Hybrid report pdf

Seminar report 2015 Hybrid Car
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Dept. of .Mechanical Engineering AXIS CET
CHAPTER-1
INTRODUCTION
Any vehicle is a hybrid when it combines two or more sources of power .In fact
many people have probably owned a hybrids vehicle at some point. For example, a moped
is type of hybrid because it combines the power or a gasoline engine with the pedal power
of its raider. Hybrid vehicles are all around us. Most of the locomotives we see pulling
trains are diesel -electric hybrids. Cities like Seattle have diesel electric buses these can
draw power from overhead wires or run on diesel when they are away from wires. Giant
mining trucks are often diesel electric hybrids. Submarines are also hybrid vehicles some
are nuclear -electric and some are diesel electric. Any vehicle that combines two or more
sources of that power that can directly or indirectly provides propulsion power is a hybrid.
The gasoline electric hybrid car is just that a cross between gasoline’s powered car
and an electric car. Hybrid electric vehicles (HEVs) are powered by two energy sources An
energy conversion unit such as a combustion engine or fuel cell. And energy storage device
such as batteries so ultras capacitors, fly wheels. A gasoline, methanol, compressed natural
gas, hydrogen, or other alternative fuels may power the energy conversion unit. The nature
of HEV configuration enables several important advantages over pure electric vehicles
(EVs). Because the HEV engine shares the workload with the electric motor, it can be
constructed smaller. This reduction in size engenders weight reductions, leading to greater
fuel economy. Also, HEV engines can be optimized to operate within a specific speed range
characterized by better fuel economy and reduced emissions. This allows HEV’s to
eliminate the higher emissions and poor fuel economy associated with conventional ICE
vehicles. Hybrid electric vehicles have the potential to be two to three times more fuel-
efficient than conventional vehicles .In general; hybrids capture energy lost during braking
and return it to the on-board battery. This process is termed regenerative braking. HEV’s
generally don't ever need to be plugged in and charged they recharge themselves during
operation. Hybrid-concept vehicles are achieving fuel economy ratings of 80 miles per
gallon. General Motors' new Precept, for example, achieves a fuel efficiency rating of 108
miles per gallon. These are the most fuel-efficient and non-polluting vehicles the emissions
that are released by these are almost zero that’s why several countries prefer these to reduce
the environmental pollution and the global warming which is the main problem of this
generation.

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Emissions from the vehicles constitute the major part of the pollution so to reduce
this several measures are being take HEV’s are best suited for this. The hybrid electric
vehicle operates the alternative power unit to supply the power required by the vehicle, to
recharge the batteries, and to power accessories like the air conditioner and heater.
Hybrid electric cars can exceed the limited 100-mile (160 km) range-per-charge of
most electric vehicles and have the potential to limit emissions to near zero. A hybrid can
achieve the cruising range and performance advantages of conventional vehicles with the
low-noise, low-exhaust emissions, and energy in dependence benefits of electric vehicles .In
the coming years, hybrids can play a significant role in addressing several of the major
problems faced by the world today: climate change, air pollution, and oil dependence. This
new technology delivers on its promise hinges on the choices automakers, consumers, and
policymakers make over the coming years. A hybrid car uses more than one power source,
almost always an internal- combustion engine and an electric motor. In the hybrid design,
the combustion engine is the final source of the energy used to power the car, though an
alternative motor assists when more power is demanded using stored energy. This contrasts
with all-electric cars which use batteries charged by an external source.

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CHAPTER-2
HISTORY
The history of hybrid cars dates back to the late 1800s and 1900s.In 1905, Mr. H
Piper filed a patent for a gasoline engine-electric motor power train. According to him, the
electric motor would augment a gasoline engine, allowing a vehicle to accelerate from zero
to 25 miles an hour in 10 seconds, much faster than the gasoline engines of that time.
Ironically, when finally Mr. H Piper was granted the patent a few years later, normal
engines were capable of producing the same kind of acceleration.
Due to rapid advancements in the gasoline engine, the popularity of a hybrid car
slowly diminished until again in the early to mid 1970s, the time of oil crisis. Many
companies poured funds to build experimental Hybrid Electric Vehicles. But as the oil
became available again, the surge for HEVs died down immediately. Hybrid technology
actually originated with Diesel Electric Submarines. Both operate in essentially the same
manner as hybrid electric cars.
The first successful hybrid electric car was engineered by Ferdinand Porsche
since1928 then, hobbyists have continued to build such cars but none was put into
production by a major manufacturer until the waning years of the twentieth century.
Automotive hybrid technology became commercially successful in the 1990s when
the Honda Insight and Toyota Prius became available. These vehicles have a direct linkage
from the internal combustion engine to the driven wheels, so the engine can provide
acceleration power. Prototypes of plug-in hybrid cars, with larger battery packs that can be
re-charged from the power grid, have been built in the U.S., notably at Prof. Andy
Frank's Hybrid Center at UC Davis and one production(parallel hybrid electric vehicles)
PHEV, the Renault Kangoo, went on sale in France in 2003. DaimlerChrysler is currently
building a small number of PHEVs based on the Sprinter van. The California Cars Initiative
has converted a 2004 Prius to become a prototype of what it calls PRIUS.
Fig.2.1: Implemented Hybrids

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CHAPTER 3
ALL ABOUT HYBRID CARS
Hybrid cars are the cars, which run on at-least one alternate source of energy and
gasoline. Most of the time that other alternate source of energy for hybrid cars is electricity
rechargeable batteries hence those are called electric hybrid cars. These new hybrid cars are
innovative, efficient and affordable.
3.1 WORKING
Hybrid Cars integrate the power of the conventional gasoline engine with that of an
electric motor. A high powered battery pack provides energy to the motor which itself gets
recharged when the car is decelerating. This is called as regenerative braking. The gas
engine can also assist the battery in recharging. This kills the need to plug the car to an
external source of energy. As of now, there are two types of hybrid vehicles.In one type, the
electric motor acts as a side-kick to the gas engine, assisting it whenever surplus power is
needed. The electric motor alone is incapable of independently operating the vehicle.
Honda's Power Assist technology in its hybrids, Civic and Insight is an example. Such
vehicles are termed as Mild Hybrids.
In mild hybrids, the gasoline engine provides the main source of power, and the
electric motor provides additional power whenever needed. The second type of hybrid can
be termed as a Full Hybrid, where the gasoline engine and the electric motor can operate the
vehicle separately. In this type, the electric motor can drive the vehicle at lower speeds. In
need of more speed, the gasoline engine kicks in. The Toyota Prius and the Ford Escape
implement the same technology.
Be it mild hybrids or full hybrids, both are capable of providing lower emissions and
better fuel efficiency. The Internal-Combustion Engines (both gasoline and diesel) installed
in Hybrid cars are often smaller than those in normal cars for a simple reason that Hybrids
have the electric motor for assistance. The motor can take care of city travel which poses
stop and go conditions as well as power-consuming add-ons such as the A/C or power-
windows and power-steering.

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At high speeds, the gasoline engine supplies power. This switching of power sources
is computer controlled and nothing needs to be manually done. Power to the electric motor
comes from the battery-pack. Recharging of the battery is automatic and need not be done
by external sources.
When the car is in uniform motion or when it is decelerating, it generates power
which charges the batteries which utilizes the valuable kinetic energy. As with any other
battery, the Hybrid car battery also has a limited life span. Auto makers however, put the
battery life at around 200,000 miles which roughly comes around to 7-8 years, depending
on the kind of travel it endures. Thus, It pays to take extra care of your vehicle and travel
when necessary.
3.2 SELECTION OF HYBRID CARS
1. A Hybrid car is environment friendly. It can reduce pollution by 90 percent.
2. Hybrid cars are economical in medium and long run than normal gasoline cars.
3. Hybrid cars are more reliable than electric cars, as they have gasoline as an alternate
fuel.
4. A hybrid car makes you less dependent on fossil fuels (gasoline).
5. Hybrid cars are more efficient, as they have smaller engines.
6. Hybrid cars help in Greenhouse Effect, as they lower the fuel emission.
7. Hybrid cars improve mileage to a great extent.
3.3 COMPONENTS OF HYBRID CARS
3.3.1 HYBRID ENGINES
The hybrid car has a gasoline engine much like the one you will find on most cars.
However, the engine on a hybrid is smaller and uses advanced technologies to reduce
emissions and increase efficiency.A number of types of engines could be use in hybrid
vehicles. A detailed review of engines for hybrid vehicle application is given in reference
30 that study was done in 1984. Summarizes the results of the study in terms of minimum
bsfc (kg/KWh),
The specific weight (Kg/KW), and specific volume (liters/KW) for the various
engine types. The engine results have been updated using information from 31-34. Based on
their relatively small size and weight, the following engine (1) the rotary engine (2)

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The direct-injected two-stroke engine and (3) the gas turbine engine use for the
application and requirements. The weight is lees then the actual car.
Fig 3.1: MR 479q Gasoline Engine
Fig 3.2: ZR 1 Sport Car Engine
3.3.2 HYBRID BATTERY
The batteries in a hybrid car are the energy storage device for the electric motor.
Unlike the gasoline in the fuel tank, which can only power the gasoline engine, the electric
motor on a hybrid car can put energy into the batteries as well as draw energy from them.
The batteries perform 2 functions: they send energy to the electric motor and store
energy that is being captured by the generator. specific energy is a key parameter to assess
the suitability of a battery for the desired driving range specific power is a key parameter to
assess the suitability of battery desired grade ability and acceleration. State of Charge
(SOC) refers to a battery's residual charge capacity on a scale from 0 (empty) to 1 (full).
SOC is not directly measurable on an actual battery, but for some battery technologies,
including Lead Acid and Lithium Ion, there is a correlation between the SOC of a battery
and the battery voltage. When the battery is discharged, the battery’s SOC is depleted.
When the battery get charged, the battery’s SOC increases.

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In order to account for energy that the battery has remaining, one must also consider
the voltage and time during which that charge is delivered.
Fig 3.3: hybrid battery
3.3.3 ELECTRIC MOTOR
The electric motor on a hybrid car is very sophisticated. Advanced electronics allow
it to act as a motor as well as a generator. For example, when it needs to, it can draw energy
from the batteries to accelerate the car. But acting as a generator, it can slow the car down
and return energy to the batteries. Electric motors are mechanically very simple. Electric
motors often achieve 90% energy conversion efficiency over the full range of speeds and
power output and can be precisely controlled. They can also be combined with regenerative
braking systems that have the ability to convert movement energy back into stored
electricity. This can be used to reduce the wear on brake systems (and consequent brake pad
dust) and reduce the total energy requirement of a trip. Regenerative braking is especially
effective for start-and-stop city use.

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Fig 3.4: Electric motor
3.3.4 GENERATOR
The generator is similar to an electric motor, but it acts only to produce electrical
power. It is used mostly on series hybrids (see below).An alternator is an
electromechanical device that converts mechanical energy to electrical energy in the
form of alternating current. Combined with the engine shaft generate the electric
current and this current is use for charging the battery.
Alternators generate electricity using the same principle as DC generators, namely,
when the magnetic field around a conductor changes, a current is induced in the
conductor. Typically, a rotating magnet, called the rotor turns within a stationary set of
conductors wound in coils on an iron core, called the stator. The field cuts across the
conductors, generating an induced EMF (Electro-Magnetic Field), as the mechanical
input causes the rotor to turn.
Fig 3.5: Generator

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3.3.5 TRANSMISSION AND GEARING
Most state of the art electric drivelines do not use a multi speed Transmission.
Gearing is used only to reduce the speed of the motor, which now have a maximum rpm of
10 -15 thousands, before input into the differential. Hence in a series hybrid there would be
no need for a multi-speed Transmission. In the parallel hybrid there is a for a multi-speed
Transmission between the engine and the main differential and clutches to decouple the
engine and electric motor from the driveshaft when their torque is not needed to propel the
vehicle.
The technology is referred to as "two-mode" hybrid transmission due to the ability to
extend the abilities of both electrical and mechanical paths of power.
The two modes of operation are:
3.3.5.1 INPUT-SPLIT MODE
At low speeds, the vehicle can move with either the electric motor/generators, the
internal combustion engine, or both, making it a so-called full hybrid. All accessories will
still remain functioning on electric power, and the engine can restart instantly if needed. In
this mode, one of the motor/generators (M/G 1) acts as a generator , while the other operates
as a motor (M/G 2). This mode is operational for the two continuously variable ranges
(input split and compound split) of the transmission.
Fig 3.6: Input-split mode

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3.3.5.2 COMPOUND-SPLIT MODE
At higher speeds or heavier loads, the internal combustion engine always runs, and
the system uses advanced technologies like Active Fuel Management and late intake valve
closing to optimize engine and fuel efficiency.
Fig 3.7: Compound-Split Mode
3.4 ADVANCED TECHNOLOGY IN HEVS
3.4.1 REGENERATIVE BRAKING
A regenerative brake is an energy recovery mechanism which slows a vehicle by
converting its kinetic energy into another form, which can be either used immediately or
stored until needed. This contrasts with conventional braking systems, where the excess
kinetic energy is converted to heat by friction in the brake linings and therefore wasted.
The most common form of regenerative brake involves using an electric motor as an
electric generator. In electric railways the generated electricity is fed back into the supply
system, whereas in battery electric and hybrid electric vehicles, the energy is stored in a
battery or bank of capacitors for later use. Energy may also be stored via pneumatics,
hydraulics or the kinetic.

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3.4.2 AUTOMATIC START AND SHUT OFF
In automobiles, a start-stop system or stop-start system automatically shuts down and
restarts the internal combustion engine to reduce the amount of time the engine spends
idling, thereby improving fuel economy and reducing emissions. This is most advantageous
for vehicles which spend significant amounts of time waiting at traffic lights or frequently
come to a stop in traffic jams. This feature is present in hybrid electric vehicles, but has also
appeared in vehicles which lack a hybrid electric power train. For non-electric vehicles
(called micro-hybrids, fuel economy gains from this technology are typically in the range of
5 to 10 percent.
Since automobile accessories like air conditioners and water pumps have typically been
designed to run off a serpentine belt on the engine, those systems must be redesigned to
function properly when the engine is turned off. Typically, an electric motor is used to
power these devices instead.
3.4.3 USE ADVANCED AERODYNAMICS TO REDUCE DRAG
When you are driving on the freeway, most of the work your engine does goes into
pushing the car through the air. This force is known as aerodynamic drag. This drag force
can be reduced in a variety of ways. One sure way is to reduce the frontal area of the car.
Think of how a big SUV has to push a much greater area through the air than a tiny
sports car. Reducing disturbances around objects that stick out from the car or eliminating
them altogether can also help to improve the aerodynamics. For example, covers over the
wheel housings smooth the airflow and reduce drag. And sometimes, mirrors are replaced
with small cameras. Use low-rolling resistance tires - The tires on most cars are optimized
to give a smooth ride, minimize noise, and provide good traction in a variety of weather
conditions. But they are rarely optimized for efficiency. In fact, the tires cause a surprising
amount of drag while you are driving. Hybrid cars use special tires that are both stiffer and
inflated to a higher pressure than conventional tires. The result is that they cause about half
the drag of tires. Use lightweight materials - Reducing the overall weight of a car is one
easy way to increase the mileage. A lighter vehicle uses less energy each time you
accelerate or drive up a hill. Composite materials like carbon fiber or lightweight metals
like aluminum and magnesium can be used to reduce weight.

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3.4.4 LOW-ROLLING RESISTANCE TIRES
The tires on most cars are optimized to give a smooth ride, minimize noise, and provide
good traction in a variety of weather conditions. But they are rarely optimized for
efficiency. In fact, the tires cause a surprising amount of drag while you are driving. Hybrid
cars use special tires that are both stiffer and inflated to a higher pressure than conventional
tires. The result is that they cause about half the drag of regular tires.
3.4.5 LIGHTWEIGHT MATERIALS
Reducing the overall weight of a car is one easy way to increase the mileage. A lighter
vehicle uses less energy each time you accelerate or drive up a hill. Composite materials
like carbon fiber or lightweight metals like aluminum and magnesium can be used to reduce
weight.
3.5 TYPE OF HYBRID CAR
3.5.1 PARALLEL HYBRID CAR
Parallel hybrid systems, which are most commonly produced at present, have both an
internal combustion engine (ICE) and an electric motor connected to a mechanical
transmission. Most designs combine a large electrical generator and a motor into one unit,
often located between the combustion engine and the transmission, replacing both the
conventional starter motor and the alternator. To store power, a hybrid uses a large battery
pack with a higher voltage than the normal automotive 12 volts. Accessories such as power
steering and air conditioning are powered by electric motors instead of being attached to the
combustion engine. This allows efficiency gains as the accessories can run at a constant
speed, regardless of how fast the combustion engine is running.
Parallel hybrids can be categorized by the way the two sources of power are
mechanically coupled. If they are joined at some axis truly in parallel, the speeds at this axis
must be identical and the supplied torques adds together. Most electric bicycles are in effect
of this type. When only one of the two sources is being used, the other must either also
rotate in an idling manner or be connected by a one-way clutch or freewheel. With cars it is
more usual to join the two sources through a differential gear.

Seminar report 2015
Thus the torques supplied must be the same and the speeds add up, the exact ratio
depending on the differential characteristics. When only one of the two sources is being
used, the other must still supply a large part of the torque or be fitted with a reverse on
way clutch or automatic clamp.
Parallel hybrids can be further categorized depending upon how balanced the different
portions are at providing motive power. In some cases, the combustion engine is the
dominant portion (the electric motor turns on only when a boost is needed) and vice versa.
Others can run with just the electric system operating. But because current parallel hybrids
are unable to provide all-electric (ICE=OFF) propulsion, they are often categorized at
hybrids.
Because parallel hybrids can use a smaller battery pack as they rely more on
regenerative braking and the internal combustion engine can also act as a generator for
supplemental recharging, they are more efficient on highway driving compared to u
stop-and-go conditions or city driving. Honda's Insight, Civic, and Accord hybrids are
examples of production parallel hybrids. General Motors Parallel Hybrid Truck and Hybrids
such as the Saturn Aura Green line and Chevrolet Malibu hybrids are also c
utilizing a parallel architecture.
3.5.2 SERIES HYBRID CAR
Structure of a series
An alternative arrangement (not shown) is to have electric motors at two or four wheels.
Series hybrids have also been referred to as range
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he torques supplied must be the same and the speeds add up, the exact ratio
used, the other must still supply a large part of the torque or be fitted with a reverse on
way clutch or automatic clamp.
Fig 3.8: Parallel Hybrid System
he electric motor turns on only when a boost is needed) and vice versa.
electric (ICE=OFF) propulsion, they are often categorized at
supplemental recharging, they are more efficient on highway driving compared to u
go conditions or city driving. Honda's Insight, Civic, and Accord hybrids are
such as the Saturn Aura Green line and Chevrolet Malibu hybrids are also c
utilizing a parallel architecture.
SERIES HYBRID CAR
ture of a series-hybrid vehicle The grey square represents a differential gear.
have also been referred to as range-extended electric vehicles,
Hybrid Car
he torques supplied must be the same and the speeds add up, the exact ratio
used, the other must still supply a large part of the torque or be fitted with a reverse one-
he electric motor turns on only when a boost is needed) and vice versa.
electric (ICE=OFF) propulsion, they are often categorized at mild
supplemental recharging, they are more efficient on highway driving compared to urban
go conditions or city driving. Honda's Insight, Civic, and Accord hybrids are
such as the Saturn Aura Green line and Chevrolet Malibu hybrids are also considered as
The grey square represents a differential gear.
extended electric vehicles,

Seminar report 2015
in order to emphasize that they are electric vehicles with a combustion engine assist.
However, range extension can be accomplished with either series or parallel hybrid layouts.
Series-hybrid vehicles are driven only by electric traction. Unlike piston internal
combustion engines, electric motors are efficient with exceptionally high power to weight
ratios providing adequate torque over a wide speed range.
Unlike combustion engin
transmission between the engine and wheels shifting torque ratios. Transmissions add
weight, bulk and sap power from the engine. Mechanical automatic shifting transmissions
can be very complex. In a series
generator instead of directly driving the wheels. The generator provides power for the
driving electric motors. In short, a series
motors with a generator set providing the electric power.
3.5.3 POWER -SPLIT OR SERIES
Power-split hybrid or series
power-split devices allowing for power paths from the engine to the wheels that can be
either mechanical or electrical. The main principle behind this system is the decoupling of
the power supplied by the engine (or
the driver.
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Fig 3.9: Series Hybrid System
hybrid vehicles are driven only by electric traction. Unlike piston internal
ratios providing adequate torque over a wide speed range.
Unlike combustion engines electric motors matched to the vehicle do not require a
a series-hybrid system, the combustion engine drives an electric
driving electric motors. In short, a series-hybrid is simple; the vehicle is driven by electric
ith a generator set providing the electric power.
SPLIT OR SERIES-PARALLEL HYBRID CAR
split hybrid or series-parallel hybrids are parallel hybrids. They incorporate
split devices allowing for power paths from the engine to the wheels that can be
the power supplied by the engine (or other primary source) from the power demanded by
Hybrid Car
hybrid vehicles are driven only by electric traction. Unlike piston internal
es electric motors matched to the vehicle do not require a
hybrid system, the combustion engine drives an electric
hybrid is simple; the vehicle is driven by electric
are parallel hybrids. They incorporate
split devices allowing for power paths from the engine to the wheels that can be
other primary source) from the power demanded by

Seminar report 2015
Fig 3.10:
A combustion engine's torque output is minimal at lower RPMs and, in a
conventional vehicle, a larger engine is necessary for acceptable a
standstill. The larger engine, however, has more power than needed for steady speed
cruising. An electric motor, on the other hand, exhibits maximum torque at standstill and is
well-suited to complement the engine's torque deficiency at lo
hybrid, a smaller, less flexible, and highly efficient engine can be used.
The conventional Otto cycle (higher power density, more low
fuel efficiency) is often also modified to a Miller cycle or Atkinson cycl
density, less low-rpm torque, higher fuel efficiency). The smaller engine, using a more
efficient cycle and often operating in the favorable region of the brake specific fuel
consumption map, contributes significantly to the higher overall e
Addition of a fixed gear second planetary gear
Toyota Highlander Hybrid. This allows for a motor with less torque but higher power (and
higher maximum rotary speed), i.e. higher power density
Addition of a Ravigneaux
of 3 and two clutches as used in the Lexus GS450h. By switching the clutches, the
ratio from MG2 the drive motor
higher speed up to 250 km/h / 155
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Power-Split Or Series-Parallel Hybrid system
conventional vehicle, a larger engine is necessary for acceptable acceleration from
An electric motor, on the other hand, exhibits maximum torque at standstill and is
suited to complement the engine's torque deficiency at low RPMs. In a power
hybrid, a smaller, less flexible, and highly efficient engine can be used.
The conventional Otto cycle (higher power density, more low-rpm torque, and lower
fuel efficiency) is often also modified to a Miller cycle or Atkinson cycl
rpm torque, higher fuel efficiency). The smaller engine, using a more
consumption map, contributes significantly to the higher overall efficiency of the vehicle.
fixed gear second planetary gear set as used in the Lexus RX400h and
higher maximum rotary speed), i.e. higher power density
Addition of a Ravigneaux-type planetary gear (planetary gear with 4 shafts instead
and two clutches as used in the Lexus GS450h. By switching the clutches, the
ratio from MG2 the drive motor to the wheel shaft is switched, either for
km/h / 155
Hybrid Car
cceleration from
An electric motor, on the other hand, exhibits maximum torque at standstill and is
w RPMs. In a power-split
rpm torque, and lower
fuel efficiency) is often also modified to a Miller cycle or Atkinson cycle (lower power
rpm torque, higher fuel efficiency). The smaller engine, using a more
fficiency of the vehicle.
set as used in the Lexus RX400h and
gear with 4 shafts instead
and two clutches as used in the Lexus GS450h. By switching the clutches, the gear
higher torque or

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3.5.4 PLUG-IN HYBRID ELECTRICAL VEHICLE
A plug-in hybrid electric vehicle (PHEV) has two defining characteristics: 1) it can
be plugged in to an electrical outlet to be charged and (2) has some range that can be
traveled on the energy it stored while plugged in. They are full hybrid, able to run in
electric-only mode, with larger batteries and the ability to recharge from the electric power
grid. And can be parallel or series hybrid designs. They are also called gas-optional, or
griddable hybrids. Their main benefit is that they can be gasoline-independent for daily
commuting, but also have the extended range of a hybrid for long trips. They can also be
multi-fuel, with the electric power supplemented by diesel, biodiesel, or hydrogen. The
Electric Power Research Institute's research indicates a lower total cost of ownership for
PHEVs due to reduced service costs and gradually improving batteries. The "well-to-wheel"
efficiency and emissions of PHEVs compared to gasoline hybrids depends on the energy
sources of the grid (the US grid is 50% coal; California's grid is primarily natural gas,
hydroelectric power, and wind power). Particular interest in PHEVs is in California where a
"million solar homes" initiative is under way, and global warming legislation has been
enacted.
Fig 3.11: working of plug in hybrid electrical vehicle

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CHAPTER-4
DISCUSSION SYNONYMS
4.1 HYBRID CAR PERFORMANCE
The key to a hybrid car is that the gasoline engine can be much smaller than the one
in a conventional car and therefore more efficient. But how can this smaller engine provide
the power your car needs to keep up with the more powerful cars on the road Let's compare
a car with its big V-8 engine, to our hybrid car with its small gas engine and electric motor.
The engine in the in V-8 has more than enough power to handle any driving situation. The
engine in the hybrid car is powerful enough to move the car along on the freeway, but when
it needs to get the car moving in a hurry, or go up a steep hill, it needs help. That help
comes from the electric motor and battery .this system steps in to provide the necessary
extra power. The gas engine on a conventional car is sized for the peak power requirement
(those few times when you floor the accelerator pedal). In fact, most drivers use the peak
power of their engines less than one percent of the time. The hybrid car uses a much smaller
engine, one that is sized closer to the average power requirement than to the peak power.
4.2 HYBRID CAR EFFICIENCY
Besides a smaller, more efficient engine, today's hybrids use many other tricks to
increase fuel efficiency. Some of those tricks will help any type of car get better mileage,
and some only apply to a hybrid. To squeeze every last mile out of a gallon of gasoline, a
hybrid car can:
Recover energy and store it in the battery - Whenever we step on the brake pedal in
your car, we are removing energy from the car. The faster a car is going, the more kinetic
energy it has. The brakes of a car remove this energy and dissipate it in the form of heat. A
hybrid car can capture some of this energy and store it in the battery to use later. It does this
by using regenerative braking. That is, instead of just using the brakes to stop the car, the
electric motor that drives the hybrid can also slow the car. In this mode, the electric motor
acts as a generator and charges the batteries while the car is slowing down.
Sometimes shut off the engine - A hybrid car does not need to rely on the gasoline
engine all of the time because it has an alternate power source the electric motor and
batteries. So the hybrid car can sometimes turn off the gasoline engine, for example when
the vehicle is stopped at a red light.

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4.3 ADVANTAGES OF HYBRID CAR
1. Less Environmental pollution
2. Fuel consumption is low
3. Less Noise is produced
4. High Energy efficiency
5. Cost of recharge is very low
6. Lighter batteries so weight of car is low
7. High Mobility
8. Value Added Features is more when compared to other cars
9. Regenerative braking system stores electrical energy in Batteries
10. Uses less fuel to recharge batteries
Hybrid Car significantly reduced the emissions of C02 into environment. A fewer and
cleaner emission is a major reason why hybrid cars are popularly known as 'green' cars.
Reduced emission ensures lower pollution levels, something which is highly necessary in
today's times. Another way in which hybrid cars benefit the environment is that they help in
lowering noise pollution levels. Hybrid car engines go about churning the required amount
of horse power without any excessive roaring. When switched onto electric power mode,
these cars are virtually silent when in operation.
4.4 DISADVANTAGES OF HYBRID CAR
1. In the event of an unfortunate accident, there is a risk of exposure to high voltage
wires.
2. They have a complicated system which needs to be taken care of by experienced
mechanic only.
3. Spare parts maybe hard to find and may be costly.
4. More expensive than conventional Vehicles
5. HEVs are partial zero-emission vehicles (PZEVs) – they produce zero emissions
only when engine is not running

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CHAPTER-5
CONCLUSION
Though at present the concept has been put in to maximum utilization by hybrid
electrical vehicle it is indeed an important research avenue for other car manufacturing units
as well. One can surely conclude that this concept, and the similar ones to follow with even
better efficiency & conservation rate are very much on the anvil in today’s energy deficit
world. A technology exists to build a future with a significant lower dependence on oil and
a cleaner, cooler atmosphere. With sufficient political will and automaker participation, this
future can arrive in time to address these significant and growing problems. Hybrids can
play an important role in realizing this future, filling the gap between immediate
improvements through conventional technology; hybrids can help drive passengers vehicle
oil consumption and global warming emulsions from cars and trucks below 1990 levels.

20
REFERENCE
[1] Eberle, R.: Methodik zur ganzheitlichen Bilanzierung im Automobilbau,dissertation,
Technical University Berlin, Institute for road and rail traffic, Berlin, 2000, pages 3,
79.
[2] Wallentowitz, H.; von Zengen, K.-H.; Parr, T.; Wohlecker, R.;Wynands, D.
Leichtbaupotenzialeines,aluminiumintensivenFahrzeugs,in:AutomobiltechnischeZeit
schrift, 03/2003, volume 105, pages 282,283.
[3] National institute of sustainable energy .hybrid electric and battery electric vehicles
dublin ireland 2007.
[4] Ruprekha bramachari. Hybrid cars. institute of technology Roorkee, india. 2010
[5] Hantula, Richard . How do hybrid car work. Newyork . chelsea house publishers
.2010.

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