Introduction of electric vehicle (EV)

SYLLABUS: Electric vehicles and hybrid vehicles: Components of an EV, EV batteries,

chargers, drives, transmission and power devices. Advantages and disadvantages of
EVs. Hybrid electric vehicles, HEV drive train components, advantages of HV

Electric vehicles and hybrid vehicles: Introduction: Technological advancements have brought a
revolution in different fields. The automotive sector is no exception to it. The latest in this trend is
the introduction of Electric vehicle that doesn‘t require any fuel to run but use rechargeable batteries.
It is a very new concept in the automobile industry. This advanced model of vehicle has been
projected as a cost-effective solution of transportation that also contributes towards a safe and
healthy environment by avoiding harmful emissions.
In the current situation of rising fuel prices and environmental pollution, one of the best available
alternatives for the conventional fuel-driven car is the electric vehicle. Although a lot of people have
some apprehension about the mainstream uses of electric vehicles, awareness is growing about how
electric vehicles can provide more economically efficient transport and help to reduce greenhouse
gasses. Another important aspect of electric vehicles is that it helps in reducing the use of non-
renewable energy resources like petrol, diesel, and natural gas which are scarce and need to be
preserved.
Electric Vehicle Promotion in India: Electric Vehicles in India are still relatively new. They
account for just 1 % of the total vehicle density. India unveiled the ‗National Electric Mobility
Mission Plan (NEMMP) 2020‘ in 2013 to address the issues of national energy security, vehicular
pollution, and growth of domestic manufacturing capabilities.
• While you might see a lot of e-rickshaws zipping across the narrow lanes of Karol Bagh in Delhi, a
major shift has yet to arrive towards Electric Vehicles. Only a handful of electric cars are available in
the market, and the small-vehicle market is still dominated by conventional vehicles.
• ―We are going to introduce electric vehicles in a very big way. We are going to make electric
vehicles self-sufficient like UJALA. The idea is that by 2030, not a single petrol or diesel car should
be sold in the country,‖ Power Minister Piyush Goyal said while addressing the CII Annual Session,
2017.
Reasons for EV development
As modern culture and technology continue to develop, the growing presence of global warming and
irreversible climate change draws increasing amounts of concern from the world's population. It has
only been recently, when modern society has actually taken notice of these changes and decided that
something needs to change if the global warming process is to be stopped.
Countries around the world are working to drastically reduce CO2 emissions as well as other harmful
environmental pollutants. Amongst the most notable producers of these pollutants are automobiles,
which are almost exclusively powered by internal combustion engines and spew out unhealthy
emissions.
According to various reports, cars and trucks are responsible for almost 25% of CO2 emission and
other major transportation methods account for another 12%. With immense quantities of cars on the
road today, pure combustion engines are quickly becoming a target of global warming blame. One
potential alternative to the world's dependence on standard combustion engine vehicles are hybrid
cars. Cost-effectiveness is also an important factor contributing to the development of an
environment friendly transportation sector.
What is an Electric Vehicle: An electric vehicle is a vehicle that is either partially or fully powered
by electricity. Electric vehicles have fewer moving parts and are easy to maintain. They are also very
environmentally friendly as they use no fossil fuels like petrol or diesel or even gasoline.
Electric vehicles have an electric motor instead of a combustion engine and use a rechargeable
battery pack to power the electric motor. The rechargeable batteries installed inside the car need to
be recharged from time to time. These batteries are not only used to power the car but also provide
power for the functioning of lights and wipers. The greatest advantage of this type of vehicle is that it
doesn‘t emit any exhaust that pollutes the air. It does not contain any typical liquid fuel components
like conventional fuel-driven vehicles so maintenance is easier and cost-effective. Some
manufacturers have come up with hybrid models of cars that can use both electric power and gas.
This concept is relatively new so people have less knowledge and awareness about it. As more and
more people start using electric vehicles they will experience the benefits and demand for electric
cars is expected to increase in the coming days.
COMPARISON OF ENGINE VEHICLES VS. ELECTRIC VEHICLES
IC Engine (ICE) Vehicles Electric Vehicles (EV)
• Powertrain: IC engine • Powertrain: Motor (+ Engine)
• High specific energy of fuel • Low specific energy of battery
• Power density: High • Power density: Low
• Emits greenhouse gases • No tailpipe emissions
• Travels > 300 miles / fill • Travels < 100 miles / charge
• Short refilling time (< 5 min.) • Long charging time (0.5-8 hr.)
• Fuel tank takes less space • Battery takes large space
• Fuel weight is very less • Batteries are very heavy
• Higher maintenance costs • Lesser maintenance costs
• Braking energy not recovered • Can recover braking energy
• Running cost: high • Running cost: low
• Engine efficiency: ~ 30% • Motor efficiency: ~ 80%
• Needs complex gear system • Needs only one gear
• Noisy operation • Quiet operation
• Ample refilling infrastructure • Lacks charging infrastructure
• Need to pick up some speed • Produce maximum torque
to deliver maximum torque instantly after starting of motor
• Uses only hydrocarbons • Uses electricity from many
resources
Why EV?
1. Pollution: • Transportation accounts for one third of all energy usage. • Use of 10% of ZEV cuts 1
million tons/year of air pollutants • With 100% EV - CO2 emission would be cut by half
2. Capital Cost and Maintenance Cost: • EV has a more capital cost • But life cycle cost of EV is
lesser than ICEV Electric Vehicles
3. Availability of Fuel Fast depletion of fossil fuel and dependence on Middle East countries for fuel.
4. Well to Wheel Efficiency The EV is found to have a better WTW (well to wheel) efficiency than
ICEV
Advantages of Electric Vehicle
 Environment-friendly: Electric vehicles do not use fuels for combustion and hence there is no
emission or exhaust of gasses. Vehicles using fossil fuels are large contributors to harmful gas
buildup in the environment so the use of an electric car can help contribute to a cleaner
atmosphere.
 Renewable energy source: Electric vehicles run on electricity that is renewable whereas
conventional cars work on the burning of fossil fuels that exhaust the fossil-fuel reserves on
earth.
 Cost-effective: Electricity is much cheaper than fuels like petrol and diesel which suffer a
frequent price hike. The recharging of batteries is cost-effective if solar power is used at home.
 Low maintenance: Electric vehicles have fewer moving parts so wear and tear is less as
compared to conventional auto parts. Repair work is also simple and less expensive relative to
combustion engines.
 Less noise and smoother motion: Electric vehicles give a much smoother driving experience.
The absence of rapidly moving parts makes them much quiet with low sound generation.
 Government support: Governments in various countries have offered tax credits as an
incentive to encourage people to use electric vehicles as a go-green initiative.
Disadvantages of Electric Vehicle
 High initial cost: Electric vehicles are still very expensive and many consumers consider them
not as affordable as conventional vehicles.
 Charging station limitations: People who need to drive long distances are worried about
getting suitable charging stations midway which is not available everywhere.
 Recharging takes time: Unlike conventional cars that require a few minutes for refilling fuel,
recharging of the electric vehicle takes much more time which is generally a few hours.
 Limited choices: Presently there aren‘t too many electric models of cars available to choose
from when it comes to the looks, designs, or customized versions.
 Less driving range: The driving range of the electric vehicles is found to be less as compared
to conventional vehicles. Electric vehicles can be suitable for day-to-day travel but can be
problematic for a long-distance journey.
Comparison Table for Advantages and Disadvantages of Electric Vehicle
Advantages Disadvantages
Electric vehicles involve a high initial cost for buying
Electric vehicles are powered by batteries so they
and many consumers aren‘t able to afford it in their
are emissions-free which helps to maintain the
budgets so they are not ready to switch from traditional
pollution level at control in the environment.
vehicles to Electric vehicles.
Electric vehicles run on renewable energy, so There aren‘t too many models of electric cars available
they help to preserve non-renewable energy to the public, so there is very limited choice for
resources that are getting exhausted rapidly due customers in terms of designs, looks, or customized
to extensive use. versions
Electric vehicles have fewer moving parts so People who drive long distances are worried about
they don‘t wear out as fast as conventional auto being stranded somewhere while driving Electric
parts. Repair work on EVs is also less expensive vehicles because there are fewer charging stations
than traditional vehicles. available.
Driving an electric vehicle is much smoother due
Recharging of an electric vehicle takes a considerable
to the absence of rapidly moving pistons and it
time which is around four to six hours.
generates less sound.
Governments around the world have offered tax The electric vehicle has less mileage as compared to
credits as an incentive to encourage people to fuel-driven cars and is considered suitable only for short
buy electric cars. distances.
FAQ’s on Advantages and Disadvantages of Electric Vehicles
Why are the running costs of electric vehicles less as compared to fuel-driven vehicles?
Electric vehicles use rechargeable batteries that can be charged easily with much less cost while
other cars use fuels like petrol and diesel that are costlier and subject to price hikes frequently.
Moreover, the maintenance cost of electric vehicles is also less as they don‘t suffer much wear and
tear.
What are the concerns of people for driving long distances with electric vehicles?
Electric vehicles have less driving range as compared to traditional cars with one-time charging.
Moreover, there are few charging stations available, and charging time is also very high so they are
worried about the breakdown in case the car requires charging midway.
Why do governments offer tax credits to consumers who buy electric vehicles replacing fuel-driven
vehicles?
Conventional vehicles use fossil fuels which not only increase pollution levels in the environment by
harmful emissions but also rapidly deplete non-renewable resources like petrol, diesel, and natural
gas. To reduce the use of fossil fuels and control pollution, the use of electric cars is being
encouraged.

Barriers to EV Adoption
Although electric vehicles offer a lot of promises, they are still not widely adopted, and the reasons
behind that are quite serious as well.

Social, technological, and economic problems faced by EVs.

Technological Problems: The main obstacles that have frustrated EVs‘ domination are the
drawbacks of the related technology. Batteries are the main area of concern as their contribution to
the weight of the car is significant. Range and charging period also depend on the battery. These
factors, along with a few others, are demonstrated below:
Limited Range: EVs are held back by the capacity of their batteries they have a certain amount of
energy stored there, and can travel a distance that the stored energy allows. The range also depends
on the speed of the vehicle, driving style, cargo the vehicle is carrying, the terrain it is being
driven on, and the energy consuming services running in the car, for example air conditioning.
This causes ‗range anxiety‘ among the users which indicates the concern about finding a charging
station before the battery drains out. Though even the current BEVs are capable of traversing
equivalent or more distance than a conventional vehicle can travel with a full tank conditioning range
anxiety remains a major obstacle for EVs to overcome. This does not affect the use of EVs for urban
areas though, as in most cases this range is enough for daily commutation inside city limits. Range
extenders, which produce electricity from fuel, are also available with models like BMW i3 as an
option. Vehicles with such facilities are currently being called as Extended Range Electric Vehicles
(EREV).
Long Charging Period: Another major downside of EVs is the long time they need to get charged.
Depending on the type of charger and battery pack, charging can take from a few minutes to hours;
this truly makes EVs incompetent against the ICE vehicles which only take a few minutes to get
refueled.
Some fast charging facilities are available at present, and more are being studied. There are also the
fuel cell vehicles that do not require charging like other EVs. Filling up the hydrogen tank is all that
has to be done in case of these vehicles, which is as convenient as filling up a fuel tank, but FCVs
need sufficient hydrogen refueling stations and a feasible way to produce the hydrogen in order to
thrive.
Safety Concerns: The concerns about safety are rising mainly about the FCVs nowadays. There are
speculations that, if hydrogen escapes the tanks it is kept into, can cause serious harm, as it is highly
flammable. It has no color either, making a leak hard to notice. There is also the chance of the tanks
to explode in case of a collision. To counter these problems, the automakers have taken measures to
ensure the integrity of the tanks; they are wrapped with carbon fibers in case of the Toyota Mirai. In
this car, the hydrogen handling parts are placed outside the cabin, allowing the gas to disperse easily
in case of any leak, there are also arrangements to seal the tank outlet in case of high-speed collision
Social Problems: Social Acceptance: The acceptance of a new and immature technology, along
with its consequences, takes some time in the society as it means change of certain habits.Using an
EV instead of a conventional vehicle means change of driving patters, refueling habits, preparedness
to use an alternative transport in case of low battery, and these are not easy to adopt.
Insufficient Charging Stations: Though public charging stations have increased a lot in number,
still they are not enough. Coupled with the lengthy charging time, this acts as a major deterrent
against EV penetration. Not all the public charging stations are compatible with every car as well;
therefore it also becomes a challenge to find a proper charging point when it is required to replete the
battery. There is also the risk of getting a fully occupied charging station with no room for another
car. But, the manufacturers are working on to mitigate this problem.. Hydrogen refueling stations are
not abundant yet as well. It is necessary as well to increase the adoption of FCVs.
Economic Problems: High Price: The price of the EVs is quite high compared to their ICE
counterparts. This is because of the high cost of batteries and fuel cells. To make people overlook
this factor, governments in different countries including India, UK and Germany, have provided
incentives and tax breaks which provide the buyers of EVs with subsidies. Mass production and
technological advancements will lead to a decrease in the prices of batteries as well as fuel cells..
ELECTRIC VEHICLE: An Electric Car is an automobile by itself and consists of many
components and a large cluster of wires connecting them all. But there are few basic bare minimum
materials for an Electric Car which is shown in the block diagram.
The Engine of a conventional IC Engine Car is replaced by an electrical Motor and the fuel tank is
replaced by the Battery Pack.

FULLY ELECTRIC VEHICLE

The main parts in an electric car are a rechargeable battery, controller and electric motor. First,
the battery is powered. Then the controller converts the current from DC-AC so that it can be used
by the motor. The motor converts electrical energy to mechanical energy.
HYBRID VEHICLE/CAR
The same technology exists in hybrid, alongside a small gasoline engine running a generator. This
powers the car at cruising speed, and batteries provide extra power when accelerating. Batteries can
recharge themselves when the car is decelerating or standing still. Hybrid technology means that
your petrol goes much further, saving you money and reducing environmental impact.
Consistent with the definition of hybrid above, the hybrid electric vehicle combines a gasoline
engine with an electric motor. An alternate arrangement is IC Engine and an electric motor

Components of a hybrid Vehicle that combines a pure gasoline with a pure EV

Electric vehicles share many of the same basic components found in traditional automobiles, but they
have unique components that separate them from conventional vehicles, such as the lithium-ion
battery and electric motor.
Components of an EV

BATTERY: It powers the electric motor. Its capacity is defined in Ah. The design of battery
includes complex calculations which determines various battery parameters
All the components only the Battery Pack and Motor alone contribute to about more than 50% of the
total cars weight and the price.
As you can see the Battery Pack, Battery Management System (BMS) Controller, Motor and
the Transmission unit forms the major components in an EV.
Tesla has 7000 batteries and the Chevrolet spark has 600 Batteries inside. The complete battery
anarchy consists of the Cell, Battery Module and Battery Pack
Batteries: Most conventional gasoline-powered vehicles use lead-acid batteries. Electric vehicles,
however, require large lithium-ion batteries or other batteries that use new technologies that
provide more power and weigh less than older batteries of a similar size. Batteries in electric
vehicles must also supply a much greater amount of electricity and recharge faster than those in
conventional vehicles. Thus, electric vehicle batteries are much larger than conventional vehicle
batteries; they usually weigh several hundred pounds, need to be replaced after several years, and can
cost more.
Scientists and engineers continue to develop new technologies to create smaller, lighter batteries that
last longer and provide more power.
POSITION OF BATTERIES
Battery Module: So to get the higher voltage from 3.7v lithium cells, battery packs are used which
are formed by combining more than one battery together.
When two batteries are connected in series their voltage ratings is added and when two batteries are
connected in parallel their Ah rating is added.
For example assume we have 3.7V 2000mAh Lithium batteries.
If you connect two of these in series the resulting system is called a module and this module will
have 7.4V 2000mAh.
If we connect two of these in parallel the resulting module will be 3.7V 4000mAh
BMS

 BMS (Battery Management System): is like the brain or caretaker of batteries, as we saw
earlier there are many batteries in an EV and each battery has to be monitored to ensure
safety. For Lead Acid batteries BMS is not mandatory although some people use it but for
Lithium cells due to its unstable nature BMS becomes essential.
 Almost all lithium cells come with their own protection circuit if they are used in consumer
electronics. This is because if they are not handled properly, like overcharging or over
discharging then the battery would get hot and might even burn.

 Every BMS measures only three vital parameters of the battery which are the Voltage,
current and Temperate of the cell.
 It constantly compares these values with safety limits and disconnects the load if they exceed
the threshold values.
Apart from safety purpose, BMS is also used for some computational purpose, like measuring the
SOC and SOH of a battery
 SOC stands for State of Charge and SOH stands for State of health.
 SOC tells you how far you can drive before recharge and SOH tells you when it‘s time to
replace your batteries.
It is the duty of the BMS to measure both these parameters
ELECTRIC VEHICLE MOTOR
Electric motors have been used for over a century; in fact, they were used in some of the earliest
cars. Electric motors are powered by an electric current that creates a magnetic charge and turns a
driveshaft. Electric motors waste less energy in the form of heat than do internal combustion
engines, so they are more efficient. Torque (a measure of the turning force on an object) and
revolutions per minute (RPM, or the speed that the motor turns) can be controlled by the electric
motor as it adjusts the electrical current fed through the motor, even making a transmission
unnecessary in some vehicles

While batteries are the fuel tanks of an EV, the motors are the Engines of them. There are many
types of Motors used in EV and the one used for Scooters and bikes is totally different form the one
that is used in cars. Let‘s have a quick look on the commonly used ones that are BLDC motors,
Brushed DC motors and AC Induction Motor
BLDC Motors have been the choice for EV‘s from its origin in 1900. Even today it is commonly
used in Electric cycles and scooters. BLDC stands for Brush Less DC motor, these motors have a
constant torque and fast response making it suitable for automotive applications. Apart from EV‘s
these motors are also used in wipers, power windows etc

BLDC OUT RUNNER MOTOR

The rotor of the magnet is the wheel itself, meaning there is no need of coupling arrangement since
the rim of the wheel forms the motor.
Advantage of this type of motor is that there is less mechanical loss and since there is no
transmission unit cost and weight is reduced

BLDC IN-RUNNER MOTOR

They are used in applications where a transmission unit is required. They are normally coupled along
with a differential for 3-wheeled or 4-wheeled EVs. These motors look like normal motors with a
shaft and the shaft rotates when the motor is powered. An In-runner type Motor of an E-rickshaw
coupled with differential is shown below

BRUSHED DC MOTORS
Also known as DC series motor was the preferable choice for all old Electric cars. These motors
provide a lot of torque which could easily give a sporty feel to the EV. The pull/pick-up of the EV
would be almost at par with an average conventional car that these motors were used by drag racers
during then. But now after 2008, these motors are not much in use any longer the reason is DC
motors cannot provide a constant torque under a varying load. Meaning cursing or climbing a
hill with the car will be difficult. Also DC motors cannot start without a load that is it cannot self
start due to its high initial current which might damage the motor itself. Today these motors are used
in Golf carts commonly a picture of the same is shown below

AC INDUCTION MOTOR
 The reason why these motors are selected is that they do not have permanent magnets within
them and thus low cost. It also has good life since there are no magnets, magnets would lose
their tendency in day course.

Tesla model S for instance uses a 3-phase AC Induction Motor.

DC series, Induction motors were used at the earlier stage. Now the scope has shifted towards special
electrical machines
CONTROLLER
The controller gets all the inputs form the user like the amount of throttle (acceleration), breaks
pressure, driving mode etc and controls the speed of the motor accordingly.
If motors are considered to the muscle of a car, controller is its brain.
A controller is often a generic term and it might include other circuits like a DC-DC converter, Speed
controller, Inverter etc.
The DC-DC converter is used to power all the peripherals of the car like the infotainment system,
Headlights and other low level electronic devices.
Power convertor: The electrical energy stored in battery is fixed DC which should be converted to
either variable DC or Variable AC which depends on the type of electric motor used for power the
wheels
EV CHARGER
 Another important component in an EV which requires advancement is the Chargers.
 It gets plugged into the AC mains and converts the AC to DC to charge the batteries. But
there are more to add to it.
 Charging is a process in which the batteries and charger should coexist you cannot push
current inside a battery if the battery is not ready to accept it.
 There are many types of chargers:
LEVEL 1 CHARGER
These are the most basic chargers and it is probably the one that you get along with your car. They
take a long time to charge the batteries since they operate in 120V AC, They convert this 120V AC
to DC and use it to charge the batteries. The current rating of the charger will also be low somewhere
near 8-10 A, this means you will be sending less current and thus taking a long time to charge your
batteries overnight.
LEVEL 2 CHARGER
These are a bit faster that Level 1 charger, it depends on the manufacturer to provide you with Level
1 or Level 2 charger. Level 2 chargers operate on higher voltages like 240V or above and also have
high current rating near 40A to 50A. This makes the car to get charged faster.
LEVEL 3 CHARGER
These are the game changers, this are also called as the super chargers or fast chargers. They can
charge your car to 60% of its total capacity within 30 minutes. The downside is that since it is
pushing a lot of current inside your battery like 100A for a Tesla, the batteries inside would feel like
taking a crash course all year. So eventually the life of the battery is reduced. Also most
superchargers do not charge the batteries till 100% since more time will be required to charge the
battery from 80% to 100%.
Clutch: The engine must be decoupled from the wheels to shift from low speed to high speed gears
or vice versa, this is done by the clutch.
Transmission: The gearbox is also called as transmission which allows transfer of power from
engine to wheels.
Drivetrain: The combination of Electric motor, Clutch, Gearbox is referred to as drivetrain

The drive train of an EV consists of three major subsystems: motor propulsion, energy source and
auxiliary. The propulsion system consists of the controller, power electronic converter, motor, torque
transmission and wheels. The energy source section includes the energy source, energy management
unit and the energy refilling unit. The auxiliary subsystem consists of power steering unit, climate
control unit, and auxiliary supply unit
 Basic arrangement of an EV drive train.

Internal combustion engines: Most hybrid vehicles contain an internal combustion engine as the
primary source of power, with a battery and electric motor acting as secondary power sources.
Because power is also available from the battery and electric motor, these engines are typically
smaller than those found in regular automobiles. Internal combustion engines in hybrid vehicles can
also be used to recharge the battery. Plug-in hybrids get most of their power from the electric system
and use the internal combustion engine to recharge the battery or to power the vehicle after the
battery runs out.

Types of Electric Vehicles: For more than 100 years, the predominant energy choice for cars
has been the internal combustion engine. Electric vehicles being designed today either augment
internal combustion or eliminate the need for it altogether.
Hybrid and electric vehicle system components may include a battery for energy storage, an
electric motor for propulsion, a generator, a mechanical transmission and a power control
system.
These components are brought together in different ways by different systems. There are four main
types of electric Vehicle
Battery Electric Vehicle (BEV)
Plug-in Hybrid Electric Vehicle (PHEV)
Hybrid Electric Vehicle (HEV)
Extended-Range Electric Vehicle (EREV)
Battery Electric Vehicle (BEV): A battery electric vehicle (BEV) is a vehicle that is powered
entirely on electric energy, typically a large electric motor and a large battery pack without the
support of a traditional internal combustion engine, and must be plugged into an external source of
electricity to recharge its battery. Like all electric vehicles, BEVs can also recharge their batteries
through a process known as regenerative braking.
Pros
 No emissions
 No gas or oil changes
 Ability to conveniently charge at home
 Fast and smooth acceleration
 Low cost of operation
Cons
 Shorter range than gasoline vehicles although most people drive well within the range of today‘s
BEV and could rent a hybrid for the rare long trips.
 Slightly more expensive than their gasoline equivalent although the gasoline savings pay off the
difference in typically 2-3 years

Plug-in Hybrid Electric Vehicle (PHEV): Plug-in hybrids (PHEVs) use an electric motor and
battery that can be plugged into the power grid to charge the battery, but also have the support of
an internal combustion engine that may be used to recharge the vehicle’s battery and/or to replace
the electric motor when the battery is low. Because Plug-in Hybrids use electricity from the power
grid, they often realize more savings in fuel costs than tradition hybrids electric vehicles (HEV). Pros
 Longer range than BEV
 Less gas consumption than gas only vehicle
 Fewer emissions
 Very simple mechanics, less to go wrong.
Cons
 Produces tailpipe emissions
 Needs gas and oil changes
 More expensive to operate than Battery Electric Vehicle (BEV) but less than traditional hybrid
vehicle (HEV)
Hybrid Electric Vehicle (HEV): A hybrid vehicle combines any two power (energy) sources.
Possible combinations include diesel/electric, gasoline/fly wheel, and fuel cell (FC)/battery.
Typically, one energy source is storage, and the other is conversion of a fuel to energy. The
combination of two power sources may support two separate propulsion systems. Thus to be a True
hybrid, the vehicle must have at least two modes of propulsion. For example, a truck that uses a
diesel to drive a generator, which in turn drives several electrical motors for all-wheel drive, is not a
hybrid. But if the truck has electrical energy storage to provide a second mode, which is electrical
assists, then it is a hybrid Vehicle. These two power sources may be paired in series, meaning that
the gas engine charges the batteries of an electric motor that powers the car, or in parallel, with both
mechanisms driving the car directly.
Hybrid Electric Vehicles (HEVs) have two complementary drive systems: a gasoline engine with a
fuel tank; and an electric motor with a battery. Both the engine and the electric motor can turn the
transmission at the same time, and the transmission then turns the wheels. HEVs cannot be recharged
from the electricity grid – all their energy comes from gasoline and from regenerative braking.
The hybrid electric vehicle uses a small electric battery to supplement a standard internal
combustion engine and increase fuel efficiency by about 25 percent from conventional light-duty
vehicles. The electric motor minimizes idling and boosts the car's ability to start and accelerate,
which is important in stop-and-go city driving. The electric motor accelerates the car to about 40
mph, depending on the vehicle, and then the internal combustion engine takes over.
The battery is recharged by the gasoline engine and regenerative braking. Regenerative braking
converts kinetic energy that otherwise would be lost as heat in the brake pads into electricity to
charge the battery. The Ford Fusion Hybrid and Toyota Prius are examples of this type of hybrid.
Pros
 Longer range than BEV
 Less gas consumption than gas only vehicle
 Fewer emissions than gas only vehicle
Cons
 Still produces emissions
 Complex mechanics – Gasoline + Electric
 Expensive to operate (8-10 times more expensive than BEV) but less than traditional gasoline
vehicle.
 No ability to conveniently charge at home.

Hybrid Vs. Electric Cars:

The main difference between a hybrid car and an electric car is that the hybrid combines an internal
combustion engine and electric motor(s) to send power to its wheels. However, the electric car draws
power from a single source of the electric motor(s) to propel the vehicle.
While hybrid cars offer better fuel efficiency or longer distances/ranges, electric vehicles are still yet
to reach that potential. That said, electric vehicles pollute lower emissions compared to hybrid cars
Difference between Hybrid and Electric EVs:
Specifications Hybrid EVs Electric EVs

Power/Fuel Electricity and Fossil Fuel (Petrol and Electricity Through Battery
Source Diesel) Pack (DC)

Internal Combustion Engine (ICE) and

Engine Electric Motor(s)
Electric Motor(s)

Fuel Efficiency Combination of ICE and Battery Range Depends on Battery Range

Lower Compared to ICE and

Emission Levels Higher Compared to Electric Cars
Hybrid Cars

Price Range Similar to Conventional ICE Cars High

Charging Not Needed Needed

Key Components of Hybrid Electric vehicle:

A hybrid electric vehicle is distinguee from a standard ICE driven by four different parts:
a) A device to store a large amount of electrical energy,
b) An electrical machine to convert electrical power into mechanical torque on the wheels,
c) A modified ICE adapted to hybrid electric use,
d) a transmission system between the two different propulsion techniques.

Main components of a hybrid electric vehicle

The devices used to store electrical energy could be batteries, hydrogen powered fuel cell or super
capacitors. Electric motors used on hybrid vehicles are DC motors, induction motors (IM),
permanent magnet synchronous motors (PMSM) or switching reluctance motors (SRM). The HEV
can use the electrical machine to behave as a generator and thereby produce electrical energy, which
can be stored and used later. The ICE may be the same type as those on conventional vehicles, but it
must be designed and optimized for hybrid vehicles. The transmission system between the ICE and
the electrical machine is typically of series or parallel architecture. For power electronics are used
and the command can be done with microprocessor, microcontroller using various techniques
On hybrid-electric vehicles, in addition to the main battery, special batteries or capacitors, as a
secondary energy source are used. These secondary energy sources are designed to provide power
for short periods of peak operating conditions - for example, during the ascent of a slope or during
acceleration. This is necessary because some batteries with the highest energy density have low
power density.
A combination of hybrid electric vehicle that is under development and of great interest,
thanks to improvements in fuel cell, is the electric vehicle powered with fuel cell and an
auxiliary battery.
Hybrid electric drive trains
The architecture of a hybrid vehicle is defined as the connection between the components of the
energy flow routes and control ports. Hybrid electric vehicles were classified into two basic types:
series and parallel. But presently HEVs are classified into four kinds: series hybrid, parallel hybrid,
series-parallel hybrid and complex. The primary power source (steady power source) is made up of
fuel tank and ICE and battery-electric motor is taken as secondary source (dynamic power source).
Advantages and Disadvantages of HEVs:
HEVs provide a broad set of benefits to consumers including better fuel economy, quiet operation,
and low to zero emissions in sensitive locations such as schools and enclosed parking areas, better
fuel economy instrumentation, longer lasting and better braking designs.
Hybrid cars may be a stepping stone before the automobile industry moves into pure electric
vehicles. So, understanding the pros and cons of hybrid cars will help you understand the technology.
Advantages of Hybrid EVs:
Compared to standard gas vehicles, hybrid versions of the same car model offer many "green"
benefits. From lower emissions to better gas mileage, you can rest assured you'll be reducing your
carbon footprint by making the switch. When weighing the environmental pros and cons of hybrid
cars, here are a few of their advantages.
1. HYBRID CARS MAY BE MORE ENVIRONMENTALLY-FRIENDLY.
 Greater Fuel Efficiency: Because hybrid cars don't solely rely on their gas engine to run,
less fuel may be needed to propel a hybrid vehicle. The effect — improved fuel efficiency.
 Reduced CO2 Emissions: Standard vehicles emit tailpipe emissions that can wreak havoc
on the environment. Hybrids have better fuel efficiency and conserve more energy, thus
emitting fewer carbon emissions.
 Less Fossil Fuel Dependency: Since hybrid vehicles are able to utilize the high voltage
battery pack and electric motor(s) for propulsion, they don't rely on fossil fuels as much as
standard gas cars.
 Regenerative Braking: When you apply the brakes while driving most hybrid vehicles,
energy is produced and used to recharge your high voltage battery. This action can result in
less fuel consumption.
2. THEY MAY REQUIRE LESS MAINTENANCE.
Since hybrid vehicles use a combination of the high voltage battery pack, electric motor, and an ICE
to propel the vehicle, you may experience less wear and tear on your car's engine. By offsetting the
typical engine wear and tear that can occur with a standard vehicle, less repairs may be needed, and
you may have fewer routine maintenance costs overall.
Note: Maintenance costs can vary depending on your hybrid's specific make and model.
3. THEY MAY HAVE A HIGHER RESALE VALUE.
As gas prices rise and hybrid cars grow in popularity, more people are opting for fuel-efficient
vehicles. In effect, hybrids have begun to increase in resale value. Should you decide to trade or sell
your hybrid car, it's possible that you may receive a higher return on your initial investment when
compared to that of your vehicle's standard counterpart.
4. "RANGE ANXIETY" MAY NOT BE A PROBLEM.
Range anxiety, or the fear that you won't have enough charge to make it from point A to point B, is a
common concern amongst battery-only electric vehicle owners. Range anxiety is not a common
concern amongst hybrid or PHEV drivers. When the high voltage battery runs low on charge in a
hybrid vehicle, the car will rely more on the ICE. This automatic switch can be much more
comforting since gas stations are more readily available.

DISADVANTAGES OF HYBRID ELECTRIC CARS

1. HIGH VOLTAGE SYSTEM REPAIR COSTS MAY BE MORE EXPENSIVE.
Although hybrid vehicles may require less regular maintenance, they can get a little pricey when they
need repairs -- especially if the issue is your car's high voltage system. Replacing a dead or damaged
high voltage battery can cost thousands of dollars depending on the battery type and specific make
and model of your ride
In addition to the standard tech installed on ICE vehicles, hybrid vehicles are jam-packed with
complex components -- from large high voltage battery packs and inverters to electric motors and
improved cooling systems. Not only can these complex mechanisms make hybrid repairs more
expensive, but not all mechanics have the equipment and knowledge to fix them properly.
2. THEY MAY HAVE A HIGHER UPFRONT COST.
When switching to a hybrid vehicle, you might have to pay a higher amount upfront. Although the
sales price for this car type is narrowing, they often remain more expensive than standard ICE
alternatives. Fortunately, you may be able to offset this initial expense with tax exemptions and
federal incentives, lower running costs, and fuel savings.
3. THEY MAY HAVE LESS POWER WHEN COMPARED TO STANDARD ICE
VEHICLES.
Hybrid vehicles are manufactured for lower CO2 emissions and improved fuel economy but are
rarely designed for racecar-like speed and acceleration. Many of the performance enhancements on
conventional cars that impact maximum horsepower are often sacrificed.
For example, since hybrid vehicles have two propulsion methods, space and size are typically
adjusted. The effect -- hybrid vehicles often have slower top-end acceleration than their conventional
contemporaries.
Lower Performance: Since the main motive is to increase the fuel efficiency or range of the hybrid
car, the power or acceleration can lag behind a conventional internal combustion engine car.
Expensive to Buy: Although car companies are trying to bridge the gap in pricing between a
conventional vehicle and hybrid, hybrids continue to demand higher costs.
High Maintenance Cost: With several mechanical parts in the cars and with two sets of engines
powering the hybrids, the maintenance continues to be on the higher side. Also, not all mechanics are
trained to repair a hybrid car.
Classification of HEV
Automobile companies use different hybrid designs to either achieve maximum fuel efficiency or to
keep the hybrid car prices as low as possible. Below are the different types of hybrid cars: In this we
are going to focus on the different types (architectures) of HEV powertrain, highlighting the working
principle and the advantages/disadvantages compared with other types.
1. Based on Architecture • Series • Parallel • Series – Parallel
2. Degree of Hybridization • Mild • Power • Energy
3. Degree of Hybridization
• It is the progression from mild to energy hybrids is related to degree of downsizing the engine and
upsizing the electric motor.
• That is the traction power provided by the IC engine is reduced and that of the electric motor is
increased by varying the capacity of the prime movers respectively.
4. Another classification
• Charge Depleting: The HEV which doesn‘t have the onboard electricity generation unit is called
as charge depleting HEV.
• Charge Sustaining: The HEV which has onboard electricity generation facility is called as charge
sustaining HEV.
Series Hybrid Electric Vehicles: IC engine and Battery operate in series
The IC engine is fueled by diesel or petrol which acts as a prime mover to an on board electric
generator which generates electricity and charges the battery through a power converter.
The electric energy stored in the battery is used to drive the electric motor which provides the full
propulsion power.
In a Series Hybrid there is a single path to power the wheels of the vehicle, but two energy sources.
As shown in figure 3, the fuel tank feeds an engine which is coupled to a generator to charge the
battery which provides electrical energy to a motor/generator to power the wheels through a
transmission although a direct coupling can also be used. The motor/generator is also used to
recharge the battery during deceleration and braking.
An example of a Series Hybrid car is the BMW i3, Kia Optima, Ford Fusion, Chevrolet Volt, etc.
Although most Series Hybrids use an ICE, it is also possible to design a Series Hybrid using a Fuel
Cell powered by hydrogen, creating a Fuel Cell Electric Vehicle (FCEV).
Advantage: Simplicity of control algorithms used to control the power converters and hence
achieving speed control of electric motors
Disadvantage Power train components has to be rated for the full rating

Parallel Hybrid Electric:

Vehicles in a Parallel Hybrid, there are two parallel paths to power the wheels of the vehicle: an
engine path and an electrical path, as shown in figure 4. The transmission couples the
motor/generator and the engine, allowing either, or both, to power the wheels. Control of a Parallel
Hybrid is much more complex that for a Series Hybrid because of the need to efficiently couple the
motor/generator and engine in a way that maintains drivability and performance.
They can run together or can be used as the primary power source while the other kicks in when
extra power is required such as a hill climb, overtake a vehicle, etc. Both power sources are parallel
connected to the gearbox or the transmission and hence they are called ―parallel‖. An example of
Parallel Hybrid Cars is the Toyota Camry, Honda Accord, Toyota Prius, Hyundai Sonata, etc.
Based on the rating of the IC engine and battery, electric motor the propulsion power is shared
between the sources
The battery can be charged through wheels by increasing the power output of the IC engine by using
the control algorithm for regenerative braking
• Advantage Reduction in size of drive train components
• Disadvantage Power blending from two sources becomes difficult and it requires additional
mechanical equipment like planetary gear arrangement.

Series-Parallel Hybrid Electric Vehicles: A Series-Parallel HEV has both Series and Parallel
energy paths. As shown in figure 5, a system of motors and/or generators that sometimes includes a
gearing or power split device couples allows the engine to recharge the battery. Variations on this
configuration can be very complex or simple, depending on the number of motors/generators and
how they are used. These configurations can be classified as Complex hybrids (such as the Toyota
Prius and Ford Escape Hybrids), Split-Parallel hybrids, or Power-Split hybrids

This type of hybrid design operates in two different ways. While on the first mode, it works just like
a regular hybrid car. In the second mode, the design can adjust to different requirements by the
engine to meet specific vehicle tasks.
It combines both respective benefits
• A power splitter is used to feed a part of IC engine power to drive the on board electric generator
which is used to charge the battery through a power converter when the SoC of the battery is below
the threshold value.

Plug-in Hybrid Electric Vehicles

PHEVs (Plug In Hybrid Electric Vehicle) are charge depleting HEV • They operate in fully electric
mode up to certain distance and then as a regular hybrid vehicle for longer distances.
• It has a large rated storage system compared to HEVs
• It has to be plugged in for recharging the battery
They are designed for daily commute to work and for longer distances the it is supplemented by the
IC engine.
• This type of PHEV is also called as range extender.
• Hence this has high potential to replace ICEV for urban commuting.
A plug-in hybrid electric vehicle (PHEV) is an HEV that can be plugged-in or recharged from wall
electricity. PHEVs are distinguished by much larger battery packs when compared to other HEVs.
The size of the battery defines the vehicle‘s All Electric Range (AER), which is generally in the
range of 30 to 50 miles. PHEVs can be of any hybrid configuration. Although no PHEVs are
available on the market today, a number of companies have begun to sell conversion kits and
services to convert a standard HEV into a PHEV by adding additional battery capacity and
modifying the vehicle controller and energy management system
Plug-in Hybrid:
Since the Plug-in Hybrid car does depend on an internal combustion engine and can be run after it is
fully charged, there is substantial improvement in the vehicle‘s fuel efficiency. An example of a
plug-in hybrid car is the BMW 330e, Hyundai Ioniq Plug-in Hybrid, Volvo XC40 Recharge Plug-in
Hybrid, etc.
 Mild-Hybrid:
In recent times, the cost to build an efficient hybrid car continues to be high. Car companies are
devising new strategies in offering hybrid technology to the common man. Mild-hybrid designs have
been adopted by car companies to adhere to emission norms as well as to slightly improve fuel
efficiency without increasing the cost considerably. In this type of hybrid, the electric motor assists
the petrol engine in increasing fuel efficiency, improving performance or both. Additionally, it acts
as a starter for the automatic start/stop function, which switches off the engine when the vehicle
comes to rest and thereby reduces the use of fuel. An example of mild-hybrid cars include Maruti
Suzuki Ertiga, Ciaz, Baleno, etc.
National Mission for Electric Mobility (NMEM)
• Government of India approved the National Mission on Electric Mobility in 2011.
• As part of the mission, Department of Heavy Industries has formulated a scheme namely
• FAME – India Faster Adoption and Manufacturing of Hybrid & Electric Vehicles in India.
Phase - 1 Proposed to be implemented in 2 year period of 2015 -2017 Focus on four Major Areas
• Technology Development
• Demand Creation
• Pilot Projects
• Charging Infrastructure
National Electric Mobility Mission Plan 2020 Launched in January 2013 by the Ministry of Heavy
Industries and Public Enterprises.
• Aims at ensuring vehicle population of 6-7 million electric/hybrid vehicles in India by the year
2020 .
• To promote eco-friendly vehicles, the government has been offering incentives on electric and
hybrid vehicles of up to Rs.29,000 for bikes and Rs.1.38 lakh for cars under the FAME India
scheme.
• In Budget 2017-18, Rs.175 crore has been earmarked for the FAME India scheme. Current Status
of NMEM On 23rd February 2017 a meeting was scheduled by Govt., of India to discuss several
factors including,
1. Higher cost of vehicles
2. Power outages
3. Lack of charging infrastructure
4. Dearth of facilities for eco-friendly disposal of batteries to curb pollution
BHEL: Pivoting from Power Sector to Transportation
• On 16th February 2017 BHEL signed an agreement with Ashok Leyland Ltd and Tata Motors Ltd
for developing a propulsion system for buses.
• It is also seeking technical collaboration to manufacture metro rail locomotives and has initiated
separate talks with Hitachi Transportation Systems, Mitsubishi Heavy Industries and Škoda
Transportation.
Global leaders in terms of total units sold
1. Renault – Nissan
2. Mitsubishi
3. General Motors
4. Toyota
5. Tesla
6. Ford
7. BYD
8. BMW
9. The Geely Group
10. Volkswagen

References
1. Electric and Hybrid Vehicles Design Fundamentals 2nd edition by Iqbal Husain.
2. Modern Electric, Hybrid Electric, and Fuel Cell Vehicles by Mehrdad Ehsani et al.
3. Energy World from Economic Times. 3. Ministry of Heavy Industries and Public Enterprises,
Govt., of India.
4.http://kseboa.org/news/bhel-looks-to-pivot-frompower-sector-to transportation-electric-
vehicles17024527.html
5. Krishnakumar R V, M.E Power Engineering And Management, Anna University, Chennai, CEG