There are several possible configurations and technologiesfor the powertrains of electric and hybrid vehicles, but most ofthem will include advanced energy storage systems comprisingbatteries and ultra-capacitors. Thus, it will be of capitalimportance to evaluate the power and energy involved inbraking and the fraction that has the possibility of beingregenerated. The Series type Plug-in Hybrid Electric Vehicle (SPHEV),with electric traction and a small Internal CombustionEngine ICE) powering a generator, is likely to become aconfiguration winner. The first part of this work describes themodel used for the quantification of the energy flows of avehicle, following a particular route. Normalised driving-cyclesused in Europe and USA and real routes and traffic conditionswere tested. The results show that, in severe urban drivingcycles,the braking energy can represent more than 70% of therequired useful motor-energy. This figure is reduced to 40% insuburban routes and to a much lower 18% on motorwayconditions. The second part of the work consists on theintegration of the main energy components of an S-PHEV intothe mathematical model. Their performance and capacitycharacteristics are described and some simulation resultspresented. In the case of suburban driving, 90% of the electricalmotor-energy is supplied by the battery and ultra-capacitors and10% by the auxiliary ICE generator, while on motorway thesewe got 65% and 35%, respectively. The simulations alsoindicate an electric consumption of 120 W.h/km for a small 1ton car on a suburban route. This value increases by 11% in theabsence of ultra-capacitors and a further 28% without regenerative braking.
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