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CONTENTS

• INTRODUCTION • DEFINITION • WHY HYBRID VEHICLES? • HOW DOES TRANSPORTATION CONTRIBUTE TO CLIMATE CHANGE? • HOW DOES A PHEV OR EREV WORK? • WORKING • VEHICLE POWER PLANT • CONFIGURATIONS • ARCHITECTURE • TECHNIQUES • DC-DC CONVERTERS FOR EV AND HEV APPLICATIONS • DESIGN PRICNCIPLE • ALTERNATIVE SOURCES • CONTROL SYSTEMS FOR THE HEV AND EVS • REGENERATIVE BRAKING • RECENT ADVANCEMENTS • PRESENT OF HYBRID ELECTRIC VEHICLE • FUTURE OF HYBRID ELECTRICAL VEHICLE • CHALLENGES • ADVANTAGES • CONCLUSION

• REFERENCES

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INTRODUCTION

What is a hybrid? A hybrid vehicle combines any two power (energy) sources. Possible combinations include diesel/electric, gasoline/fly wheel, and fuel cell (FC)/battery.

Typically, one energy source is storage, and the other is conversion of a fuel to energy. The combination of two power sources may support two separate propulsion systems.

Thus to be a True hybrid, the vehicle must have at least two modes of propulsion.

DEFINITION OF ELECTRIC VEHICLES

Pev-Plug in electric vehicle consists of two categories:-

1 . EV: Electric Vehicle or BEV: Battery-only Electric Vehicle

Fig.1 Electrical vehicle

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2.PHEV: Plug-in Hybrid Electric Vehicle or EREV: Extended Range Electric Vehicle

Fig.2. plug in hybrid electrical vehicle

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Fig.3.Differences between electric,hybrid and conventional vehicle

WHY HYBRID VEHICLES?

• As there is a constant rise in the fuel prices ,it is a must for us to look for alternatives such as hybrids

• Hybrids have the optimum mileage in its class • Dependency on fossils fuels can be decreased • They produce much less emissions and use about 50% less fuel than the average new

vehicle In the same class(partial –Zero emissions). • Regenerative braking actually makes city driving more economical than on the highway • Plug-in Hybrid vehicles eventually can be charged at parking locations using renewable

energy . They will use at least half as much fuel as the Hybrids.

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HOW DOES TRANSPORTATION CONTRIBUTE TO CLIMATE CHANGE?

Fig.4.Role of transportation in harmful emissions

HOW DOES A PHEV OR EREV WORK?

• PHEVs overcome the range problem of BEVs

• Electric-only range vary with battery size • PHEV20 = 20 miles range

• PHEV40 = 40 miles range • PHEVs well suited for our daily driving patterns

• 50% of all daily drives <25 miles • 80% of all daily drives <50 miles

• Average daily driving=33 miles

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Fig.5.An HEV

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Fig.6 PHEV

WORKING

• Integrate power of gasoline engine with electric motor

• High powered battery pack provides energy to motor • Electric motor assist whenever surplus power is needed

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VEHICLE POWER PLANT

Fig.7 An automatic mobile train

THREE FACTORS ARE CONSIDERED WHILE SELECTING SUITABLE POWER PLANT

operating performance

economy environmental friendliness

MAIN COMPONENTS ARE:

internal combustion engine electric motor

gear box

HEV CONFIGURATIONS

• series configuration

• parallel configuration • series-parallel configuration

• complex configuration

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FIG.8 Showing possible configurations

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SERIES HYBRID

PARALLEL HYBRID

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SERIES-PARALLEL HYBRID

COMPLEX HYBRID

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BASIC ARCHITECTURE OF ELECTRIC DRIVE TRAINS

The EV has three major subsystems:

• Electric propulsion • Energy source

• Auxiliary system

Electric propulsion consists of

• The electronic controller • Power converter • Electric Motor (EM) • Mechanical transmission • Driving wheels

Energy sources consists of

• The energy source (battery, fuel cell, ultracapacitor) • Energy management unit • Energy refueling unit

Auxiliary system consists of

• Power steering unit

• Temperature control unit • Auxiliary power supply

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Fig.9 Showing detailed components

ADVANCED TECHNIQUES USED BY PHEV

• Regenerative braking • Electric motor drive/assist • Automatic start /shut off • Use low rolling resistance tires • Use lightweight materials

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DC-DC CONVERTERS FOR EV AND HEV APPLICATIONS

Fig.10. Role of converters

• The most commonly DC-DC converters used in an HEV or an EV are: • Unidirectional Converters: They cater to various onboard loads such as sensors,

controls, entertainment, utility and safety equipments. • Bidirectional Converters: They are used in places where battery charging and

regenerative braking is required. During regenerative braking, the power flows back to the low voltage bus to recharge the batteries.

DESIGN PRINCIPLES OF HEVS

• DEFINITION OF HYBRIDNESS

H=(sum of power of all traction motors)/(sum of traction motors+ engine power)

• For example; Diesel engine: 110 kW at 3000 rpm • Electric motor: 23 kW; maximum torque 243 N-m at 500 rpm

• H=17%

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ALTERNATIVE AND NOVEL ENERGY SOURCES

• Solar Photovoltaics

• Flywheels • Supercapacitor

CONTROL SYSTEMS FOR THE HEV AND EVS

• The major functions of the control system are: • to maximize the fuel efficiency

• to minimize the exhaust emissions.

• The minor functions of the control system are component monitoring and protection such as:

• battery state of charge (SOC) monitoring

• Battery temperature monitoring • EM overheating

• ICE overheating

CONTROL SYSTEM FOR VEHICLE SPEED CONTROL

Fig.11.control system

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REGENERATIVE BRAKING

• The electric motors in EVs and HEVs can be controlled to operate as generators to convert the kinetic or potential energy of the vehicle mass into electric energy that can

be stored in the energy storage and reused. A successfully designed braking system for a vehicle must always meet two distinct demands:

– In emergency braking, the braking system must bring the vehicle to rest in the shortest possible distance.

– The braking system must maintain control over the vehicle’s direction, which requires braking force to be distributed equally on all the wheels.

• When the vehicle experiences braking, the traction motor, EM or both can produce braking torque and recapture part of the braking energy to charge the electrical energy storage device (also known as peaking power source). In this mode of operation the

engine is switched off and the energy flow path is shown in Figure

Fig.12.Regenerative braking with TM alone

Fig.13 Regenerative braking with EM alone

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Fig.14 Regenerative braking with both EM and TM

RECENT ADVANCEMENTS

• Today’s automotive starter batteries:lead acid • RAV4 EV(toyota prius hybrid battery),Nickel Metal hydride • New batteries based on lithium I-ion or Li-polymer;5x lighter for same energy!

• These advancements make it possible for larger battery storage in vehicles .

PRESENT OF HYBRID ELECTRIC VEHICLE

• Toyota is the most prominent of all manufacturers when it comes to hybrid cars. As well

as the specialist hybrid range they have produced hybrid versions of many of their existing model lines, including several Lexus (now owned and manufactured by Toyota)

vehicles. They have also stated that it is their intention to release a hybrid version of every single model they release in the coming decade. As well as cars and SUVs, there

are a select number of hybrid motorcycles, pickups, vans, and other road going vehicles available to the consumer and the list is continually increasing.

FUTURE OF HYBRID ELECTRICAL VEHICLE

• Since petroleum is limited and will someday run out of supply. In the arbitrary year

2037, an estimated one billion petroleum-fueled vehicles will be on the world’s roads. gasoline will become prohibitively expensive. The world need to have solutions for the “400 million otherwise useless cars”. So year 2037 “gasoline runs out year” means, petroleum will no longer be used for personal mobility. A market may develop for solar-

powered EVs of the size of a scooter or golf cart. Since hybrid technology applies to heavy vehicles, hybrid buses and hybrid trains will be more significant.

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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 • Very sensitive to overcharge/undercharge(Battery life reduces dramatically)

ADVANTAGES

• Use less oil than ICE • Reduce emissions • Fuel efficiency increased

• Regenerative braking • Quiet operation

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 to some extent. • If proper research and development is done in this field, hybrid vehicle promises a

practical, efficient, low pollution vehicle for the coming era. • 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.

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REFERENCES

[1] A. E. Fuhs, Hybrid Vehicles and the Future of Personal Transportation, CRC Press, 2009

[2]Gianfranco, Electric and Hybrid Vehicles: power sources, models, sustainability, infrastructure and the market, Pistoia Consultant, Rome, Italy, 2010

[3]I. Husain, Electric and Hybrid Electric Vehicles, CRC Press, 2003

[4]M. Ehsani, Modern Electric, Hybrid Electric and Fuel Cell Vehicles: Fundamentals, Theory and Design, CRC Press, 2005

[5]” Introduction to Hybrid and Electric Vehicles”, Electrical Engineering ,NPTEL