Transcript Fiber Optic Sensors

Mechanical and Electrical Systems
SKAA 2032
Muhammad Ramlee Kamarudin
Wireless Communication Centre (WCC)
Universiti Teknologi Malaysia
Brief Biodata
Name
Position
Affiliation
Email Address
Office Address
: Muhammad Ramlee Kamarudin
: Associate Professor
: Wireless Communication Centre (WCC)
: [email protected]
: Wireless Communication Centre (WCC),
Universiti Teknologi Malaysia,
81310 Skudai, Johor, Malaysia.
Room Number
: P15a-level 2
Phone Number
: 07- 5535350 / 019-7007001
Personal webpage : muhdramlee.wordpress.com
Qualification
• PhD: University of Birmingham, UK (Sept 2007)
• MSc: University of Birmingham, UK (Sept 2004)
• B.Eng: Universiti Teknologi Malaysia (March 2003)
Research Area
: Antenna Design
Course Outline
1. Power Supply (AC and DC)  4 hrs
1.1 Current, Voltage, Power and their relationships
1.2 Single and Three Phase System (star and delta)
1.3 Source of Supply, Transmission and Distribution
2. Electrical Machinery (Transformer and Three Phase
Induction Motor)  6 hrs
2.1 Transformer: Principle of operation and application,
Rating, Losses and Efficiency
2.2 Induction Motor: Principle of operation and
application, Synchronous speed, Rotor speed and sleep,
Rating and starting circuits.
Course Outline
3. Electrical Distribution and Wiring  4 hrs
3.1 Wiring system, Types and size of cables
3.2 Protections and Grounding
3.3 Electrical Load (Estimation)
3.4 Substation, Switchboard and Distribution Board
3.5 Symbols and Single line diagram
References
1. B. L. Theraja, Electrical Technology
2. Hughes, Electrical Technology, 9th Edition
3. D. E. Johnson, J.R. Johnson, J.I. Hilburn, Electrical Circuit Analysis, Prentice Hall
4. Thomas L. Floyd, Electric Circuits Fundamentals, 5th Edition, Prentice Hall
5. P.C. Sen, Principles of Electrical Machines and Power electronics, 2nd Edition
John Wiley & Sons 1997
6. Stephen J. Chapman, Electrical Machinery Fundamentals, 4th Edition
McGrawHill 2005
7. Theodore Wildi, Electrical Machines, Drives and Power System, 4th Edition,
Prentice Hall
Lecture notes and tutorials will be informed
through email
Course Objectives
• To give basic information about electrical
principle, electrical machinery, distribution
system, wiring and protection
Course Assessment
• Electrical System
(50%)
– Assignment : 10%
– Midterm Test : 15%
– Final Exam
: 25%
• Mechanical System (50%)
• Total: 100%
• Students need to attend 80% of the classes to
be in final exam
• Class replacement :
Class we missed: 29 Oct (I haven’t been told), 5
Nov (Japan) and 3 Dis (Korea)
Class: 19 Nov, 26 Nov, 10 Dis (Not sure,
Melaka), 17 Dis
Replace: 3 Classes….When??
Familiarization With Electricity
Electrical shock!
Electrical Engineering
• Professional engineering discipline that deals
with the study and application of electricity,
electronics and electromagnetism
• Among subdivisions of electrical engineering
are: power, optoelectronics, digital
electronics, analog electronics, artificial
intelligence, control systems, electronics,
signal processing and telecommunications.
Electrical Engineering
Power
• This field deals with energy production, energy conversion to
and from electrical form, energy transmission over long
distances, and energy distribution to houses and industrial
complexes.
Control Systems
• This field concern with information gathering from sensors
and the use of electrical energy to control physical process.
Electronics
• Electronics is the study and application of materials, devices,
and circuits used in amplifying and switching electrical signals.
Electrical Engineering
Telecommunications
• Transport information in electrical form. Cellular telephones,
radio, satellite television and the internet are examples of
communication systems.
Signal Processing
• Is concerned with information-bearing electrical signal. Often,
the objective is to extract useful information from electrical
signals derived from sensors. Application are machine vision
and robotics.
Basic of Electrical System
• Electricity is a form of energy. We use
electricity for various purposes such as:
– Lighting, heating, cooling and other domestic
electrical appliances used in home.
– Street lighting, flood lighting
of sporting arena, office
building lighting, powering
PCs
– Running motors, furnaces of
various kinds, in industries.
Basic of Electrical System
• Examples of energy source hydro, coal, gas,
wind, nuclear and solar
• Electricity can be generated from these
sources.
Basic of Electrical System
• Electrical systems
permit us to easily
transmit energy
from a source of
supply to a point of
application
Basic of Electrical System
1. The source - to provide energy for the
electrical system, e.g. Battery, generator, socket
outlet
2. The load - to absorb the electrical energy
supplied by the source, e.g. Lamps, air-cond.
3. The transmission system - conducts energy
from the source to the load, e.g. Insulated wire
4. The control apparatus - permits energy to
flow or interrupts the flow, e.g. switch
Basic of Electrical System
Example of Electrical System
Electrical Power Systems
Electrical engineer design systems objective:
To gather, store, process, transport, and
present information
To distribute, store, and convert energy
between various form
Manipulation of energy
interdependent
Manipulation of information
Mechanical and Electrical Systems
SKAA 2032
Power Supply (AC and DC)
Power Supply (AC and DC)
• Electricity is the movement of free electrons in
a material toward an area of positive (+)
charges.
• The conduction of those electrons is
determined by the type of material. Some
conduct well, while other materials prevent
the movement of electrons.
• Electricity can take the form of static
electricity, direct current (DC) electricity, or
alternating current (AC) electricity.
Power Supply (AC and DC)
• What are free electrons?
• What determines the conduction of electricity?
• What are the different types of electricity?
Free electrons
• All matter is made up of atoms
• The basic atom consists of a nucleus surrounded by
electrons going round the nucleus in orbit
Lithium atom
Proton charge= 1.602 x 10-19 Coulomb
Elec. charge= -1.602 x 10-19 Coulomb
• The nucleus consists of:
– Protons which are positively charged
– Neutrons that have no charge.
• The electrons have a negative (-) electrical charge
Free electrons
• Most electrons are bound in orbit around atoms.
• But in many substances, there are electrons that
are not connected to any atom and are roaming
freely throughout the material.
• These electrons may have been knocked free in
the creation of ions or may be the result of a
collision of a high energy particle, such as from
radioactive materials or cosmic rays.
Free electrons
• Atoms with an excess of electrons are called
negative ions and those that are missing
electrons in the shells or orbits are called positive
ions.
• An electric force field causes particles with
opposite charges to attract each other.
• A buildup of opposite charges creates an electric
potential.
• Release of the potential energy results in the
movement of free electrons, which is called
electricity.
Valence electrons
• Valence electrons are the electrons contained in the
outermost, or valence, electron shell of an atom.
• Important in determining how an element reacts
chemically with other elements.
• The fewer valence electrons an atom holds, the less
stable it becomes and the more likely it is to react.
Proton charge= 1.602 x 10-19 Coulomb
Elec. charge= -1.602 x 10-19 Coulomb
Conductors
• Conductors are materials that permit electrons to
flow freely from atom to atom and molecule to
molecule.
• An object made of a conducting material will permit
charge to be transferred across the entire surface of
the object
• This relative mobility of
electrons within a material is
known as electric conductivity.
Conductors
• Solid metals are good conductors of electricity,
because electrons are allowed to move freely
throughout the material.
• Copper and gold are some of the best
conductors of electricity.
• Although iron is a good conductor, iron oxide
(rust) is not.
• In the solid state, the atoms of metals are held
in place and only vibrate. This allows free
electrons to roam about the material.
Semiconductors and Nonconductors
Semiconductors
• Has electrical conductivity intermediate to that of a conductor
and an insulator
• This behavior is useful in in designing computer chips—the
electrons have limitations to their movement, such as only being
allow to move in one direction or in one plane.
Nonconductors/insulators
• Prevent the movement of electrons within the material. But they
often do allow electrons and ions to collect on their surfaces.
• Examples of nonconductors or electrical insulators are: Plastic,
Rubber, Glass, Most metal oxides (like rust), Air, Oil, Pure, deionized water
• Gases are not good conductors of electricity because of the
distances between atoms.
Energy bands
Types of electricity
• Common types of electricity are:
– static electricity,
– direct current (DC) electricity
– alternating current (AC) electricity.
Static electricity
• Static electricity refers to the built up electric charge
on the surface of objects or excess of electric charge
(imbalance) trapped on the surface of an object.
• Charge exchange can happen when any two surfaces
come into contact or rubbed.
• When the materials are
separated they retain this
charge imbalance.
• Since opposite charges attract,
there is a tendency for the
electrons to attract toward the
positive ions.
AC electricity
• Electrons will flow from an area of an excess negative (-)
charges to an area of positive (+) charges.
• Alternating current (AC) is when the electrons flow in both
directions — AC terminals constantly switch their polarity
from (+) to (-) and back again.
• An AC voltage is continually changing between positive (+)
and negative (-).
• Electrical power grids that provide electricity to homes and
other buildings use AC.
DC electricity
• In direct current (DC, also dc), the flow of electric
charge is only in one direction. It may increases or
decreases.
• Sources of DC voltage are include cells, batteries and
regulated power supply.
• A DC voltage is always positive (or always negative).
Unit Used in Electrical Quantities
•
•
•
•
•
•
•
•
Charge
Force
Work
Electric current
Electrical Potential
Power
Resistance
Conductance
Charge
• The unit of charge is the Coulomb (C).
• The coulomb is defined as the quantity of
electricity which flows past a given point in an
electric circuit when a current of one ampere
is maintained for one second.
• Charge, in coulombs: Q=It
– I is the current in ampere
– t is the time in seconds
Force
• The unit of force is the newton (N).
• One newton is one kilogram meter per second
squared ( kg·m·s-2)
• Force, in newton: F=ma
– m is the mass in kg
– a is the acceleration in ms-2
Work
• The unit of work or energy is the joule (J)
• Joule is defined as the work done or energy
transferred when a force of one newton is
exerted through a distance of one meter.
• The work done, in joules: W=Fs
– F is the force in newtons
– s is the distance in meter
Electric current
• Electric current is the rate of charge flow past a given point in
an electric circuit, measured in coulombs/second which is
named amperes.
• In most DC electric circuits, it can be assumed that the
resistance to current flow is a constant so that the current in
the circuit is related to voltage and resistance by Ohm's law.
Electrical potential and e.m.f.
• The unit of electric potential is the volt (V)
• The potential difference indicates the flow of
electric current (from high to low)
• The potential difference is also called voltage.
Analogy
Electrical potential and e.m.f.
The units of the potential difference is given by
Volts = watts/amperes
= joules/amperes·second
= joules/coulombs
• A device that maintains potential difference between
two points is said to develop and electromotive force
(e.m.f.).
Power
• The unit of power is watt (W)
• One watt is one joule per second
• Power, in watts : P=W/t
– W is the work done
– t is the time in second
• DC electrical power, in watts: P=VI
– V is the voltage across the load
– I is the current flows through the load
• Energy, in joules, W=Pt
Resistance
• The unit of electric resistance is the ohm (Ω)
• It is defined as the property of a substance due
to which it opposes the flow of electricity (or
electrons) through it.
• Resistivity, in ohms·meter (Ω·m) : ρ=AR/l
– A is the cross section of the conductor
– L is the length of the conductor
• Note that the resistance is dependent on the
nature of the material and also the temperature.
Resistance
• R = 0 Ω – short circuit (large current flow)
• R = ∞ Ω – open circuit (no current flow)
Open circuit
Short circuit
• The reciprocal of resistance is called
conductance and is measured in siemens (S).
• Conductance, in siemens: G=1/R
Ohm's Law for Electrical Circuits
• Ohm's Law states that in a simple electrical
circuit, the voltage equals the electrical current
times the resistance.
V = IR
where:
V is the voltage in volts
I is the current in amperes or amps
R is the resistance in ohms
IR is I times R
Example
• How many amperes of current are in the
circuit below?
100 V
R 20 Ω
Vs
Using Ohm’s law: I =
Vs
R
=
100 V
20 Ω
= 5A
Examples
1. An electric bulb uses 0.5 A of current with
voltage generated being 120 V. Determine the
value of resistance.
2. If a current of 0.5 A flows through resistor of
15 Ω, calculate the voltage drop across the
resistor.
1. Ans; R = V/I = 120/0.5 = 240 Ω
2. Ans; V = IR = 0.5 x 15 = 7.5 V
Examples
3. (i) For the circuit shown,
determine current flowing and
power absorbed by the resistor
if the resistance is 1 kΩ and
+
voltage across it is 10 V
(ii) If the current flowing
Vs
through the circuit is 3A and
power absorbed is 72 W,
determine the resistor value
and voltage across it.
I
+
V
R
-
DC Power
• The electric power in watts represents the rate
at which energy is converted from the electrical
energy of the moving charges to some other
form, e.g., heat, mechanical energy, or energy
stored in electric fields or magnetic fields.
• For a resistor in a DC circuit, the power is given
by the product of applied voltage and the
electric current :
P = VI
Power (watts) = Voltage (volts) x Current (amperes)
DC Power
• Although the unit of energy is the joule
(W=Pt), when dealing with large amounts of
energy, the unit used is the kilowatt hour
(kWh) where:
1kWh = 1000 watt hour
= 1000 X 3600 wat seconds (or joules)
= 3 600 000 J
Electricity Bill = Electricity (kWh) x tariff rates (sen/kWh)
Calculating your electric bill
Computer : 500 watts (12 hours usage)
TV : 400 watts (5 hours usage)
Lighting : 3 units x 15 watt = 45 watts (6 hours usage)
Others : 100 watts (2 hours usage)
Power consumed :
(500 x 12) + (400 x 5) + (45 x 6) + (100 x 2) = 8470 wh = 8.47kWh
Electricity bill per month :
8.47 kWh x RM 0.218/kWh x 30 = RM 55.50
Summary of terms, units and symbols