PSATPSAT

((Power System Analysis ToolboxPower System Analysis Toolbox))

By : By : H. LotfizadH. Lotfizad

HistoryHistory PSAT is a Matlab toolbox for static and dynamic analysis PSAT is a Matlab toolbox for static and dynamic analysis

and control of electric power systems. and control of electric power systems.

PSAT is written by Federico Milano , in September 2001, PSAT is written by Federico Milano , in September 2001, while he was studying as Ph.D. student at the Universita di while he was studying as Ph.D. student at the Universita di Genova, Italy, Genova, Italy,

First public version of PSAT completed in November 2002, First public version of PSAT completed in November 2002, when he was a Visiting Scholar at the University of when he was a Visiting Scholar at the University of Waterloo, Canada. Waterloo, Canada.

Now Federico Milano is working as assistant professor at Now Federico Milano is working as assistant professor at the Universidad de Castilla-La Mancha, Ciudad Real, Spain the Universidad de Castilla-La Mancha, Ciudad Real, Spain but he maintains PSAT in the spare timebut he maintains PSAT in the spare time

OverviewOverview

PSAT is a Matlab toolbox for electric power system PSAT is a Matlab toolbox for electric power system analysis and control.analysis and control.

PSAT includes Power Flow , continuation power PSAT includes Power Flow , continuation power flow, optimal power flow, small signal stability flow, optimal power flow, small signal stability analysis and time domain simulation.analysis and time domain simulation.

All PSAT operations can be assessed by means of All PSAT operations can be assessed by means of graphical user interfaces (GUIs) and a Simulink-graphical user interfaces (GUIs) and a Simulink-based library provides an user friendly tool for based library provides an user friendly tool for network design.network design.

OverviewOverview

PSAT core is the power flow routine, which also takes PSAT core is the power flow routine, which also takes care of state variable initialization.care of state variable initialization.

Once the power flow has been solved, further static Once the power flow has been solved, further static and/or dynamic analysis can be performed. and/or dynamic analysis can be performed.

These routines are:These routines are:

1. Optimal power flow (OPF)1. Optimal power flow (OPF) 2. Continuation Power flow (CPF)2. Continuation Power flow (CPF) 3. Small signal stability analysis3. Small signal stability analysis 4. Time domain simulations4. Time domain simulations 5. Phasor measurement unit (PMU) placement.5. Phasor measurement unit (PMU) placement.

Useful featuresUseful features

Mathematical Models & UtilitiesMathematical Models & Utilities

A variety of utilitiesA variety of utilities

Bridges to other programsBridges to other programs

Data Format Conversion capabilityData Format Conversion capability

Mathematical ModelsMathematical Models

In order to perform accurate power system In order to perform accurate power system analysis, PSAT supports a variety of static analysis, PSAT supports a variety of static and dynamic component models, as and dynamic component models, as follows:follows:

Mathematical ModelsMathematical Models

Power Flow DataPower Flow Data CPF and OPF DataCPF and OPF Data Switching OperationsSwitching Operations LoadsLoads MachinesMachines ControlsControls Regulating TransformersRegulating Transformers FACTSFACTS Other ModelsOther Models

PSAT utilities

Simulink library for drawing networks;Simulink library for drawing networks;

GUIs for settings system and routine parameters;GUIs for settings system and routine parameters;

User defined model construction and installation;User defined model construction and installation;

GUI for plotting results;GUI for plotting results;

Filters for converting data to and from other formats;Filters for converting data to and from other formats;

Command logs.Command logs.

PSAT bridges to other programs

PSAT includes bridges to GAMS and PSAT includes bridges to GAMS and UWPFLOW programs.UWPFLOW programs.

This bridges highly extend PSAT ability of This bridges highly extend PSAT ability of performing optimization and continuation performing optimization and continuation power flow analysis. power flow analysis.

Comparison between PSAT & Other Matlab Power System Toolboxes

standard power flow (PF)standard power flow (PF)continuation power flow and/or voltage stability analysis (CPF-VS)continuation power flow and/or voltage stability analysis (CPF-VS)optimal power ow (OPF)optimal power ow (OPF)Small signal stability analysis (SSSA)Small signal stability analysis (SSSA)time domain simulation (TDS)time domain simulation (TDS)Electro Magnetic Transient analysis (EMT)Electro Magnetic Transient analysis (EMT)graphical user interface (GUI)graphical user interface (GUI)graphical network construction (CAD)graphical network construction (CAD)

PSAT Users PSAT is currently used in several countries. These include:PSAT is currently used in several countries. These include:

Modern Countries like : USA , Canada , England , France, Australia, Japan , Modern Countries like : USA , Canada , England , France, Australia, Japan , Italy , Spain , Sweden , China , Norway Italy , Spain , Sweden , China , Norway

Under developing countries like : Algery, Argentina, Brasil, Chile, Colombia, Under developing countries like : Algery, Argentina, Brasil, Chile, Colombia, Egypt, Guatemala, Hong Kong, India, Indonesia, Egypt, Guatemala, Hong Kong, India, Indonesia, IranIran, ,

Costa Rica, Macedonia, Malaysia, Mexico, Nigeria, Peru, Philippines, Costa Rica, Macedonia, Malaysia, Mexico, Nigeria, Peru, Philippines, Puerto Rico, Romania, Sudan, Thailand, Turkey, Venezuela. Puerto Rico, Romania, Sudan, Thailand, Turkey, Venezuela.

PSATusers around the world.PSATusers around the world.

PSAT Installation

1- Download the last PSAT version : 1- Download the last PSAT version : http://thunderbox.uwaterloo.ca/fmilanohttp://thunderbox.uwaterloo.ca/fmilano

2- Requirements (ver 1.2.2) : Matlab 6.52- Requirements (ver 1.2.2) : Matlab 6.5 (ver 2) : Matlab 7(ver 2) : Matlab 7

3- Installation :3- Installation :

Extract PSAT zip files in a good locationExtract PSAT zip files in a good location

Open MATLABOpen MATLAB

Add PSAT’s Path to MATLAB default pathAdd PSAT’s Path to MATLAB default path

PSAT quick tutorial

PSAT InstallationPSAT Installation Launching PSATLaunching PSAT Loading DataLoading Data Running the Power flow ProgramRunning the Power flow Program Displaying ResultsDisplaying Results Saving ResultsSaving Results SettingsSettings

Launching PSATLaunching PSATType psat in MATLAB Prompt

>> psat

This will create all the structures required by the toolbox , then opens psat GUI

Loading DataLoading 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 ProgramRunning the Power flow Program

To run the power flow routine:Menu Run/Power FlowShort 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 AnalysisOther 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 menu-bar of the main window.

Displaying ResultsDisplaying 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 ResultsSaving Results

To save actual System status in a .mat file :To save actual System status in a .mat file :

Menu File/Save/Current SystemMenu File/Save/Current System Shortcut <Ctrl-a>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.

SettingsSettings The main settings of the system are directly included in the main window

Base frequency Base Power Start & End Simulation Time static and dynamic tolerance Maximum number of iterations

Other general settings Menu Edit/General Settings or <Ctr-k>

To change the default values for some fields of the Settings structure 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 :

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.

However,

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 Using PSAT for analysis of Voltage CollapseVoltage 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 limitsvoltage limits flow transmission limits.

CPF SettingsCPF Settings

PSAT plot for DM & CPF ResultsPSAT 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 Special Thanks to

Session AudiencesSession Audiences