TRANSMISSION &
TRANSMISSION &
DISTRIBUTION
A Division of Global Power
POWER SYSTEM STABILITY CALCULATION TRAINING
Day 1 - Review of the Main Topics Covered in Course A
December 6, 2013Prepared by: Frida Ceja-Gomez
eBook for You
OUTLINE
• Overview of the IEEE 24 Bus System
• Load Flow Analysis
•
N
-
1 Contingency Analysis
2
•
N
-
1 Contingency Analysis
• Short-Circuit Analysis
• PV & QV Analysis
• Dynamic Analysis of 3-ph and SLG Faults
eBook for You
3
IEEE 24 BUS SYSTEM REVIEW
System Components
&
Load Flow Simulation
eBook for You
The IEEE 1996

Reports to identify overloads
or voltage issues
eBook for You
N-0 Criteria
6
• How did we resolve the
issues encountered in
Course A?
• Transformer
overloads
LOAD FLOW ANALYSIS
overloads
• Low voltages
• Swing machine’s
reactive power limit
exceeded
eBook for You
Eliminating the overloads
7
• All the transforms originally had a rating of 100MVA
• It was necessary to modify the transformers’ ratings as
shown below
LOAD FLOW ANALYSIS
• Note that the resistance/reactance values do not need to
be modified since these parameters were input with
respect to the winding MVA base, which was left
unchanged
eBook for You
Correcting the voltage issues
8

subsystem for each area
N-1 CONTINGENCY ANALYSIS
eBook for You
Preparing the input files for the DFAX file
12
• Also, a monitoring file was created for
• overloads on all branches
•
the buses for each subsystem having a
N-1 CONTINGENCY ANALYSIS
•
the buses for each subsystem having a
voltage below 0.9pu or above 1.1pu
eBook for You
Preparing the input files for the DFAX file
13
• Finally, we wrote contingency file to trip
each of the branches in the system, one at a
time
N-1 CONTINGENCY ANALYSIS
eBook for You
Creating the DFAX file
14
• Go to AC contingency solution (ACCC) and
build the distribution factor data file
N-1 CONTINGENCY ANALYSIS
eBook for You
Creating the DFAX file
15
• Verify the output bar for any problems with

N-1 CONTINGENCY ANALYSIS
reports to
generate a report
of the AC
contingency
analysis
eBook for You
AC Contingency Analysis Results
19
• How many contingencies cause line
overloads?
•
How many contingencies overload the
N-1 CONTINGENCY ANALYSIS
•
How many contingencies overload the
transformers?
• How many contingency cause voltage
violations?
eBook for You
AC Contingency Analysis Results
20
• What lines should be upgraded to avoid
major overloads?
•
Where should more lines be built to
N-1 CONTINGENCY ANALYSIS
•
Where should more lines be built to
prevent excessive overloads?

parameters are not available?
eBook for You
Negative and Zero Sequence Parameters
24
• Negative-sequence impedance is equal to positive-
sequence impedance for all equipment
• Zero-sequence impedance of generators is equal to ¼
of positive
-
sequence impedance
SHORT-CIRCUIT ANALYSIS
of positive
-
sequence impedance
• Zero-sequence impedance of transformer is equal to
positive-sequence impedance
• Zero-sequence impedance of lines is equal to three
times the positive-sequence impedance (B0 = ½ B1)
eBook for You
Automatic Sequencing Fault Calculation in
PSS®E
25
• Go to the Misc menu,
and select Change
Program Settings
•
Change the short
-
SHORT-CIRCUIT ANALYSIS
•