Vh

1. ❖TRANSMISSION SYSTEM
OF HEV’S.
BY:-
YASH JOSHI TMHC72
SHIVAM PAWAR TMHC73
Guided by:- m.s.patil.

2. introduction
• A hybrid electric vehicle (HEV) augments an electric
vehicle (EV) with a second source of power referred
to as the alternative power unit (APU).
• A hybrid can achieve the cruising range and
performance advantages of conventional vehicles
with the low-noise, low-exhaust emissions, and energy
independence benefits of electric vehicles.
• Accordingly, the hybrid concept, where the
alternative power unit is used as a second source of
energy, is gaining acceptance and is overcoming some
of the problems of pure electric vehicles.

3. What is an hev
HEV – Hybrid Electric Vehicle
• A vehicle that has two or more energy conversion
technologies combined with one or more energy
storage units.

4. HEV OJECTIVES
Objectives the HEV wants to obtain:
• Maximize fuel economy
• Minimize fuel emissions
• Minimize propulsion system cost to keep affordable
• Maintain acceptable performance with a reasonable
cost
• Reduce the conventional car weight

5. Hev advantages over conventional
engines.
• Regenerative Braking.
• Reduction in engine and vehicle weight.
• Fuel efficiency is increased.
• Emissions are decreased.
• Cut emissions of global warming pollutants by 1/3 or 1/2.
• Reduce the dependency on fossil fuels.
• Some states offer incentives with owning an HEV.
• ~2 times more efficient than conventional engines.

6. HYBRID STRUCTURE
• Two types of hybrid vehicle configurations.
• 1.parallel hybrids.
• 2.series hybrids.

7. Parallel hybrids
• Fuel tank, which supplies gasoline to t
h
e
engine.
• Set of batteries that supplies power to a
nelectric
motor.
• Both the engine and the electric motor c
a
nturn the
transmission at the same time, and the transmission
then turns the wheels.

8. • When the APU is off, the parallel hybrid runslike an
electric vehicle.
• When the APU is on, the controller divides energy between
the drive train (propulsion) and the batteries (energy
storage).
• Under acceleration, more power is allocated t
othe drive
train than to the batteries. During periods of idle or low
speeds, more power goes to the batteries than the drive
train.
• The batteries also provide additional power t
othe drive
train when the APU is not producing enough and also to
power auxiliary systems such as the air conditioner and
heater.

9. Series hybrid
• Similar to an electric vehicle with an on- board
generator
• The vehicle runs on battery power like a pure electric
vehicle until the batteries reach a predetermined
discharged level.
• At that point the APU turns on and begins recharging
the battery.
• The APU operates until the batteries are charged to a
predetermined level.
• APU never directly powers the vehicle

10. • The length of time the APU is on depends on the
size of the batteries and the APU itself.
• Since the APU is not directly connected tothe
drive train, it can be run at its optimal operating
condition; hence, fuel economy is increased and
emissions are reduced relative to a pure IC
engine vehicle.

11. Components of hev
❑ Electric drive motors.
• to provide the power forpropulsion.
• converts electric energy to mechanical energy
(motion) to drive the hybrid vehicle.
• Direct Current Motors, Alternating Current Motors.
• The two possible configurations of electric drive motors
in a hybrid vehicle.
• single electric motor connected to the wheels through adrive
train and multiple electric motors, one located at each wheel.
❑ Auxiliary Power Units
• Supplies the baseline power required to the vehicle, recharges
the batteries and powers accessories such as the air
conditioner andheater.
• The APU can consist of a mechanical type engine or afuel cell.
• Spark Ignition Engine, Compression Ignition Engines, FuelsCells

12. • Generators
• To convert the mechanical power into electrical
power when used in series hybrids.
❑ Energy Storage Systems
• Peak power required in hybrid vehicles is m
e
tby devices
like batteries, capacitors or a flywheel.
• store energy and readily release it w
h
e
n
needed.

13. ❑ Regenerative Braking
• Some of the energy is converted into
electrical energy and stored.
• rotational energy of the braking mechanism
generates electrical power and stores it in
thebatteries.
❑ Control Systems
• contains two main components-command and
power components.
• command component manages and processes
the driver’s instructions.
• power component chops power flows to
control the motor’s power intake.

14. fuel cell hybrid vehicle
• Electric vehicle equipped with a fuelcell.
• Use hydrogen as a fuel and power the electric
battery when it is depleted.
• In the 21 century, the auto fuel will be replaced b
y
such regenerative resources as hydrogen and the
power system with traditional internal combustion
engine will be replaced by hybrid system and finally
be replaced by fuel cell power system to realize
multi-resources, electric driving and zero emission.
• For the fuel cell hybrid electric bus developed, high-
pressure PEMFC and high-power NiMH battery pack
forms the hybrid system.
• In order to obtain the higher fuel efficiency and a
v
oid
the frequent charge & discharge of battery pack, the
active control for the fuel cell pack to follow the
driver’s pedal and the surplus peak power from NiMH
battery pack passively is used.

15. • Fuel cell Hybrid Power Train Structure.
• Fuel Cell Indirect Powersystem
.
• FCE is connected with ESS in parallel after DC/DC
converter.
• better for the optimization and control of the FCE and is
an economic selection for the fuel cell vehicle nowadays

16. • Fuel Cell Direct Power System.
• FCE’s output is directly inputted to DC/AC
and the ESS is connected with the FCE’s
output in parallel after a bidirectional
DC/DC.
• FCE outputs power directly into DC/AC, the
FCE must have good dynamic response to
output enough power quickly to meet the
vehicle’s driving performance requirement
and good voltage maintained performance to
avoid the large voltage drop of bus line and
the large torque drop of electric motor. On
the other side, the FCE must be overlarge to
avoid the possible damage.

17. • The main controller receives the pedal signals from
the driver. With the values of pedal, speed, the driving
power required is calculated by look-up table of motor
performance map.
• The target power of fuel cell engine is the sum of the
driving power and the SOC-regulated power of battery
pack.
• The target current of the DC-DC converter is real-time
calculated by the target driving power divided by the
bus voltage. The air compressor’s speed control is based
on the target power of fuel cell engine.

18. System control srategy
• Two kinds of control strategies.
▪ Conventional fuel cell outputpower
oriented control strategy
• Setting the FCE as the main power sources and controlling the
FCE’s output power to follow the vehicle’s driving power
requirement at some extent. The FCE is working on nearly for all of
the driving time expect for the first cold start and small driving
power requirement while battery pack is at high SOC.

19. conclusions
• Using the concept of Hybridization of cars results in
better efficiency and also saves a lot of fuel in today’s
fuel deficit world.
• A hybrid gives a solution to all the problems t
o some
extent.
• If proper research and development is done in this
field,hybrid vehicle,promises a practical,efficient low
pollution vehicle for coming era.
• One can surely conclude that this concept andthe similar
ones to follow with even better efficiency &
conservation rate are very much on the anvil in today’s
energy deficit world.

20. Thank you.