Start Date: 1.7.2009
End Date: 1.7.2013
Stijn v. Dooren
31.1.2011 Nachhaltigkeit.org repeats the ETH Life article.
21.1.2011 ETH Life reports on Philipp Elbert winning the Hans-Eggenberger Prize for his Masterthesis.
1.1.2011 Congratulations! Philipp Elbert's Masterthesis "Optimal Component Design for Serial Hybrid Electric Buses" was awarded the Hans Eggenberger Prize.
1.10.2007 Stadtbus.de Onlinemagazin
AHEAD Project Impressions
18m Hybrids by HESS on Schweiz Aktuell
Vossloh-Kiepe explain their Hybrid Technology used in HESS's lighTram Hybrid
A test drive in HESS's lighTram Hybrid
Peer Reviewed Journals
Elbert P., Ebbesen S., Guzzella L., "Implementation of Dynamic Programming for n-Dimensional Optimal Control Problems with Final State Constraints," 2012, IEEE Transactions on Control Systems Technology, Vol 21, No. 3, pp. 924-931
Ebbesen S., Elbert P., Guzzella L., "Engine Downsizing and Electric Hybridization Under Consideration of Cost and Drivability," 2012, Oil & Gas Science and Technology – Rev. IFP Energies nouvelles, doi: dx.doi.org/10.2516/ogst/2012030
Peer Reviewed Conferences
Elbert P., Ebbesen S., Guzzella L., "Economic Viability of Battery Load-Leveling in Hybrid Electric Vehicles using Supercapacitors," 2011, Int. Scientific Conference on Hybrid Electric Vehicles, RHEVE 2011, Rueil-Malmaison, France
Ebbesen S., Elbert P., Guzzella L., "Engine Downsizing and Electric Hybridization Under Consideration of Cost and Drivability," 2011, Int. Scientific Conference on Hybrid Electric Vehicles, RHEVE 2011, Rueil-Malmaison, France
Elbert P., Nüesch T., Ritter A., Murgovski N., Guzzella L., "Engine On/Off Control for the Energy Management of a Hybrid Electric Bus via Convex Optimization," 2013, Submitted to IEEE Transactions on Vehicular Technology.
Nüesch T., Flankl M., Elbert P., Onder, C., Guzzella L., "Convex Optimization for the Energy Management of HEVs Considering Engine Start and Gearshift Costs," 2013, Submitted to Energies, Special Issue Advances in Hybrid Electric Vehicles.
Guzzella L., Gisler H.J., Elbert P., Widmer M., Onder C., "Systematic Optimization of a Serial Hybrid Electric Bus," 2013, in preparation.
This project aimed at optimizing the powertrain of a serial hybrid electric bus for public transportation. First the optimal sizing of the powertrain components (sizes of combustion engine, supercapcitor, traction motor, etc) were found using optimal control theory. Then an optimal energy management was implemented on the vehicle. Using the standardized on-road test procedure it was shown that the serial hybrid electric bus consumes between 17.5 and 27.5% less fuel than a comparable diesel bus. Running on a real busline for 3 weeks, the serial hybrid bus consumed in average 25% less than a comparable diesel bus.
This project is a cooperation of HESS AG (Bellach, Solothurn) and ETH Zürich. It is sponsored by KTI and BFE. This project was awarded the Hans Eggenberger Preis 2010, and won the second prize in the European Satellite Navigation Competition.
Hardware of a serial hybrid powertrain: The bus is propelled by an electric traction motor (see figure below). Electric energy is delivered by an engine-generator set in the back of the vehicle. During downhill driving and braking maneuvers, the traction motors regenerate kinetic and potential energy, which is then stored in the electric double-layer capacitors (EDLCs) on the roof of the bus. This "recuperated" energy can be used for propulsion later on.
Components have to fit vehicle and mission: The components of the powertrain have to be adjusted to the primary use of the bus. If for example the route is a flat and straight road without many stops the components will be very different from the case where the bus is driven in a hilly city. This project develops methods and tools to find the optimal design for a vehicle's primary use.
Optimal energy management needed: During operation, the vehicle requires an energy management controller that decides upon the power split, i.e., how the traction power to be delivered is split up between the diesel generator set and the superacapacitors. A good energy management controller is crucial for good fuel economy. In this project, a fuel-optimal energy management controller was developed and implemented on the vehicle. Using the standardized on-road test procedure, it was shown that the serial hybrid electric bus together with the fuel-optimal energy management reduces consumption by 17.5-27.5% compared to a conventional diesel bus.
Information about future elevation profile allows saving energy: Nowadays, a GPS almost every city bus is equipped with a GPS receiver that allows to detect the position of the bus on the busline. Together with a map of the busline stored on-board, the system can provide specific data to the energy management system. This way, the supercaps can be discharged prior to long descend and recuperation energy that otherwise would have been lost can be used to recharge the supercapacitors. This way, the system is more robust to altitude variations on buslines.
Project goals: In public transportation, where buses run only on very few routes, the design of the vehicle can be specialized and optimized. This project seeks
i) to find the fuel-optimal component sizes for a given vehicle on a given route;
ii) to implement a fuel-optimal, predictive energy management strategy that takes into account the future elevation profile.
Practical outcomes: HESS benefits from
i) reduced time and cost for development and design;
ii) the possibility to demonstrate and compare the performance of powertrain designs.
The costumer of a HESS bus benefits from
iii) 25% reduced CO2 emissions;
iv) 25% reduced fuel cost.
Scientific research topics: Hybrid electric vehicle design and optimization and predictive control of hybrid electric vehicles.
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