Grady, Notes_on_Thevenin_Equivalents.doc
Notes on Thevenin Equivalents. Dr. Mack Grady.
The three cases to consider are
Case 1. All sources are independent
Case 2. The circuit has dependent sources and independent
sources
Case 3. The circuit has only d
_08_EE394J_2_Spring12_Screwbean_Wind_Farm_Study.doc
The Screwbean 138kV substation is located in west Texas, halfway between Midland/Odessa
and El Paso, near Guadalupe Mountains National Park. It is about 400 miles from Austin. This
is prime wind country,
_06_EE394J_2_Spring12_Short_Circuits.doc
Short Circuits
1.
Introduction
Voltage sags are due mostly to faults on either transmission systems or distribution feeders.
Transmission faults affect customers over a wide area, possibly dozens of miles, but dist
_10_EE394J_2_Spring12_Inertia_Calculation.doc
Procedure for Estimating Grid Inertia H from Frequency Droop Measurements
While the expressions for inertia and frequency droop are well known, it is prudent to rederive
them here. Treating all the grid genera
_12_EE394J_2_Spring12_Lightning_Step Potential_Shock Energy_Problem.doc
Solve this homework using Excel. Make your time stepsize equal to the travel time down the tower.
Problem. A 35kA, 1 x 20 (i.e., 35kA peak, rise time = 1s, fall time = 20s) lighting b
_16_EE394J_2_Spring11_Short_Circuits.doc
Stevenson Problem 6.15, Phase A to Ground Fault at Bus #4
Enter
Press
Results
Enter Polar Form 012 Currents at Gen #1, Compute the ABC Currents
_
Enter Polar Form 012 Voltages at Gen #1, Compute the ABC Voltages
Pa
AMERICAN ELECTRIC POWER
Transmission Facts
Q1. What are AEP transmission mileage statistics?
AEP owns the nations largest electricity transmission system, a thirty-nine-thousand miles network
operating in 11 states that includes more 765 kV extra-high-vol
_35_EE394J_Spring11_Second_Order_Illustrator.doc
Ringdown Analysis of Voltage Phase Angle Using 30 Point-per-Second Synchrophasor
Data and the Excel Solver
Start Sec
52.5
Stop Sec
57
Exponential Steady State Transition Curve
A
B
T1
Tau1
-26.75
-28.19
52.9
_36_EE394J_2_Spring11_Inertia_Calculation.doc
Procedure for Estimating Grid Inertia H from Frequency Droop Measurements
While the expressions for inertia and frequency droop are well known, it is prudent to rederive
them here. Treating all the grid genera
EE394J_2_Spring11_Test2.pdf
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_05_EE394J_2_Spring12_Power_System_Matrices.doc
Power System Matrices and Matrix Operations
Nodal equations using Kirchhoff's current law. Admittance matrix and building algorithm.
Gaussian elimination. Kron reduction. LU decomposition. Formation of imped
_03_EE394J_2_Spring12_Transmission_Lines.doc
Transmission Lines
Inductance and capacitance calculations for transmission lines. GMR, GMD, L, and C matrices,
effect of ground conductivity. Underground cables.
1.
Equivalent Circuit for Transmission Lines (I
_01_EE394J_2_Spring12_Power_Refresher_Problems.doc
Problem 1. Carefully sketch each of the following three waveforms on the graph provided.
10 cos(t 90) , 5 cos(t + 30) , 8 cos(t + 45)
+10
0
-10
-360 -270
-180
-90
t = 0
90
180
Page 1 of 13
270
360
_01_EE3
Grady, Symmetrical Components, June 2007, Page 1
Symmetrical Components
Transformation matrices and the decoupling that occurs in balanced three-phase systems.
Physical significance of zero sequence.
1.
Transformation Matrix
Fortescue's Theorem: An unbala
Notes on Nodal Analysis, Prof. Mack Grady, Sept. 15, 2007
Definitions
Node:
A point or set of points at the same potential that have at least two branches
connected to them.
Branch:
A circuit element that connects nodes.
Major Node: A node with three or m
Grady, Per Unit, Jan. 2009, Page 1
1.
Single-Phase Per Unit System
Advantages of the per unit system:
1. Transformers can be replaced by their equivalent series impedances.
2. Equipment impedances can be easily estimated since their per unit impedances li
Grady, Transmission Lines, June 2007, Page 1
Transmission Lines
Inductance and capacitance calculations for transmission lines. GMR, GMD, L, and C matrices,
effect of ground conductivity. Underground cables.
1.
Equivalent Circuit for Transmission Lines (I
Procedure for Computing Positive/Negative/Zero Sequence Line Constants for
Transmission Lines in Air
POSITIVE/NEGATIVE SEQUENCE CALCULATIONS
Assumptions
Balanced, far from ground, ground wires ignored. Valid for identical single conductors per
phase, or f
Grady, Transformers, June 2007, Page 1
Transformers
Transformers. Transformer phase shift. Wye-delta connections and impact on zero sequence.
Inductance and capacitance calculations for transmission lines. GMR, GMD, L, and C matrices,
effect of ground con
Grady, Loadflow, June 2007, Page 1
Loadflow
Formulation of the loadflow problem. Gauss-Seidel, Newton-Raphson, and Stott's algorithm.
Calculation of line flows, system losses, and area interchange.
1
Formulation of the Problem
The loadflow problem is one
Grady, Short Circuits, June 2007, Page 1
Short Circuits
1.
Introduction
Voltage sags are due mostly to faults on either transmission systems or distribution feeders.
Transmission faults affect customers over a wide area, possibly dozens of miles, but dist
Grady, Programming Consideration, June 2007, Page 1
Programming Considerations
Methods for efficient programming. Sparsity techniques. Optimal bus ordering.
1.
Sparsity Programming
Many power system matrices tend to be very large and very sparse. A typica
Grady, Notes on System Matrices, June 2007, Page 1
Power System Matrices and Matrix Operations
Nodal equations using Kirchhoff's current law. Admittance matrix and building algorithm.
Gaussian elimination. Kron reduction. LU decomposition. Formation of im