Environmental Engineering Reference
In-Depth Information
TRASMISSION
DC-DC
DC-AC
CONVERTER
ELECTRIC
MOTOR
Electric Drive
Rechargable
BATTERY
Fig. 5.20
Solar vehicle configuration
road vehicle. However, solar cells could be used to keep the batteries of any type
of electric vehicle topped up.
In Fig.
5.20
, the scheme for the configuration of a solar vehicle is reported. The
DC-DC converter is required to adapt the voltage generated by the solar system to
the voltage range proper of battery pack and electric drive. The converter is mono-
directional because no energy flux goes from the battery and motor drive toward
the solar panel [
3
,
4
].
5.5.3 Vehicles Using Flywheels and Super Capacitors
Due to the small amount of energy that flywheels can store, vehicles using fly-
wheels are generally trams or city busses equipped with one or more flywheels.
These devices can be speed up by an electric motor, supplied when the vehicle
stops at the bus station to pick up passengers. Moreover, the flywheel is acceler-
ated by the regenerative braking, when the kinetic energy of the vehicle is
transferred to the kinetic energy of the flywheel. Flywheels can also be combined
with batteries with the advantage of reducing battery weight. In Fig.
5.21
,a
simplified scheme for a vehicle equipped with battery and flywheel is shown.
Super capacitors can be used in addition to batteries in electric vehicles. In
Fig.
5.22
, a simplified scheme for a vehicle equipped with battery and super
capacitors is shown [
4
]. The super capacitors allow the kinetic energy of the
vehicle to be recovered when the vehicle slows down, increasing the availability of
power peaks during rapid accelerations. In this way, an optimal management of
batteries can be accomplished.
Super capacitors and flywheels, as high power storage systems, can be used in a
wide range of hybrid vehicles, combined with one or more power energy devices,
