oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 14 )

2018 ( 40 )

2017 ( 34 )

2016 ( 58 )

Custom range...

Search Results: 1 - 10 of 23579 matches for " Fernando Villada "
All listed articles are free for downloading (OA Articles)
Page 1 /23579
Display every page Item
Diagnostico de Fallas en Motores de Inducción Mediante la Aplicación de Redes Neuronales Artificiales
Villada,Fernando; Cadavid,Diego R;
Información tecnológica , 2007, DOI: 10.4067/S0718-07642007000200016
Abstract: a new algorithm to diagnose inter-turn faults in induction motors based on artificial neural networks (ann) is presented in this work. a machine model able to simulate internal faults under different load conditions and voltage unbalance was implemented and tested, in order to generate the training patterns of the ann. an electrical network analyzer and a digital signal processor (dsp) are used to show the implementation of the method. experimental results in a 2 hp and 3 hp induction motors show the robustness of the algorithm allowing detect incipient faults and its implementation feasibility at industrial plants.
Diagnostico de Fallas en Motores de Inducción Mediante la Aplicación de Redes Neuronales Artificiales Fault Diagnosis in Induction Motors Using Artificial Neuronal Networks
Fernando Villada,Diego R Cadavid
Información Tecnológica , 2007,
Abstract: En este trabajo se presenta un algoritmo para diagnosticar fallas entre espiras del estator de motores de inducción mediante la aplicación de redes neuronales artificiales (RNA). Los patrones de entrenamiento de las RNA son obtenidos a partir de un modelo de máquina que permite simular fallas internas bajo diferentes condiciones de carga y desequilibrio de tensión. Se muestra la implementación del método utilizando un analizador de redes eléctricas y un procesador digital de se ales (DSP). Los resultados obtenidos experimentalmente en dos motores de 2 Hp y 3 HP permiten concluir la fortaleza del algoritmo al permitir detectar fallas incipientes en motores de inducción y la factibilidad de implementación del mismo a nivel industrial. A new algorithm to diagnose inter-turn faults in induction motors based on Artificial Neural Networks (ANN) is presented in this work. A machine model able to simulate internal faults under different load conditions and voltage unbalance was implemented and tested, in order to generate the training patterns of the ANN. An electrical network analyzer and a digital signal processor (DSP) are used to show the implementation of the method. Experimental results in a 2 Hp and 3 Hp induction motors show the robustness of the algorithm allowing detect incipient faults and its implementation feasibility at industrial plants.
Modelo de Vida útil para Estructuras Acero-Zinc Utilizadas en la Transmisión de Energía Eléctrica en Colombia
Villada,Fernando; Molina,Juan D; Velilla,Esteban;
Información tecnológica , 2009, DOI: 10.4067/S0718-07642009000600008
Abstract: an atmospheric corrosion degradation model for steel and zinc used in the transmission system of electric power in colombia is developed. three important aspects are identified: the definition of corrosion rate, the probability distribution function of useful life and the inspection/maintenance plan that favours a longer useful life. the model identifies mass loss and thickness loss functions, defining limits for degradation and fault modes which are simulated using markov chains to evaluate the structure availability and the optimal inspection and maintenance frequency. the results allow establishing zones with lower service life and their impact on the regulatory life. it is concluded that knowledge of degradation mechanisms allows a better definition of inspection and maintenance frequencies under a regulatory life.
Estudio del comportamiento de motores de inducción ante fallas estatóricas
Villada Duque,Fernando; Parra,Diego; Ocampo,Guillermo;
Revista Facultad de Ingeniería Universidad de Antioquia , 2007,
Abstract: results of a study of the behavior of induction motors under stator faults are presented in this paper. laboratory controlled short-circuits are induced between stator turns of induction motors. mechanical vibrations, axial leakage flux and stator current are sensed in these motors; signals are then identified and compared to find the main harmonic components showing larger amplitude variations.
Modelo de Vida útil para Estructuras Acero-Zinc Utilizadas en la Transmisión de Energía Eléctrica en Colombia Useful Life Model for Steel-Zinc Structures used in the Transmission of Electric Power in Colombia
Fernando Villada,Juan D Molina,Esteban Velilla
Información Tecnológica , 2009,
Abstract: Se desarrolla un modelo de degradación por corrosión atmosférica para el acero y el zinc utilizados en el sistema de transmisión de energía eléctrica en Colombia. Se identifican tres aspectos importantes: la definición de la tasa de corrosión, la función distribución de probabilidad de la vida útil y las actividades (Inspección/mantenimiento) que favorezcan una mayor vida útil. El modelo identifica las funciones de pérdida de masa y grosor en el tiempo, lo que define límites de estados de degradación y falla los cuales son simulados mediante cadenas de Markov para evaluar la disponibilidad de la estructura y la frecuencia óptima de inspección y mantenimiento. Los resultados obtenidos permiten establecer zonas con menor vida útil y su impacto con la vida útil regulatoria. Se concluye que conocer los mecanismos de degradación permite de manera más acertada definir las frecuencias de inspección y mantenimientos respecto a la vida regulatoria. An atmospheric corrosion degradation model for steel and zinc used in the transmission system of electric power in Colombia is developed. Three important aspects are identified: the definition of corrosion rate, the probability distribution function of useful life and the inspection/maintenance plan that favours a longer useful life. The model identifies mass loss and thickness loss functions, defining limits for degradation and fault modes which are simulated using Markov chains to evaluate the structure availability and the optimal inspection and maintenance frequency. The results allow establishing zones with lower service life and their impact on the regulatory life. It is concluded that knowledge of degradation mechanisms allows a better definition of inspection and maintenance frequencies under a regulatory life.
Pronóstico del Precio de la Energía Eléctrica usando Redes Neuro-Difusas
Villada,Fernando; García,Edwin; Molina,Juan D;
Información tecnológica , 2011, DOI: 10.4067/S0718-07642011000600012
Abstract: a forecasting model for the price of electricity in colombia using neurofuzzy networks is proposed. two network structures including the price series in the first and the price series plus the reserve water levels in the latter are used. the results are compared with two neural networks structures and a generalized autoregressive conditional heteroscedasticity model (garch). historical data were supplied by the company xm of the isa group; data for 120 days were used as for training the network and the following 31 days were used for testing the predictive capabilities of the model. the garch model shows better adjustment within the training period for the prices series as input, but the neurofuzzy networks have better forecasting performance for one and for two input variables.
Algoritmo Evolutivo Eficiente Aplicado a la Planeación de la Expansión de Sistemas de Distribución
García,Carlos; García,Edwin; Villada,Fernando;
Información tecnológica , 2012, DOI: 10.4067/S0718-07642012000400002
Abstract: the optimization of the expansion planning of the real distribution system in the city of medellin in colombia, is analyzed in this work. the distribution system has 155 nodes and 154 branches at a voltage level of 13200 volts. efficient evolutionary algorithms are applied, with the purpose of observing their improvements and performance when compared with conventional evolutionary algorithms. besides, a mono-stage and mono-objective distribution planning model, which objective function is the optimization of construction costs and technical losses of the system is also studied. finally, the impact of specially designed efficient operators for optimization is discussed and the estimated costs are analyzed.
Aplicación de las Redes Neuronales en la Protección Diferencial de Generadores Sincrónicos
Villada,Fernando; Valencia,Jaime A; Orille,Angel L;
Información tecnológica , 2006, DOI: 10.4067/S0718-07642006000500013
Abstract: this study proposes a new algorithm for the differential protection of synchronous generators based on finite impulse response artificial neural networks. also, a model for a synchronous machine was developed. the model allowed simulation of internal defects in the windings of the stator using the atp-emtp electromagnetic transient program. this was done to generate training patterns for neural networks. the results led to the conclusion that the new schemes proposed for differential protection were more effective than those known to date. response times of about 2.5 microseconds were obtained against internal faults, with a high capacity for discrimination between internal and external faults.
Análisis de los Flujos de Potencia de Sistemas Eléctricos y su Interpretación Física
Mu?oz,Nicolás; Villada,Fernando; Cadavid,Diego R;
Información tecnológica , 2012, DOI: 10.4067/S0718-07642012000500007
Abstract: in this paper, the instantaneous power theory of the institute of electrical and electronics engineers (ieee, std. 1459 of 2010) used for single-phase electric systems is expanded to three-phase electric systems. a general instantaneous power expression is obtained through instantaneous voltages and currents. this expression is useful to explain the phenomena in electrical systems. this expression is also verified through experimental tests relating power flow and its causes. there are numerous instantaneous power expression reported in the literature, but these expressions do not relate physically and mathematically the electrical phenomena and its causes. for this reason, it is proposed to use the instantaneous power theory to explain physical phenomena in electrical systems contributing with a power theory that can be simultaneity used for measuring or monitoring to revenue purposes, for evaluating the power quality, for designing active filters, and for detecting sources of harmonic distortion.
Aplicación de las Redes Neuronales al Pronóstico de Precios en el Mercado de Valores
Villada,Fernando; Mu?oz,Nicolás; García,Edwin;
Información tecnológica , 2012, DOI: 10.4067/S0718-07642012000400003
Abstract: an artificial neural network model to forecast the price of two of the main shares traded in the colombian stock exchange is proposed in this work. the model is applied to study the shares of ecopetrol and preferencial bancolombia, companies that trade in the stock exchanges of colombia and new york. two network structures including the daily price series in the first and the price series plus the dollar index dxy in the latter are used. different neural networks configurations are trained using a series of six months, where five months are used as training patterns and the next month is left to test the predictive capabilities of the network. the results show good performance of the neural networks with low training and testing errors.
Page 1 /23579
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.