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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Controlador supervisório inteligente para sistemas híbridos eólico-diesel-bateria de pequeno porte. / An intelligent supervisory controller for wind-diesel-battery systems.

Martinez Bolaños, Julio Romel 07 December 2007 (has links)
Este trabalho apresenta o desenvolvimento e simulação de um Controlador Supervisório Inteligente para sistemas híbridos de energia de pequeno porte. O controlador utiliza técnicas de inteligência artificial, baseadas em redes neurais artificiais e lógica neuro-fuzzy, para realizar previsões de velocidade de vento e demanda de curto prazo, permitindo a tomada de decisões otimizadas de despacho para o sistema híbrido de energia. Os principais objetivos do controlador são: o atendimento à carga, a maximização na utilização da fonte renovável eólica e a redução da participação do gerador diesel, assim como são tomados procedimentos adequados para preservar a vida útil da bateria. Um modelo computacional foi criado para calcular o balanço energético de qualquer sistema híbrido a partir de séries de dados medidos de demanda e velocidade de vento. A avaliação do desempenho do controlador foi realizada comparando-se os resultados obtidos com dois outros algoritmos comumente usados para controle de sistemas híbridos. Também foi feita uma análise econômica simplificada usando a figura de mérito do custo de ciclo de vida (CCV) para destacar as vantagens do novo controlador supervisório inteligente para sistemas híbridos. / This work presents the development and simulation results of an Intelligent Supervisory Controller for hybrid power systems. The controller uses artificial intelligence techniques, based on artificial neural networks and neuro-fuzzy logic, to forecast both wind power and load, and to take optimal dispatch decisions for hybrid power systems. The main controller objectives are: supply the load, priorize wind power and minimize diesel contribution while following appropriate procedures to preserve batteries life. A simulation tool has been created to compute the energy balance of any hybrid system using measured load and wind speed time series. The performance analysis was carried out by comparing the simulation results against two other common hybrid systems\' control algorithms. Also, a simplified life cycle cost analysis (CCV) has been executed in order to point out the economic advantages of the new intelligent supervisory controller for hybrid power systems.
2

Controlador supervisório inteligente para sistemas híbridos eólico-diesel-bateria de pequeno porte. / An intelligent supervisory controller for wind-diesel-battery systems.

Julio Romel Martinez Bolaños 07 December 2007 (has links)
Este trabalho apresenta o desenvolvimento e simulação de um Controlador Supervisório Inteligente para sistemas híbridos de energia de pequeno porte. O controlador utiliza técnicas de inteligência artificial, baseadas em redes neurais artificiais e lógica neuro-fuzzy, para realizar previsões de velocidade de vento e demanda de curto prazo, permitindo a tomada de decisões otimizadas de despacho para o sistema híbrido de energia. Os principais objetivos do controlador são: o atendimento à carga, a maximização na utilização da fonte renovável eólica e a redução da participação do gerador diesel, assim como são tomados procedimentos adequados para preservar a vida útil da bateria. Um modelo computacional foi criado para calcular o balanço energético de qualquer sistema híbrido a partir de séries de dados medidos de demanda e velocidade de vento. A avaliação do desempenho do controlador foi realizada comparando-se os resultados obtidos com dois outros algoritmos comumente usados para controle de sistemas híbridos. Também foi feita uma análise econômica simplificada usando a figura de mérito do custo de ciclo de vida (CCV) para destacar as vantagens do novo controlador supervisório inteligente para sistemas híbridos. / This work presents the development and simulation results of an Intelligent Supervisory Controller for hybrid power systems. The controller uses artificial intelligence techniques, based on artificial neural networks and neuro-fuzzy logic, to forecast both wind power and load, and to take optimal dispatch decisions for hybrid power systems. The main controller objectives are: supply the load, priorize wind power and minimize diesel contribution while following appropriate procedures to preserve batteries life. A simulation tool has been created to compute the energy balance of any hybrid system using measured load and wind speed time series. The performance analysis was carried out by comparing the simulation results against two other common hybrid systems\' control algorithms. Also, a simplified life cycle cost analysis (CCV) has been executed in order to point out the economic advantages of the new intelligent supervisory controller for hybrid power systems.
3

Design and Implementation of a Supervisory Controller for PV and Storage

Persson, Björn January 2018 (has links)
Battery energy storage systems are a key factor for enabling a continuous increase of the fraction of photovoltaics in the Swedish electricity grid. One big challenge is to utilise all potential services of such a storage system. The aim of this study was to improve the supervisory controller for an existing battery storage and photovoltaic solution marketed by the Swedish company Ferroamp AB. This has been done by developing a combined peak reduction and time-of-use bill management algorithm, together with a simulation and evaluation software for optimisation of algorithm parameters. The algorithms and tools were evaluated using an installation made by Ferroamp AB and Vattenfall Eldistribution AB as a case study. Sensitivity analyses has been performed on economic parameters and length of the algorithm training data set. Improvement of economic profit, in this case study, were 300 % compared to the currently used algorithm and 32 % compared to a conventional threshold peak reduction algorithm. Despite this improvement, the battery energy storage system is shown to be non-profitable, with the economic profit only covering 36 % of the investment costs, not taking interest rate into account. Like in many other studies, power storage was found more profitable than energy storage. An increase of the grid power tariff and the grid energy fee of 30 % to 40 % is found to make the system viable. One interesting finding is that by using the proposed optimal algorithm, 55 % of the cycle life of the battery storage is still accessible for other services when considering 10 years of economic depreciation time for the system.
4

Dynamic modeling and feedback control with mode-shifting of a two-mode electrically variable transmission

Katariya, Ashish Santosh 31 August 2012 (has links)
This thesis develops dynamic models for the two-mode FWD EVT, develops a control system based on those models that is capable of meeting driver torque demands and performing synchronous mode shifts between different EVT modes while also accommodating preferred engine operating points. The two-input two-output transmission controller proposed herein incorporates motor-generator dynamics, is based on a general state-space integral control structure, and has feedback gains determined using linear quadratic regulator (LQR) optimization. Dynamic modeling of the vehicle is categorized as dynamic modeling of the mechanical and electrical subsystems where the mechanical subsystem consists of the planetary gear sets, the transmission and the engine whereas the electrical subsystem consists of the motor-generator units and the battery pack. A discussion of load torque is also considered as part of the mechanical subsystem. With the help of these derived dynamic models, a distinction is made between dynamic output torque and steady-state output torque. The overall control system consisting of multiple subsystems such as the human driver, power management unit (PMU), friction brakes, combustion engine, transmission control unit (TCU) and motor-generator units is designed. The logic for synchronous mode shifts between different EVT modes is also detailed as part of the control system design. Finally, the thesis presents results for responses in individual operating modes, EVT mode shifting and a full UDDS drive cycle simulation.
5

Modelling, simulation and control of the filtration process in a submerged anaerobic membrane bioreactor treating urban wastewater

Robles Martínez, Ángel 28 November 2013 (has links)
El reactor anaerobio de membranas sumergidas (SAnMBR) está considerado como tecnología candidata para mejorar la sostenibilidad en el sector de la depuración de aguas residuales, ampliando la aplicabilidad de la biotecnología anaerobia al tratamiento de aguas residuales de baja carga (v.g. agua residual urbana) o a condiciones medioambientales extremas (v.g. bajas temperaturas de operación). Esta tecnología alternativa de tratamiento de aguas residuales es más sostenible que las tecnologías aerobias actuales ya que el agua residual se transforma en una fuente renovable de energía y nutrientes, proporcionando además un recurso de agua reutilizable. SAnMBR no sólo presenta las principales ventajas de los reactores de membranas (i.e. efluente de alta calidad, y pocas necesidades de espacio), sino que también presenta las principales ventajas de los procesos anaerobios. En este sentido, la tecnología SAnMBR presenta una baja producción de fangos debido a la baja tasa de crecimiento de los microorganismos implicados en la degradación de la materia orgánica, presenta una baja demanda energética debido a la ausencia de aireación, y permite la generación de metano, el cual representa una fuente de energía renovable que mejora el balance energético neto del sistema. Cabe destacar el potencial de recuperación de nutrientes del agua residual bien cuando el efluente es destinado a irrigación directamente, o bien cuando debe ser tratado previamente mediante tecnologías de recuperación de nutrientes. El objetivo principal de esta tesis doctoral es evaluar la viabilidad de la tecnología SAnMBR como núcleo en el tratamiento de aguas residuales urbanas a temperatura ambiente. Por lo tanto, esta tesis se centra en las siguientes tareas: (1) implementación, calibración y puesta en marcha del sistema de instrumentación, control y automatización requerido; (2) identificación de los parámetros de operación clave que afectan al proceso de filtración; (3) modelación y simulación del proceso de filtración; y (4) desarrollo de estrategias de control para la optimización del proceso de filtración minimizando los costes de operación. En este trabajo de investigación se propone un sistema de instrumentación, control y automatización para SAnMBR, el cual fue esencial para alcanzar un comportamiento adecuado y estable del sistema frente a posibles perturbaciones. El comportamiento de las membranas fue comparable a sistemas MBR aerobios a escala industrial. Tras más de dos años de operación ininterrumpida, no se detectaron problemas significativos asociados al ensuciamiento irreversible de las membranas, incluso operando a elevadas concentraciones de sólidos en el licor mezcla (valores de hasta 25 g·L-1 ). En este trabajo se presenta un modelo de filtración (basado en el modelo de resistencias en serie) que permitió simular de forma adecuada el proceso de filtración. Por otra parte, se propone un control supervisor basado en un sistema experto que consiguió reducir el consumo energético asociado a la limpieza física de las membranas, un bajo porcentaje de tiempo destinado a la limpieza física respecto al total de operación, y, en general, un menor coste operacional del proceso de filtración. Esta tesis doctoral está integrada en un proyecto nacional de investigación, subvencionado por el Ministerio de Ciencia e Innovación (MICINN), con título ¿Modelación de la aplicación de la tecnología de membranas para la valorización energética de la materia orgánica del agua residual y la minimización de los fangos producidos¿ (MICINN, proyecto CTM2008-06809- C02-01/02). Para obtener resultados representativos que puedan ser extrapolados a plantas reales, esta tesis doctoral se ha llevado a cabo utilizando un sistema SAnMBR que incorpora módulos comerciales de membrana de fibra hueca. Además, esta planta es alimentada con el efluente del pre-tratamiento de la EDAR del Barranco del Carraixet (Valencia, España). / Robles Martínez, Á. (2013). Modelling, simulation and control of the filtration process in a submerged anaerobic membrane bioreactor treating urban wastewater [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34102 / Premios Extraordinarios de tesis doctorales

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