Page 180 - Automotive Engineering Powertrain Chassis System and Vehicle Body

CH AP TER 7 .1 Hybrid vehicle design

Fig. 7.1-8 Advanced PM motor system: (a) trapezoidal iron conductors; (b) motor performance; (c) motor curve; (d) target performances.

7.1.3.6 Taxi hybrid drive for the engine is further away from its design point and
greater energy wastage is involved in braking. In urban
Based on a Range Rover, an EC project involving Rover, gas usage, the average power consumption of the vehicle is
turbine maker OPRA, Athens Technical University, quite low since average vehicle speeds are low. Typical
Hawker Batteries and Renault was carried out at Imperial power consumption figures are shown at (b) with only
College so as to provide a hybrid powertrain for a Euro- 5 kW being sufficient to drive the vehicle at a speed of
pean taxi, Fig. 7.1-10, and in particular the development 60 km/h, generally above the average vehicle speed for
of a turbogenerator. A system involving a gas turbine and European cities. However, large, short duration power
high speed generator together with a small battery pack demands must be met to provide sufficient acceleration.
for power storage and zero-emission city driving in a series Since the rate of energy consumption is low in the urban
configuration has been proposed by the EC and the tur- regime, this energy can be provided by means of a lead–
5
bogenerator work is reported by Pullen and Etemad , (a). acid battery and give an acceptable range of 50–70 km.
Its proponents point to the unpleasant side-effects of Such a battery must, however, be capable of meeting the
traffic congestion with conventional vehicles in that re- peak power demands for acceleration without over-
duced vehicle speeds cause the engine to run more than heating. High specific energy ‘advanced’ lead–acid bat-
necessary for each journey: the average operating point teries are hence required.

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