Abstract
This paper presents an evaluation of battery requirements for hybrid and electric city buses. Technical specifications of recently developed lithium based batteries and vehicle simulation results are used as basis for the evaluation. The battery requirements are evaluated in terms of power and energy capacity, calendar and cycle life as well as costs. Conventional diesel, parallel and series hybrid, plug-in hybrid, and electric city bus were chosen as different bus applications. The simulation results of the diesel powered city bus were used as reference for performance requirement and a point of comparison in operation cost analysis. Simulations were carried out in four different types of driving cycles. The evaluation shows that lithium based batteries offer sufficient specific power and energy capacity meanwhile requirements for costs and cycle life durability are dependent on the bus application, the driving cycle, and the operation schedule. Especially a power intensive driving cycle can be challenging for the high energy batteries in terms of cycle life. There are also noticeable differences in performance between different battery chemistries. For plug-in hybrid and electric city buses, fast recharge capability can increase significantly the costeffectiveness in bus fleet operation. The operation cost analysis also indicates that the battery cost is more important for the plug-in hybrid and electric buses whereas the initial cost of the bus is a major factor for the charge sustaining parallel and series hybrid buses.
Highlights
For hybrid and electric city buses, the energy storage is one of the most important components in terms of overall energy efficiency, bus lifecycle and costs [1]
This paper evaluates battery requirements for parallel (PAR) and series (SER) hybrid, plug-in hybrid (PHV), and electric (EV) city buses
As typical operation pattern of a city bus is energy intensive, cycle life requirement can be quite high for lithium based batteries which leads to the need of replacing the battery pack many times during the lifetime of a bus
Summary
For hybrid and electric city buses, the energy storage is one of the most important components in terms of overall energy efficiency, bus lifecycle and costs [1]. Lithium based batteries have proven to be suitable choice for hybrid and electric passenger vehicles. They offer sufficient power and energy capacity, they are relatively safe, and their calendar and cycle life is long enough at least for hybrid vehicles [2], [3]. Battery aging and lifecycle has been under growing interest in several research studies e.g. In hybrid and electric city buses, the most typical choice is to use batteries as sole energy storage. The energy efficiency of the different bus applications was analysed and the battery impact on the cost effectiveness in bus fleet operation was evaluated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
