Fundamentals of Electric and Hybrid Vehicles

3
Fundamentals of vehicle, components of conventional vehicle and
propulsion load; Drive cycles and drive terrain; Concept of electric vehicle
and hybrid electric vehicle; History of hybrid vehicles, advantages and
applications of Electric and Hybrid Electric Vehicles, different Motors
suitable for of Electric and Hybrid Electric Vehicles.
Architectures of HEVs, series and parallel HEVs, complex HEVs .Plug-in
hybrid vehicle, constituents of PHEV, comparison of HEV and PHEV;
Fuel Cell vehicles and its constituents.
PHEVs and EREVs blended PHEVs, PHEV Architectures, equivalent
electric range of blended PHEVs; Fuel economy of PHEVs, power
management of PHEVs, end-of-life battery for electric power grid support,
vehicle to grid technology, PHEV battery charging.

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Rectifiers used in HEVs, voltage ripples; Buck converter used in HEVs,
non-isolated bidirectional DC-DC converter, voltage source inverter,
current source inverter, isolated bidirectional DC-DC converter, PWM
rectifier in HEVs, EV and PHEV battery chargers.
Energy Storage Parameters; Lead–Acid Batteries; Ultra capacitors;
Flywheels – Superconducting Magnetic Storage System; Pumped
Hydroelectric Energy Storage; Compressed Air Energy Storage – Storage
Heat; Energy Storage as an Economic Resource

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TEXT BOOKS:
 Ali Emadi, Advanced Electric Drive Vehicles, CRC Press, Ist Edition 2017.
 Iqbal Hussein, Electric and Hybrid Vehicles: Design Fundamentals, CRC Press,3rd
Edition 2021.
REFERENCE BOOKS:
 MehrdadEhsani, YimiGao, Sebastian E. Gay, Ali Emadi, Modern Electric, Hybrid
Electric and Fuel Cell Vehicles: Fundamentals, Theory and Design, CRC Press,3rd
Edition 2019.
 James Larminie, John Lowry, Electric Vehicle Technology Explained, Wiley,2nd
Edition 2017.
 H. Partab Modern Electric Traction – Dhanpat Rai& Co, 2017.
 Pistooa G., “Power Sources Models, Sustanability, Infrstructure and the market”,
Elsevier 2008
 Mi Chris, Masrur A., and Gao D.W., “ Hybrid Electric Vehicle: Principles and
Applications with Practical Perspectives” 2nd Edition,2017.
 Dr.G.Nageswara Rao...“Hybrid Electric Vehicles Principles And Applications” B R
Publications.

2
UNIT-1
INTRODUCTION
Fundamentals of vehicle, components of conventional vehicle and
propulsion load; Drive cycles and drive terrain; Concept of electric vehicle
and hybrid electric vehicle; History of hybrid vehicles, advantages and
applications of Electric and Hybrid Electric Vehicles, different Motors
suitable for of Electric and Hybrid Electric Vehicles.

4
Force is basically a push or a pull that causes an object to undergo a
change in speed, a change in direction, or a change in shape. A force
has both magnitude (size) and direction.

5
Weight is the force of gravity. It acts in a downward direction—
toward the center of the Earth.
Thrust is the force that propels a Vehicle in the direction of motion.
Engines produce thrust.
Drag is the force that acts opposite to the direction of motion. Drag
is caused by friction and differences in air pressure.
Lift is the force that acts at a right angle to the direction of motion
through the air. Lift is created by differences in air pressure.

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The major components and functions of Vehicle
Engine: It makes sense to start with the most important part under the hood of a vehicle,
which is the engine. Most modern vehicles run on internal combustion engines, which
generate energy by igniting a mixture of air and fuel that moves pistons, which in turn
move the vehicle.
Battery: The battery has several important works, including providing vehicle with power
to start when turn on the ignition. Batteries also ensure that other electrical components
in the vehicle work properly.
Alternator: The alternator is responsible for generating electricity. It keeps battery
charged by converting mechanical energy into electrical energy while the vehicle is
operating. By continuously charging the battery and keeping the battery charged
throughout every trip, it keeps the vehicle and all of the electrical components working
correctly.
Brakes: The brakes on vehicle are used to help slow down and stop your vehicle, as well as
keep it in place when parked. Most vehicle feature either a disc or drum brake system.
Parts in a disc brake system include calipers, rotors and pads. Drum brake systems are
comprised of brake drums and shoes.

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Radiator: Engine creates a lot of heat when it’s running, so it makes sense that there would be a
cooling system to help manage it. The radiator is one of the major components of this system. It
works to remove heat via liquid coolant before it circulates back to your engine. The radiator ensures
your engine doesn’t overheat, increasing performance and longevity. You can help maintain your
radiator by checking coolant levels at least twice a year.
Transmission: The transmission, otherwise known as the vehicle’s gearbox, is what takes the engine’s
power and transfers it to the wheels through various components. Without it, you would simply go
nowhere. Manual transmissions are controlled by the driver using a gear lever or shifter inside the
vehicle, while automatics do not require any driver input to change gears. Whether it’s a manual or
an automatic, there’s a lot going on inside a transmission. Changing the transmission fluid at the
manufacturer’s recommended intervals will help you maintain this important component and
prevent it from wearing out.
Shock Absorbers: The suspension system in your car helps stabilize it while you drive. This way, you
get a smooth ride and you’re not bouncing around every time you hit a bump or dip. There are many
parts that make up the suspension, and shock absorbers play an important role in this system.
Shock absorbers help stabilize your vehicle while you drive.
The shock absorbers’ main function is to ensure your tires are contacting the road at all times. This
allows you to drive the vehicle safely and efficiently. They also help the brakes do their job by always
keeping the tires in contact with the road surface. Worn shocks can result in vibrations when you’re
driving and uneven tire wear, among other issues.

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Catalytic Converter: When your vehicle is running, it generates fumes and gases called
emissions. To help regulate emissions and remove them from vehicle efficiently, there is an
exhaust system hard at work. One of the main components in this system is the catalytic
converter.
The catalytic converter helps change harmful compounds in emissions into safe gases before
they’re released into the air through tailpipe. Issues with the catalytic converter can cause a
drop in performance and fuel efficiency.

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Damping Variation Effects in Vehicle

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History of the Electric Vehicle
The Early Years (1890 to 1930)

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CONCEPT OF ELECTRIC VEHICLE
Electric Vehicle (EV)
 An EV is defined as a vehicle that can be powered by an electric motor
that draws electricity from a battery and is capable of being charged
from an external source.
 An EV includes both a vehicle that can only be powered by an electric
motor that draws electricity from a battery (all-electric vehicle) and a
vehicle that can be powered by an electric motor that draws electricity
from a battery and by an internal combustion engine (plug-in hybrid
electric vehicle).
 An electric vehicle, also called an electric drive vehicle, uses one or
more electric motors or traction motors for propulsion. An electric
vehicle may be powered through a collector system by electricity from
off-vehicle sources, or may be self-contained with a battery, solar
panels or a generator to convert fuel to electricity. EVs include road and
rail vehicles, surface and underwater vessels, electric aircraft and
electric spacecraft.

Dr.G.Nageswara Rao
Professor
HYBRID ELECTRIC VEHICLES
INTRODUCTION

ELECTRIC VEHICLES
 Transport is a fundamental requirement of modern life, but the
traditional combustion engine is quickly becoming outdated.
 Petrol or diesel vehicles are highly polluting and are being quickly
replaced by fully electric vehicles.
 Fully electric vehicles (EV) have zero tailpipe emissions and are much
better for the environment.
The electric vehicle revolution
is here, and you can be part of
it. Will your next vehicle be an
electric one?
1. Lower running costs
2. Low maintenance cost
3. Zero Tailpipe Emissions
4. Tax and financial benefits
5. Petrol and diesel use is destroying our planet
6. Electric Vehicles are easy to drive and quiet
7. Convenience of charging at home
8. No noise pollution

Electric vehicles are not just the wave of the future.
They are saving lives today
1. Electric vehicles now include cars, transit buses, trucks of all
sizes, and even big-rig tractor trailers that are at least
partially powered by electricity.
2. Electric vehicles are saving the climate — and our lives.
3. Electric vehicles have a smaller carbon footprint than
gasoline-powered cars, no matter where your electricity
comes from.
4. Through their entire lifetime, electric cars are better for the
climate.
5. Electric vehicles can charge up at home, at work, while
you’re at the store.
6. Through all our electric vehicle work, Earth justice aims to
ensure that the people who are most impacted by pollution

Electric
Vehicle
vs
Petrol
Vehicle
Parameter Electric Vehicle Petrol Vehicle
Fuel Electrical energy Petrol
Power Electric motor
Internal combustion
engine
Cost
Expensive (High
price)
Affordable than
EVs
Cost of fuel Low High
Cost of maintenance Low High
Fuel efficiency
Higher in the city
and lower on
highways
Higher on highways
and lower in city
roads
Carbon emissions Zero High

Advantages of electric vehicle
1. Electric vehicles are easy to drive due to simple
controls.
2. They are silent in operation due to the absence
of mechanical parts.
3. EVs deliver quick acceleration due to the high
torque available.
4. Low maintenance and the service intervals are
not as frequent as petrol vehicles.
5. Low running cost.
6. Electric vehicles produce zero emissions and
help to reduce carbon footprints.
7. You can charge electric vehicle at your home
provided you install a home charging system.
8. Electric vehicles are eligible for government-
provided subsidies and tax benefits if you buy
an EV on loan.
Disadvantages of electric vehicle
1. The driving range of electric vehicles is
low, and you cannot cover long distances
without charging the vehicle.
2. Lack of public charging stations can be
an issue when driving your EV for long
distances.
3. Installing a home charging module is an
added expense.
4. Lack of expert mechanics to
service/repair eco-friendly vehicles.
5. Replacing the battery pack of an EV is
costly.

A vehicle that works on an electric motor
instead of an internal combustion engine
is called an Electric Vehicle
Electric Vehicles are useful as they reduce the harmful
emission released by the engine-based vehicle. They can
be very helpful in reducing air pollution in the
atmosphere.

WORKING OF ELECTRIC VEHICLE
 Electricity is transferred from a
battery to a controller.
 The controller then sends the
electricity to the electric motors
when needed.
 The accelerator is connected to a
variable switch which tells the
controller how much power to
send to the electric motors.
 Power output can vary from zero
to full as needed.

Electric Vehicle (EV)
•An EV is defined as a vehicle that can be powered by an electric motor that draws
electricity from a battery and is capable of being charged from an external source.
•An electric vehicle, also called an electric drive vehicle, uses one or more electric motors
or traction motors for propulsion. An electric vehicle may be powered through a
collector system by electricity from off-vehicle sources, or may be self-contained with a
battery, solar panels or a generator to convert fuel to electricity. EVs include road and
rail vehicles, surface and underwater vessels, electric aircraft and electric spacecraft.

Key Parts Of A
Battery Electric Vehicle

Key Parts Of A Battery Electric Vehicle
Charging port or vehicle inlet: It is a connector present on the electric vehicle to allow it to
be connected to an external source of electricity for charging.
Power electronic converter: A power electronic converter is made of high power fast-acting
semiconductor devices, which act as high-speed switches. Different switching states alter the
input voltage and current through the use of capacitive and inductive elements. The result is an
output voltage and current, which is at a different level to the input.
On-board charger: It is an AC-to-DC power electronic converter (often referred to as a
rectifier) that takes the incoming AC electricity supplied via the charge port and converts it to
DC power for charging the traction battery. Using the battery management system, it regulates
the battery characteristics such as voltage, current, temperature, and state of charge.
Traction battery pack: It is a high voltage battery used to store energy in the electric car and
provide power for use by the electric traction motor.
Battery power converter: It is a DC-to-DC power electronic converter that converts the
voltage of the traction battery pack to the higher-voltage of the DC-bus used for power
exchange with the traction motor.

Motor drive: It is a DC-to-AC (often referred to as inverter or the variable frequency drive)
or at times a DC-to-DC power electronic converter, used to convert power from the high
voltage DC bus to AC (or at times DC) power for the operation of motor. The converter is
bidirectional for operating in both driving and regenerative braking mode.
Traction electric motor/generator: It is the main propulsion device in an electric car that
converts electrical energy from the traction battery to mechanical energy for rotating the
wheels. It also generates electricity by extracting energy from the rotating wheels while
braking, and transferring that energy back to the traction battery pack.
Transmission: For an electric car, usually a single gear transmission with differential is used
to transfer mechanical power from the traction motor to drive the wheels.
Power electronics controller: This unit controls the flow of electrical power in the different
power electronic converters in the electric car.
Battery (auxiliary): In an electric drive vehicle, the auxiliary battery provides electricity to
start the car before the traction battery is engaged and is also used to power the vehicle
accessories.

EV parameters:
Important parameters for understanding electric vehicles.
1.Battery Capacity
2.State Of Charge
3.Range
4.Energy Consumption Per Kilometer
5.Motor Power

1.Nominal battery capacity (Enom, in Wh or kWh): It is total electric energy that can be
stored in the battery. Alternately, it is the maximum amount of electric energy that can be
extracted from a fully charged battery state to the empty state.Generally speaking, EV
batteries have a battery capacity between 5 kWh to 100 kWh depending on the type of EV.
The higher the battery capacity, the more energy it can store and the longer the time it takes to
fully charge it. The battery capacity is often referred to as the energy content or energy
capacity of the battery.
2.State of charge, SOC (BSOC, in %): The battery state of charge (SoC) is defined as the
ratio between the amount of energy currently stored in the battery, Ebatt and the total battery
capacity, Enom BSOC=(Ebatt / Enom) 100.
3.Range (Rmax, in km): It is the maximum distance that can be driven by an electric car
when the battery is full. Usually an electric car is tested using a standardized driving cycle to
estimate the range, e.g. New European Driving Cycle (NEDC), Worldwide harmonized Light
vehicles Test Procedure (WLTP) or the EPA Federal Test Procedure. The range can be
expressed in miles, kilometer or other units based on the region. In this set of definitions, we
stick to the European convention of using kilometer.

Available Range (R, in km): It is the maximum distance that can be driven by an electric car
based on the current state of charge of the battery.
4.Energy consumption per kilometer (D, in kWh/km): When an electric car is tested using
a standardised driving cycle, the EV efficiency is the energy consumed from the batteries per
unit distance drive. In some cases, the energy drawn from the grid to charge the battery is
considered as well. It can be expressed in kilowatt-hour per kilometer (or) kilowatt-hour per
mile.
MPGe or miles per gallon equivalent: MPGe is the distance in miles traveled per unit of
electric energy consumed by the vehicle. The ratings are based on United States
Environmental Protection Agency (EPA) formula, in which 33.7 kilowatt-hours (121
megajoules) of electricity is equivalent to one gallon of gasoline.
5.Motor power (Pm, in W): It is the power delivered by the motor to the wheels for
propulsion. The motor power is positive or negative based on whether the car is driving or
under regenerative braking. The motor power can be expressed as a product of the motor
torque, Tm and the motor rotational speed, wm and the units normally used are watts (W),
kilowatts (kW) or horsepower(hp). The rotational speed is normally expressed in radians per
second (rad/s) or rotations per minute (rpm). The torque is normally expressed in newton-
meter (Nm).

BATTERY ELECTRIC VEHICLES (BEV)

Plug in Hybrid electric vehicle (PHEV)

Schematic diagram of the hybrid power system structure

Hybrid electric Vehicle key components
•The auxiliary battery: It provides electricity to start the car before engaging the traction battery;
•The DC/DC converter: It converts the higher-voltage DC power from the traction battery to the lower-voltage
DC power to run the vehicle accessories and recharge the auxiliary battery;
•The electric generator: This component provides electricity from rotating the wheels while braking,
transferring the energy to the traction battery.
•The electric traction motor: This motor uses power from the traction battery to drive the wheels.
•The exhaust system: It is designed with a three-way catalyst to reduce emissions from the engine out through
the tailpipe.
•The spark-ignited internal combustion engine: It allows air to combine with fuel and ignite by the
spark from a spark plug.
•The power electronics controller: This part manages the flow of electric energy from the traction battery,
allowing the control of the speed of the traction motor and the torque being produced.
Regenerate Braking
Unlike an electric vehicle (EV), a hybrid electric vehicle cannot be plugged in for the battery to charge. Instead, the battery is
charged with the help of regenerative braking and by the internal combustion engine. The electric motor powers the vehicle
as well as resists its motion. When you apply the brakes to slow down, this resistance slows down the wheel and
simultaneously recharges the batteries.
Dual Power
Power can come from the engine, motor, or both, depending on driving circumstances and whether the car is a full hybrid or
mild hybrid.

1. Battery Electric Vehicles (BEVs): vehicles 100% are propelled by electric power. BEVs
do not have an internal combustion engine and they do not use any kind of liquid fuel.
BEVs normally use large packs of batteries in order to give the vehicle an acceptable
autonomy. A typical BEV will reach from 160 to 250 km, although some of them can
travel as far as 500 km with just one charge. An example of this type of vehicle is the
Nissan Leaf , which is 100% electric and it currently provides a 62 kWh battery that
allows users to have an autonomy of 360 km.
2. Plug-In Hybrid Electric Vehicles (PHEVs): hybrid vehicles are propelled by a
conventional combustible engine and an electric engine charged by a pluggable external
electric source. PHEVs can store enough electricity from the grid to significantly
reduce their fuel consumption in regular driving conditions. The Mitsubishi Outlander
PHEV provides a 12 kWh battery, which allows it to drive around 50 km just with the
electric engine. However, it is also noteworthy that PHEVs fuel consumption is higher
than indicated by car manufacturers.
3. Hybrid Electric Vehicles (HEVs): hybrid vehicles are propelled by a combination of a
conventional internal combustion engine and an electric engine. The difference with
regard to PHEVs is that HEVs cannot be plugged to the grid. In fact, the battery that
provides energy to the electric engine is charged to the power generated by the vehicle’s

4. Fuel Cell Electric Vehicles (FCEVs): these vehicles are provided with an electric engine
that uses a mix of compressed hydrogen and oxygen obtained from the air, having water as the
only waste resulting from this process. Although these kinds of vehicles are considered to
present “zero emissions”, it is worth highlighting that, although there is green hydrogen, most
of the used hydrogen is extracted from natural gas. The Hyundai Nexo FCEV is an example of
this type of vehicles, being able to travel 650 km without refueling.
5. Extended-range EVs (ER-EVs): these vehicles are very similar to those ones in the BEV
category. However, the ER-EVs are also provided with a supplementary combustion engine,
which charges the batteries of the vehicle if needed. This type of engine, unlike those provided
by PHEVs and HEVs, is only used for charging, so that it is not connected to the wheels of the
vehicle. An example of this type of vehicles is the BMW i3, which has a 42.2 kWh battery that
results in a 260 km autonomy in electric mode, and users can benefit an additional 130 km
from the extended-range mode.

CONCEPT OF
HYBRID ELECTRIC VEHICLE
What is a Hybrid Electric Vehicle (HEV)
A Hybrid Electric Vehicle is a type of vehicle that uses a combination of an
Internal Combustion (IC) engine and an electric propulsion system. The
electric powertrain may enhance fuel efficiency, increase performance, or
independently propel the vehicle on pure electric power, depending on the
type of hybrid system.
Hybrid Electric Vehicle (HEV) is a vehicle which is using two energy
sources for propulsion, at least one of the energy sources being electrical
energy. The vast majority of hybrid electric vehicles are using a combination
of petrol (gasoline) engines and electric motor(s).

Hybrid vehicle technology
Hybrid vehicle technology is a combination of an internal
combustion engine and an electric battery operated motor.
Advantages of hybrid vehicle technology:
1. Fuel consumption is less due to electric batteries.
2. Less emission of carbon dioxide makes it eco-friendly.
3. Gives better mileage than a conventional engine
vehicle, thus is cost effective.
4. Less dependence on fossil fuels.

Hybrid-Electric Vehicles (HEVs) combine the advantages of both the internal combustion engine (or
gasoline engines if you like) and electric motors that use energy stored in batteries. The key areas of
performance are regenerative braking, dual power sources, and less idling. Hybrid electric cars work
by charging the battery through regenerative braking and by the internal combustion engine, and
not only by directly plugging in the vehicle to charge the batteries. Through the electric motor and
the battery, extra power is provided, which allows the use of a smaller engine and even provides
auxiliary loads, which could reduce the engine’s idling. These features result in better fuel economy
while maintaining great vehicle performance.
Hybrid electric Vehicle key components.
The auxiliary battery: It provides electricity to start the car before engaging the traction battery;
The DC/DC converter: It converts the higher-voltage DC power from the traction battery to the lower-voltage DC power
to run the vehicle accessories and recharge the auxiliary battery;
The electric generator: This component provides electricity from rotating the wheels while braking, transferring the
energy to the traction battery.
The electric traction motor: This motor uses power from the traction battery to drive the wheels.
The exhaust system: It is designed with a three-way catalyst to reduce emissions from the engine out through the
tailpipe.
The spark-ignited internal combustion engine: It allows air to combine with fuel and ignite by the spark from a spark
plug.
The power electronics controller: This part manages the flow of electric energy from the traction battery, allowing the
control of the speed of the traction motor and the torque being produced.

Working Principle of HEV
Fuel Tank
Battery
Primary Energy Converter - Internal Combustion Engine
Secondary Energy Converter - Electric Machine (Motor/Generator)

Hybrid vehicle is using 2 energy sources, with 2 energy converters.
There is primary energy source (1) and a secondary energy source (2)
There is primary energy converter (1) and a secondary energy converter (2)
 for a HEV, the primary energy source is the fuel tank and the secondary energy source is
the battery
 the primary energy source has much more energy content than the secondary energy
source
 energy can be transferred from the primary energy source towards the secondary energy
source but not vice versa
 the transfer of energy from the primary source towards the secondary source is done
through energy converters
 for a HEV, the primary energy converter is the internal combustion engine and the
secondary energy converter is the electric machine (motor/generator)
 part of the kinetic energy of the vehicle can be recovered during braking only by the
secondary energy converter and stored in the secondary energy source
 both energy converters can apply traction torque to the wheel in the same time

How does an HEV work?
 Powering a hybrid electric vehicle is an IC engine and an electric motor.
 The electric motor utilises the electrical energy stored in the battery pack.
 The battery pack gets charged via regenerative braking or through a generator
that is run by the internal combustion engine.
 An HEV does not need to be plugged into a power source to charge the
battery.
 The electric motor and IC engine work in conjunction to propel the vehicle.
 The additional power from the electric motor assists the engine, and it
enhances the performance and improves the fuel economy.
 The battery pack can also power other electrical components such as lights.
 The electric powertrain also saves fuel via the engine start/stop technology,
wherein the engine automatically shuts off when idle and starts automatically
when the driver presses the throttle pedal.

Types of Hybrid Electric Vehicles
There are three types of HEVs based on power delivery and distribution.
1. Series hybrid
In a series hybrid system, the IC engine powers the electric generator, which drives the electric
motor and charges the battery. In this setup, the engine does not directly power the wheels.
Series hybrid is also called a range extender since the engine powers the electric motor and the
battery pack.
2. Parallel hybrid
In this system, both the engine and electric motor work parallel to propel the vehicle. The
engine and the electric motor deliver optimum power for the efficient functioning of the car.
The battery pack gets charged via regenerative braking. Regenerative braking is a process of
utilising the kinetic energy produced while slowing the vehicle down to charge the battery
pack.
3. Series-parallel hybrid
A series-parallel is a flexible system wherein the IC engine, and electric motor can work in
conjunction or independently. The power delivery or the power distribution helps the vehicle
achieve maximum efficiency in terms of power output or fuel-efficiency.

Difference between Electric Vehicles and Hybrid Electric Vehicles
Parameters Electric Vehicles Hybrid Electric Vehicles
Primary power source Electricity Gasoline fuel
Working mechanism
Electric motor powers
the wheels.
The IC engine and electric motor work in
tandem to propel the vehicle.
Battery charging
You need to plug into a
power source to charge
the battery pack.
You don't need to plug into an external power
source as the battery gets charged via
generator/regenerative braking.
Emission levels
EVs produce zero
emission.
HEVs are Low Emission Vehicles (LEVs) since
they produce fewer emissions than conventional
vehicles.
Running cost Low High
Upfront cost (Price) High Lower than electric vehicles.
Driving range Low High
Vehicle life
You can use an EV until
the battery pack lasts.
You can drive an HEV for a longer period since
an IC engine lasts longer than a battery pack.

Advantages of Electric Vehicles
1. Low Noise Pollution
2. Secure Environment
3. Low Maintenance Cost
4. More Convenient
5. No Fuel
6. Natural Resource Saving
7. Increasing Popularity
8. Parking For a Low Fee
9. Golden Investment Opportunities
10. Subsidy Benefits
Disadvantages of Electric Vehicles
1. Higher Purchase Cost
2. Low Speed and Range
3. Low Price on Selling
4. The Inconvenience of Service
Station
5. Low Energy
6. Battery Expenses
7. Slow Charging
8. Expensive Recharging Options
9. Problem For Fuel-Producing
Countries
10. Fewer Users

1.Consumer Electronics.
2.Public Transportation.
3.Aviation.
4.Electricity Grid.
5.Renewable Energy Storage.
6.Military.
7.Spaceflight.
8.Wearable Technology.
APPICATIONS OF ELECTRIC VEHICLES

Advantages of a Hybrid Vehicles
1. Environmentally Friendly: One of the biggest advantages of a hybrid car over a gasoline-powered car is that
it runs cleaner and has better gas mileage, which makes it environmentally friendly.
A hybrid vehicle runs on a twin-powered engine (gasoline engine and electric motor) that cuts fuel
consumption and conserves energy. Sure, it still uses gasoline, but the amount it needs to operate is
significantly reduced.
2. Financial Benefits:Hybrid cars are supported by many credits and incentives that help make them
affordable. Lower annual tax bills and exemption from congestion charges make running these cars generally
cheaper than their pure gasoline-powered counterparts.
3. Less Dependence on Fossil Fuels:A Hybrid car is much cleaner and requires less fuel to run, which means
fewer emissions and less dependence on fossil fuels. This, in turn, also helps to reduce the price of gasoline in
the domestic market.
4. Regenerative Braking System:Each time you apply the brake while driving a hybrid vehicle, it helps you
recharge your battery a little. An internal mechanism kicks in that captures the energy released and uses it to charge the
battery, which in turn eliminates the amount of time and need for stopping to recharge the battery periodically.
5. Built From Light Materials:Hybrid vehicles are made of lighter materials, meaning less energy is required to run them.
The engine is also smaller and lighter, which also saves a lot of energy.
6. Assistance From Electric Motor:The electric motor assists the internal combustion engine in case of accelerating, passing
or climbing a hill.
7. Smaller Engines:The gasoline engines in hybrid cars are usually small, light, and highly efficient as they don’t have to
power the car alone.

8. Automatic Start and Stop: In hybrid cars, the engine is automatically shut off when the
vehicle is idle and starts when the accelerator is pressed.
Compared to traditional hybrid vehicles, PHEVs can drive longer distances at higher
speeds. Hydrogen fuel cell vehicles have lower energy emissions because they emit only water
vapor and warm air.
9. Electric-Only Drive: Hybrid vehicles can be driven entirely on electricity. This usually
happens while moving at low speeds, when the engine is idling at a stoplight, or when the engine
starts up.
Normally, the internal combustion engine starts operating only at higher speeds, where it has
more efficiency. This helps increase the overall fuel efficiency of the vehicle.
10. Higher Resale Value: With a continuous increase in the price of gasoline, more and more people are turning towards
hybrid cars. The result is that these green vehicles have started commanding higher-than-average resale values. So, if you
are unsatisfied with your vehicle, you can always sell it at a premium price to buyers looking for it.
There are many advantages to owning a hybrid car. The one thing you will like the best is how it helps control your budget
as gas prices increase.
The other benefit that is not seen directly is how owning and driving a hybrid car impacts the environment. That’s
because it reduces your dependence on fossil fuels and lowers your carbon imprint on the environment.

Disadvantages of a Hybrid Electric Vehicles:
There are disadvantages to owning a hybrid car, but they are probably not what you think.
Contrary to the popular myth, hybrid cars have just as much power as regular cars and have no
issues with mountain driving or towing. The disadvantages will depend on the type of hybrid fuel
that your vehicle uses.
1. Less Power;Hybrid cars have twin-powered engines. The gasoline engine, which is the primary power source,
is much smaller than what you get in single-engine powered cars, while the electric motor isn’t as powerful
either.
The combined power is often less than that of a gas-powered engine. In fact, the power generated by this car is
more suited for city driving and not for long-distance travel or applications where speed and acceleration are
imperative.
2. Can Be Expensive: Hybrid cars are comparatively more expensive than regular petrol cars. However, that
extra amount can be offset with lower running costs and tax exemptions.
3. Poorer Handling: Incorporating both a gasoline-powered engine and a lighter electric engine, hybrid cars
require powerful battery packs, which increase weight and consume additional space within the vehicle.
Unfortunately, the extra weight contributes to fuel inefficiency, prompting manufacturers to prioritize weight
reduction. Consequently, they have downsized motors and batteries while providing less support in the
suspension and body to counterbalance the added mass.
4. Higher Maintenance Costs:The presence of a dual engine and continuous technological improvements make
it difficult for mechanics to repair the car, and the maintenance cost is also much higher. It is also difficult to find
a mechanic with such expertise.

5. Accidents from High Voltage in Batteries
In an accident, the high voltage inside the batteries can prove lethal for you. There is a high
chance of you getting electrocuted in such cases, which can also make the task difficult for
rescuers to get other passengers and the driver out of the car.
6. Battery Replacement is Pricey
According to Green Car Reports, battery replacement in hybrid vehicles is currently rare.
However, if a battery needs to be replaced, it can get pricey.
7. Battery Recycling Is Very Expensive
Once batteries pass their useful life cycle, they can be recycled to harvest usable materials for
repurposing. This removes waste from the environment, which by the way, is a good thing.
However, the main issue with recycling lies in the recycling costs. Although lithium is 100% recyclable, extracting it costs
too much, and sometimes economic gain may not adequately justify the effort put into the recycling process.
In fact, in most cases, lithium recycling is only done because of federal mandates and/or ecological purposes.
8. Hydrogen Fuel Cell Issues
The source of hydrogen can be both “clean” sources, such as solar or wind power, or “dirty” sources like coal and natural
gas. Sourcing from coal and natural gas undermines the ecological motive for using hydrogen fuel cell vehicles.
Production of hydrogen is also expensive, and the fuel cells require refueling at a hydrogen station. At present, these
stations are only located in California and near Toronto.

Assess Your Priorities – Pick your top priorities, including price, range, top speed,
and acceleration. This will enable you to concentrate on the motors that best suit your
demands while also reducing the number of possible choices.
Compare Motor Types – Compare the various motor types covered earlier in this post,
assessing the advantages and disadvantages of each. Remember that AC motors offer
superior performance and efficiency even when DC motors could be cheaper.
Consult Experts and Online Resources – Consult specialists, either in person or online,
and use online tools like forums and blogs to gain insight from other people’s experiences.
You can obtain important insights and decide more wisely as a result of this.

Types of Motors used in Electric Vehicles
Electric Motors used in Electric Vehicles
1. DC Series Motor
2. Brushless DC Motor
3. Permanent Magnet Synchronous Motor (PMSM)
4. Three Phase AC Induction Motors
5. Switched Reluctance Motors (SRM)

1. DC Series Motor
High starting torque capability of the DC Series motor makes it a suitable option for
traction application. The advantages of this motor are easy speed control and it can also
withstand a sudden increase in load. All these characteristics make it an ideal traction
motor. The main drawback of DC series motor is high maintenance due to brushes and
commutators.
2. Brushless DC Motors
It is similar to DC motors with Permanent Magnets. It is called brushless because it does
not have the commutator and brush arrangement. The commutation is done electronically
in this motor because of this BLDC motors are maintenance free. BLDC motors have
traction characteristics like high starting torque, high efficiency around 95-98%, etc.
BLDC motors are suitable for high power density design approach. The BLDC motors are
the most preferred motors for the electric vehicle application due to its traction
characteristics.

BLDC motors further have two types
i. Out-runner type BLDC Motor:
In this type, the rotor of the motor is present outside and the stator is present inside. It is also
called as Hub motors because the wheel is directly connected to the exterior rotor. This type of
motors does not require external gear system. In a few cases, the motor itself has inbuilt
planetary gears. This motor makes the overall vehicle less bulky as it does not require any gear
system. It also eliminates the space required for mounting the motor. There is a restriction on
the motor dimensions which limits the power output in the in-runner configuration. This motor
is widely preferred by electric cycle manufacturers like Hullikal, Tronx, Spero, light speed
bicycles, etc. It is also used by two-wheeler manufacturers like 22 Motors, NDS Eco Motors,
etc.
ii. In-runner type BLDC Motor:
In this type, the rotor of the motor is present inside and the stator is outside like conventional
motors. These motor require an external transmission system to transfer the power to the
wheels, because of this the out-runner configuration is little bulky when compared to the in-
runner configuration. Many three- wheeler manufacturers like Goenka Electric Motors,
Speego Vehicles, Kinetic Green, Volta Automotive use BLDC motors. Low and medium
performance scooter manufacturers also use BLDC motors for propulsion.

It is due to these reasons it is widely preferred motor for electric vehicle application. The main drawback is the high cost
due to permanent magnets. Overloading the motor beyond a certain limit reduces the life of permanent magnets due to
thermal conditions.
3. Permanent Magnet Synchronous Motor (PMSM)
This motor is also similar to BLDC motor which has permanent magnets on the rotor. Similar to BLDC motors these
motors also have traction characteristics like high power density and high efficiency. The difference is that PMSM has
sinusoidal back EMF whereas BLDC has trapezoidal back EMF. Permanent Magnet Synchronous motors are available for
higher power ratings. PMSM is the best choice for high performance applications like cars, buses. Despite the high cost,
PMSM is providing stiff competition to induction motors due to increased efficiency than the latter. PMSM is also costlier
than BLDC motors. Most of the automotive manufacturers use PMSM motors for their hybrid and electric vehicles. For
example, Toyota Prius, Chevrolet Bolt EV, Ford Focus Electric, zero motorcycles S/SR, Nissan Leaf, Hinda Accord, BMW i3,
etc use PMSM motor for propulsion.
4. Three Phase AC Induction Motors
The induction motors do not have a high starting toque like DC series motors under fixed voltage and fixed frequency
operation. But this characteristic can be altered by using various control techniques like FOC or v/f methods. By using these
control methods, the maximum torque is made available at the starting of the motor which is suitable for traction
application. Squirrel cage induction motors have a long life due to less maintenance. Induction motors can be designed up
to an efficiency of 92-95%. The drawback of an induction motor is that it requires complex inverter circuit and control of
the motor is difficult.

In permanent magnet motors, the magnets contribute to the flux
density B. Therefore, adjusting the value of B in induction
motors is easy when compared to permanent magnet motors. It is
because in Induction motors the value of B can be adjusted by
varying the voltage and frequency (V/f) based on torque
requirements. This helps in reducing the losses which in turn
improves the efficiency.
Tesla Model S is the best example to prove the high performance
capability of induction motors compared to its counterparts. By
opting for induction motors, Tesla might have wanted to
eliminate the dependency on permanent magnets. Even Mahindra
Reva e2o uses a three phase induction motor for its propulsion.
Major automotive manufacturers like TATA motors have planned
to use Induction motors in their cars and buses. The two-wheeler
manufacturer TVS motors will be launching an electric scooter
which uses induction motor for its propulsion. Induction motors
are the preferred choice for performance oriented electric
vehicles due to its cheap cost. The other advantage is that it can
withstand rugged environmental conditions. Due to these
advantages, the Indian railways has started replacing its DC
motors with AC induction motors.

5. Switched Reluctance Motors (SRM)
Switched Reluctance Motors is a category of variable reluctance motor with double saliency. Switched
Reluctance motors are simple in construction and robust. The rotor of the SRM is a piece of laminated steel
with no windings or permanent magnets on it. This makes the inertia of the rotor less which helps in high
acceleration. The robust nature of SRM makes it suitable for the high speed application. SRM also offers high
power density which are some required characteristics of Electric Vehicles. Since the heat generated is mostly
confined to the stator, it is easier to cool the motor. The biggest drawback of the SRM is the complexity in
control and increase in the switching circuit. It also has some noise issues. Once SRM enters the commercial
market, it can replace the PMSM and Induction motors in the future.
Insights for Selecting the Right Motor for your EV
For selecting the appropriate electric vehicle motors, one has to first list down the requirements of the
performance that the vehicle has to meet, the operating conditions and the cost associated with it. For example,
go-kart vehicle and two-wheeler applications which requires less performance (mostly less than 3 kW) at a low
cost, it is good to go with BLDC Hub motors. For three-wheelers and two-wheelers, it is also good to choose
BLDC motors with or without an external gear system. For high power applications like performance two-
wheelers, cars, buses, trucks the ideal motor choice would be PMSM or Induction motors. Once the
synchronous reluctance motor and switched reluctance motor are made cost effective as PMSM or Induction
motors, then one can have more options of motor types for electric vehicle application.

maglev, also called magnetic levitation train or maglev train, a
floating vehicle for land transportation that is supported by either
electromagnetic attraction or repulsion. Maglevs were
conceptualized during the early 1900s by American professor and
inventor Robert Goddard and French-born American engineer Emile
Bachelet and have been in commercial use since 1984, with several
operating at present and extensive networks proposed for the future

 Maglev (magnetic levitation), is a system of train transportation that uses
two sets of electromagnets:
 one set to repel and push the train up off the track, and another set to
move the elevated train ahead, taking advantage of the lack of friction.
 Such trains rise approximately 10 centimetres (4 in) off the track.
 There are both high-speed, intercity maglev systems (over 400 kilometres
per hour or 250 miles per hour), and low-speed, urban maglev systems
(80–200 kilometres per hour or 50–124 miles per hour) under
development and being built.
 The Shanghai maglev train is the only maglev train in commercial
operation that can be considered as high speed.

MAGLEV is an acronym of magnetic levitation. The most spectacular applications of this would
be maglev trains. The coaches of the train do not slide over steel rails but float on a four inch air cushion above
the track using Meissner effect of super conducting magnets.
 The train has a superconducting magnet built into the base of the carriages.
 An aluminium guide way is laid on the ground and carriers electric current.
 The walls of the guide way have a series of horizontal and vertical coils mounted inside the guide
way. These coils are made up of normal conductors
 The current flowing through its horizontal coils produce a vertical magnetic field. By Meissner
effect the superconducting magnet S expels the vertical magnetic flux. This levitates the train and
keeps it afloat the guide way, the horizontal coils are thus called levitating coils.
 On the other hand current passing through the vertical coil produce a horizontal magnetic field
which pushes the train forward. Thus the vertical coils are called propelling coils.
 The train is fitted with retractable wheels similar to the wheels of an aircraft. Once the train is
levitated in air the wheels are retracted into the body and the train glides forward on the air
cushion.
 When the train is to be halted the current through the levitating and propelling coils are switched
off. The train descends slowly on to the guide way and runs some distance on it till it stops.
 The utility of such levitation is that in the friction the energy loss is minimized allowing the speed
of the train rise up to 581 kmph.

Principle behind maglev trains
 Maglev is short for Magnetic Levitation, in which trains float on a
guideway using the principle of magnetic repulsion.
 When two magnets are brought near each other, either their north
poles or south poles face each other; they repel each other.
 When the north pole of a magnet is brought near the south pole of
another magnet, they attract each other.
 Thus, like poles repel and, unlike poles, attract each other.
Hence, the magnetic repulsion principle is used in maglev trains.

Advantages of Hybrid Vehicles
1. Fuel Economy
2. Require Less Maintenance
3. Light Materials
4. A More Reliable Fuel Type
5. Good Resale Value
Disadvantages of Hybrid Vehicles
1. Higher Insurance
2. Higher Upfront Cost
3. Performance
4. Poorer Handling
5. Battery Replacement Can Be Expensive

Hybrid Electric Vehicles
Topologies
3
(HEV
Configurations)

4
Series Hybrid Electric Vehicle

5
Detailed Configuration of Series Hybrid Electric Vehicle

6
Figure 1a: Mode 1, normal driving or acceleration
Figure 1b: Mode 2, light load
Figure 1c: Mode 3, braking or deceleration
Figure 1d: Mode 4, vehicle at stop
B:Battery
E: ICE
F: Fuel tank
G: Generator
M: Motor
P: Power Converter
T: Transmission
(including brakes,
clutches and gears)

7
Power Flow Control in Series Hybrid In the series hybrid system
there are four operating modes based on the power flow:
Mode 1: During startup (Figure a), normal driving or acceleration of the series
HEV, both the ICE and battery deliver electric energy to the power converter which
then drives the electric motor and hence the wheels via transmission.
Mode 2: At light load (Figure b), the ICE output is greater than that required to
drive the wheels. Hence, a fraction of the generated electrical energy is used to
charge the battery. The charging of the batter takes place till the battery capacity
reaches a proper level.
Mode 3: During braking or deceleration (Figure c), the electric motor acts as a
generator, which converts the kinetic energy of the wheels into electricity and this,
is used to charge the battery.
Mode 4: The battery can also be charged by the ICE via the generator even when
the vehicle comes to a complete stop (Figure d).

8
Parallel Hybrid Electric Vehicle

9
Figure a: Mode 1, start up Figure b: Mode 2, normal driving
Figure c: Mode 3, braking or deceleration Figure d: Mode 4, light load
B:Battery
E: ICE
F: Fuel tank
G: Generator
M: Motor
P: Power
Converter

10
Power Flow Control in Parallel Hybrid
The parallel hybrid system has four modes of operation. These four modes
of operation are
Mode 1: During start up or full throttle acceleration (Figure a); both the ICE
and the EM share the required power to propel the vehicle. Typically, the
relative distribution between the ICE and electric motor is 80-20%.
Mode 2: During normal driving (Figure b), the required traction power is
supplied by the ICE only and the EM remains in off mode.
Mode 3: During braking or deceleration (Figure c), the EM acts as a
generator to charge the battery via the power converter.
Mode 4: Under light load condition (Figure d), the traction power is
delivered by the ICE and the ICE also charges the battery via the EM.

11
Series - Parallel Hybrid Electric Vehicle

12
Figure a: Mode 1, start up Figure b: Mode 2, acceleration
Figure c: Mode 3, normal drive
Figure d: Mode 4,
braking or deceleration
Figure e: Mode 5,
battery charging during driving
Figure f: Mode 6,
battery charging during standstill

13
The operating modes of EM dominated system are:
Mode 1: During startup (Figure a), the EM provides the traction
power and the ICE remains in the off state.
Mode 2: During full throttle (Figure b), both the ICE and EM provide
the traction power.
Mode 3: During normal driving (Figure c), both the ICE and EM
provide the traction power.
Mode 4: During braking or deceleration (Figure d), the EM acts as a
generator to charge the battery.
Mode 5: To charge the battery during driving (Figure e), the ICE
delivers the required traction power and also charges the battery. The
EM acts as a generator.
Mode 6: When the vehicle is at standstill (Figure f), the ICE can
deliver power to charge the battery via the EM

14
Complex Hybrid Electric Vehicle

15
Figure a: Mode 1, start up Figure b: Mode 2, acceleration Figure c: Mode 3, normal drive
Figure d: Mode 4
braking or deceleration
Figure e: Mode 5
battery charging during driving
Mode 6,
battery charging during standstill

16
Power Flow Control Complex Hybrid Control
The complex hybrid vehicle configurations are of two types:
 Front hybrid rear electric
 Front electric and rear hybrid
Both the configurations have six modes of operation:
Mode 1: During startup (Figure a), the required traction power is delivered by the EMs and the engine is
in off mode.
Mode 2: During full throttle acceleration (Figure b), both the ICE and the front wheel EM deliver the
power to the front wheel and the second EM delivers power to the rear wheel.
Mode 3: During normal driving (Figure c), the ICE delivers power to propel the front wheel and to drive
the first EM as a generator to charge the battery.
Mode 4: During driving at light load (Figure d) first EM delivers the required traction power to the front
wheel. The second EM and the ICE are in off sate.
Mode 5: During braking or deceleration (Figure e), both the front and rear wheel EMs act as generators to
simultaneously charge the battery.
Mode 6: A unique operating mode of complex hybrid system is axial balancing. In this mode (Figure f) if
the front wheel slips, the front EM works as a generator to absorb the change of ICE power. Through the
battery, this power difference is then used to drive the rear wheels to achieve the axle balancing.

17
Plug-In Hybrid Electric Vehicles (PHEV)

21
Plug-In Hybrid Electric Vehicles (PHEV)
A plug-in hybrid electric vehicle (PHEV) uses a battery to power an electric
motor and uses another fuel, such as gasoline or diesel, to power an internal
combustion engine. The battery pack in a PHEV is generally larger than in a
standard hybrid electric vehicle.
The larger battery pack allows the vehicle to operate predominantly on
electricity during short trips. For longer trips, a PHEV can draw liquid fuel from
its on-board tank to provide a driving range similar to that of a conventional
vehicle. An on-board computer decides when to use which fuel according to
which mode allows the vehicle to operate most efficiently.
The battery can be charged by plugging into an electric power source, through
regenerative braking, and by the internal combustion engine. In regenerative
braking, kinetic energy normally lost during braking is captured and stored in
the battery

22
Plug-in Hybrid Electric Vehicles, or PHEVs, are the next generation of hybrid
electric vehicles that are fairly new to the scene but are quick to gain traction
because of their increased efficiency. They are also called range-extended electric
vehicles for the obvious reason that the vehicles always have gasoline as a
potential back-up that can extend the driving range. They are equipped with a
larger and a powerful battery compared to HEVs, which can be recharged at the
electricity grid.
PHEVs operate in two different modes based on the charge of the battery. It mostly
uses electric motor to propel the engine which automatically reduces the fossil fuel
consumption, and it will only switch to ICE if the battery level drops below the set
limit.

23
Why plug-in hybrid?
Many car owner do not use the car for business travel, and they do not drive daily
more than 50km. for such distance it is not necessary to spend any petrol, because
this distance can be easily realized by energy from battery, but great disadvantage of
electric drive is, that the “empty” battery cannot be recharged in minutes and in the
case of longer trip, the safety return is not sure. Also in some rare trips during
holidays etc. cannot be realized by electric vehicle that means you must have or
purchase another car. All these problems are solved by serial hybrid with greater
battery, which can be driven first 50km from battery only and in the case of longer
trip; the engine is started and operated in the optimal efficiency work point with
constant power and speed. The generated electricity is either used for motors supply
or in case of low load is simultaneously stored in empty battery.
The PHEV must be able to work in electric mode only at any speed, during the short
trips under the daily limit. Therefore it must have strong enough electric motor EM
and this condition results in serial concept hybrid, when the ICE is not mechanically
connected with wheels, because its help is not necessary

25
Components of a
Plug-In Hybrid Electric Vehicle
1. Battery (auxiliary)
2. Charge port
3. DC/DC converter
4. Electric generator
5. Electric traction motor
6. Exhaust system.
7. Fuel filler
8. Fuel tank (gasoline)
9. Internal combustion engine
(spark-ignited)
10. On-board charger
11. Power electronics controller
12. Thermal system (cooling)
13. Traction battery pack
14. Transmission

26
How Do Plug-In Hybrid Electric Cars Work?
Plug-in hybrid electric vehicles (PHEVs) use batteries to power an electric motor and another fuel,
such as gasoline, to power an internal combustion engine (ICE). PHEV batteries can be charged
using a wall outlet or charging equipment, by the ICE, or through regenerative braking. The vehicle
typically runs on electric power until the battery is nearly depleted, and then the car automatically
switches over to use the ICE
Components of a Plug-In Hybrid Electric Vehicle
Battery (auxiliary): In an electric drive vehicle, the low-voltage auxiliary battery provides electricity
to start the car before the traction battery is engaged; it also powers vehicle accessories.
Charge port: The charge port allows the vehicle to connect to an external power supply in order to
charge the traction battery pack.
DC/DC converter: This device converts higher-voltage DC power from the traction battery pack to
the lower-voltage DC power needed to run vehicle accessories and recharge the auxiliary battery.
Electric generator: Generates electricity from the rotating wheels while braking, transferring that
energy back to the traction battery pack. Some vehicles use motor generators that perform both the
drive and regeneration functions.
Electric traction motor: Using power from the traction battery pack, this motor drives the vehicle's
wheels. Some vehicles use motor generators that perform both the drive and regeneration
functions.

27
Exhaust system: The exhaust system channels the exhaust gases from the engine out through the
tailpipe. A three-way catalyst is designed to reduce engine-out emissions within the exhaust
system.
Fuel filler: A nozzle from a fuel dispenser attaches to the receptacle on the vehicle to fill the tank.
Fuel tank (gasoline): This tank stores gasoline on board the vehicle until it's needed by the engine
Internal combustion engine (spark-ignited): In this configuration, fuel is injected into either the
intake manifold or the combustion chamber, where it is combined with air, and the air/fuel mixture is
ignited by the spark from a spark plug.
On-board charger: Takes the incoming AC electricity supplied via the charge port and converts it to
DC power for charging the traction battery. It also communicates with the charging equipment and
monitors battery characteristics such as voltage, current, temperature, and state of charge while
charging the pack.
Power electronics controller: This unit manages the flow of electrical energy delivered by the
traction battery, controlling the speed of the electric traction motor and the torque it produces.
Thermal system (cooling): This system maintains a proper operating temperature range of the
engine, electric motor, power electronics, and other components.
Traction battery pack: Stores electricity for use by the electric traction motor.
Transmission: The transmission transfers mechanical power from the engine and/or electric
traction motor to drive the wheels.

32
Full hybrid cars Plug-in hybrid
cars
Electric power
Can power the car at
slower speeds
Can power the car in
all uses
Battery size and cost
Smaller, less
expensive
Larger, more
expensive
Recharging Regenerative braking External power source
Gasoline power
(ICE)
Used in most driving
conditions
Used simultaneously
or only when electric
power runs low

34
Companies of BEV, PHEV and HEV
BEV PHEV HEV
Tesla Model S BMW i3 REX PHEV Audi Q5
Nissan Leaf BEV BMW i8 PHEV Acura ILX Hybrid
Mitsubishi iMiEV BEV Cadillac ELR PHEV Cadillac Escalade Hybrid
BMW i3 BEV GM Chevy Volt PHEV BMW Active Hybrid
Smart EV BEV Porsche Panamera S E PHEV BMW Active Hybrid 5
Ford Focus EV BEV Ford Fusion Energi PHEV BMW Active Hybrid 7
- Ford Cmax Energi PHEV Honda Civic Hybrid
- Toyota Prius Plugin PHEV Honda CR-Z Hybrid
- - Hyundai Sonata Hybrid
- - Infiniti Q50 Hybrid
- - Infiniti Q70 Hybrid

36
Fuel cell vehicle Components

38
FCEVs use a propulsion system similar to that of electric vehicles, where energy
stored as hydrogen is converted to electricity by the fuel cell. Unlike
conventional internal combustion engine vehicles, these vehicles produce no
harmful emissions.
FCEVs are fuelled with pure hydrogen gas stored in a tank on the vehicle.
Similar to conventional internal combustion engine vehicles, they can fuel in less
than four minutes and have a driving range of over 300 miles. FCEVs are
equipped with other advanced technologies to increase efficiency, such as
regenerative braking systems that capture the energy lost during braking and
store it in a battery. Major automobile manufacturers are offering a limited but
growing number of production fcev to the public in certain markets, in sync with
what the developing infrastructure can support.

39
 The gas (H2), along with dioxygen (O2) from the surrounding air, are supplied to
the fuel cell. These two gases then undergo an electrochemical reaction inside the
cell, in turn producing electricity, heat and water vapor (H2O), which is released in
the form of a gas via a small tube located underneath the vehicle.
 A fuel cell is composed of two electrodes, an electrolyte, fuel (hydrogen), and a
power supply. The reduction and oxidation reaction happens through a multi-step
process involving the anode, the cathode, and the electrolyte membrane.
 At the negatively-charged anode site, hydrogen molecules are split into electrons
and protons. The electrons are then forced through a circuit where they generate
an electric current and excess heat. The protons go on to the electrolyte
membrane. At the cathode, the protons, electrons, and oxygen combine to
produce water molecules. Flow plates facilitate the transfer between the anode
and cathode. Because an individual fuel cell only produces less than 1.16 volts of
electricity, fuel cell stacks are needed to increase the amount of electricity
generated.

45
Fuel cells are a type of energy conversion technology which take the chemical energy contained within a fuel
and transform it into electricity along with certain by-products (depending on the fuel used). [1] It's
important to note that fuel cells are not heat engines, so they can have incredibly high efficiencies. However,
when a heat engine is used to power a fuel cell, the heat engine still has a limiting thermal efficiency.
Fuel cells can be seen as an energy storage device, as energy can be input to create hydrogen and oxygen,
which can remain in the cell until its use is needed at a later time. In this sense they work much like a battery.
There are multiple types of fuel cells, but two common types are the solid oxide fuel cell (SOFC) and the
polymer electrolyte membrane fuel cell (PEMFC).
To produce electricity in a solid oxide fuel cell, oxygen in the air combines with free electrons to form oxide
ions. The oxide ions travel through a ceramic electrolyte and react with molecular hydrogen to form water.
The reaction that makes water also releases electrons which travel through an external electrical circuit,
producing electricity.[4]
This process can be seen in figure 1.
To produce electricity in a polymer electrolyte membrane fuel cell, a gaseous fuel is input and reacts with a
catalyst made of platinum nanoparticles. When molecular hydrogen comes into contact with this, it splits
into two H+
ions and two electrons. The electrons are conducted through an electromotive force and
electricity is produced. The hydrogen ions pass through a proton exchange membrane (also known as a
polymer electrolyte) where it reaches the cathode and combines with oxygen to form water. This process can
continue as long as there is hydrogen and oxygen supplied to the cell.[1]
Figure 2 shows this process in a
PEMFC.
Fuel Cell

46
Solid oxide fuel cell (SOFC). Molecular
oxygen becomes oxide ions (O2-) and
combines with hydrogen to form water,
while simultaneously producing electricity
Polymer electrolyte membrane fuel cell
(PEMFC). Molecular hydrogen fuel becomes
hydrogen ions (H+) that travel through a polymer
electrolyte. The hydrogen ions combine with
oxygen to form water, while simultaneously
producing electricity

47
In contrast to conventional battery electric vehicles, hydrogen fuel cell electric vehicles
generate their energy using a fuel cell powered by hydrogen, as opposed to relying
completely on batteries. As a main energy source, hydrogen is used for fuel cell electric
vehicles. They generate no pollutants from the exhaust and emit no greenhouse gases into
the atmosphere, making them more energy efficient than internal combustion engines.
As depicted in Figure, the propulsion technique is comparable to that of a battery electric
vehicle, with hydrogen being transformed into electricity. The hydrogen gas is stored in the
hydrogen tank until it is required by the fuel cell stack, which is located inside the vehicle. A
fuel cell stack is a device of separate membrane electrodes that combine hydrogen and
oxygen to generate electricity. DC-DC converter transforms higher-voltage DC power
coming from the fuel cell stack into the lower-voltage DC power required to operate the
electronics and recharge the battery of the vehicle. The DC-AC converter controls the
motor's speed and torque by regulating the flow of electrical energy generated by the fuel
cell stack and the battery. As a result, the rotation of the wheels is performed and the vehicle
is driven by the electric motor.
Working Principle of a Hydrogen Fuel Cell Electric Vehicle

48
The polymer electrolyte membrane (PEM) fuel cell where an electrolyte membrane is
positioned between the cathode and anode, is the most popular kind of fuel cell used in
hydrogen fuel cell electric vehicles. The cathode receives oxygen from the air, whereas the
anode receives hydrogen from the hydrogen tank. An electrochemical process takes place in
the fuel cell stack, causing the hydrogen molecules to split into protons and electrons. After
that, the protons pass through the membrane and are transported to the cathode and the
electric vehicle is powered by electrons being pushed through an external circuit, with the
electrons eventually recombining the protons on the cathode side to generate an H2O
molecule.
As a result of the interaction between the protons, electrons, and oxygen molecules, only heat
and water vapor are released into the atmosphere from this process. Several catalysts that are
nano-sized particles can be used with various hydrogen fuel cell designs. Fuel cells are very
effective since chemical energy does not have to be transformed into thermal energy and
mechanical energy. Fuel cells reduce pollution in two ways, they produce fewer carbon
emissions than conventional internal combustion engines and they waste less energy in the
form of heat. Due to many positive aspects, fuel cells can be used in a broad variety of
applications, from huge facilities like power plants to transportation.

50
Pros of Hydrogen Cars:
Faster refueling: It will take only a few minutes to refill/refuel the hydrogen
gas tank due to its time-effective and instantaneous process.
Distant range: Hydrogen cars are not only faster but also offer a distant
range with just a single tank of fuel.
Zero emissions: The only thing that a hydrogen car emits is water vapor,
making it a zero-emission vehicle.
Cons of Hydrogen Cars:
Lack of infrastructure: With the limited refueling stations or lack of
infrastructure, hydrogen cars would not be a viable option.
Quite expensive: Hydrogen-powered cars are not cheap, and the refueling
charge differs considerably among different countries.
Production challenges: When it comes to the production of hydrogen, it
can be energy-intensive and may rely on various non-renewable sources.

51
Pros of Electric Cars:
Advanced infrastructure: Compared to hydrogen cars, electric cars have advanced
infrastructure and charging stations in which governments worldwide are investing.
Emissionless and cheaper: Electric cars run silently and produce no pollution or
emissions. Also, electric cars are more affordable, and the cost of recharging the
batteries is convenient.
Lower maintenance: Due to the lack of moving parts, battery-powered electric cars
are reliable and require less maintenance, resulting in less cost.
Cons of Electric Cars:
Limited range: One of the most considerable drawbacks of electric cars is the
limited range compared to the time it takes to recharge the batteries.
Battery lifespan: The lifespan of the batteries is limited, and it becomes difficult to
dispose of them properly. It will be essential to replace the old batteries with new
ones at a regular period.
Limited charging stations: The charging or refueling stations are currently in the
development phase, having around 1000 charging stations.

52
Advantages and Disadvantages of Battery and Hydrogen Fuel Cell Technologies

53
Fuel cells are a type of energy conversion technology which take the chemical
energy contained within a fuel and transform it into electricity along with certain
by-products (depending on the fuel used). [1] It's important to note that fuel cells
are not heat engines, so they can have incredibly high efficiencies. However, when
a heat engine is used to power a fuel cell, the heat engine still has a limiting
thermal efficiency.
Fuel cells can be seen as an energy storage device, as energy can be input to create
hydrogen and oxygen, which can remain in the cell until its use is needed at a later
time. In this sense they work much like a battery. There are multiple types of fuel
cells, but two common types are the solid oxide fuel cell (SOFC) and the polymer
electrolyte membrane fuel cell (PEMFC).

54
Fuel Cell Working Principle and
Schematic Diagram:
Fuel Cell Working Principle explains that it is an
electrochemical device that converts chemical
energy of a conventional fuel directly into low
voltage D.C. electrical energy. It is then described
as a primary battery in which fuel and oxidizer are
stored external to the battery and fed to it when
needed. A schematic diagram of fuel cell is shown
in Fig. The fuel gas is diffused through the anode
and is oxidized, thus releases electrons to the
external circuit. The oxidizer is diffused through
the cathode and is reduced by the electrons
coming from the anode through the external
circuit. The fuel cell keeps permitting the fuel
molecule to mix with the oxidizer molecules, and
allow the transfer of electron by a metallic path
that contains a load.

56
The gases diffuse through the electrodes by undergoing the following reaction.
When the temperature is high, the electrolyte material acts as a sieve and the hydrogen
ions migrates through the material. An electrical load is connected between the anode and
the cathode. The chemical reaction in the cathode, the energy representing the enthalpy of
combustion of fuel is released and a part of it is available for conversion into electrical
energy. The water formed is drawn off from the side
This fuel cell uses hydrogen as fuel and oxygen as an oxidiser. A typical hydrogen-oxygen
fuel cell is shown in the Fig. There are three chambers separated by two porous electrodes,
the anode and cathode. The middle chamber between the two electrodes is filled with
electrolyte (strong solution of potassium hydroxide). The electrodes surfaces are chemically
treated to repel the electrolyte in order to restrict the flow of potassium hydroxide to the outer
chambers.

57
Advantages of fuel cells:
1.Conversion efficiency is high.
2.Easy and simple construction.
3.Require very little attention and maintenance.
4.High power to weight ratio.
5.Fuel cell does not make any noise.
6.Less space required.
7.Quick operation.
8.Can be installed at the use point.
Disadvantage of fuel cell:
1. It is very costly.
2. Short service life.
3. Low voltage output.
4. Proper attention is needed while selection of
Application of fuel cell:
1. Domestic use
2. Automotive vehicle
3. Central power station

Plug-in Hybrid Electric Vehicles
Dr.G.Nageswara Rao
Professor
Plug-in Hybrid Electric Vehicles
Dr.G.Nageswara Rao
Professor
UNIT-III

2
PHEVs and EREVs blended PHEVs, PHEV
Architectures, equivalent electric range of blended
PHEVs; Fuel economy of PHEVs, power
management of PHEVs, end-of-life battery for electric
power grid support, vehicle to grid technology, PHEV
battery charging.

3
Introduction to PHEVs
 Plug-in hybrid electric vehicles (PHEVs) have the potential to displace
transportation fuel consumption by using grid electricity to drive the car.
 PHEVs can be driven initially using electric energy stored in the onboard
battery, and an onboard gasoline engine can extend the driving range.
 In the 1990s and early 2000s, pure electric cars were not successful, one
of the major reasons being the limited driving range of the battery-
powered cars available at that time.
 For example, the GM electric vehicle (EV) had a range of about 100
miles (160 km) and the Ford Ranger electric truck had a range of
approximately 60 miles (96 km).

4
How does a Plug-in Hybrid Electric Vehicle Work?
 PHEV vehicles work in the same way as conventional hybrid
vehicles generally. The bigger battery pack that has to be connected
to an external electrical source, is the primary distinction.
 Plug-in hybrid automobile operates on the following points:
 Normally, a PHEV comes up in all-electric mode, where the electric
vehicle autonomously moves the car forward.
 Until the battery pack runs out of power, the car will remain running
entirely electrically.
 Upon reaching driving speeds, certain PHEVs automatically
transition to hybrid mode (Electric Motor + Internal Combustion
Engine).
 When the battery charge runs out, the internal combustion engine
kicks in, and the automobile runs like regular gasoline or diesel car.
 The battery pack is connected to an external power source, which
begins charging the vehicle.
 Regenerative braking and the internal combustion engine both
assist in charging the battery.

10
Criteria PHEV HEV BEV
Mode of Operation The vehicle is
propelled by a
combination of an IC
engine and an electric
motor.
An electric motor
helps the traditional
Internal combustion
engine run more
efficiently or function
better.
The car is driven by
an electric motor.
Emission levels Compared to gasoline
and diesel
automobiles, they
emit fewer
greenhouse gases.
Lesser carbon
footprints than those
of traditional cars.
There are no
pollutants from their
tailpipes.
Charging The recharging period
is less since battery
packs are more
compact.
There is no
requirement for
recharging because
the battery pack is
charged while the car
is moving due to
regenerative braking
or a generator.
Battery packs in
BEVs are bigger.
Thus, the charging
time extends.
Price High Low Low

11
Advantages of Plug-In Hybrid Electric Vehicles
 PHEVs have no pollutants when operating exclusively on electricity.
 When compared to normal petrol/diesel automobiles, they emit less
CO2 into the atmosphere.
 The electric vehicle helps the motor, making plug-in hybrid vehicles
propellant at slower speeds.
 If you only travel domestically, then the operating costs are cheap.
 There is no reason to worry about mileage as the internal
combustion engine can handle vast intervals.
Disadvantages of Plug-In Hybrid Electric Vehicles
 PHEVs are more costly than traditional and regular hybrid vehicles.
 During lengthy highway trips, the fuel usage can be comparable to
that of a regular car.
 The declining battery life might harm the efficiency of pure electric
vehicles.
 Regardless of the type of charger, the battery charges in a few hrs.
 Electric vehicle can be expensive to fix.

12
Parameters PHEVs BEVs
Working principle
An electric motor and IC engine work
independently or in tandem to propel
the vehicle.
An electric motor propels the
vehicle.
Electric range
The pure electric range is limited or
lesser than BEVs due to a smaller
battery pack.
Since BEVs rely on pure
electric power, they comprise
larger battery packs. Hence,
the electric range is greater
than PHEVs.
Emissions
They produce lower carbon emissions
than conventional petrol/diesel cars.
They produce zero tailpipe
emissions.
Charging time
Since the battery packs are smaller in
size, the charging time reduces.
BEVs have larger battery
packs. Hence, the charging
time increases.
Running cost High Low
Vehicle price Expensive but costs less than BEVs. Expensive

13
Parameters PHEVs HEVs
Working principle
An electric motor and an IC
engine propel the vehicle,
wherein they can operate
independently or in tandem.
An electric motor assists the
conventional IC engine in
improving fuel efficiency or
performance.
Electric range Limited
Typically, an HEV cannot
operate in pure electric mode.
However, some HEVs do offer
pure EV mode at slow speeds
for limited distances.
Emissions
They produce lower carbon
emissions compared to petrol
and diesel cars.
Lower carbon footprints
compared to conventional
vehicles.
Charging
They need to be plugged into
an external power source to
charge the battery pack.
No need for charging; since the
battery pack gets charged
within the vehicle via
regenerative braking or a
generator.
Battery pack
They comprise larger battery
packs.
HEVs come with smaller
battery packs.
Running cost Low High
Vehicle price Expensive than HEVs. Affordable than PHEVs.

14
PHEVs and EREVs
 PHEVs are sometimes called range-extended electric vehicles
(ReEVs) or extended range electric vehicles (EREVs), in the
sense that these vehicles always have on-board gasoline or diesel
that can be used to drive the vehicle for an extended distance
when the on-board battery energy is depleted.
 Furthermore, these vehicles can provide high fuel economy during
the extended driving range due to the large battery pack that can
accept more regenerative braking energy and provide more
flexibility for engine optimization during the extended driving range.
 However, EREVs, such as the GM Chevy Volt, must be equipped
with a full-sized electric motor so that pure electric driving can be
realized for all kinds of driving conditions.
 It is shown that, for some driving conditions, all-electric drive
sometimes does not provide the most benefits, given the limited
battery energy available.

15
Types of PHEVs
1. EREV Type 2. Blended Type

17
Series Configuration
PHEV Architectures

18
Figure shows the architecture of a series PHEV. In the series configuration, the
gasoline engine output is connected to a generator. The electricity generated by the
generator can be used to charge the battery or supply power to the powertrain
motor. The electric motor is the only component driving the wheels. The motor can
be an induction motor, a switched reluctance motor, or a permanent magnet motor.
The motor can be mounted on the vehicle in the same way as in a conventional
vehicle, without the need for transmission. In-wheel hub motors can also be
chosen. In the series configuration, the motor is designed to provide the torque
needed for the vehicle to drive in all conditions. The engine/generator can be
designed to provide the average power demand.
Parallel and complex hybrids can be designed as PHEVs as well. In parallel and
complex configurations, the engine and the motor can both drive the wheels.
Therefore, the motor size can be smaller than those in series configurations. In
comparison to regular hybrid electric vehicles (HEVs), a parallel or complex PHEV
will have a larger-sized battery pack that provides longer duration for extended
electric drive. The engine is turned onwhenever the vehicle’s power demand is
high.

20
 In the EREV specification, the car comes with a 1.5 liter turbo-
charged 4-cylinder engine with 123 hp - that power doesn’t count
though towards the total output of the vehicle since it isn’t
connected to the wheels.
 The battery has 40 kWh capacity and offers 140 km of electric-
only range. After that the extender kicks in giving the car a total
range of over 1,000 km. The EREV is available in two versions
with the latter having two electric motors with total power output
of 315 kW and 720 Nm of torque - the resulting sprint from 0 to
100 km/h takes just 4.4 seconds.
 The claimed 1,000 km range means that the car uses 56 liters of
fuel to cover 860 km which gives us a theoretical consumption of
6.5l/100km

21
 Extended-range electric vehicles (EREVs), commonly known as series
hybrid electric vehicles (Series-HEV), have better autonomy than electric
vehicles (EV) without range extenders (REs).
 EREVs can go from one city to another or make long journeys in general. In
recent years, EREVs have attracted considerable attention because of the
necessity to improve autonomy using new and different technologies to
generate extra energy for EVs.
 Today, fossil fuels meet the needs of the transportation sector to a significant
extent, but bring on various adverse effects, such as air pollution, noise, and
global warming.
 Compared to internal combustion engine vehicles (ICEVs), EREVs reduce
emissions and are considered a favourable alternative.
 EREVs, compared with EV, not only have the advantage of “zero fuel
consumption and zero emissions” they also effectively solve the problem of
having an inadequate driving range due to power storage limitations in
batteries

22
Extended Range Electric
Vehicle Technology
 A range extender (RE) is a small electricity generator (APU) which
operates when needed as a solution to increase autonomy in EVs.
 The main components of the RE are the generator and internal or
external combustion engine; the internal or external combustion
engine is coupled to the generator in a series configuration.
 The primary function of the RE for an EV is to extend the vehicle’s
mileage. Operation of the range extender is initiated if the SOC
(state of charge) of the EVs battery drops below a specified level.
 In this situation, the engine provides electricity by recharging the
battery or directly driving the EV during travel and continues the
vehicle’s operation.
 The difference in a plug-in hybrid electric vehicle (PHEV) is that
the electric motor always propels the wheels.
 The engine acts as a generator to recharge the vehicle’s battery
when it depletes or as it propels the vehicle.

23
 A series configuration is used as the main system, which is considered an
APU.
 The system is connected to several subsystems, such as the generator,
battery, electronic management system, and electric motor.
 The electric motor converts electrical energy from the battery to
mechanical power.
 It propels the wheels while the APU generates electric energy to recharge
the battery. Finally, the electronic management system controls all the
systems for optimal functioning.
 The EREV has two operation modes: pure electric vehicle and extended-
range mode. If the distance is short, the vehicle operates in pure electric
vehicle mode without the RE.
 If the distance is long, the vehicle operates in extended-range electric
vehicle mode.
 The RE is off as long as there is sufficient energy in the battery for purely
electric driving, and activated whenever the SOC drops below a certain
level. The RE works until the desired SOC is achieved. The battery power
manager gives this function.

24
Technological Classification of EREV
The electric propulsion system is the heart of an EREV. It consists
of the motor drive, a transmission (optional) device, and wheels.
There are three kinds of electric motors: direct or alternating
current and in-wheel motors (also called wheel motors).
The primary requirements of the EREV motor are summarized as
follows:
 High instant power and high power density.
 High torque at low speeds for starting and climbing, and high power
at high speeds for cruising.
 An extensive speed range including constant-torque and constant-
power regions. In this case, the APU, when it is on, needs to operate
in the same regions.
 Fast torque response.
 High efficiency over a large speed and torque ranges.
 High reliability and robustness for various vehicle operating
conditions.
 Reasonable cost.

26
HOW DOES AN EXTENDED-RANGE HYBRID WORK?
 When the battery is discharged to a specific level, the
combustion unit starts up, thereby turning on the generator.
 Its task is to provide energy to the electric motor, as well as
charge the battery.
 It becomes possible to increase range, which can be quite a
problem in other electric or hybrid vehicles.
 The biggest advantage of EREVs is that, despite the presence
of an internal combustion engine, they are almost as
environmentally friendly and energy-efficient as BEVs.
 The internal combustion unit is used only to keep the battery
charged and not to directly propel the vehicle.
E-REVs’ electric-only range varies but typically it will be more than 40 miles — the BMW i3 Range
Extender can manage around 50-80 miles before needing petrol assistance, for a total range
between stops of 160 to 186 miles.

28
Blended PHEVs
 Blended PHEVs have become more popular because of the
reduced system cost (smaller electric motor, smaller battery
pack, and lower battery power ratings), as well as the
flexibility of optimizing fuel economy for different driving
conditions.
 Compared to an EREV, a blended PHEV usually uses a
parallel or complex configuration in which the engine and
the motor can both drive the wheels directly.
 Since the engine is available for propulsion at high power
demand, the size of the electric motor and the power
requirement for the battery pack can be much smaller than
the one in an EREV.
 Therefore, the cost of the vehicle is reduced. Planetary gear-
based hybrid vehicles, such as the Toyota Prius, and the GM
two-mode hybrid, can be considered as parallel
configurations since the electric motor is in parallel with the

31
Why PHEV?
 A survey showed that 78% of the US population drives an average
of 40 miles (64 km) or less in their daily commuting. Figure shows
the distribution of daily miles driven versus percentage of
population.
 Based on this survey, a PHEV with an electric range of 40 miles (or
PHEV40) will satisfy the daily driving needs of 78% of the US
population while driving on electricity in their daily commuting.
 Furthermore, people owning a 40 mile electric range PHEV but
driving less than 40 miles daily will not need to refuel gasoline if
they charge their car at night on a daily basis. PHEVs can produce
significant environmental and economic benefits for society.
 The advantages of PHEVs can be evaluated by how much fuel is
displaced, as well as by how much pollution, including greenhouse
gas (GHG) emissions, can be reduced

10/7/23 32
Data from the U.S. Bureau of Transportation show that 78% of commuters travel 40
miles or less each day-the expected battery-only range of PHEVs with routine
overnight charging. For longer distances, the vehicles could run indefinitely in
hybrid (gasoline/electric) mode.

33
The main purpose for developing PHEVs can be summarized as follows:
1. Displacement of fossil fuel consumption in the transportation sector: Since
PHEV owners will not need to refuel gasoline or need less gasoline, a significant
amount of fossil fuel can be saved. This will have a long-term impact on the
economy, environment, and political arena.
2. Reduction of emissions: Due to the reduced use of gasoline, a significant
amount of emissions can be reduced due to the large deployment of PHEVs.
Centralized generation of electricity is much more efficient and has much less
emissions than gasoline-powered cars. Mitigation of emissions from urban (by
cars) to remote areas (in power plants) where electricity is generated can also
mitigate the heavy pollution in population-dense metropolitan areas. As more and
more electricity in the future will come from renewable energy sources (which will
be used by PHEVs), the emissions can be further reduced.
3. Energy cost savings: PHEVs use electricity for the initial driving range. Since
electricity is cheaper than gasoline on an equivalent energy content basis, the cost
per mile driven on electricity is cheaper than on gasoline.
4. Maintenance cost savings: PHEVs can generally save maintenance costs.
Due to the extensive use of regenerative braking, braking system maintenance and
repair is less frequent, such as brake pad replacement, brake fluid change, and so
on. Since the engine is not operating, or operating for much less time, there will be
longer intervals for oil changes and other engine maintenance services.

34
5. Backup power: A PHEV can be used as a backup power source when a
bidirectional charger is provided. A typical PHEV battery pack can provide a
home or office with 3–10kW of power for a few hours, and the onboard engine
generator/motor can further extend the backup duration by using gasoline to
generate electricity.
6. End-of-life use of the battery: Batteries that can no longer provide the
desired performance in a PHEV can potentially be used for grid energy storage,
which provides voltage regulation, system stability, and frequency regulation for a
power grid. In particular, frequency regulation and stability become more and
more important as more and more renewable energy generation is put on the
power grid. These “retired” batteries, which may still have 30–50% of their
original energy capacity, can provide this type of service.

35
Equivalent Electric Range of Blended PHEVs
 For an EREV, the electric range can be easily calculated.
 For a blended PHEV, there may be no pure electric driving
range available for some driving cycles.
 To find the equivalent electric range, it is useful to compare the
fuel economy of a blended mode PHEV during charge-
depletion (CD) mode to that of a comparable HEV.

41
 The extended-range electric vehicle (E-REV) is effectively an all-electric
vehicle, with all the motive power provided by an electric motor, but
with a small ICE present to generate additional electric power.
Alternatively, it may be viewed as a series hybrid with a much larger
battery, namely, 10–20 kWh.
 When the battery is discharged to a specified level, the ICE is switched
on to run a generator that, in turn, supplies power to the electric motor
and/or recharges the battery. With this arrangement, the range
limitation that is inherent in a BEV can be overcome.
 For moderate distances, E-REVs can operate in full-electric mode and
are then as clean and energy-efficient as BEVs (unlike parallel hybrids
and other series hybrids with their smaller batteries and very limited
electric range).

42
For longer distances, E-REVs utilize the ICE to keep the battery charged, but
consume noticeably less fuel than conventional ICEVs for the following two
reasons:
(i) The engine of an E-REV is significantly smaller than that of a conventional
ICEV – it only needs to meet average power demands because peak power is
delivered by the battery pack. The engine of an ICEV, on the other hand, must
also cover peak-power surges, e.g. accelerations.
(ii) The engine of an E-REV operates at a constant, highly efficient, rotation
speed; whereas that of an ICEV often runs at low or high rotation speeds
during which, in both situations, its efficiency is low.
The different modes of E-REV operation are shown schematically in Figure. The
vehicle begins its journey with the battery SoC close to 100%. All the vehicle
power is provided by the electric motor, which draws energy only from the
battery, and there are no local exhaust emissions. The battery is partly
recharged with each regenerative braking event. When the battery is depleted
to a pre-ordained SoC – marked in Figure 5 at three levels of increasing
severity, viz., green, orange and red – the vehicle switches to extended-range
mode

43
While the vehicle is operating in this mode the ICE is switched on as and
when necessary to keep the battery within the SoC range marked by the
green and red dashed lines. After the journey, the battery SoC is returned to
100% with power taken from the grid. A future possibility would be to
replace the piston engine with a micro gas-turbine as the range extender.
Jaguar has produced the C-X75 hybrid concept car, which is an E-REV with
two small gas turbines (each 35 kg) to charge the battery (15-kWh lithium-
ion). Four 145-kW electric motors, one at each of the wheels, can drive the
1350-kg vehicle up to 205 mph (330 km h−1) with a total torque of 1600 N
m. The C-X75 has an electric-only range of 70 miles (113 km), and a 60-L fuel
tank.

44
Fuel Economy of PHEVs
The fuel economy of conventional vehicles is evaluated by fuel consumption
(liters) per100 km, or miles per gallon. In the United States, the Environmental
Protection Agency sets the methods for fuel economy certification. There are
usually two numbers, one for city driving and one for highway driving. There is
an additional fuel economy number that evaluates the combined fuel economy
by combining the 55% city and 45% highway MPG numbers
For pure EVs, the fuel economy is best described by electricity consumption for
a
certain range, for example, watt hour/mile or kWh/100 km. For example, a typical
passenger car consumes 120–250 Wh/mile.

45
Therefore, a passenger car that consumes 240 Wh/mile will have an
equivalent gasoline mileage of 140MPG from the energy point of view.
In order to compare the fuel efficiency of EVs with conventional gasoline or
diesel vehicles, the energy content of gasoline is used to convert the
numbers. Since 1 gallon of gasoline contains 33.7 kWh energy, the
equivalent fuel economy of an EV can be expressed as
1. Well-to-Wheel Efficiency
2. PHEV Fuel Economy
3. Utility Factor

46
Well-to-Wheel Efficiency
The above fuel efficiencies are also called tank-to-wheel efficiencies. This does
not reflect the losses during the refining and distribution. It is sometimes easier
to compare the overall fuel efficiencies of conventional vehicles and EVs. For
gasoline, this efficiency is 83%, which reflects a lumped efficiency from the
refining and distribution of gasoline. For electricity generation, this efficiency is
30.3%, which reflects a lumped efficiency that includes electricity generation of
32.8% (assume electricity is generated from gasoline) and distribution of
electricity at 92.4%. Charge efficiency of the battery also needs to be reflected

47
Fuel economy labeling for all-electric-capable PHEV
Fuel economy labeling for blended PHEV
PHEV Fuel Economy

48
For PHEVs, it is usually confusing as to which number should be
used. Here, we discuss two different scenarios: all-electric
capable PHEVs and blended PHEVs.
For all-electric capable PHEVs, it is useful to indicate the electric
range, in miles or kilometers, and associated energy consumption
during that range, in kilowatt hours/mile,and potentially gas
equivalent MPG. Another set of numbers is needed to show the
MPG during CS mode driving. A suggested label is shown in
Figure 1.
For blended PHEVs, since there is no pure electric driving range,
it is useful to label the fuel economy in CD and CS mode
separately as shown in Figure 2 . It may be preferred to include
the electric energy consumption during CD mode as well.

49
Utility Factor
Another approach for fuel economy clarification is to use a utility
factor. A utility factor is defined as the ratio of CD range of a
PHEV to the total distances driven in daily commuting by all the
US population. For example, a CD range of 20 miles will result in
a utility factor of 40% (Figure). Using the utility factor, the
combined fuel economy can be expressed as
where UF is the utility factor, and FECD and FECS are the fuel
economy during CD and CS operation of a PHEV, respectively.

Fundamentals of Electric and Hybrid Vehicles

Fundamentals of Electric and Hybrid Vehicles

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