1. |
- Murgovski, Nikolce, 1980, et al.
(författare)
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Convex optimization of charging infrastructure design and component sizing of a plug-in series HEV powertrain
- 2011
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902661937 ; 18:PART 1, s. 13052-13057
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Konferensbidrag (refereegranskat)abstract
- With the topic of plug-in HEV city buses, this paper studies the highly coupled optimization problem of finding the most cost efficient compromise between investing in onboard electric powertrain components and installing a charging infrastructure along the bus line. The paper describes how convex optimization can be used to find the optimal battery sizing for a series HEV with fixed engine and generator unit and a fixed charging infrastructure along the bus line. The novelty of the proposed optimization approach is that both the battery sizing and the energy management strategy are optimized simultaneously by solving a convex problem. In the optimization approach the power haracteristics of the engine-generator unit are approximated by a convex, second order polynomial, and the convex battery model assumes quadratic losses. The paper also presents an example for a specific bus line, showing the dependence between the optimal battery sizing and the number of charging stations on the bus line.
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2. |
- Johannesson, Lars, 1979, et al.
(författare)
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Including a battery state of health model in the hev component sizing and optimal control problem
- 2013
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; , s. 398-403
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Konferensbidrag (refereegranskat)abstract
- This paper studies convex optimization and modelling for component sizing and optimal energy management control of hybrid electric vehicles. The novelty in the paper is the modeling steps required to include a battery wear model into the convex optimization problem. The convex modeling steps are described for the example of battery sizing and simultaneous optimal control of a series hybrid electric bus driving along a perfectly known bus line. Using the proposed convex optimization method and battery wear model, the city bus example is used to study a relevant question: is it better to choose one large battery that is sized to survive the entire lifespan of the bus, or is it beneficial with several smaller replaceable batteries which could be operated at higher c-rates?
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3. |
- Löfstrand, Sofia, et al.
(författare)
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Feasibility of Electrifying Urban Goods Distribution Trucks
- 2013
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Ingår i: SAE International Journal of Commercial Vehicles. - : SAE International. - 1946-391X .- 1946-3928. ; 6:1, s. 24-33
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses the feasibility of electrifying medium to heavy urban goods distribution trucks. As a case study, an existing transport system in the Swedish city of Gothenburg is used. The project is a joint research effort between a vehicle OEM, an electric utility, a fleet operator, the Swedish Transport Administration and two research organizations. One main objective is to determine if and when different electrified powertrains are cost efficient to the end user. The results indicate that by 2015 conventional powertrains are still probably the most cost effective alternative in all applications studied. But in 2025, electrified powertrains are most cost efficient for most transport scenarios. These results indicate a transition in preferred powertrain technology for urban trucks within the coming ten years. It is important to point out that this result may not be general. Driving patterns, energy price developments and technology maturity of components such as batteries and motors greatly influence the total cost of ownership and large regional differences in when such a transition may occur are expected. In addition to the total cost of ownership, important issues for a successful deployment are policies (e.g. restricting access to urban areas for noisy and polluting vehicles), information and communication solutions (e.g. adapted route planning), access to a cost effective charging infrastructure (and low-carbon electricity production) and new business models. These must all be developed in parallel to the vehicle and powertrain technology. The large number of different stakeholders involved in this transition is also a challenge in itself.
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