Modelling and simulation
The planning, design, and
operation of industrial and commercial power systems
require engineering studies to evaluate existing and
proposed system performance, reliability, safety, and
economics. Studies, properly conceived and conducted,
are a costeffective way to prevent surprises and to
optimize equipment selection. In the design stage, the
studies identify and avoid potential deficiencies in the
system before it goes into operation. In existing
systems, the studies help locate the cause of equipment
failure and misoperation, and determine corrective
measures for improving system performance.
Power system studies
provides you with the information necessary to upgrade
and maintain your power delivery infrastructure. The
results focus on reducing operating costs, improving
efficiency, increasing reliability and improving system
maintainability. This studies might be classified in a
great umber of way: operational conditions, time regime
of the phenomenon dominant, or terminal conditions.
The complexity of modern
industrial power systems makes studies difficult,
tedious, and timeconsuming to perform manually. The
computational tasks associated with power systems
studies have been greatly simplified by the use of
digital computer programs.
Professor Francisco M.
GonzalezLongatt since 1995 has stated research in
modelling and simulation. This research have led to
development of several power system analysis program.
First power system
analysis program, PCC. This program was developed in
19941995 during the end career project of Professor
Francisco M. GonzalezLongatt. It was a program
developed in C++ for D.O.S in personal computer. It
calculate load flow and shortcircuit. Shortcircuit is
performed using the bus impedance matrix. Load flow
calculation are made by simple GaussSeidel algorithm.
The input data is formatted in .txt format and output
presented in screen or saved in .txt format. This
program was useful for several years and used in a lot
of end career projects.
ASP
ASP Program. In
2001 the Professor Francisco M. GonzalezLongatt decided
the development of a full graphic program with a good
interface graphic friendly to users. This is the origin
of the program called: ASP. ASP is the abbreviation of
Analyzer of Power System (in Spanish: Analizador de
Sistemas de Potencia). This program is a windows base
application full graphic to power system analysis. The
first stage of the project started in 1999 with a
conceptual structure and general ideas for algorithm and
data base. The final prototype was ended in 2002. This
program is completely developed in Delphy programming
language.
Today ASP include the
most important power system analysis: load flow,
shortcircuit (ANSI C57, IEC 60909), transient stability
(several model of excitation and governor systems),
great data base of typical parameter of transmission
lines, generators, motors, cables, transformer, etc.
For more
information about ASP, follow the following link.
If you are interested in
more detailed information of this project visit:
Development of a power system analysis
program, Design and implementation
of computational module for the analysis of transient
stability of power systems into ASP program,
Implementation
of a computational module for short ANSI circuit calculation
software for ASP (Analyzer Power Systems) Program"
DOWNLOAD ASP VERSION
2.0
MCCL
MCCL. In 2003, the
Professor Francisco M. GonzalezLongatt decide develop a
program, included into ASP program as a module), to
calculate the electrical parameter (resistance,
impedance series and admittance shunt) in transmission
lines. Tris program is called "MCCC" Program for Line
Constant Calculation (MCCCL in spanish: Modulo de
Calculo de Constantes de Lineas").
This program compute the self and mutual coupling
impedances of overhead lines and to do so for realistic
combinations of circuits in dense or sparse
rightsofway. The program in fully graphics and allow
any number of circuit and ground cables, considering
transposition or not. Furthermore, the program consider
the resistivity of the soil in unbalanced conditions
(not available in demo version). The result could be
stored in a database used Microsoft Access.
If you are interested in more detailed information
of this project visit:
Implementation
of a computational module for short ANSI circuit calculation
software for ASP (Analyzer Power Systems) Program"
MCCC
MCCC. A great
evolution of MCCL was development of MCCC in 2003. MCCC
is the abbreviation of Program for Electric Parameter
Calculation in Power Cables (in Spanish MCCC: Modulo de
Calculo de Constantes de Lineas).
MCCC program perform calculation of the self and mutual
coupling impedances in underground power cables
distribution systems. This program has a powerful
graphic interface. It permit the use of user define
parameter to provide flexibility in the calculations. A
comprehensive database of power cables are included and
results could be saved in the database.
If you are interested in more detailed information
about this project visit:
Implementation
of a computational module for short ANSI circuit calculation
software for ASP (Analyzer Power Systems) Program"
SimSP
is a complete program for power system analysis with
research purposes. This program was developed using
Matlab language by Professor Francisco M. GonzalezLongatt.
SimSP is the abbreviation of Power Sistem Simulator (in
Spanish Simulador de Sistemas de Potencia). This tool
has been developed for research purpose for this reason
no graphic interface was considered. In fact, the main
contributions are in modelling and simulation. The input
and output of this program are formatted in Microsoft
Excel. This program was developed to considerer de main
aspect of fundamental frequency operation, for this
reason all results are provided in this way, rms values
of main variables (full configurable, depending on wich
study is carried out). Furthermore, fundamental
frequency studies implies a los of supposition admitted
in this program. capacities of this program involve the
following studies:

Load flow.
A full load flow routine is included in this
program. Load flow equations are formulated in
polar form. The network is modelled by an
admittance matrix. Model of under load tap
changer, shut compensation, voltage dependence
of the static load and other elements are
included. Single cage induction machines are
modelled with steady state model, considering
completely the voltage dependence and including
the slip as variable into the power flow
solution. A NewtonRaphson iterative technique
is used for the load flow solution. Reactive
power generation limits in generator are
included into the program. This program include
the possibility of model wind turbines, using a
power coefficient Cp, and considering the wind
speed. A further development include in this
routine is the detailed wind park simulation
considering the wind speed variation caused by
turbulence between turbines. A complete report
of load flow calculations is formatted in
Microsoft Excel. 

Shortcircuit.
This module of SimSP is used to calculate the
current and voltages during a triphase fault. A
impedance matrix was used for shortcircuit
calculations, considering sparse techniques.
Model of inductions generators was included in
this program, and inverter fed power into the
power system. 

Transient
stability. The transient stability program
enables accurate model for power system dynamics
simulation and permit simulate system
disturbances and events. The main disturbance is
triphase shortcircuit but the program might
simulate load rejections, changes in adjust of
power or voltage or any variable, outages of
transmission lines, etc. This program include a
complete models of: synchronous & induction
machines, excitation system, governorturbine
models, etc. SimSP is different to the
conventional transient stability program because
include the models of most important new
technologies:

Micro
turbines (simpleshaft and slitshaft) 

Fuel
cells (SOFC and PEMFC) 

Wind
turbines (constant and variable speed
speed). In wind power generation, a
detailed models of wind turbines
include: shaft, pitch angle control,
model of double fed induction generator
including electronic power converter,
single cage induction generator. 
The transient
stability program is based in partitioned
explicit method to resolve de differential
algebraic model of the power system. the
algebraic equations are resolved by a Newton
Raphson iterative technique. The set of
differential equations are resolved using a
Modified Euler methods. The magic in this
program is in the way of programming. An open
programming is based in black box principle.
Just inputs and outputs. This vision permits add
more devices in a easy way. 

Voltage
stability. A implementation of the
Continuation Method for voltage stability
analysis including reactive power generation was
used in this program. Tap Changer Limits was not
considered. This is a first version of the
program for the voltage security assessment of
power systems. this program assess the voltage
stability of a power system by means of the two
most common static voltage stability analysis
techniques: PV Analysis (PV Curves) and
VQ Analysis (VQ curves). Modal analysis is
coming soon. 
For more information about SimSP go to the project
PhD Thesis of Professor
Francisco M. GonzalezLongatt.
FluPot. This is a
program developed using Matlab programming language in
2006. It permits the load flow calculations in more
complex way. The load flow formulation was bead in polar
form and the set of equations is resolved using NewtonRaphson
iterative methods. The main contributions of this
program are: (1) include a complete model in steady
state of single cage induction machine (operation as
motor or generator), (2) consider the model of wind
turbines, (3) it program consider a model of a complete
wind park (including the effect of turbulence between
turbines, because consider the exact location of each
wind turbine into the wind park). FluPot is the
abbreviation of power flow (in Spanish "Flujo de
Potencia").
This program was developed in Matlab, without graphic
interface. The main purpose of this program is research
for this reason input and output are formatted in
Microsoft Excel. This program is based in:
[1] J. Cidrás, J. A. Martínez, J. A. Peças, and F.
P. Maciel, “Modelling of Nonlinear nodal Admittances
in Load Flow Analysis”, in Proceedings of IFAC,
Artículo Técnico,1992
[2] J. Cidrás, José A. Martínez V., Joao Pecas L. y
Maciel Barboza. (1991). “Simulation of MV
distribution networks with Asynchronous local
Generation Sources
For more information about Flupot go to the project
Design and develop
of software to load flow calculation including the model of
wind farms.
LFRGD. This is a load flow program developed for
distribution network, considering the typical
characteristics of it (low X/R ratio, typically radial).
LFGCD is a load flow program programmed in Matlab for
distribution system including the integration of
distributed generation. A compensationbase power flow
algorithm was used in this program because provide a
good performance for weakly meshed distribution and
transmission systems. This program was developed for
research. Inputs are outputs are formatted in Microsoft
Excel. The main contribution of this program is a robust
algorithm for radial distribution network, fast and easy
to programming. This program is based in:
[1] Hong H. y Shirmohammadi D. “A CompensationBased
Power Flow Method for Weakly Meshed Distribution and
Transmission Networks”. IEEE Transactions on Power
Systems, Vol. 3, No. 2, Mayo, 1988.
If you are interested about more detailed information of
this project visit: Design and development
of computational tool in MATLAB™ for load flow calculations
in distribution network including distributed generation
CurvasRemi is a
Matlab base program developed in 2007 by Professor
Francisco M. GonzalezLongatt. This program provide a
complete evaluation of the steady state performance for
a simple induction machine. This program provide several
operating point of the induction machine (motor and
generator operation mode). A complete set of
characteristics curves are plotted with this program:
torque, active power, reactive power, current, power
factor efficiency (all variables versus slip). The
program is configurable for evaluation of dependence of
the characteristic curves of main variables versus
voltage in terminals.
This program was developed in Matlab. The input and
outputs are available in screen. for more detailed
information review: "Program
to plot of characteristics curves of single cage
induction machines in steady stated: CurvasRemi:
Validation
26th April 2009. www.fglongatt.org.ve 