Page 156 - Automotive Engineering Powertrain Chassis System and Vehicle Body

Battery/fuel-cell EV design packages CHAPTER 6.1

bottled hydrogen as fuel and has a service range of 145 km,
and a performance similar to its diesel counterpart. This
design works well because the stop–start nature of the
traffic provides time for the low output of the fuel cell to
replenish the energy drawn from the battery during pre-
vious spells of vehicle motion. At a later date, this type of
taxi may be fitted with a cryogenic hydrogen-storage
system, perhaps placed between the two layers of a
sandwich-floor construction of the vehicle. With such an
arrangement, it is expected that the fuel cell would be
refuelled with very cold liquid hydrogen in minutes and,
thereby, would extendthe vehicle’srangedramatically, but
only in stop–start traffic.
Harding opines that what the world really needs is
vehicles fitted with fast-response, high-output fuel cells
together with on-board clean reformers which would Fig. 6.1-13 Road-induced electricity.
enable a liquid fuel to be turned into hydrogen on vehicles.
Initially, the most likely liquid fuel would seem to be efficiencies of over 50% meant a 45% fuel conversion
methanol, butarranging formethanoltobewidelyavailable efficiency could be obtained compared with 30% for the
would necessitate some large changes in infrastructure. If petrol engine. His C10 proposal shown in Fig. 6.1-12 must
all this is possible, then refuelling vehicles with liquid fuel mean his faith in the future of the electric car is still
would be, inprinciple, littleornodifferent fromtoday. The maintained.
eventual aim is said, by those developing high-output fuel There are other initiatives, too, such as the desire to
cells, to be the development of reformers which can pro- make motorway driving under very high density peak
duce hydrogen from gasoline. In this case, only the current traffic conditions less dangerous and less tiring. This is
gasoline infrastructure would be required. Interest and generating fresh interest in reserved lanes for vehicle
investment in fuel cells is increasing, and the joint ar- guidance systems. Where these additionally provide
rangements between the Canadian fuel cell company roadway-induced powering, Fig. 6.1-13, as described by
Ballard and motor industry giants Mercedes and Ford researchers from the Lawrence Livermore National
6
would appear to be an almost irresistible force on a course Laboratory , a case for a car to suit relatively long-distant
aimed at solving some daunting problems. The Ballard unit commuters can be made. The success of trials on GM’s
is a proton exchange membrane (PEM) fuel cell and Impact electric car have so far pointed to the very con-
amongst early examples of road vehicles fitted with this are siderable importance of light weight, good aerodynamics
busesin the USA. Quite apart from the technical problems and low rolling resistance but the electrical breakthrough
still to be resolved, the problem of cost is very great. has come in the electronics technology of the DC/alter-
nating current (AC) converter. Ford, too, have had very
6.1.5 Contemporary electric car promising prototype results from their Ecostar 1 car-
derived van, using a transistorized DC to AC inverter.
technology
6.1.5.1 Honda ‘EV’
According to Sir Clive Sinclair, whose abortive efforts to
market an electric tricycle have led him to concentrate on The state of the art in pilot-production electric cars is
economical bicycle conversions, peak efficiencies of 90% typified by Honda’s nickel–metal hydride battery driven
are available with EVs for converting electricity into trac- electriccar,Fig.6.1-14; ithasbeengiventhename ‘EV’and
tive energy – and that attainable electrical generating claims twice the range obtainable with comparable lead–
acid batteried cars. The car is not a conversion of an ICE
model and has 95% new componentry. It is a 3-door,
4-seater with battery pack in a separated compartment
between the floor. The pack comprises 24 12 V batteries
and rests between virtually straight underframe longitu-
dinal members running front to rear for maximum crash
protection. The motor is a brushless DC type with rare
earth high strength magnets and is said to give 96% effi-
ciency. There is a fixed ratio transmission with parking
Fig. 6.1-12 Sinclair C 10 proposal. lock. Maximum torque is 275 Nm, available from 0 to

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