Source: EPRI study
Energy storage systems are biggest problems

18. Ｃｈａｒａｃｔｅｒｉｓｔｉｃｓ ｏｆ Various Energy Storage Systems
Flywheel Battery
Capacitor
Li-ion Battery
Ni-MH Battery
Lead battery
Charge/discharge mechanism
Flywheel rotation
Electric
charge
Chemical reaction
SOC tracking
Flywheel rpm
Voltage (1/2CV2)
Voltage
Current integration
Self-discharge
Large
Low
Life
Semi-permanent
500
Temperature dependency
High
Power density
Very high
Energy density
Medium

19. Honda IMA System Production HEVs in Japan Parallel HEVs
INSIGHT (Honda)
Parallel HEVs
CIVIC（HONDA)
Honda IMA System
(Integrated Motor Assist)
Engine +
Motor Assist
Battery
Engine
PCU
Motor &
Generator
Honda Multimatic
ホンダＩＭＡシステム
これはプリウスに続き1998年に量産開始したホンダインサイトです。
ハイブリッドとしては典型的なパラレル方式を採用し、通常はエンジンで走行し、加速時にモーターからの動力を利用しています。エンジンを停止させたままのEV走行は行わず、パワーアシストタイプのマイルドハイブリッドと言えます。
このハイブリッドシステムに加え、車両の軽量化、Ｄrag Coｰefficient、高効率エンジンにより高い燃費性能を実現させています。
Motor Assist

20. (Toyota Hybrid System)
Production HEVs in Japan
Series/Parallel HEVs
PRIUS(TOYOTA)
THS
(Toyota Hybrid System)
Gasoline
engine
Power split
device
Generator
Inverter
Motor
Battery
Here, we have the Toyota series parallel hybrid system we call “THS”. This system has two motors and a planetary gear.
This is installed in the world first production hybrid car “Prius”
This is in the “strong HV” category that means that the engine can be stopped while the car is being driven and car can then be operated using its EV system.
We think the THS has the ideal hybrid configuration to achieve high fuel economy performance and clean potentials.

21. (Toyota Hybrid System)
Production HEVs in Japan
Series/Parallel HEVs
HARRIER(TOYOTA)
THS-II
(Toyota Hybrid System)
Gasoline
engine
Power split
device
Generator
Inverter
Motor
Battery
Front wheel
Rear wheel
Rear Mot
KLUGER(TOYOTA)
Here, we have the Toyota series parallel hybrid system we call “THS”. This system has two motors and a planetary gear.
This is installed in the world first production hybrid car “Prius”
This is in the “strong HV” category that means that the engine can be stopped while the car is being driven and car can then be operated using its EV system.
We think the THS has the ideal hybrid configuration to achieve high fuel economy performance and clean potentials.
Engine 155kW
System 200kW

22. (Toyota Hybrid System-CVT)
Production HEVs in Japan
Series/Parallel HEVs
ESTIMA(TOYOTA)
THS-C
(Toyota Hybrid System-CVT)
Battery
Inverter Rr
Rear MG
CVT
Inverter Fr
Engine
Fr. MG
Front Wheel
Rear Wheel
St. MG
ALPHARD(TOYOTA)
This slide shows the THS-C, a ‘strong’ or ‘full’ hybrid system similar to the Prius THS. This system has been mounted on an Estima, a large RV. It has been introduced in Japan last year.
It differs from the Prius system because it will also have a mechanical CVT feature.
The drive power is mainly supplied from the engine, with some motor assist.
And, there is a second motor at the rear, so it is possible to create a 4WD without a drive shaft.

23. Production HEVs in Japan LEXUS GS450h (TOYOTA) Series/Parallel HEVs
Engine 218kW
Motor 147kW
Front Engine/Rear Drive

24. Production HEVs in Japan Parallel HEVs (NISSAN DIESEL)
Capacitor Hybrid M.D. Diesel Truck
Inverter
Diesel Engine
Electronic Control Mechanical A/T
Electronic Control Brake System
EDLC* System
(*Electric Double Layer Capacitor)
Motor / Generator x 1
Max. 55kW
Electronic Control Mechanical Clutch
Gearbox
Nissan Diesel EDLC System
( Super Power Capacitor TM )
Max. 346V,583Wh

25. Incentive for introduction A - B ×C 2
   
                                                                              
Incentive for introduction
A - B = ×C 2
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

26. 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.