1. Electric Vehicles

2. Content
• Background
• History
• Components
• Materials
• Electric Vehicle Configuration
• Design
• Manufacturing Process
• Optimization
• Charging System
• Electric vs Gasoline
• Energy Efficiency
• Conclusion

3. Background
Unlike the gas-powered automobile, the electric automobile did not easily develop
into a viable means of transportation
Why?
- The easily mass-produced gasoline-powered automobile squelched interest in the
project
- Technologies that support a reliable battery and the weight of the needed number
of batteries elevated the price of making an electric vehicle

4. Background
Although
- Research waned from 1920-1960 and worries about environmental issues of
pollution and diminishing natural resources reawakened the need of a more
environmentally friendly means of transportation.
- Automotive electronics have become so sophisticated and small that they are ideal
for electric vehicle applications.

5. History
In 1837, Robert Davidson of Scotland appears
to have been the builder of the first electric
car

6. History
During the late 1890s, United States roads were populated by
more electric automobiles than those with internal combustion
engines.

7. History
The history of the electric car is related with the history of the development of the
battery.
Why were they popular?
They were clean, quiet, and easy to operate
However
- The industry improved the gasoline-powered vehicle so much so that competition was nonexistent.
- Between 1920 and 1960, the low price of combustion engine vehicles made disappear almost every
electric car companies.

8. History
In the 1960’s, interest in the electric car rose again due to the escalating cost and
diminishing supply of oil and concern about pollution generated by internal
combustion engines
The resurgence of the electric car in the last part of the 20th century has, however,
been fraught with technical problems.
During the 90’s, some electrical cars were brought to the market but batteries were
the weakness of this electric car because they needed to be replaced every two
years, doubling the vehicle's cost

9. History
Nowadays, automotive electronics have become so sophisticated and small that they
are ideal for electric vehicle applications.
Batteries are more efficient and capable so every car firm has its own line of electric
cars.

10. Components
Here we have the main components of an Electrical car:
- Electric Motor: Every electric car needs a motor. They can use AC or DC electricity.
- Motor Controller: The purpose of the motor controller is to adjust the speed at which the
motor spins.
- Throttle Pot Box: Is a small part that connects to your stock throttle cable. When you push on
your throttle, the pot box sends a signal corresponding to the amount of pressure you’re putting on
the pedal to the controller which then sends the proper power to the motor.

11. Components
- Batteries: Batteries are the source of energy
of the car. As fuel is for combustion vehicles. The
type of batteries will affect performance and
range.
- DC/DC Converter: The DC/DC converter
takes the voltage of your main (traction) battery
pack and reduces it to 12V which keeps your 12V
battery charged.

12. Components
Complete scheme of
componentes:

13. Electrical circuit scheme:
Components

14. Materials
- The electric car's skeleton is made of aluminum to be both strong and
lightweight.
- Seat frames and the heart of the steering wheel are made of magnesium, a
lightweight metal
- The body is made of an impact-resistant composite plastic that is recyclable.

15. Materials
- Electric car batteries consist of plastic housings that contains metal anodes and
cathodes and fluid called electrolyte
- The motor or traction system has metal and plastic parts that do not need
lubricants
- Plastics, foam padding, vinyl, and fabrics form the dashboard cover, door liners,
and seats.

16. - The tires are rubber, but, unlike
standard tires, these are designed to
inflate to higher pressures so the car
rolls with less resistance to conserve
energy.
- Materials that provide thermal
conservation reduce the energy drain
that heating and air conditioning
impose on the batteries.
Materials

17. Electric Vehicle
Transmission
Power Unit
(motor/controller)
Fuel (batteries)
Regenerative Brakes
(energy returns to batteries)

18. Electric Vehicle

19. Electric Vehicle Configuration

20. Design
To design an electric vehicle, it is important to match the motor-drivetrain combination
to the body style selected. Various factors can influence the design of an electric
vehicle such as the cost and weight of components and accessories, among others.

21. Design-Weight
• Research the structural strength and loading capacity of any vehicle under
consideration. Electric components may add weight to a vehicle, especially
if choosing lead acid batteries. This affects:
Handling, and front end alignment,
Suspension component sizes (springs, shock absorbers, brakes)
Suspension mounts (may need to be reinforced).
• There is a diminishing rate of return as we add batteries – eventually the
power of extra batteries is used up by moving their extra weight. Limit
battery weight to 33% - 45% of total vehicle weight.

22. Weight Comparisson
Front-to-rear Weight Distribution Trade-off

23. Design - AC vs. DC Systems
• AC systems offer better performance but at higher cost.
• AC cars consume 0.11 to 0.18 kW-hr / kilometer, while DC cars consume about
0.25 kW-hr / kilometer.
• AC systems can use batteries that are rated at lower kW-hr capacity.
• However, most AC systems use higher voltages than DC systems so there is no
overall savings in battery pack weight and size.
• Regenerative braking is easier to implement in AC systems.
• DC system failures can allow sudden runaway (full uncontrollable power to
the motor).
• AC systems can use smaller diameter cables.
• AC motors and controllers must be more tightly matched than DC motors and
controllers.
• Generally, AC motors are more reliable than DC motors.

24. Design - AC vs. DC Systems
AC Motor
Single speed transmission
Light weight
Less expensive
95% efficiency at full load
More expensive controller
Motor/controller/inverter is
more expensive
DC Motor
Multi-speed transmission
Heavier for same power
Higher cost
85-89% efficiency at full load
Simple controller
Motor/controller - lower cost

25. Design-Batteries
• The battery pack is the heart of an electric vehicle.
• Batteries that store energy and power the electric motor are a science
of their own in electric car design, and many options are being studied
to find the most efficient batteries that are also safe and cost
effective.
• Many different battery types exist, e.g., lead-acid, nickel-metal
hydride, lithium ion, etc.
• However, today the lithium ion is the preferred choice due to its
relatively high specific energy and power.
• An electric motor that converts electrical energy from the battery and
transmits it to the drive train.

26. Design-Chargers
• Two varieties of chargers are needed.
• A full-size charger for installation in a garage is needed to
recharge the electric car overnight, but a portable recharger
(called a convenience recharger) is standard equipment for the
trunk so the batteries can be recharged in an emergency or
away from home or a charging station.
• For safety, an inductive charger was created for electric cars
with a paddle that is inserted in the front end of the car. It uses
magnetic energy to recharge the batteries and limit the
potential for electrocution.

27. Design-Transmission
• Electric motors produce high torque almost down to zero rpm, so
why add the extra weight of a transmission?
• The reason is that at low rpm, especially while starting, electric
motors consume a lot of battery power.
• Also, one gear ratio becomes a compromise between top speed
and hill climbing ability.
• A transmission can also provide reverse; otherwise we need extra
contactors and wiring. AC systems may not need transmissions.

28. Design-Acessories
• Lights, turn signals and the horn were designed for 12 V DC so
an auxiliary system is required.
• Heat, air conditioning, power brakes and power steering
reduce battery range.
• Devices that used engine vacuum now need a pump. If using
resistive heating, wire the ventilation fan to keep the element
from burning out.

29. Manufacturing Process - Body shop
The body for the electric car is handcrafted at 3 work stations
• First: Parts of the aluminum space frame are put together in sections called
subassemblies that are constructed of prefabricated pieces that are welded or
glued together. As the subassemblies for the undercarriage of the car are
completed, they are bonded to each other until the entire underbody is
finished.
• Second: The subassemblies for the upper part of the body are also bonded to
make larger sections. The completed sections are similarly welded or glued
until the body frame is finished. The body is added to the underbody.
• Third: The roof is attached. Like other parts of the exterior, it has already been
painted. The underbody and the rest of the frame are coated with protective
sealants, and the finished body is moved to the general assembly area.

30. Manufacturing Process - General Assembly
1. The first set of the electric car's complex electronics are put in place.
2. The interior is outfitted. Flooring, seats, carpeting, and the console and dash
are placed in the car.
3. The air conditioning, heating, and circulation system is inserted, and the system
is filled.
4. The battery pack is added. The T-shaped unit is seated by lifting the heavy pack
using a special hoist up into the car.
5. The windshield is installed and other fluids are added and checked. The door
systems (complete with vinyl interiors, arm rests, electronics, and windows) are
also attached, and all the connections are completed and checked.
6. The alignment is checked and adjusted, and the under-body panel is bolted into
place. The process concludes with the last, comprehensive quality control
check.

31. Optimization
• Weight and climbing and acceleration
• Aerodynamic drag and wind
• Rolling and cornering resistance
• Drivetrain system

32. The Charging System
• Any electric car that uses batteries needs a charging system to
recharge the batteries
• To pump electricity into the batteries as quickly as the batteries
will allow
• To monitor the batteries and avoid damaging them during the
charging process
• It takes about 12 kilowatt-hours of electricity to charge the car
after a 80-kilometer trip.

33. Car Charger

34. Fuel Costs
12
10
8
6
4
2
Fuel
cost
¢/mile
Gasoline
vehicle
Electric
vehicle

35. Electric vc Gasoline

36. Energy Efficiency
- Internal combustion engines are relatively inefficient at converting on-board fuel
energy to propulsion as most of the energy is wasted as heat
- On the other hand, electric motors are more efficient in converting stored energy
into driving a vehicle
- Some of the energy lost when braking is captured and reused
through regenerative braking

37. Energy Efficiency
- Typically, conventional gasoline engines effectively use only 15% of the fuel
energy content to move the vehicle
- Diesel engines can reach on-board efficiencies of 20%
- Electric drive vehicles have on-board efficiency of around 80%

38. Energy Efficiency
- Approximately 20% of power consumption is due to inefficiencies in charging the
batteries
- Electric vehicles generate very little waste heat and resistance electric heat may
have to be used to heat the interior of the vehicle

39. Conclusion – The Future
- Electric cars are critically important to the future of the automobile industry
and to the environment.
- Consumption of decreasing oil supplies, concerns over air and noise pollution,
and pollution caused (and energy consumed) by abandoned cars and the
complications of recycling gasoline-powered cars are all driving forces that seem
to be pushing toward the success of the electric car