THE IMPORTANCE OF ELECTRIC VEHICLES
• Gas is a scarce, natural resource.
• Electricity is cheaper than gas. Electricity can come from renewable resources such as solar and
• Electric cars pollute less than gas-powered cars.
• Electric cars are much more reliable and require less maintenance than gas-powered cars. You
don't even need to get your oil changed every 3,000 miles!
• By using domestically-generated electricity rather than relying on foreign oil, the USA can
become more independent.
• Cheapness in amount of fuel consumed.
• produce 27 per cent less CO2 than petrol cars
• help to reduce greenhouse gas emissions
TYPES OF ELECTRIC VEHICLES
• PLUG-IN-ELECTRIC VEHICLE (PEV)
A PEV is any motor vehicle that can be recharged from any
external source of electricity, such as wall sockets, and the
electricity stored in the rechargeable battery packs drives.
•HYBRID ELECTRIC VEHICLE (HEV)
A hybrid EV combines a conventional (usually fossil fuel-powered)
powertrain with some form of electric propulsion. Common
examples include hybrid electric cars such as the Toyota Prius. The
Chevrolet Volt is an example of a production Extended Range Plug-
In Electric Vehicle.
• PLUG-IN-HYBRID VEHICLE (PHEV)
A PHEV is a kind of vehicle in which the charge to the batteries is
provided through both A Plug In Source and Electric Propulsion.
TYPES BY DRIVE TRAIN STRUCTURE
• PARALLEL HYBRID SYSTEM (PHV)
PHV, which are most commonly produced at present, have both
an internal combustion engine (ICE) and an electric motor
coupled. If they are joined at an axis in parallel, the speeds at
this axis must be identical and the supplied torques add
together. The Honda Insight uses this system
•SERIES HYBRID SYSTEM (SHV)
In a series-hybrid system, the combustion engine drives an electric generator instead of directly
driving the wheels. The generator provides power for the driving electric motors. In short, a
series-hybrid is simple, the vehicle is driven by electric motors with a generator set providing the
INSIDE AN ELECTRIC CAR
• The heart of an electric car is the combination of:
•The electric motor
•The motor's controller
• The controller takes power from the batteries and delivers it
to the motor.
• The accelerator pedal hooks to a pair of potentiometers
(variable resistors), and these potentiometers provide the
signal that tells the controller how much power it is supposed to
• In this car, the controller takes in 300 volts DC from the
battery pack. It converts it into a maximum of 240 volts AC,
three-phase, to send to the motor. It does this using very
large transistors that rapidly turn the batteries' voltage on
and off to create a sine wave.
DC CONTROLLER AND POTENTIOMETER
•When you push on the gas pedal, a cable from the pedal connects to these two potentiometers.
•The controller reads both potentiometers and makes sure that their signals are equal. If they are not,
then the controller does not operate. This arrangement guards against a situation where a potentiometer
fails in the full-on position.
• Let's assume that the battery pack contains 12 12-volt batteries, wired in series to create 144 volts. The
controller takes in 144 volts DC, and delivers it to the motor in a controlled way.
•The very simplest DC controller would be a big on/off switch wired to the accelerator pedal. When you
push the pedal, it would turn the switch on, and when you take your foot off the pedal, it would turn it off.
•Most controllers pulse the power more than 15,000 times per second, in order to keep the pulsation
outside the range of human hearing.
• Regenerative braking is used in vehicles that make use of electric motors. One of the more interesting
properties of an electric motor is that, when it's run in one direction, it converts electrical energy into
mechanical energy that can be used to perform work (such as turning the wheels of a car), but when the
motor is run in the opposite direction, a properly designed motor becomes an electric generator, converting
mechanical energy into electrical energy.
• This electrical energy can then be fed into a charging system for the car's batteries.
•Once the motor has been reversed, the electricity generated by the motor is fed back into the batteries,
where it can be used to accelerate the car again after it stops.
•In some cases, the energy produced by these types of brakes is stored in a series of capacitors for later
THE MAGNA-CHARGE SYSTEM
The Magna-Charge system consists of two parts:
•A charging station mounted to the wall of the house
•A charging system in the trunk of the car
The charging station is hard-wired to a 240-volt 40-amp circuit
through the house's circuit panel.
The charging system sends electricity to the car using this inductive
The paddle acts as one half of a transformer. The other half is inside
the car, positioned around the slot behind the license plate. When you
insert the paddle, it forms a complete transformer with the slot, and
power transfers to the car.
1. One advantage of the inductive system is that there are no exposed
electrical contacts. You can touch the paddle or drop the paddle into a
puddle of water and there is no hazard.
2. The other advantage is the ability to pump a significant amount of
current into the car very quickly because the charging station is hard-
wired to a dedicated 240-volt circuit.
•An EV has a string of batteries (somewhere between 10 and 25 modules, each containing three to
six cells). The batteries are closely matched, but they are not identical. Therefore they have slight
differences in capacity and internal resistance.
•All batteries in a string necessarily put out the same current (laws of electricity), but the weaker
batteries have to "work harder" to produce the current, so they're at a slightly lower state of
charge at the end of the drive. Therefore, the weaker batteries need more recharge to get back to
•Since the batteries are in series, they also get exactly the same amount of recharge, leaving the
weak battery even weaker (relatively) than it was before. Over time, this results in one battery
going bad long before the rest of the pack.
•The common solution to the problem is "equalization charge." You gently overcharge the batteries
to make sure that the weakest cells are brought up to full charge. The trick is to keep the
batteries equalized without damaging the strongest batteries with overcharging.
•There are more complex solutions that scan the batteries, measure individual voltages, and send
extra charging current through the weakest module.
Benefits of electric vehicles?
• cheaper to run because electricity is cheaper than petrol
• better for the environment
• reduce noise pollution
• less environmental impacts across their life-cycle (manufacturing, use
• Less dependency on foreign oil.
What are some disadvantages of EVs?
• currently more expensive than normal cars
• not many places to charge your car
• can only travel 100-160km between charges
• Charging can take hours
• Silent operation – potentially dangerous for pedestrians
• COST : The most significant technological challenges currently facing electric-drive vehicles are the cost
and performance of their components, particularly the battery.
•RANGE LIMITATIONS: REAL AND PERCEIVED : The sizable EV price premium perhaps would be
acceptable to a large number of consumers if the vehicles offered more range or differentiated
functionality than is currently on the market. With a usable range of about 100 kilometres (km), the 24
kWh battery-powered Nissan LEAF achieves about a fifth of the range of a comparable ICE vehicle.
•SAFETY AND RELIABILITY : Perceptions regarding the safety and reliability of EVs also remain an
issue throughout the market. Fire-related incidents in China and the United States in 2011, for instance,
attracted high-profile media attention.
•PROGRESS THROUGH RESEARCH AND DEVELOPMENT
Recently, the cost of batteries has been steadily decreasing as a result of both public and private sector
advances and will likely drop even further in the next five years due to pack design optimisation and cell
count reduction, lower cost of cell materials, economies of scale, and improved manufacturing processes.