Hybrid Electric Vehicles(HEV)

STUDY OF HYBRID ELECTRIC VEHICLES (HEV)
A Mini Project Report
Submitted in partial fulfillment of the
Requirements for the award of the Degree of
BACHELOR OF TECHNOLOGY
IN
MECHANICAL ENGINEERING
By
SAMALA HARISH 18P65A0332
Under the esteemed guidance of
Mr. BH.SRIDHAR
ASSISTANT PROFESSOR
DEPARTMENT OF MECHANICAL ENGINEERING
VIGNANA BHARATHI INSTITUTE OF TECHNOLOGY
(Accredited by NBA and NAAC, New Delhi)
(Affiliated to JNTU Hyderabad, Approved by AICTE)
Aushapur (v), Ghatkesar (m), Medchal Dist, Hyderabad-501301
2020-21

CERTIFICATE
This is to certify that the Mini project report entitled, “STUDY OF HYBRID ELECTRIC
VEHICLES(HEV)”,done by SAMALA HARISH bearing Admn. No:(18P65A0332)
submitted to the faculty of Mechanical Engineering, in partial fulfillment of the requirements
for the Degree of BACHELOR OF TECHNOLOGY from VBIT, Aushapur, Hyderabad.
Signature of the Supervisor Signature of the Head of the Department
Mr.BH SRIDHAR Dr.P.Kishore Kumar
MTech MTech,PhD
Assistant Professor Head of the Department
Signature of the External

ACKNOWLEDGEMENT
We wish to thank various people for the successful completion of our Mini project
Report with a good insight of the work and we wish to thank various personalities for their
help and advice given to us. It is with great sense of gratitude that we would like to thank
each of them for helping us throughout this project.
We would like to thank our Principal Dr.G. Amarendar Rao, for having given us the
opportunity to work on this project and his valuable suggestions.
We are extremely grateful to our Head of the Department Dr. P. Kishore Kumar,
Assoc. Professor, for his continued support and guidance.
We are grateful to our mini project coordinator Mr. B.Satish Kumar Assoc.
Professors for his continuous encouragement, to complete the project.
We are grateful to our mini project guide Mr.BH Sridhar, Assistant Professor for his
contious support and guidance.
We also thank the faculty of the department of mechanical for their support in
completion of the project.
By
SAMALA HARISH 18P65A0332

ABSTRACT
Many efforts have been made to reduce emissions into the atmosphere in the past 25
years. The diffusion of hybrid electric technology in vehicles without compromising vehicle
functionality and driving performances. The hybrid engine in vehicles has he potential to
reduce the fossil fuel use, decrease pollution and allow renewable energy sources for
transportation.
Conventional vehicles use gasoline and diesel to power an Internal Combustion
engine. Hybrids also use the internal combustion engine and can be fueled as normal cars The
vehicle is lighter and roomier than a purely electric vehicle, because there is less need to
carry as many heavy batteries. The internal combustion engine in hybrid-electric is much
smaller and lighter and more efficient than the engine in a conventional vehicle. In fact, most
automobile manufacturers have announced plans to manufacture their own hybrid versions.
Hybrid electric 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 electric
power from overhead wires or run on diesel when they are away from the wires. Giant
mining trucks are often diesel-electrichybrids.Submarines are also hybrid vehicles -- some are
nuclear-electric and some are diesel electric. Any vehicle that combines two or more sources
of power that can directly or indirectly provide propulsion power is a hybrid.
The demand for Hybrid Electric Vehicles is rising due to stringent emission regulation
standards and growing demand for low or zero-emission vehicles, in India the market volume
is 4,169 thousand units in 2018 and is estimated to be grown 7,593 thousand units in 2025
and to reach Net worth of $707.4 million by 2025.

CONTENTS
Chapter No Tittle Name Page No
ABSTRACT
ACKNOWLEDGEMENT
LIST OF FIGURES
1. INTRODUCTION 1-5
1.1 Introduction of Hybrid Vehicle 1
1.2 History of hybrid vehicle 2
1.3 Basic Characterstics 4
2. TYPES OF HYBRID VEHICLE 6-10
2.1 Series type HEV 6
2.2 Parallel type HEV 8
2.3 Series-Parallel type HEV 10
3. COMPONENTS OF HYBRID VEHICLE 11-18
3.1 Engine 11
3.1.1 Gasoline Engine 11
3.1.2 Diesel Engine 11
3.1.3 Hydrogen Engine 12
3.2 Battery 13
3.2.1 Cylindrical 13
3.2.2 Prismatic 14
3.2.3 Button 14
3.2.4 Pouch 15
3.3 Electric Motor 15
3.3.1 Motor Components 16
3.4 Controller 18
3.5 Generator 18
3.6 Power split Device 18

4. LITERATURE REVIEW 19-23
4.1 The Toyota prius and IMA 19
4.2 Drive Train Modeling 20
4.3 Prius and Civic Drive Chain 21
4.4 E-CVT and electric machines 21
4.5 Advantages 22
4.6 Disadvantages 23
5. MODERN HYBRID PRODUCTION 24-28
5.1 Introduction 24
5.2 Future Work 26
6. CONCLUSION 29
7. REFERENCES 30

LIST OF FIGURES
Figure No Figure Name Page No
1.1 The first gasoline-Electric Vehicle 2
1.2 Cycle life 5
1.3 Energy Densities 5
2.1 Series Type HEV 6
2.1.2 Power Flow in Series type HEV 7
2.2 Parallel type HEV 8
2.2.2 Power flow in parallel type HEV 9
2.3 Series-Parallel type HEV 10
3.1 Cost per mile EV v/s Gasoline engines 12
3.2.1 Cylindrical battery packing 13
3.2.2 Prismatic battery packing 14
3.2.3 Button type battery packing 14
3.2.4 Pouch type battery packing 15
3.1.1 Motor Parts 17
3.1.2 Components of Electric Motor 17
4.1 Toyota pirus and civic 20
5.2 1997 Toyota Pirus 26
5.2.1 Honda in Sight 26

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CHAPTER 1
INTRODUCTION
1.1.INTRODUCTION OF HYBRID ELECTRIC VEHICLE
A hybrid vehicle, abbreviated HEV, is one that uses both an internal combustion
engine (ICE) and an electric motor to propel the vehicle. Most hybrids use a high- voltage
battery pack and a combination electric motor and generator to help or assist a gasoline
engine.[1]
The ICE used in a hybrid vehicle can be either gasoline or diesel, although only gasoline-
powered engines are currently used in hybrid vehicles. An electric motor is used to help
propel the vehicle, and in some designs, capable of propelling the vehicle alone without
having to start the internal combustion engine.
The presence of the electric power train is intended to achieve either better fuel economy
than a conventional vehicle or better performance. There are a variety of HEV types, and
the degree to which they function as EVs varies as well. The most common form of HEV
is the hybrid electric car, although hybrid electric trucks (pickups and tractors) and buses
also exist. Modern HEVs make use of efficiency- improving technologies such as
regenerative braking, which converts the vehicle's kinetic energy into electric energy to
charge the battery, rather than wasting it as heat energy as conventional brakes do. Some
varieties of HEVs use their internal combustion engine to generate electricity by spinning
an electrical generator (this combination is known as a motor-generator), to either
recharge their batteries or to directly power the electric drive motors.
Many HEVs reduce idle emissions by
shuttingdowntheICEatidleandrestartingitwhenneeded;thisisknownasastart-
stopsystem.Ahybrid-electricproduceslessemissionsfromitsICEthana

2
comparably-sized gasoline car, since an HEV's gasoline engine is usually smaller than a
comparably-sized pure gasoline-burning vehicle (natural gas and propane
fuelsproduceloweremissions)andifnotusedtodirectlydrivethecar,canbegeared to run at
maximum efficiency, further improving fuel economy.[1]
1.2.HISTORY OF HYBRID ELECTRIC VEHICLE
In 1900 Ferdinand Porsche developed the Lohner-Porsche Mixte Hybrid, the first
gasoline-electric hybrid automobile in the world, a 4WD series-hybrid version of
"SystemLohner-Porsche"electriccarriagepreviouslyappearedin1900ParisWorld Fair. The
Mixte included a pair of generators driven by 2.5-hp Daimler IC engines to extend
operating range and it could travel nearly 65 km on battery alone. It was presented in the
Paris Auto Show in 1901. The Mixte broke several Austrian speed
records,andalsowontheExelbergRallyin1901withPorschehimselfdriving.The Mixte used a
gasoline engine powering a generator, which in turn powered electric hub motors, with a
small battery pack for reliability. It had a top speed of 50 km/h and a power of 5.22 kW
during 20 minutes. George Fischer sold hybrid buses to England in 1901; Knight Neftal
produced a racing hybrid in 1902.[2]
Fig. 1.1 The first gasoline-electric hybrid vehicle
In 1905, Henri Pieper of Germany/Belgium introduced a hybrid vehicle with an electric
motor/generator, batteries, and a small gasoline engine. It used the electric

3
motor to charge its batteries at cruise speed and used both motors to accelerate or climb a
hill. The Pieper factory was taken over by Imperia, after Pieper died. The
1915DualPower,madebytheWoodsMotorVehicleelectriccarmaker,hadafour- cylinder ICE
and an electric motor. Below 15 mph (24 km/h) the electric motor alone drove the
vehicle, drawing power from a battery pack, and above this speed
the"main"enginecutintotakethecaruptoits35mph(56km/h)topspeed.
About 600weremadeupto1918.TheWoodshybridwasacommercialfailure,provingto
betooslowforitsprice,andtoodifficulttoservice.TheUnitedStatesArmy's1928 Experimental
Motorized Force tested a gasoline-electric bus in a truck convoy. In 1931 Erich Gaichen
invented and drove from Altenburg to Berlin a 1/2 horsepower electric car containing
features later incorporated into hybrid cars. Its maximum speed was 25 miles per hour (40
km/h), but it was licensed by the Motor Transport Office, taxed by the German Revenue
Department and patented by the German Reichs-Patent Amt. The car battery was re-
charged by the motor when the carwent downhill. Additional power to charge the battery
was provided by a cylinder of compressed air which was re-charged by small air pumps
activated by vibrationsof the chassis and the brakes and by igniting oxy-hydrogen gas. An
account of the car and his characterization as a "crank inventor" can be found in Arthur
Koestler's autobiography, Arrow in the Blue, pages 269-271, which summarize a
contemporaneous newspaper account written by Koestler. No production beyond the
prototype was reported. The hybrid-electric vehicle did not become widely available until
the release of the Toyota Prius in Japan in 1997, followed by the Honda Insight in
1999.While initially perceived as unnecessary due to the low cost
ofgasoline,worldwideincreasesinthepriceofpetroleumcausedmanyautomakers
toreleasehybridsinthelate2000s;theyarenowperceivedasacoresegmentofthe
automotivemarketofthefuture.Morethan5.8millionhybridelectricvehicleshave been sold
worldwide by the end of October 2012, led by Toyota Motor Company
(TMC)withmorethan4.6millionLexusandToyotahybridssoldbyOctober2012, followed by
Honda Motor Co., Ltd. with cumulative global sales of more than 1
millionhybridsbySeptember2012,andFordMotorCorporationwithmorethan 200 thousand
hybrids sold in the United States by June 2012. Worldwide sales of hybrid vehicles
produced by TMC reached 1 million units in May 2007; 2 million in August 2009; and
passed the 4 million mark in April 2012.As of October 2012, worldwide hybrid sales are
led by the Toyota Prius lift back, with cumulative sales of 2.8 million units, and available

4
in almost 80 countries and regions. The United States is the world's largest hybrid market
with more than 2.5 million hybrid automobiles and SUVs sold through October 2012,
followed by Japan with more
than2millionhybridssoldthroughOctober2012ThePriusisthetopsellinghybrid
carintheU.S.market,surpassingthe1millionmilestoneinApril2011.Cumulative sales of the
Prius in Japan reached the 1 million mark in August 2011.
1.3.Basic Characteristics
 State of Charge(SOC)
 Measured as a percentage of total battery energy(0-100%)
 Typically, should not go below20%
 Depth of Discharge (DoD)
 Inverse ofSOC
 Power(kW)
 Energy(kWh)
 A-h
 Typically used for powerbatteries
 Cells often described inmA-h
 CRate
 A normalized rate of power use to qualifytesting
 100% discharge divided by the time inhours
 C2 means the discharge rate was 100% in ½hour
 C/2 means the rate was less aggressive – over 2hours
 CycleLife

5
 Always measured based onDoD
 Ex. 1000 cycles at 80%DoD
Fig. 1.2 Cycle life
 Weight/Volume
 Measures in terms of W/kg andW-h/kg
 W/l andW-h/l
Fig. 1.3 Energy Densities

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CHAPTER 2
TYPES OF HYBRID ELECTRIC VEHICLE
2.1.SERIES TYPE HEV
In series hybrids, only the electric motor drives the drive-strain, and the ICE works as a
generator to power the electric motor or to recharge the batteries. The battery pack can be
recharged through regenerative braking or by the ICE. Series hybrids usually have a
smaller combustion engine but a larger battery pack as compared to parallel hybrids,
which makes them more expensive than parallels. This configuration makes series
hybrids more efficient in city driving. The Chevrolet Volt is a series plug-in hybrid,
although GM prefers to describe the Volt as an electric vehicle equipped with a "range
extending" gasoline powered ICE as a generator and therefore dubbed an "Extended
Range Electric Vehicle" or EREV. Means In a series driveline, onlyan electric motor is
connected to drive the wheels. In it gasoline motor turns a generator, generator may either
charge the batteries or power an electric motor that drives the transmission and at low
speeds is powered only by the electric motor. In a series-hybrid design, the engine turns a
generator, which can charge batteries or power[4]
anelectricmotorthatdrivesthetransmission.Theinternalcombustionenginenever powers the
vehicledirectly.
Fig. 2.1 Series typeHEV

7
Fig. 2.1.1 Series typeHEV
This diagram shows the components included in a typical series hybrid design. The solid-
linearrowindicatesthetransmissionoftorquetothedrivewheels.Thedotted- line arrows
indicate the transmission of electrical current.[4]
Fig. 2.1.2 Power flow in series type HEV

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2.2.PARALLEL TYPE HEV
In parallel hybrids, the ICE and the electric motor are both connected to the
mechanicaltransmissionandcansimultaneouslytransmitpowertodrivethewheels, usually through a
conventional transmission. Honda's Integrated Motor Assist (IMA) system as found in the
Insight, Civic, Accord, as well as the GM Belted Alternator/Starter (BAS Hybrid) system found
in the Chevrolet Malibu hybrids are examples of production parallel hybrids. Current,
commercialized parallel hybrids use a single, small (<20 kW) electric motor and small battery
pack as the electric motor is not designed to be the sole source of motive power from launch.
Parallelhybridsarealsocapableofregenerativebrakingandtheinternalcombustionengine canal so ac
t as a generator for supplemental recharging.
Parallelhybridsaremore efficient than comparable non-hybrid vehicles especially
during urban stop-and-go conditions and at times during highway operation where the
electric motor is permittedtocontribute.Meansinaparallelsystem,boththegasolineandtheelectric
motorareconnectedtothedrivewheels.Gasolinemotor,batterieswhichpowersan electric motor, both
can power the transmission at the same time and electric motor supplements the gasoline engine.
In a parallel-hybrid design, multiple propulsion sources can be combined, or one energy source
alone can drive the vehicle. The battery and engine are both connected to the transmission. The
vehicle can be powered by internal combustion alone, by electric motor alone, (full hybrids), or
a combination. In most cases, the electric motor is used to assist the internal combustionengine.
Fig. 2.2 Parallel type HEV

9
Fig. 2.2.1 Parallel type HEV
Diagramshowingthecomponentsinvolvedinatypicalparallel-hybridvehicle.The solid-line
arrows indicate the transmission of torque to the drive wheels, and the dotted-line arrows
indicate the flow of electricalcurrent.
Fig. 2.2.2 Power flow in parallel type HEV

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2.3.SERIES-PARALLEL TYPE HEV
Series-Parallel type also called Power-split hybrids have the benefits of a
combinationofseriesandparallelcharacteristics.Asaresult,theyaremoreefficient
overall,becauseserieshybridstendtobemoreefficientatlowerspeedsandparallel
tendtobemoreefficientathighspeeds;however,thecostofpower-splitthehybrid is higher than
a pure parallel. Examples of power-split (referred to by some as "series-parallel") hybrid
power-strains include current models of Ford, General Motors, Lexus, Nissan, and
Toyota. Means a series-parallel hybrid design allows
thevehicletooperateinelectricmotormodeonlyorincombinationwiththeinternal combustion
engine. In it characteristics of both series and parallel type hybrid electric vehicle are
used, it’s cost is more than both single type HEV’s.[4]
Fig. 2.3 Series- parallel type HEV

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CHAPTER 3
COMPONENTS OF HYBRID ELECTRIC VEHICLE
3.1.ENGINE
It’smuchsameasothervehiclesengine,butthesizeofhybridelectricvehicleengine is small and
it’s more fuelefficient.
 Higher energy density thanbatteries,
1,000 pounds of batteries = 1 gallon (7 pounds) of gas.
It has three types. [5]
3.1.1Gasolineengine
Gasoline engines are used in most hybrid electric designs, and will likely remain
dominant for the foreseeable future. While petroleum-derived gasoline is the
primaryfuel,itispossibletomixinvaryinglevelsofethanolcreatedfromrenewable energy
sources. Like most modern ICE powered vehicles, HEVs can typically use up to about
15% bio-ethanol. Manufacturers may move to flexible fuel engines, which would
increase allowable ratios, but no plans are in place atpresent.
3.1.2.Diesel engine
Diesel-electric HEVs use a diesel engine for power generation. Diesels have
advantages when delivering constant power for long periods of time, suffering less
wearwhileoperatingathigherefficiency.Thedieselengine'shightorque,combined with
hybrid technology, may offer substantially improved mileage. Most diesel vehicles can
use 100% pure bio-fuels (biodiesel), so they can use but do not need petroleum at all
for fuel (although mixes of bio-fuel and petroleum are more common). If diesel-electric
HEVs were in use, this benefit would likely also apply.

12
(particularly buses); as of 2007, no light duty diesel-electric hybrid passenger cars are
currently available, although prototypes exist.
3.1.3.Hydrogenengine
Hydrogencanbeusedincarsintwoways:asourceofcombustibleheat,orasource of electrons
for an electric motor. The burning of hydrogen is not being developed in practical terms;
it is the hydrogen fuel-cell electric vehicle (HFEV) which is garnering all the attention.
Hydrogen fuel cells create electricity fed into an electric
motortodrivesthewheels.Hydrogenisnotburned,butitisconsumed.Thismeans molecular
hydrogen, H2, is combined with oxygen to form water. 2H2(4e-) + O2--
> 2H2O(4e-). The molecular hydrogen and oxygen's mutual affinity drives the fuel cell to
separate the electrons from the hydrogen, to use them to power the electric
motor,andtoreturnthemtotheionizedwatermoleculesthatwereformedwhenthe electron-
depletedhydrogencombinedwiththeoxygeninthefuelcell.Recallingthat
ahydrogenatomisnothingmorethanaprotonandanelectron;inessence,themotor is driven by
the proton's atomic attraction to the oxygen nucleus, and the electron's attraction to the
ionized water molecule.[5]
An HFEV is an all-electric car featuring an open-source battery in the form of a hydrogen
tank and the atmosphere. HFEVs may also comprise closed-cell batteries
forthepurposeofpowerstoragefromregenerativebraking,butthisdoesnotchange the source of
the motivation. It implies the HFEV is an electric car with two types of batteries. Since
HFEVs are purely electric, and do not contain any type of heat engine, they are not
hybrids.[5]
Fig. 3.1.3 Cost per mile EV v/s Gasoline Engine

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3.2.BATTERY
It stores the energy generated from gasoline engine or during regenerative braking, from
the electric motor. It’s power the vehicle at low speed, it’s size is larger and holds much
more energy than non-hybrid electric vehicle. [5]
 Batteries rule the performance of thevehicle
 They dictate how much power you get (kW)
 They dictate how much energy you get(kWh)
 A single cell dictates the battery voltage each cell mates two dissimilar materials
Table 3.2 Battery types
Batteries packaging
3.2.1.Cylindrical
Fig. 3.2.1 Cylindrical type battery packaging

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3.2.2.Prismatic
Fig. 3.2.2 Prismatic type battery packaging
3.2.3.Button
Fig. 3.2.3 Button type battery packaging

15
3.2.4.Pouch
Fig. 3.2.4 Pouch type battery packaging
3.3.ELECTRIC MOTOR
It’s power the vehicle at low speed and assist the gasoline engine when additional power
is needed, it’s also convert otherwise wasted energy from braking into electricity and
store it in battery. Most of the electric machines used in hybrid
vehiclesarebrushlessDCmotors(BLDC).Specifically,theyareofatypecalledan interior
permanent magnet (IPM) machine (or motor). These machines are wound similarly to the
induction motors found in a typical home, but (for high efficiency) use very strong rare
earth magnets in the rotor. These magnets containneodymium, iron and boron, and are
therefore called Neodymium magnets. The magnetmaterial
isexpensive,anditscostisoneofthelimitingfactorsintheuseofthesemachines.

16
3.3.1.Motorcomponents
 Rotatingcomponents
[1] Shaft
[2] Rotor
[3] Rotorfins
[4] Fan
 Housingcomponents
[5] End bells / bearinghousings
[6] Statorhousing
[7] Coolingfins
[8] Junctionbox
[9] Fanshroud
 Fixedcomponents
[10] Seals
[11] Statorwindings
[12] Core iron / laminationstack
[13] Bearings

17
Fig. 3.1.1 Motor Parts
Fig. 3.1.2 Components: Electric Motor – DC
Fig. 3.1.3 Components: Electric Motor – A

18
3.4.CONTROLLER
The controller is used to charge the battery or to supply the power to electric motor.
 Converts Battery DC to a chopped DCpower
 Can chop in amplitude (DC) or frequency(AC)
 Power is based on low voltage input signal 4-20 mA or0-5V
 In other fields this is called a drive orinverter
• Variable Frequency(AC)
• Pulse Width Modulation(AC)
• Buck Conversion (Reduce -DC)
• Boost Conversion (Increase -DC)
3.5.GENERATOR
Itconvertsmechanicalenergyfromengineintoelectricalenergy,whichcanbeused by electric
motor stored in the battery. It’s also used to start the gasoline engine instantly.[5]
3.6.POWER SPLITDEVICE
It’sagearboxconnectingthegasolineengine,electricmotorandgenerator.Itallows the engine
and motor to power the car independently or in tandem and allows the gasoline engine to
charge the batteries or provide power to the wheels as needed.

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CHAPTER 4
LITERATURE REVIEW
4.1.The Toyota Prius and IMA
Based on the theoretical discussion of the eco-innovation topic (see above), in the
following sections the case of the Toyota Prius is introduced and studied.
In Japan, 1997 the Toyota Motor Corporation launched the sale of the Toyota Prius I - the
world’s first commercialized hybrid car which combined an internal combustion engine and an
electric motor (NONAKA & PELTOKORPI 2006, P. 98).
The Toyota Motor Corporation (TMC) is a Japanese multinational car company. The firm was
founded in 1937 as a spinoff from Toyota Industries which originally manufactured automatic
looms (TOYOTA 2012A). Today Toyota operates factories in 27 countries in most parts of the
world (TOYOTA 2012B) and employs about 325,000 people (TOYOTA 2012C). Having sold
9.7 million cars in 2012 Toyota is currently the largest automotive company worldwide
(KÖLLING 2013, P. 1).
Hybrid electric cars like the Toyota Prius are highly fuel efficient and have reduced CO2 and
other emissions compared to conventional cars that are only driven by an internal combustion
engine (DIJK ET AL. 2013, P. 137). Making use of innovative technologies like regenerative
braking and a start-stop system the Prius I even had the lowest fuel consumption in its category
(3.6 l / 100 km) (ibid.). In the 2000s the Prius I has been further developed and the Prius II and
later the Prius III were launched - this time also in other countries than Japan as e.g. in Europe
and the US (ibid.). Until the end of 2012 Toyota has sold a total of more than 2.8 Million Prius
models worldwide (TOYOTA 2012D). Overall the Prius has been “a huge success for Toyota”
(DIJK ET AL. 2013, P. 137).
With regard to the eco-innovation definition proposed by Rennings (see section 2.1) the Toyota
Prius can be classified as product eco-innovation since Toyota as firm has developed and
introduced a new product, the Prius, which contributes to a reduction of environmental burdens,
namely to a reduction of fossil fuel consumption, CO2 emissions and other emissions1
. Since the
Prius has not only improved the environmental performance of the automotive sector2
but since

20
the Prius has also been a huge commercial success for Toyota the Prius can even be classified as
product eco-innovation applying the more restrictive definition as it is proposed by the
ECODRIVE project.
THS – Toyota Hybrid System IMA – Integrated Motor Assist
Figure 4.1: Toyota Prius with THS and Honda Civic with IMA
4.2.Drivetrain modeling
In this section the models used for the system components are described as a static function of
several state variables. Some of these state variables may also be control inputs, e.g., gear ratio
speed change CVT and power flow out of the battery. This section starts with describing the
Specification Prius-THS Civic-IMA
Fuel consumption (combined, EG-
norm) 4.3 [l/100km] 4.9 [l/100km]
CO2 - emission 104 [g/km] 116 [g/km]
Acceleration performance 0 – 100
[km/h] 10.9 [s] 12.9 [s]
Top speed 170 [km/h] 177 [km/h]

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integrated models of the Prius and the Civic in which the static component maps and the
drivetrain dynamics are combined.
4.3.Prius and Civic Drivetrains
In this section the equations describing the drivetrain dynamics of the THS and IMA concepts
will be given. In Figure 2, the outline of the drivetrain in the Prius and the block diagram
showing the power flow paths are depicted.
CVT
The IMA has a mechanical V-belt CVT. The losses of such a CVT consist of friction losses and
hydraulic pump losses. The overall CVT efficiency including the pump losses and the losses of
the final gear as a function of three input variables: (i) input torque, (ii) input speed and (iii)
CVT gear ratio. The efficiency can be written as a non-linear static function of the form
ηcvt=ηcvt(Tp,ωp,rcvt). The input torque and
speed are equally to that of the engine, because the input shaft of the CVT is directly connected
to output shaft of the engine. The overall efficiency data is obtained from measurements
performed on a high dynamic CVT test bench at the Technische Universiteit of Eindhoven. The
subject transmission is the Jatco CK2. The CVT efficiency is assumed to be independent of the
gear ratio change rate of the CVT, simulations with detailed models and measurements under
dynamic conditions show that this is valid (see also [4]).
4.4.E-CVT and Electric Machines
The Toyota Hybrid System (THS) is equipped with two electric machines EM1 and EM2 (see
Figure 2). The first machine EM1 is connected to the sun gear of the planetary set and can

22
generate 22 [kW] of mechanical power. The second machine EM2 is connected to the ring gear
of the planetary gearset, which is also connected via a chain drive to the final reduction with
differential. The EM2 machine can produce 50 [kW] of mechanical power. In Figure 6, the
torque-speed maps of EM1 and EM2 are shown, along with their iso-efficiency lines [5]. The
electric machine EM3 in the IMA can produce/generate 10 [kW] of mechanical power. For
reasons of space the characteristics of EM3 are not shown here.
4.5.ADVANTAGES
a) Hybrid cars emit up to 90% less toxic emissions and half as much greenhouse-this
causes carbon dioxide as an average car (therefore drivers would not have to
worry about polluting theenvironment).
b) Hybrids can run on electricity orgas.
c) Less fuel consumption. Current HEVs reduce petroleum consumption under
certain circumstances, compared to otherwise similar conventional vehicles,
primarily by using threemechanisms:
Reducing wasted energy during idle/low output, generally by turning the
ICEoff
Recapturing waste energy (i.e. regenerativebraking)
ReducingthesizeandpoweroftheICE,andhenceinefficienciesfrom under-
utilization,byusingtheaddedpowerfromtheelectricmotorto compensate for
the loss in peak power output from the smaller ICE. Any combination of
these three primary hybrid advantages may be used in different vehicles to
realize different fuel usage, power,emissions, weight and cost profiles. The
ICE in an HEV can be smaller, lighter, and more efficient than the one in a
conventional
vehicle,becausethecombustionenginecanbesizedforslightlyabove average
power demand rather than peak power demand. The drive system in a
vehicle is required to operate over a range of speed and power, but an
ICE's highest efficiency is in a narrow range of operation, making
conventional vehicles inefficient. On thecontrary,in most HEV designs, the

23
ICE operates closer to its range of highest efficiency more frequently. The
power curve of electric motors is better suited to variable speeds and can
provide substantially greater torqueatlowspeedscomparedwithinternal-
combustionengines.The greater fuel economy of HEVs has implication for
reducedpetroleum consumption and vehicle air pollution
emissionsworldwide.
d) The battery pack of a hybrid vehicle never needs to be charged from an external
source. It’s charged by ICE and by motor from brakingsystem.
e) Hybrids have smaller engines; therefore, they tend to weigh less than non- hybrids
(but this can lead to problems in the future). Since hybrid cars can run on
alternative fuels, this allows us to decrease our dependency on fossil fuel and
enables us to increase fuel options. (hybrids reduce fuel costs).[7]
f) A person who purchases a hybrid car is entitled to a federal taxdeduction.
4.6.DISADVANTAGES
i. Hybrids are more expensive than non-hybrids. The cost of HEV is more
because it’s using more parts than non-HEV and these all arecostly.
ii. It requires more maintenance. It’s using more parts so all require more
maintenance.
iii. It has low towing capacity. It’s engine size is small so it’s don’t able to
import and export more things.
iv. The parts that make up the hybrid car are more expensive and are more
difficult to acquire for one’scar.
v. Since a hybrid is electrical, Water cannot be used to put out a fire that
starts in thehybrid.
vi. Hybrids (in regards to a car accident) have a much higher risk of
exploding (depending on the impact of the vehicle) because it has a
combination of gasoline and ethanol (which are both highly
flammable).[7]

24
CHAPTER 5
MODERN HYBRIDS PRODUCTION
5.1.MODERN HYBRID PRODUCTION
1. Automotivehybridtechnologybecamewidespreadbeginninginthelate1990s.The
firstmass-producedhybridvehiclewastheToyotaPrius,launchedinJapanin1997,
andfollowedbytheHondaInsight,launchedin1999intheUnitedStatesandJapan.
ThePriuswaslaunchedinEurope,NorthAmericaandtherestoftheworldin2000. The first
generation Prius sedan has an estimated fuel economy of 52 miles per US
gallon(4.5L/100km;62mpg-imp)inthecityand45milesperUSgallon(5.2L/100 km; 54
mpg-imp) in highway driving. The two-door first generation Insight was estimated at
61 miles per US gallon (3.9 L/100 km; 73 mpg-imp) miles per gallon in city driving
and 68 miles per US gallon (3.5 L/100 km; 82 mpg-imp) on the highway.
2. TheToyotaPriussold300unitsin1997,19,500in2000,andcumulativeworldwide
Priussalesreachedthe1millionmarkinApril2008.Byearly2010,thePriusglobal cumulative
sales were estimated at 1.6 million units. Toyota launched a second generation Prius in
2004 and a third in 2009. The 2010 Prius has an estimated U.S.
EnvironmentalProtectionAgencycombinedfueleconomycycleof50milesperUS gallon
(4.7 L/100 km; 60 mpg-imp).[9]
3. TheAudiDuoIIIwasintroducedin1997,basedontheAudiB5A4Avant,andwas the only
Duo to ever make it into series production. The Duo III used the 1.9 litre Turbocharged
Direct Injection (TDI) diesel engine, which was coupled with a 21 kilowatts (29 PS; 28
bhp) electric motor. Unfortunately, due to low demand forthis hybrid because of its
high price, only about sixty Audi Duos were produced. Until
thereleaseoftheAudiQ7Hybridin2008.
4. everputintoproduction.TheHondaCivicHybridwasintroducedinFebruary2002 as a 2003
model, based on the seventh generation Civic. The 2003 Civic Hybrid
appearsidenticaltothenon-hybridversion,butdelivers50milesperUSgallon(4.7 L/100 km;

25
60 mpg-imp), a 40 percent increase compared to a conventional Civic LX sedan. Along
with the conventional Civic, it received styling update for 2004. The redesigned 2004
Toyota Prius (second generation) improved passenger room, cargo area, and power
output, while increasing energy efficiency and reducing emissions. The Honda Insight
first generation stopped being produced after 2006 and has a devoted base of owners.
A second generation Insight was launched in
2010.In2004,HondaalsoreleasedahybridversionoftheAccordbutdiscontinued it in 2007
citing disappointing sales.[10]
5. The Ford Escape Hybrid, the first hybrid electric sport utility vehicle (SUV) was
releasedin2005.ToyotaandFordenteredintoalicensingagreementinMarch2004 allowing
Ford to use 20 patents[citation needed] from Toyota related to hybrid technology,
although Ford's engine was independently designed and built.[citation needed] In
exchange for the hybrid licenses, Ford licensed patents involving their European diesel
engines to Toyota.[citation needed] Toyota announced calendar year 2005 hybrid
electric versions of the Toyota Highlander Hybrid and Lexus RX 400hwith4WD-
i,whichusesarearelectricmotortopowertherearwheelsnegating the need for a transfer
case.[10]
6. In 2006, General Motors Saturn Division began to market a mild parallel hybrid in the
form of the 2007 Saturn Vue Green Line which utilized GM's Belted Alternator/Starter
(BAS Hybrid) System combined with a 2.4 litre L4 engine and a
FWDautomatictransmission.Thesamehybridpower-strainwasalsousedtopower
the2008SaturnAuraGreenlineandMalibuHybridmodels.AsofDecember2009, only the
BAS equipped Malibu is still in (limited) production.[10]
7. Summer 2006 in the United States and Canada. Nissan launched the AltimaHybrid
with technology licensed by Toyota in2007.
8. Commencing in the fall of 2007 General Motors began to market their 2008 Two-
Mode Hybrid models of their GMT900 based Chevrolet Tahoe and GMC Yukon
SUVs,closelyfollowedbythe2009CadillacEscaladeHybridversion.Forthe2009 model
year, General Motors released the same technology in their half-ton pickup truck
models, the 2009 Chevrolet Silverado and GMC Sierra Two-Mode Hybrid models.

26
9. The Ford Fusion Hybrid officially debuted at the Greater Los Angeles Auto Show in
November 2008, and was launched to the U.S. market in March 2009, together with
the second generation Honda Insight and the Mercury Milan Hybrid.
Fig. 5.2 1997 Toyota Prius (first generation)
Fig. 5.2.12000 Honda Insight (firstgeneration)
5.2.Future works
1. Thereareseveralsubjectsconcerningcontrolofhybridelectricvehiclesthatarenot dealt with.
Some interesting questions to investigate are suggestedbelow.
2. The control strategy optimizing for ICE efficiency, does not consider the overall
efficiency at all. An interesting study would therefore be to develop an algorithm that
optimizes for the overall efficiency.
3. The hybrid vehicle in the simulation model is run on diesel fuel, but it would be

27
interesting to study the efficiency and emission formation with bio fuels, like Ethanol
or DME, when used in a hybrid vehicle.
4. Cylinder deactivation is used in this study to adapt the ICE power for low power
requirements. Another solution could be using a small ICE that is strongly
overchargedtohandlethehighestpowerrequirements.Theenginecouldinthatcase be
provided with an electric turbocharger.
5. If the unit that distributes the demanded power to the electric machine(s) and the
ICEwouldbeabletopredictthedrivingcycle,newpossibilitiesopenup.Thiswould influence
the usage of the batteries, i.e. there is a potential to reduce losses. One solution is to use
a GPS that can predict the route. Another possibility is to use a control algorithm that
by means of the last time period (µs/ms/s/min) can calculate a forecast of the
demandedpower.
6. This study presents a number of different parameters but only a limited number of
possible alternatives and simulations. There are programs available which purpose is to
find an optimized solution in a system containing a number of adjustable parameters.
Such a procedure might be interesting to try out on this simulation model. All
parameters investigated in the previous study (Jonasson, 2002) should also be included
in such optimization.
7. Whenimplementingcylinderdeactivation,thenecessityofalargebatterydecreases since the
range of load points including high ICE efficiency increases. Therefore, it would be
interesting to carry out further investigations where the battery size is decreased.
8. A particular type of electric hybrid vehicles is called plug in-hybrids. The idea is to
mainlyutilizetheelectricmachine(s)inthesevehiclesandmainlychargethebattery from the
grid. The ICE is more or less utilized as a range extender. An advantage with this,
which would be interesting to investigate further, is the environmental potential
itimplies.
9. The optimization has not been carried out with intention to choose the best temperature
condition, regarding SCR. This can of course be tried out in further works.
10. The received results points at the need of a control algorithm adjusted for hybrid

28
implementation. It would therefore be valuable to perform measurements on the engine
when the different control algorithms are implemented and adjusted. One
questionstoansweris,forexample,whathappenstotheenginewhilelargeamount of EGR is
used? How would the hybrid vehicle be affected by changes of the injection angle and
other means of combustioncontrol?
11. In the model it has been assumed that the included filter for PM is sufficient. It
wouldbeinterestingtostudythisassumptioncloser,andtoinvestigatetheinfluence on the
filter performance with higher EGRrates.

29
CONCLUSION
Means a hybrid vehicle is a vehicle that uses two or more distinct power sources to
move the vehicle. The term most commonly refers to hybrid electric vehicles (HEVs),
which combine an internal combustion engine and one or more electric motors.
Modern HEVs make use of efficiency-improving technologies such as regenerative
braking, which converts the vehicle's kinetic energy into electric energy to charge the
battery, rather than wasting it as heat energy as conventional brakes do. Some varieties of
HEVs use their internal combustion engine to generate electricity by spinning an
electrical generator (this combination is known as a motor-generator),
toeitherrechargetheirbatteriesortodirectlypowertheelectricdrivemotors.Many HEVs reduce
idle emissions by shutting down the ICE at idleandrestarting it when needed; this is
known as a start-stop system. A hybrid-electric produces less emissions from its ICE than
a comparably-sized gasoline car, since an HEV's gasoline engine is usually smaller than a
comparably-sized pure gasoline-burning vehicle (natural gas and propane fuels produce
lower emissions) and if not used to directly drive the car,can be geared to run at
maximum efficiency,further improving fuel economy.

30
REFERENCES
[1] https://en.m.wikipedia.org/wiki/Hybrid_electric_vehicle
[2] http://www.hybridcars.com/history-of-hybrid-vehicles
[3] https://www.fueleconomy.gov/feg/hybridtech.shtml
[4] https://www.denso.com/global/en/business/products-and-services/mobility/pick-up/pcu/
[5] http://www.fueleconomy.gov/feg/hybridtech.shtml
[6] https://www.google.com/images (All images from Googleimages)

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