Homework #3
Questions from Chapter 3
3.1) Is the turns ratio of a transformer the same as the ratio
of voltages across the transformer? Why or Why not? 5%
No, there is a small difference due to the voltage drop across the 2
windings
3.4) What is the leaka
ECE 3304 Homework 5
Q1) What Factors influence the resistance of a Transmission line? (5%)
Length of the line
Ambient temperature
Size (radius) of conductor
Resistive of material
Q2) (9.3) What Factors influence the Inductance of a Transmission line? (5%)
ECE 3304 Homework 4
Questions:
Q1) What are instruments transformers?
Special transformers that bring the high voltages and high currents
to magnitudes that are acceptable for metering and protection
devices .
Q2) What are transformer taps? What are they
ECE 3304
Introduction to Power Systems
Lecture 3
Power System Basics
Fall 2016
August 30
Three Phase Circuits
Reference : Book, Chapter 1 & 2
ECE 3304
3.1 Review Example for Single Phase Circuits:
In the following circuit, find the Phasor currents
I, IA,
ECE 3304
Introduction to Power Systems
Lecture 9
Power System Basics
Fall 2016
Transmission Lines Model
September 29
Reference : Book, Chapter 9
ECE 3304
We Remember 4/16/07
9.1 Transmission Line Equivalent Circuit Models
The effect of the resistance, ind
ECE 3304
Introduction to Power Systems
Lecture 10
Fall 2016
Electric Machines
October 11th
Reference : Book, Chapters 1and 4
ECE 3304
10.1 Electrical Machines
Electrical machines are electromechanical energy converters
They are divided in two types:
Gener
ECE 3304
Introduction to Power Systems
Lecture 12
Fall 2016
Cont. Synchronous Motors
October 18th
Reference : Book, Chapters 5
We Remember 4/16/07
ECE 3304
12.1 Effect of Field Current in Motor Operation
The voltage Ea is a function of the applied field c
ECE 3304
Introduction to Power Systems
Lecture 8
Transmission Lines
Fall 2016
Introduction
September 27th
Reference : Book, Chapter 9
We Remember 4/16/07
ECE 3304
8.1 Transmission Lines
Transmission lines are used
to transfer energy from
generation plants
ECE 3304
Introduction to Power Systems
Lecture 5
Transformer Model from Testing
September 6
Fall 2016
Transformer Model from Testing
Reference : Book, Chapter 3
ECE 3304
5.1 Derivation of Transformer Model Parameter from Tests
If you are given a transform
ECE 3304
Introduction to Power Systems
Lecture 11
Fall 2016
Synchronous Machines
October 13th
Reference : Book, Chapters 4 and 5
ECE 3304
11.1
SYNCHRONOUS MACHINES (Chapter 5)
Synchronous Machines:
AC machines that under steady state conditions operate at
Three Phase Configuration Prof S. A. Soman Motivation Two Phase Balanced System Three Phase Balanced System Star (Y) and Delta () Connection Conversion N-Phase
Basics of Power Systems: Three Phase Configuration
Prof S. A. Soman
Visiting Faculty Department
Review of Phasors Prof S. A. Soman Sinusoidal Nature Back to Phasors Phasor Computation Behaviour of Circuit Elements Working with Complex Exponential Examples
Basics of Power Systems: Review of Phasors
Prof S. A. Soman
Visiting Faculty Department of Elec
Induction Motor: Torque Derivation Prof S. A. Soman Torque Equation Thevenin's Equivalent Circuit Approach Maximum Torque condition
Induction Motor: Torque Derivation
Prof S. A. Soman
Visiting Faculty Department of Electrical and Computer Engineering Virg
Induction
Motor:
Problems
Prof S. A.
Soman
Induction Motor: Problems
Problems
Prof S. A. Soman
Visiting Faculty
Department of Electrical and Computer Engineering
Virginia Tech
[email protected]
Department of Electrical Engineering
IIT-Bombay
December 2, 2012
Induction
Motor:
Introduction
Prof S. A.
Soman
Induction Motor: Introduction
Introduction
Stator and
rotor
equivalent
circuits
Prof S. A. Soman
Visiting Faculty
Department of Electrical and Computer Engineering
Virginia Tech
[email protected]
Department of E
Synchronous Machine Prof S. A. Soman Example 7.16
Synchronous Machine Numerical Example
Prof S. A. Soman
Visiting Faculty Department of Electrical and Computer Engineering Virginia Tech [email protected] Department of Electrical Engineering IIT-Bombay
Novemb
ECE 3304
Introduction to Power Systems
Lecture 4
Power System Basics
Fall 2016
September 1
Transformer Modeling
Reference : Book, Chapter 1 & 3
ECE 3304
4.1 Motivation for Transformer Modeling
Transformers are key for the efficient transmission of
AC elec
1)Would you expect a 400 Hz Generator to be bigger or smaller (size) than a 60 Hz
generator of the same power rating.
Bigger
b) Smaller
c) Same
2) What is slip in an induction machine? (PLEASE no formulas)
Percentage difference between mechanical speed of
ECE 3304 Homework 8
Questions:
Q1) (8.3) What is armature reaction? How does it affects the operations of a
DC machine? (7%)
A field created in the stator when the rotor field crosses the airgap. The
main effect is the shift on the zero crossing of the ro
ECE 3304 Homework 11
Questions:
1) A relay that fails to operate for a true fault has this type of failure (10%)
a) Security failure
b) Dependability failure
c) Hidden failure
2) What is the difference between a symmetrical and unsymmetrical
fault? 10%
Sy
ECE 3304 Homework 6
Q1) (4.2) Why does switching the current flows in any two phases reverse the
direction of rotation of the stators magnetic field? (5%)
The switching results in a negative sequence causing the forward rotating
portions of the fields to
ECE 3304 Homework 7
Q1) What is the principal difference between a synchronous machine and an
induction machine? (5%)
The rotor currents DC (synchronous) versus AC (induction)
Q4) Why must the oncoming generator in a power system be paralleled at a
bigger
9/10/2015
Homework #1 Due September 1st 2015
Questions :
L1.1 What are the three recognized electric load sectors? (10%)
Residential, Commercial and Industrial
L1.1 Does the largest load sector pays the lowest price for
electricity? Why or Why not? (10%)
9/17/2015
Homework #2
Questions:
Q1) (3.1) Is the turns ratio of a transformer the same as the ratio of voltages
across a transformer? Why or Why not? 10%
No, there is small voltage drop across both windings from their resistance and
leakage inductance.
Q
ECE 3304
Introduction to Power Systems
Lecture 2
Review of Magnetic Circuits and
Single Phase AC
Fall 2015
August 27th
Reference : Book, Chapter 1
ECE 3304
2.1 Magnetic Fields Review
a) Amperes Circuital Law:
D
H dl J
ds
S
t
Where:
J = Current Density
Questions:
1. Would you expect a 400 Hz Generator to be bigger or smaller (size) than a 60 Hz
generator of the same power rating.
a) Bigger
b) Smaller
c) Same
2. What is slip in an induction machine? (PLEASE no formulas)
3. You are asked to move an extrem
Questions:
a) The main difference between the field winding of an induction and a synchronous
machine is:
1) They travel at the same speed
2) One is DC the other AC
3) None
4) Number of poles
b) There are no induction generators
1) True
2) False
c) You ar