The aim of this paper is to propose a methodology for managing the Li-ion battery lifetime of a whole fleet with the aim to improve the total cost of ownership of hybrid electric buses. This approach has been addressed from two points of view the bus-to-route and route-to-bus approaches. The bus-to-route optimization is focused on the energy management strategy generation of each bus of the fleet. A techno-economic, route energetic evaluation and battery aging analysis of the fleet have been performed. From the outcome of this analysis, the buses have been grouped, according the state of health of each bus. Based on the analysis and classification, the route-to-bus approach is applied. This technique lies on both, a re-evaluation of the energy management system and/or the re-organization of the buses according to the state of health of each bus. Increases of BT lifetimes up to 10.7% are obtained with the proposed approach.

In order to be attractive in a very competitive market, hybrid electric buses and full electric buses need to reduce the total cost of ownership (TCO) compared to conventional buses. In this regard, the sizing of the onboard energy storage and the charging infrastructure becomes a key design stage. An optimal onboard storage and charging facilities are necessary to offer an appropriate vehicle autonomy, but they involve high investment costs for the manufacturer and fleet operator. Furthermore, the complex interrelations between these parameters make the best-performed system design a challenging process. To face this issue, the paper proposes an optimization methodology for the onboard storage capacity sizing, charging points rate and charging points location, aiming a total cost of ownership improvement for hybrid and full electric bus routes. As case study, several routes have been selected in the city of Donostia (Spain) to techno-economically evaluate the proposed methodology regarding factors such as: onboard storage cost, charging infrastructure cost, fuel cost, and electricity-grid cost.

The aim of this paper is to propose a battery aging conscious energy management strategy. The initial design of an energy management strategy is a significant point, in order to fulfill the efficiency goals in a short term. However, with the aging, the initial conditions vary. The new trend of digitalization allows to monitor the operation, having the possibility to improve the performance of the initial proposed strategy in a long term. Therefore, a methodology for updating the energy management strategy along the bus lifetime is proposed, in order to improve the operation costs and extend the battery lifetime. This methodology is based on a dynamic programming optimization, tuning the membership functions in a fuzzy logic control. The simulation results show a reduction of the operation costs up to 47% together with a BT lifetime extension of around 2.94%.