1. ATT Conference Barcelona, October 1-3, 2001
How to improve hybrid vehicles for environmental sustainability.
A case study of their impact. Antonio MATTUCCI, Mario CONTE, Giovanni PEDE ENEA – Advanced Energy Technologies Division
C.R. Casaccia - Via Anguillarese 301
00060 Rome (Italy)
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2. ENEA SPECIFIC ACTIVITIES IN TRANSPORT FIELD
Among the ENEA interests in the transport field, special attention is paid to the vehicle efficiency and environmental impact; in particular with:
Realisation of integrated facilities to assist design and testing of electric and hybrid vehicles and specific components of the traction system
Fleet tests under operational conditions of hybrid vehicles
Fuel cells and H2 Program
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3. Vehicle drivetrain integrated testing facility
The main parts of the facility, interconnected each other in order to provide high test flexibility , are:
Power generation section
Energy storage section
Driving motors section
Integrated control room
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4. Fleet test of hybrid vehicles
Public transport fleets have been tested in three selected cities, where 24 IVECO 490 buses have been purchased and operated for 3 year ( )
4 in Terni
8 in Ferrara
12 in Rome
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5. Fleet test of hybrid vehicles
2.8 l diesel engine
30 kW DC electric generator
164 kW AC electric motor
60 kWh capacity lead acid batteries
km range of in thermal mode and 20 km in pure electric mode
60 km/h max speed
manual selection of driving mode
IVECO 490 hybrid bus characteristics
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6. Hybrid and conventional bus test results
Fleet test of hybrid vehicles
Hybrid and conventional bus test results
Need of a control system to increase hybrid vehicle efficiency
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7. Hybrid vehicle control system framework
Series hybrid vehicle fuel consumption dependent on battery State Of Charge (SOC) and generator power
Test campaign to get additional information on hybrid specific consumption, using a purpose-designed series hybrid vehicle with the same driveline of 6m ALTROBUS
Control strategy constrains the battery SOC to stay in a selected interval and allows modifications of the thermal engine working point, with variations in a range of 20-25%, as in such interval the environmental and energetic efficiency remains high
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8. Hybrid vehicle driveline characteristics
Internal combustion engine
1.2 l diesel engine
24 kW max power 3600 rpm)
2200 rpm rating speed
Synchronous PM Machine
10 kW rating power 2200 rpm)
Storage system (battery)
96 lead acid cells
100 Ah capacity, 192 V
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9. IVECO Daily hybrid vehicle layout
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10. Hybrid vehicle DC source behaviour
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11. Daily hybrid vehicle controller development
Low cost controller, 200 ms. sampling time
Step by step controller development
Final controller version based on a forecast of the power required (based on previous average power + trip route)
Controller algorithm processes data related to battery voltage, current and SOC
First controller version has no power forecast and requires manual setting of: generator power and SOC interval limits
Controller switches on-off the thermal engine to keep the battery SOC between predefined limits
Controller effectiveness verified by means of many tests based on European, American and Japanese cycles
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12. Daily hybrid vehicle test results
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13. Effectiveness of hybrid vehicle controller
Testing on the vehicle has shown the following results:
Considerable improvement on fuel efficiency achieved, especially for the American cycle
Important to minimise start/stops of the thermal engine
Next step with thermal engine load prediction requires more sophistication for the control algorithm
Need to modify the thermal engine working point (power and speed) to gain additional efficiency
30-40% of fuel consumption reduction achievable, with similar benefits in terms of pollutant emission reduction
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Requirements for hybrid vehicle fleet deployment effectiveness analysis
Main requirements
Identification of effective application domains, where hybrid vehicles can play a special role
Measurability of resulting effects at global scale
Different effects (such as pollutant emissions, fuel consumption and even the resulting traffic conditions) to be considered at the same time
Identification of economically and technically affordable deployment experiences
Identification of appropriate analysis tools in order to simulate the resulting scenario
Use of conservative assumptions where sound information is lacking
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15. LDVs viability for hybrid vehicle fleet deployment application
Initial considerations
Light Duty Vehicles (LDVs) cover approximately 5% of the Italian fleet (2 millions of vehicles)
LDVs cover the main share of freight transport in urban areas
LDVs are responsible of relevant shares of pollutant emissions in urban areas
Results of ENEA hybrid vehicle experimental test campaign fit perfectly LDVs behaviour
TREMOVE model and reliable database are already available for a deployment study
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16. Share of LDVs pollutant emission in Italian urban areas
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17. Hybrid LDVs reduction factors for impact analysis
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18. V Incontro Expert Panel Emissioni da Trasporto su Strada
LDVs behaviour
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LDVs behaviour
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20. Hybrid LDVs urban deployment study
Milan city selected for the analysis
LDVs operating in Milan area
Introduction of hybrid LDVs begins in year 2002
The shares of new hybrid LDVs covers 20% in the year 2002, 55% in 2003 and 100% in 2004 and beyond
Total extra-cost in is about 174 MEuros, of which 12 in the year 2002 (2000 new LDVs deployed)
Two scenarios have been analysed with TREMOVE model, the first one only with hybrid introduction and the second one with also the integration of telematic systems to improve freight delivery effectiveness
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21. Hybrid LDVs first scenario results
Comparison to reference basecase shows relevant differences only on emissions
Considerable effect specially on PM ( 5%)
After 2008 no more PM reduction as almost all the oldest and dirtiest LDVs have been removed
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22. Hybrid LDVs second scenario results
Two beneficial effects, i.e. direct reduction of emissions and increase of commercial speed, respect to reference basecase
Relevant decrease of all the pollutants ( >5%)
Higher effects on fuel consumption, CO2 and CO emission
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Conclusions
Fleet tests of hybrid vehicles have shown positive performances and provided information for the fields where additional research is required
Series hybrid vehicles can be improved by the adoption of a control system able to manage the battery SOC and the thermal engine working point
Series hybrid vehicles can provide good results for applications in domains where both the vehicle efficiency and emission reduction are to be considered
The combination of hybrid technology with other provisions (technological, legislative, informative, etc.) can provide very important additional benefits
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