Abstract
Battery electric vehicles (BEVs) are a critical pathway towards achieving energy independence and meeting greenhouse and criteria pollutant gas reduction goals in the current and future transportation sector. Emerging connected and automated vehicle (CAV) technologies further open the door for developing innovative applications and systems to leverage vehicle efficiency and substantially transform transportation systems. Therefore, we present a simulation study of various BEV types and compare the performance when driving on real-road drive cycles to highly optimized eco-driving cycles using advanced CAV technologies. The results demonstrate that eco-driving has a high potential to reduce energy consumption for all types of BEVs considered. The investigated BEVs include a compact vehicle, a transit city bus, and a Class 7 delivery truck. The impact of eco-driving on conventional vehicles was also compared to comparable BEVs. Compared to the BEVs, eco-driving provides a larger reduction in the conventional vehicle's braking energy loss, and also provides conventional vehicles with greater reductions in the engine mechanical energy output but the fuel savings did not show a consistent trend among all the conventional vehicle types. As part of the study, a comprehensive EV powertrain model was developed to account for key EV components and powertrain configurations.
Original language | English |
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Pages (from-to) | 823-839 |
Number of pages | 17 |
Journal | Energy |
Volume | 172 |
DOIs | |
State | Published - Apr 1 2019 |
Funding
This work was sponsored by the U.S. Department of Energy's Vehicle Technologies office and ARPA-E NEXT-CAR program. The authors thank our colleagues for their helpful suggestions and insights in this work. Thanks also go to the editors and reviewers for their support and volunteered time. A f Frontal area C d Aerodynamic drag coefficient C r r Rolling resistance coefficient C t r a n , S Capacity-related short-time constant of the step response of RC networks C t r a n , L Capacity-related long-time constants of the step response of RC networks F t r a c t Required vehicle tractive force h A Battery cell heat transfer rate I b a t t Battery package current output I c e l l Single battery cell outlet current I f d Final drive inertia I m o t Motor inertia I t c Torque coupler inertia I t o t Total inertia I w h Wheel tire inertia K p and K l PI control parameters m Vehicle mass m c e l l C p c e l l Mass capacity M p a r a l l e l Battery cells in parallel N s e r i e s Battery cells in series R o Series resistor R f d Final drive ratio R t c Torque coupler ratio R t r a n , S Resistance-related short-time constant of the step response of RC networks R t r a n , L Resistance-related long-time constants of the step response of RC networks R w h Wheel radius T a m b Ambient temperature T c e l l Battery cell temperature V c e l l Single battery cell outlet voltage V and V d r v Vehicle velocity V b a t t Battery package voltage output V d r v Driving vehicle speed V S O C Open circuit voltage for single battery cell V t a r g e t Targeted vehicle speed V t r a n , S Voltage of short-time step response of RC networks V t r a n , L Voltage of long-time step response of RC networks W a c c e l e c Electric accessary load W b a t t , c h g _ b d r y Battery charging power boundary W b a t t , d i s c h g _ b d r y Battery discharging power boundary W i n v , e e Motor mechanical power output W m o t , m e Inverter electrical power input
Keywords
- Component efficiency
- Eco-driving
- Electric vehicle
- Powertrain modeling