Rafael Peña

Wind speed forecasting using genetic programming

This contribution presents the application of genetic programming to the problem of time series forecasting. This forecast technique is applied to wind speed time series. The results obtained from the forecasting are used to determine the power generation capacity of a fixed-speed wind turbine, which includes a squirrel cage induction generator. The forecast values obtained with the genetic programming are compared against the original time series data in order to show the precision of this forecast technique.

Steady-state solution of fixed-speed wind turbines following fault conditions through extrapolation to the limit cycle

A methodology to efficiently calculate the steady-state solution of fixed-speed induction generator (FSIG) based wind turbines, using a Newton algorithm and a Numerical Differentiation (ND) process for the extrapolation to the limit cycle is presented. This approach can be extremely useful in the development of steady-state studies of modern large-scale power systems with significant share of wind power based on FSIGs. A conventional Brute Force (BF) procedure is applied for comparison purposes to demonstrate the efficiency of the proposed methodology. The study involves the starting sequence of wind turbines and also the transient behavior of a single wind turbine after a disturbance. The simulations are conducted using a modeling platform developed by the authors to analyze power networks with high penetration of renewable sources.

Real time simulation of a power system including renewable energy sources

This paper deals with the simulation of a power system including renewable energy sources under transient conditions. Hydraulic and wind generation sources are considered. The simulations were carried-out in a specialized computer hardware, RTDS, specifically designed for the real time solution of electromagnetic transients. Power system components were represented using the RSCAD software.

Fast steady-state parallel solution of the induction machine

A Newton method based on a Numerical Differentiation (ND) process is applied to achieve the periodic steady-state solution of an induction machine in an efficient way. In order to increase the efficiency of the ND process, a parallel implementation of this method is applied. The efficiency of the proposed method is compared against the simulation time taken in achieve the solution of the induction machine using a conventional Brute Force (BF) method. The ND process is applied during the simulation of the induction machine start-up sequence and the parallel implementation of the method is tested using a wind park with fixed-speed wind turbines including induction machines. A state-space model of the induction machine in the abc reference frame is used to represent its dynamic behavior.

Fast steady-state solution of the induction machine following disturbance conditions

This contribution describes and applies a Newton method based on a Numerical Differentiation (ND) process for the fast periodic steady-state solution in the time domain of an induction machine following disturbance conditions. A state-space model of the induction machine in the arbitrary two-axis reference frame (dq frame) is used to represent its dynamic behavior. The efficiency of the methodology is compared against the solution obtained with the conventional Brute Force (BF) procedure. The ND process is applied during the simulation of the induction machine start-up and after a solid three-phase fault has been applied at the induction machine terminals.

Feasibility assessment of the installation of a photovoltaic system as a battery charging center in a mexican mining company

This paper presents a study of feasibility assessment of the installation of a photovoltaic system to supply energy to the external lighting of a private mining company, located in Cerro de San Pedro, San Luis Potosí, Mexico. The photovoltaic system will charge batteries during the day, and then these batteries will be used to provide the electricity to the external lighting over the night. This scheme aims to replace the utilization of diesel generators used in conjunction with the lightning system. For completeness of this work, the economical study including the payback time is reported.

Using a Newton method and LAPACK libraries to initialize electromagnetic transient simulations in power systems

This paper describes and applies a Newton method based on a Numerical Differentiation process to initialize electromagnetic transient simulations in power systems. In order to increase the simulation speed, LAPACK libraries are used to efficiently handle matrix operations. Simulations of the application of the method to the IEEE 5, 14, 30, 57 and 118-bus test systems are presented. Comparisons with a classical Brute Force approach are conducted to establish the efficiency of the proposed numerical algorithm. This method can be used as an alternative to the application of power-flow program to solve the initial value problem in electromagnetic transient studies.

Wind resource assessment in the surroundings of San Luis Potosi, Mexico

The use of alternative sources of energy addresses a series of steps to be undertaken in order to maximize its commercial exploit. This requires a set of guidelines to determine the best way in which these sources can be evaluated. This contribution focuses on the principles of wind resource assessment and the application of them for the wind energy evaluation in the surroundings of the San Luis Potosi city.

DGIS: Interactive Simulator for Distributed Generation Systems

An interactive software to simulate and to study the steady state and transient operation of distributed generation systems with a large number of elements is presented. This software can be an effective tool to give students better understanding of the behavior of power systems under various operating conditions, and can motivate them to learn more about power systems. It may also be useful for advanced users such as PhD students and researchers as they can implement their own algorithms and models, without the necessity of buying expensive licenses for commercial software. In addition, the software may well be used for teaching introductory courses into the analysis of network with high penetration of distributed generators. A detailed software description, comparison with similar available software, potential educational applications and future enhancements of this simulation tool are presented and discussed.

An interactive visual enviroment based on advanced numerical and computer techniques for power systems applications

This contribution details the application of a developed interactive visual environment for power system analysis. In principle, it is based on a methodology to obtain the numerical solution of the Ordinary Differential Equations (ODEs) that represent the dynamic behavior of power systems. The methodology relies on the application of Object Oriented Programming (OOP) techniques, so that power system components can be represented as objects, which are later used as functional blocks, facilitating the representation of a system of any type of complexity. Parallel Programming (PP) techniques are also applied in order to fully exploit the capabilities of new micro-processors of executing more than one process simultaneously, with the aim of reducing the simulation time. Besides, the parallel evaluation scheme presented in this paper has shown to be effective and can be easily adapted to any other numerical integration method without the need to modify the numerical algorithm. Case studies are presented which demonstrate the effectiveness of the proposed interactive digital tool and the methodology for power system analysis.