1. TESLA
ELECTRIC
CARS-LEARN
ENGINEERING
VIDEOSTUDY
ESBEEM Technologies
Sanjeev Koushik

2. This Book is a reference to the Video
available on Youtube. The Link and the
Title of the same is available as below:
How does an
Electric Car Work
https://www.youtube.com/watch?v=3SAxXUIre28&

3. Induction Motor: Stator and the Rotor

4. Stator: 3 phase AC power
- producing a rotating
magnetic field
Rotor: short circuited by
end rays

5. 3 phase AC Power produces Rotating magnetic field and
induces current to make rotor turn

6. Induction motor has neither brushes nor permanent
magnet at the same time it is robust and powerful
Its speed depends on the frequency of AC power supply
Just by varying the power supply we’ll be able to alter
the drive wheel speed

7. This simple fact makes it easy for electric cars to be
controlled and reliable
The motor supply is from a variable frequency drive, which
in turn controls the motor speed
The motor speed can be 0-18000 RPM
Internal Combustion Engine (ICE) produces usable torque
and power oblique only within limited speed range
Therefore, connecting engine rotation to drive wheel is not
a clever idea. A transmission must be introduced to vary
the drive wheel speed
An induction motor will work in any speed range and thus
no speed varying transmission is needed for electric cars
moreover the ICE does not produce direct rotational
motion

8. The linear
motion of the piston has to be converted into rotational motion
This causes major problems for mechanical balancing
Not only ICE not so started like an induction motor further the power output of the ICE is uneven
Many accessories like Alternator (for charging) Flywheel (for power smothering) DC Motor (for starting),
counter weights (for dynamic balancing) are required to solve these issues
On the other hand, you’ll have direct rotational motion and uniform power output with the induction
motor
Many components in the ICE can be avoided here.
As a result of these factors, a great response rate and higher power to weight ratio comes naturally to
the induction
motor resulting
in superior
vehicle
performance

9. Moreover, the invertor can even vary the amplitude of the AC power which
inturn controls the motor power output. Thus the invertor acts as the brain
of the electric car
Now, battery pack..They
seem that they are just
the collection of li-ion
battery packs.
The cells are connected
in combination of series
and parallel to produce
the electric power in the
car.

10. Glycol coolant is passed through the metallic inner tubes between
the cells. This is one principle innovation of TESLA cars

11. By using small cells instead of few big cells effective
cooling is guaranteed

12. This minimizes the temperature hot spots and even
temperature distribution is achieved leading to higher
battery pack life. The cells are arranged in the detachable
modules.

13. The heated
glycol is cooled
down by
passing through
a radiator which
is fitted at the
front of the
There are 16
such modules
constituting
over 7000
cells.

14. The low fitted battery pack closed to ground level
will lower
the Vehicle
centre of
The lower centre
of gravity
improves the
stability of the
car considerably
The large battery
pack is spread
across the floor
offering the
structural rigidity
against side
collisions

15. Tesla’s drive train:
The power
produced by the
motors is
transferred to the
drive wheels via
gearbox.
Model S uses a
Single speed
transmission
coz the motor is
efficient in the
wide range of
operating
conditions

16. The output of the motor speed is reduced in two steps:
Motor output and transmission output

17. Even achieving the reverse gear is easy in electric car, just
change the order of power phase for this ie (Reverse Motor
Rotation and Reverse Drive wheel rotation

18. The only purpose of electric car transmission is speed
reduction and associated torque multiplication

19. The reduced speed drive is passed through it.
The second component in a gear box is a differential.

20. Open differential has a traction control when there’s combination of
dead wheel, spinning wheel with slippery surface, but open
differential can carry more torque with the help of two magnets that
enables selective braking and free power supply, in an IC Engine this
Power Flow Cut supply is not so responsive.

21. In an induction Motor the Power supply has High responsive rate and
effective to traction control.
In electric cars this can be accomplished using the state of the art
algorithm with help from sensors and controllers. Tesla has eliminated the
complex hardware mechanical system with smart responsive software.

22. It’s a one-pedal driving system in Tesla.

23. This is due to powerful regenerative braking system
That is savage huge kinetic energy of the car in the form of electricity
without wasting heat. As soon as the feet is taken back from the pedal,
the regenerative braking system activates. During this process, same
induction motor acts as a generator.

24. The convert the motor into
the generator you just have
to make sure that the rotor
speed is > than the RMF
Speed
The inverter plays a crucial rule
in adjusting the input power
frequency and keeping the
RMF speed below the rotor
speed

25. This would generate
the electricity in the
stator coils which is
way higher than the
supplied electricity
The generated electricity
can be stored in the
Battery pack after the
conversion.
An opposing Electro magnetic force
acts on the rotor during this
process, so the drive wheel and the
car would slow down.

26. This way vehicle speed
can be accurately
controlled during the
drive using a single
pedal.
The break pedal can be
applied for a complete
stop.
Electric Cars are much
safer than the Internal
Combustion Engine
Cars. The cost of
maintaining and driving
an electric car is much
lower than the ICE car.

27. With the drawbacks faded with the advent
of the new technology, Electric cars are
promised to be the cars of the future.