hybrid and electric cars

2. HYBRID VEHICLE
PREPARED BY;
M Junaid Mushtaq (UET/SCET-13F ME 79)
Mechanical Engineering Department
Session 2013-17

3. WHAT IS A HYBRID VEHICLE?
Any vehicle which combines two or more sources of power.
Examples:
 Diesel – electric
 Gasoline– CNG
 Gasoline - electric

4. Need Electric and Hybrid vehicles
 Over dependence on petrol/diesel
 Rising petrol/diesel prices
 Pollution and the resultant global warming
 Noise in conventional vehicles
 Need for alternate power sources
 Need for Eco friendly vehicles
 Then The solution is EV, HEV

5. Concept of hybridization
Multiple sources of power
Making ICE work in most efficient range

6. Hybrid Vehicles
The term hybrid vehicles in general usage refer to vehicles with
two or more different type of sources delivering power to the
wheels for propulsion.
The most common hybrid vehicles have an IC engine and one
or more electric machines for vehicle propulsion.
The IC engine can be used to generate electric energy ‘on
board’ to power the machines.

7. Classification
Based on the path of energy flow
Mechanical power transmission path (MPTP)
Electrical power transmission path (EPTP)
Combination of MPTP and EPTP
Based on architecture
Series
Parallel
Series-Parallel

8. Mechanical power transmission path (MPTP)
The primary powertrain components in a conventional ICE
vehicle are engine and transmission. The energy flow in a
vehicle starts from source of energy and ends at wheels with the
delivery of propulsion power known as power transmission.
Mechanical Power transmission path

9. Electrical power transmission path (EPTP)
In electric vehicle power transmission is almost electrical except
for coupling devices between electric propulsion motor and
wheels. The coupling device can simply be a gear to match
electric machine speeds to vehicle speeds.
Electric Power transmission path

10. Combination of MPTP and EPTP
The propulsion power is transmitted to wheels through either
MPTP or EPTP or combination of both.
The MPTP is associated with an IC engine and transmission,
whereas EPTP consists of energy storage system, a generator,
propulsion motor and transmission.

11. Block diagram
A hybrid electric vehicle power transmission

12. Series HEV
A series hybrid is one in which only one energy converter can
provide propulsion power.
Only electric motor provides all propulsion power to wheels.
A downsized IC engine drives a generator, which supplements
batteries and can charge them when it fall below certain charge
level.
The drawback is size of traction motor, which as to be rated for
max. power requirement of vehicle.

13. Block diagram
Series HEV powertrain

15. Parallel HEV
A parallel hybrid is one in which more than one energy
conversion device can deliver propulsion power to the wheels.
The IC engine and electric motor are configured in parallel
with a mechanical coupling.
The power requirements of electric motor is lower than that of
series HEV.

17. Block diagram
Parallel HEV powertrain

18. Series-Parallel HEV
It combines the benefits of series and parallel architecture with
charge sustaining capability.
The power-split device divides the output from the engine into
mechanical and electrical transmission paths.
Even IC engine is also used to charge the battery.
They are capable of providing continuous high output power
compared to series or parallel powertrain.

19. Block diagram
Series –Parallel combination HEV

20. IF WE USE ELECTRIC CARS ?

21. Electric vehicles
An Electric vehicle is an automobile that is propelled by one or
more electric motors, using electrical energy stored in energy
storage device.
The primary components are motor, controller, power source,
and transmission.

22. Block diagram of electric vehicles
An Electric vehicle system

23. Advantages
No Gas Required
No Emissions
Cost Effective
Low Maintenance
Low noise

24. Disadvantages
High Initial Cost- Many times that of conventional vehicles
Short Driving Range
Recharging takes much longer time than refueling gasoline
Battery pack takes space and weight of the vehicle which otherwise
is available to the people

25. HIGH VOLTAGE ELECTRICAL
SYSTEMS
Power for the electric motor is supplied by high-voltage nickel-
metal hydride battery
Batteries for all hybrids are produced by Panasonic EV Energy in
Japan
Voltage ranges from 144 volts to 650 volts of DC current

26. HIGH VOLTAGE
ELECTRICAL SYSTEMS

27. Commercial vehicles
Toyota Prius
Toyota Highlander
Ford Escape
Mercury Mariner
Honda Civic HEV
Honda Accord HEV

28. Challenges in hybrid vehicles
Time of battery changing is long
Batteries are heavy (100kg extra weight consumes 2L/100km
more)
Batteries are expensive
Low performance in hot or cold temperatures also may damage
the battery
Very sensitive to overcharge/undercharge(Battery life reduces
dramatically)

29. Advantages of a Hybrid Car
Environment friendly
Financial benefits
Less dependence on fossil fuels
Regenerative braking system
Built from lighter materials

30. Disadvantages of a Hybrid car
Less power
Expensive
Poor handling
Higher maintenance cost