INTRODUCTION
The ELIICA is a revelation of a concept car made in
Japan that is totally electric. The ELIICA short form for Electric Lithium Ion
Car was developed and created by Prof. Hiroshi Shimizu of Keio University,
Tokyo. The ELIICA is powered by lithium ion batteries and uses eight 60kw
in-wheel drive motors to provide the equivalent of 800hp. The in-wheel drive
eliminates the need for the power transmission devices connecting the engine
and the wheels that are necessary in conventional cars. Because all the wheels
are driven, spin is minimized and the vehicle can be easily controlled, even
under difficult road conditions. The amazing factor about this car is its
performance. It can accelerate from 0 to 100km/h in just 4 seconds. The car has
recorded a top speed of 370km/h (230mph), although it could hit 400 km/h
(250mph) in the correct conditions. The electric car ELIICA requires 10hours to
charge fully.
The ELIICA is a
demonstration car made in Japan that is totally electric. The ELIICA short form
for Electric Lithium Ion CAr was developed and created by Prof. Hiroshi Shimizu
of Keio University, Tokyo. ELIICA is powered by lithium ion batteries and uses
eight 60kw in-wheel drive motors to provide the equivalent of 800hp.The ELIICA
is just five meters long, 2.5 ton weight bullet shaped and in-wheel drive
eliminates the need for the power transmission devices connecting the engine
and the wheels that are necessary in conventional cars. The motor, reduction
gears, wheel bearing and braking system are integrated in a single unit and the
suspension arm adapter is attached to the outer motor casing. That is how
ELIICA hits .8G in acceleration. Because all the wheels are driven, spin is
minimized and the vehicle can be easily controlled, even under difficult road
conditions. The amazing factor about this car is its performance. It can
accelerate from 0 to 100km/h in just 4 seconds. The car has recorded a top
speed of 370km/h (230mph), although it could hit 400 km/h (250mph) in the
correct conditions. The electric car ELIICA requires 10hours to charge fully.
THE
PLATFORM OF ELIICA
LITHIUM ION BATTERIES
Lithium ion batteries are the fastest and promising
battery chemistry today, which offers higher capacities. Lithium is the
lightest of all metals, has the greatest electrochemical potential and provides
the largest energy density for weight. The energy density of lithium ion is
typically twice that of the standard nickel cadmium. The high cell voltage of
3.6 - 4.1 volts allows battery pack designs with only one cell.
Lithium ion is a low maintenance battery.
There is no memory and no scheduled cycling is required to prolong the
batteries life. In addition self -discharge is less than half compared to
nickel cadmium, making lithium ion well suited for modern fuel gauge
applications. Lithium ion cells cause little harm when disposed. Another
special feature about this cell is its fast charging, 300-500 charge cycles
Eliica uses L.I. batteries with serial
no-18650 (18 is its diameter and 650 is its length in mm) which gives an output
of 4.1v, 80Ah per cell.2 cells constitute one packet, such 84 packets are in
ELIICA In addition auxiliary power sources are there when there is need.
CONTROLLER
The controller
takes power from batteries and delivers it to the motor. The accelerator pedal
hooks to a pair of potentiometers 1 (variable resistors) and these
potentiometers provide the signal that tell the controller how much power is
supposed to deliver. The controller can deliver zero power (when the car is
stopped), full power (when the driver floors the accelerator pedal) or any
power level in between The controller converts the dc power in to ac supply.
Controller creates 3 pseudo sine waves by pulsing the dc voltage on and off.
Six sets of transistors are used for generation of pulsed waves & reversing
the polarities. Most controllers pulse the power more than 15,000times per
second, in order to keep the pulsation outside the range of human hearing. The
pulsed current causes the motor housing to vibrate at that frequency, so by
pulsing at more than 15,000 cycles per second, the controller and motor are
silent to the human ears. Controller also recharges the batteries at the time
of braking using the principle of regenerative braking. So the function of
controller can be summarized in to following Three purposes
1.
Converts dc supply into ac supply
2.
Delivers power supply to motor from
batteries according to the accelerator position
3.
Recharging the batteries
ELECTRIC MOTOR
ELIICA is driven
with eight 100 watt motors each connected to the eight wheels. These motors are
given power equally from the controller.ELIICA uses permanent magnet
synchronous motor for its propulsion, because of its high accelerating torque,
variable speed, better stability, less maintenance and high efficiency. When
the accelerator pedal is pressed proportionate charge flows to the motors from
the battery pack and provides the necessary thrust to move the vehicle. As the
motors are running at the same time, there will be better control and speed
Charging system
The controller
maintains charging system. There are two ways of charging
1.
Normal charging
2.
Regenerative braking
IN normal charging Lithium ion battery is
connected to appropriate charging voltage .There are two kinds of charging
system
Plug-in charging
Magna charge system
Plug in charging
In plug in
charging a cable is connected from the charger to the socket in the car The
charger is a box separate box located under the hood or could even be a free standing
unit that is separate from the car.
This charging system sends electricity to the car
using an inductive paddle. The paddle acts as one half of a transformer. The
other half is inside the car. When you insert the paddle it forms the complete
transformer with the slot and power transfers to the car.
One advantage of
magna charging system is that there are no exposed electrical contacts. Other
advantage is the ability to pump a significant amount of current to into the
car very quickly.
FUTURE
About two third of
ELIICA's cost is dominated by the battery price, If we could reduce cost of the
Lithium ion batteries ELIICA could be affordable to the layman in the future,
as it is going to conquer the world of automobile. The charging time for the
batteries is now 10 hours. Research is going on to decrease the charging time
Presently ELIICA has recorded a top speed of 370 km/h. Research is going on to
increase that to 400 km/h
The future of battery electric vehicles depends
primarily upon the availability of batteries with high energy densities, power
density, long life, and reasonable cost as all other aspects such as motors,
motor controllers, and chargers are fairly mature and cost competitive with
Internal Combustion Engine components.
CONCLUSION
It is sure that
the introduction of Eliica will change the face of the automobile industry. As
now a day nothing will run without the presence of electricity in its direct
form or indirect form, Eliica is a proud achievement for the electrical field.
Research and developments
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