THE UNIVERSITY OF TRINIDAD & TOBAGO

B.A.S.c Utilities Engineering

Power Converters and Drives

Report # 1

Electric Vehicle

Student Name: Rajiv Gangaram

Student ID #: 50193

Electric Vehicle

1. History

The first electric vehicle was designed by Professor Stratingh from Holland and built by

Christopher Becker in 1835. In 1842 the first non-rechargeable electric cells vehicle were

built by Thomas Davenport and Scotsmen Robert Davidson. Over the years until 2011

the electric vehicle improved by increasing battery life. The era of electric vehicles had

gone ghost by 1935 until 1960 due to a need for vehicles with alternative fuel and lower

exhaust emissions. Between 1973 to 1983 the electric cars production were large, in 1998

the Toyota RAV4, Honda EV Plus sedan, and the Chrysler EPIC minivan had advanced

nickel metal hydride battery packs. In 2011 electric cars have grown drastically, electric

cars are setting a positive environmental statement due to the concern of global warming.

2. Electricity sources

2.1. Connection to generator plants

There are direct connection to generating plants for electric trains, busses and trucks.

2.2. Onboard generators and hybrid EV’s

There are onboard generators for using renewable sources, diesel engine, fuel cell and

nuclear energy.

2.3. Onboard storage

Electric vehicles can receive its power from different sources and is transmitted to the the

vehicle through inductive charging or a direct connection through n electrical cable. This

power need to be stored and it can be stored by using batteries, fly wheel, super capacitor

or fuel cell these are the onboard storage of these vehicles.

3. Lithium-ion Battery

Lithium-ion battery smaller size and lighter weight, it delivers performance that helps to

protect the environment with features such as improved charge efficiency without

memory effect. Memory effect is by repeatedly recharging a battery while it still contains

a certain level of charge, causing the discharge voltage to lessen and the capacity of the

battery to diminish as a result. These batteries have a higher output, higher efficiency and

provide excellent durability.

4. Electric Motor

The electric motor converts electrical energy to mechanical energy, they can be either DC

motors or AC motors. The AC motors are Single-speed transmission, light weight, less

expensive, 95% more efficiency at full load and has a more expensive controller and

motor/controller/inverter more expensive. Whereas the DC motor has multi-speed

transmission, heavier at equivalent power, more expensive, 85-95% Efficiency at full

load, simple controller and motor/controller less expensive. There are different types of

electric drive system such as; a single larger electric motor coupled to the rear wheels

through a different housing and two small motors to power each wheel separately through

independent drive shafts. The most efficient motors are the ones connected directly to the

wheel. The electric motor is equipped with both drive and control system power is

delivered to the motor from the batteries which then turns the the drive wheel through the

gear box.

5. Vehicle Types

5.1.1. Plug in Electric Vehicle

Plug-in electric vehicles run mostly on batteries that are recharged by plugging into

the power grid. They are also equipped with an internal combustion engine that can

recharge the battery and/or to replace the electric drive train when the battery is low

and more power is required.

5.1.2. Hybrid Electric Vehicle

Hybrid Electric Vehicles have two complementary drive systems: a gasoline engine

and fuel tank and an electric motor, battery and controls. The engine and the motor

can simultaneously turn the transmission, which powers the wheels. Hybrid Electric

Vehicles cannot be recharged from the power grid. Their energy comes entirely from

gasoline and regenerative braking.

5.1.3. On and Off-road Electric Vehicles.

On and off road EVs are helping to reduce emissions and fuel consumption in

locations that have limited travel and specific purpose. This specialized equipment

cannot only save end-use customers' money but improve their operating efficiencies

and maintenance programs as well.

5.1.4. Railborne Electric Vehicles

These rail lines has a permanent overhead power line which can constantly supply

power to the vehicle eliminating onboard batteries. The Railborne Electric Vehicles

has a very food power to weight ratio and allows the trains to reach a speed up to

320km/h they have a much higher power output than diesel. It also has higher short-

term surge power for fast acceleration, and using regenerative braking can put

braking power back into the electrical grid rather than wasting it.

5.1.5. Space Rover vehicles

The power sources used for these space vehicles can be batteries, solar panels and

nuclear power. It can be propelled by arcjet rocket, the electrostatic ion thruster, the

Hall effect thruster, and Field Emission Electric Propulsion all powered by electricity.

5.2. Air Borne EV’s

Experimenting electric power for aircrafts has been since aviation started currently flying

electric aircraft include manned and unmanned aerial vehicles.

5.3. Sea Borne EV’s

These vehicles are electric motors that can be powered by solar cells instead of diesel

engines, others use batteries which are constantly charged with diesel or gasoline engines.

Electric motor driven propellers uses nuclear power or fuel cells to power them.

5.4. Electrically powered space craft

These space craft power are batteries, solar panels and nuclear power.

6. Energy and motors

The use of regenerative braking is when the motors reverse spin to transform the motor to

a generator that was the electricity is fed back in to the lines and it isn’t wasted.

7. Properties of Electric Vehicle.

7.1. Components

The component that make up and electric vehicle are:

Battery

Motor

Motor controller

Accelerator pedal

Shifter

Braking

7.2. Energy Sources

Energy sources for Electric Vehicles are:

Solar energy

Electricity

Fossil fuels

Nuclear energy

Renewable Sources

Fuel cells

7.3. Issues With Batteries

They are expensive, heavy and take about 4 hours to charge.

7.4. Efficiency

Electric vehicles convert about 59%–62% of the electrical energy from the grid to power

at the wheels.

7.5. Electromagnetic radiation

Electric vehicles emit extremely low frequency electromagnetic radiation and occupants

may be at an increased risk of getting cancer or other health problems.

7.6. Charging

There are two types of charging:

Inductive Charging: An inductive charger has no direct electrical connection to the

vehicle. Power is transferred to the vehicle’s charge port via magnetic field. There is a

Bi-directional communication and built-in diagnostics to ensure a safe connection and

prevent the vehicle from being driven while connected.

Conductive Charging: Energy is transferred to the vehicle via metal to metal contact a

connector is connected between the power source and the vehicle charge port.

7.7. Other in development technologies

Technologies that are being developed are to achieve better density of lithium batteries to

get almost unlimited life span and no environmental problems by increasing the di-

electric constant of capacitors.

7.8. Safety

The Lithium-ion batteries in the EV’s have a high energy density and could over heat

causing a fire or explosion.

7.9. Advantages and Disadvantages of Electric Vehicles

7.9.1. Environmental

One advantage they do not produce pollution however the disadvantage burning

fossil fuels produces pollution but the pollution caused to produce these electricity

is only half of what is produced from internal combustion engine. There are

cleaner methods of producing electricity such as nuclear plants and hydro power.

7.9.2. Mechanical

It has a higher torque from rest, has less noise and vibration with regenerative

braking it reduces wear on brake systems. Due to lack of sound it is more difficult

to tell if vehicles are approaching.

7.9.3. Energy Resilience

The fuel required for EV’s are electricity and since it can be produced from many

difference sources it is an advantage to EV’s

7.9.4. Energy Efficiency

It is very efficient up till 90% efficiency.

7.9.5. Cost of recharge

Has a major advantage over gasoline where gasoline is 12 cents per mile and

electricity is 2 cents per mile.

7.9.6. Stabilization of the grid

The disadvantage is if everyone switches to electric vehicle there won’t be enough

electricity to power them all. However those who have EV’s could power the grid

at peak hours when not in use if they don’t mind reducing their battery life.

7.9.7. Range

The range of these batteries is limited and therefore cannot travel long distances

this is a disadvantage. However batteries are being tested to increase energy

storage to it can give the same range as today’s fossil fuelled vehicle.

7.9.8. Heating of EV’s

To heat these vehicles in cold countries more energy is required from the batteries

and therefore could reduce the life of the battery.

8. Electric Public Transit efficiency

People prefer vehicle that are quitter and therefore make it more efficient to travel also

reducing the fossil fuel consumption.

9. Incentives and promotion

The environment is everyone’s concern and caring and protecting the environment is a must

so the use of EV”S will reduce this. Some incentive would be investing in charging stations,

getting a tax break.

10. Future

10.1. Improved Batteries

In future the review on improving batteries life span and reducing the charging time as

well as reducing the cost of these batteries.

10.2. Battery management and Intermediate Storage

Another improvement is to decouple the electric motor from the battery through

electronic control, employing ultra-capacitors to buffer large but short power demands and

regenerative braking energy.

References

https://www.fueleconomy.gov/feg/evtech.shtml

http://www.utc.edu/college-engineering-computer-science/research-centers/cete/electric.php

http://everything.explained.today/Electric_vehicle/

http://auto.howstuffworks.com/fuel-efficiency/vehicles/electric-car-battery3.htm