Why the need? Why electric vehicles are at present not a solution and the types of hybrid architecture.

1. Abhilash R
CB.EN.U4MEE10001

2. Contents
Part I: Current transportation scenario
Part II: EV & why that is not the solution now
Part III: Concept of hybridization
Part IV: Architectures of Hybrids
Part V: Commercial models

3. Part I: Current transportation scenario
Over dependence on petrol/diesel-it’s depletion
Rising petrol/diesel prices
Pollution and the resultant global warming
Noise in conventional vehicles
Need for alternate power sources
EV, HEV - The solution?

4. HEV,EV?
 A traditional vehicle has sole propulsion by ICE or diesel engine
 EV - Electric Vehicle, battery (or ultra capacitor, fly wheels) operated only.
Sole propulsion by electric motor
 An HEV (Hybrid Electric Vehicle) is a vehicle which involves multiple
sources of propulsions

5. Part II: EV & why that is not the solution now
 High Initial Cost- Many times that of conventional vehicles
 Short Driving Range- Range anxiety
 Recharging takes much longer time than refueling gasoline-lack of
charging infrastructure
 Battery pack takes space and weight of the vehicle which otherwise is
available to the people
 Grid load
 ICE + Electric motor = Propulsion

6. Part III: Concept of hybridization?
 Multiple sources of power
 Making ICE work in most efficient range
 Sizing of motor and ICE lower compared to conventional vehicles and EV
 Modes of operation

7. Part IV: Architectures of Hybrids
According to the method the energy sources are arranged
 Parallel HEV: Multiple propulsion sources can be combined, or
drive the vehicle alone with one of the energy sources
 Series HEV: Sole propulsion by electric motor, but the electric
energy comes from another on board energy source, such as ICE
 Power-split hybrid: Can work both as a series & parallel type
hybrid

9. Series architecture
Operation Mode of Series Architecture
 Battery alone mode: engine is off, vehicle is
powered by the battery only
 Engine alone mode: power from ICE/G
 Combined mode: both ICE/G set and battery
provides power to the traction motor
 Power split mode: ICE/G power split to drive
the vehicle and charge the battery
 Stationary charging mode
 Regenerative braking mode

10. Advantages of Series
Architecture
 ICE operation can be
optimized, and ICE itself can
be redesigned to satisfy the
needs
 Smaller engine possible
 High speed engine possible
 Single gear box. No
transmission needed. Multiple
motors or wheel motors are
possible
 Simple control strategy
Disadvantages of Series
Architecture
 Energy converter twice (ICE/G
then Motor), plus battery
 Additional weight/cost due to
increased components
 Traction motor, generator, ICE
are full sized to meet the
vehicle performance needs

11. Parallel Architecture Operation Mode of Parallel
Architecture
 Motor alone mode: engine is off,
vehicle is powered by the
battery/motor only
 Engine alone mode: ICE drive the
vehicle alone
 Combined mode: both ICE and motor
provide power to drive the vehicle
 Power split mode: ICE power split to
drive the vehicle and charge the
battery
 Stationary charging mode
 Regenerative braking mode (include
hybrid braking mode)

12. Advantages of Parallel
Architecture
 ICE operation can be optimized,
with motor assist or share the
power from the ICE
 Flexible in configurations and
gives room for optimization of
fuel economy and emissions
 Reduced engine size
 Possible plug-in hybrid for
further improved fuel economy
and emission reduction
Disadvantage of Parallel
Architecture
 Complicated control strategy
 Complex transmission

13. TOYOTA Prius (Power-split) architecture

14. Modes of operation-TOYOTA Prius

15. Modes of operation-TOYOTA Prius
 At start-off/low-speeds, HSD
runs the car on the electric
motor(s) only
 CRUISING: ICE power
 FULL ACCELERATION: ICE power
+ battery power
 CRUISING: ICE power + battery
charging
 DECELERATION, BRAKING: kinetic
energy recuperation for battery
charging

16. Key advantages of HEVs
 Optimize the fuel economy
– Optimize the operating point of ICE
– Stop the ICE if not needed (ultra low speed and stops)
– Recover the kinetic energy at braking
– Reduce the size (hp and volume) of ICE
 Reduce emissions
– Minimize the emissions when ICE is optimized in operation
– Stop the ICE when it’s not needed
– Reduced size of ICE means less emissions

17.  Quiet Operation
– Ultra low noise at low speed because ICE is stopped
– Quiet motor, motor is stopped when vehicle comes to a
stop, with engine already stopped
– Reduced maintenance because ICE operation is
optimized, less hazardous material, fewer tune ups,
longer life cycle of ICE
– Fewer spark-plug changes
– Fewer oil changes
– Fewer fuel filters, antifreeze, radiator flushes or water
pumps
– Fewer exhaust repairs or muffler changes

18. Key Concerns of HEVs
 High initial cost
– Increased components such as battery, electric machines, motor controller,
etc.
 Reliability concern
– Increased components, especially power system, electronics, sensors
 Warranty issues
– Issues on major electric components
– Dealership and repair shop not familiar with new components
 Safety: high voltage system employed in HEV

19. Part V: Commercial models
 Toyota Prius
 Toyota Highlander
 Ford Escape
 Mercury Mariner
 Honda Insight
 Honda Civic HEV
 Honda Accord HEV