PSAT
(Power System Analysis Toolbox)
By :
H. Lotfizad
History

PSAT is a Matlab toolbox for static and dynamic analysis
and control of electric power systems.

PSAT is written by Federico Milano , in September 2001,
while he was studying as Ph.D. student at the Universita di
Genova, Italy,

First public version of PSAT completed in November 2002,
when he was a Visiting Scholar at the University of
Waterloo, Canada.

Now Federico Milano is working as assistant professor at
the Universidad de Castilla-La Mancha, Ciudad Real, Spain
but he maintains PSAT in the spare time
Overview

PSAT is a Matlab toolbox for electric power system
analysis and control.

PSAT includes Power Flow , continuation power
flow, optimal power flow, small signal stability
analysis and time domain simulation.

All PSAT operations can be assessed by means of
graphical user interfaces (GUIs) and a Simulinkbased library provides an user friendly tool for
network design.
Overview

PSAT core is the power flow routine, which also takes
care of state variable initialization.

Once the power flow has been solved, further static
and/or dynamic analysis can be performed.

These routines are:





1. Optimal power flow (OPF)
2. Continuation Power flow (CPF)
3. Small signal stability analysis
4. Time domain simulations
5. Phasor measurement unit (PMU) placement.
Useful features
 Mathematical
 A variety
 Bridges
 Data
Models & Utilities
of utilities
to other programs
Format Conversion capability
Mathematical Models
 In
order to perform accurate power system
analysis, PSAT supports a variety of static
and dynamic component models, as
follows:
Mathematical Models









Power Flow Data
CPF and OPF Data
Switching Operations
Loads
Machines
Controls
Regulating Transformers
FACTS
Other Models
PSAT utilities

Simulink library for drawing networks;

GUIs for settings system and routine parameters;

User defined model construction and installation;

GUI for plotting results;

Filters for converting data to and from other formats;

Command logs.
PSAT bridges to other programs
 PSAT
includes bridges to GAMS and
UWPFLOW programs.
 This
bridges highly extend PSAT ability of
performing optimization and continuation
power flow analysis.
Comparison between PSAT
& Other Matlab Power System Toolboxes
standard power flow (PF)
continuation power flow and/or voltage stability analysis (CPF-VS)
optimal power ow (OPF)
Small signal stability analysis (SSSA)
time domain simulation (TDS)
Electro Magnetic Transient analysis (EMT)
graphical user interface (GUI)
graphical network construction (CAD)
PSAT Users

PSAT is currently used in several countries. These include:

Modern Countries like : USA , Canada , England , France, Australia, Japan ,
Italy , Spain , Sweden , China , Norway

Under developing countries like : Algery, Argentina, Brasil, Chile, Colombia,
Egypt, Guatemala, Hong Kong, India, Indonesia, Iran,
 Costa Rica, Macedonia, Malaysia, Mexico, Nigeria, Peru, Philippines,
Puerto Rico, Romania, Sudan, Thailand, Turkey, Venezuela.

PSATusers around the world.
PSAT Installation
1- Download the last PSAT version :
http://thunderbox.uwaterloo.ca/fmilano
2- Requirements (ver 1.2.2) : Matlab 6.5
(ver 2) : Matlab 7
3- Installation :
 Extract PSAT zip files in a good location
 Open MATLAB
 Add PSAT’s Path to MATLAB default path
PSAT quick tutorial
 PSAT
Installation
 Launching PSAT
 Loading Data
 Running the Power flow Program
 Displaying Results
 Saving Results
 Settings
Launching PSAT
Type psat in MATLAB Prompt
>> psat
This will create all the structures required by the
toolbox , then opens psat GUI
Loading Data

Almost all operations require that a data file is loaded.
 To load a file:
Load only a data file :
- Menu File/Open/Data File
- Short cut <Ctr-d>
Load a saved system:
- File/Open/Saved System
- Short cut <Ctr-y>

To allow portability the .out files used for saving system results include also the
original data which can be saved in a new .m data file.

The data file can be either a .m file in PSAT format or a Simulink model created
with the PSAT library.

If the source is in a different format supported by the PSAT format conversion
utility, first perform the conversion in order to create the PSAT data file.
Running the Power flow Program

To run the power flow routine:
Menu Run/Power Flow
Short cut <Ctr-p>

It is not necessary to load again the data file every
time it is modied, bacause :


The last version of the data file is read each time the power flow is
performed.
The data are updated also in case of changes in the Simulink
model originally loaded.
Other Analysis
 After
solving the first power flow, the
program is ready for further analysis, such
as CPF , OPF , …
 Each
of these procedures can be
launched from the tool-bar or the menubar of the main window.
Displaying Results

Results can be generally displayed in more than one way,
either by means of a graphical user interface in Matlab or as a
ascii text file.

These routines only create a text report:




Standard Power flow (in a .txt , .xls or .tex file)
PMU placement (in a .eig file)
SSSA (Small Signal Stability analysis) (in a .pmu file)
These routines create graphical output :


CPF
OPF
Saving Results

To save actual System status in a .mat file :


Menu File/Save/Current System
Shortcut <Ctrl-a>

All global structures used by PSAT are stored in this
file which is placed in the folder of the current data file

all static computations allow to create a report in a text
file that can be stored and used later.
Settings

The main settings of the system are directly included in the main window






Other general settings


Menu Edit/General Settings or <Ctr-k>
To change the default values for some fields of the Settings structure


Base frequency
Base Power
Start & End Simulation Time
static and dynamic tolerance
Maximum number of iterations
Menu Edit/Set Default
To save a customize settings , use it as default values for the next sessions

Menu File/Save/Settings
Network Design

Using The Simulink environment :





However,




Creating a CAD able to design power networks
visualize the topology
change the data stored in it
without the need of directly dealing with lists of data.
Simulink has been thought for control diagrams with outputs and inputs
variables
This is not the best way for approaching a power system network.
Thus, the time domain routines that come with Simulink and its ability to
build control block diagrams are not used.
PSAT simply reads the data from the Simulink model and writes
down a data file.
Network Design
 To



launch PSAT library
click on Simulink icon in the menu-bar,
the menu Edit/Network/Edit Network or
the short cut <Ctr-s>.
Tools

Tools that provided with PSAT


data format conversion functions
user defined model routines.

PSAT static data files can be converted in the
IEEE Common Data Format

User defined model routines provide a simple
way for extending the capabilities of PSAT
PSAT Interfaces

PSAT provides interfaces :


GAMS and UWPFLOW,
These interfaces highly extend PSAT ability to perform OPF and CPF
analysis

The General Algebraic Modeling System (GAMS) is a high-level
modeling system for mathematical programming problems.

UWPFLOW is an open source program for sophisticated continuation
power flow analysis

UWPFLOW consists of a set of C functions and libraries designed for
voltage stability analysis of power systems
Using PSAT for analysis of
Voltage Collapse

Based on C. A. Canizares, “Voltage Stability Assessment: Concepts,
Practices and Tools," Tech. Rep. IEEE/PES Power System Stability
Subcommittee.

Direct Methods for determining



Saddle-Node Bifurcations (SNB)
Limit-Induced Bifurcations (LIB)
Continuation Power Flow (CPF)


The CPF is more general than DMs
CPF can be used for determining:
 generator reactive power limits
 voltage limits
 flow transmission limits.
CPF Settings
PSAT plot for DM & CPF Results
 This
Figure depicts CPF nose curves as
displayed by means of the PSAT GUI for
plotting results system.
 The
graphic refers to three load voltages
of the IEEE 14-bus test system
IEEE 14-bus test system psat plots
Special Thanks to
Session Audiences