7. HEVs will contain a mix of aluminum,
steel, plastic, magnesium, and
composites (typically a strong,
lightweight material composed of
fibers in a binding matrix, such as
fiberglass).
10. Lead acidbatteries, used
currently in many electric
vehicles, are potentiallyusable
in hybrid applications.Lead acid
batteries can be designed tobe
high power andare inexpensive,
safe, and reliable.
11. Flywheels store kineticenergy within a
rapidly spinning wheel-likerotor or disk.
Ultimately, flywheels could store
amounts of energy comparable to
batteries. They contain no acids or other
potentially hazardous materials.
Flywheels are not affected by
temperature extremes, as most batteries
are.
12. Fuelcellsoffer highly efficientand
fuel-flexiblepower systems with
low to zero emissionsfor future
HEV designs.There are a variety of
thermal issuesto be addressedin
the development and application
of fuel cells for hybridvehicles.
13. Sparkignition engine mixes
fuel and airin a pre-chamber.
Throttle and heat losses,
which occuras the fuel
mixture travels from pre-
chamberinto the combustion
chamber.
14. A Compression Ignitionengine
achieves combustionthrough
compressionwithoutuse of
sparkplug.It becomes CIDI engine
when itis enhanced with direct
injection.
15.
16.
17. Motors are the"workhorses" of HEV drive systems.In anHEV, an
electric traction motorconvertselectrical energy fromthe energy
storage unit to mechanicalenergy thatdrives the wheels ofthe
vehicle. Unlike atraditional vehicle, wherethe engine must"ramp
up"before full torquecanbe provided,anelectric motorprovides
fulltorque at low speeds. Thischaracteristic givesthe vehicle
excellent "offtheline" acceleration.
18. As emissionsstandards tighten and
exhaust control technologies
improve, the issue of evaporative
emissionsbecomes increasingly
important.Thermalmanagement
of fuel tanks is one approachto
reducingthese emissions.
19. 60% to 80% of amissionsin an
autostypicaldriving cycle comes
from coldstartemissions,that is,
pollutants thatare emitted before
the catalyticconverter is hot enough
to begin catalyzingcombustion
products.
20. Heat recovered from any of the above
sources can be used ina variety of ways.
For winterdriving,heat recovery from
HEV sources such as the power unit
exhaust, propulsion motors, batteries,
and power invertercan significantly
improve cabin warm-up.
21. HEVs are now at the forefrontoftransportation
technology development. Hybrids have the
potential to allow continued growth in the
automotive sector, while also reducing critical
resourceconsumption, dependence on foreign oil,
air pollution, and traffic congestion.