There are several possible configurations and technologies
for the powertrains of electric and hybrid vehicles, but most of
them will include advanced energy storage systems comprising
batteries and ultra-capacitors. Thus, it will be of capital
importance to evaluate the power and energy involved in
braking and the fraction that has the possibility of being
regenerated. The Series type Plug-in Hybrid Electric Vehicle (SPHEV),
with electric traction and a small Internal Combustion
Engine ICE) powering a generator, is likely to become a
configuration winner. The first part of this work describes the
model used for the quantification of the energy flows of a
vehicle, following a particular route. Normalised driving-cycles
used in Europe and USA and real routes and traffic conditions
were tested. The results show that, in severe urban drivingcycles,
the braking energy can represent more than 70% of the
required useful motor-energy. This figure is reduced to 40% in
suburban routes and to a much lower 18% on motorway
conditions. The second part of the work consists on the
integration of the main energy components of an S-PHEV into
the mathematical model. Their performance and capacity
characteristics are described and some simulation results
presented. In the case of suburban driving, 90% of the electrical
motor-energy is supplied by the battery and ultra-capacitors and
10% by the auxiliary ICE generator, while on motorway these
we got 65% and 35%, respectively. The simulations also
indicate an electric consumption of 120 W.h/km for a small 1
ton car on a suburban route. This value increases by 11% in the
absence of ultra-capacitors and a further 28% without regenerative braking.Fundação para a Ciência e a Tecnologia (FCT) - MIT-Pt/EDAMSMS/0030/200
