ESTGL - DICCF - Artigo em ata de evento científico internacional
URI permanente para esta coleção:
Navegar
Percorrer ESTGL - DICCF - Artigo em ata de evento científico internacional por tipo de recurso "journal article"
A mostrar 1 - 7 de 7
Resultados por página
Opções de ordenação
- Active Flux Based Finite Control Set Model Predictive Control of Synchronous Reluctance Motor DrivesPublication . Hadla, Hazem; Cruz, SérgioThis paper presents two new finite control set model predictive control (FCS-MPC) strategies for synchronous reluctance motor (SynRM) drives, using the active flux concept. Both control strategies guarantee a fast and independent control of the torque and active flux of the SynRM, in order to obtain a high performance drive. The first strategy relies on a more conventional implementation of a FCS-MPC algorithm, which requires some effort to tune the weighting factors used in the cost function. The second control approach corresponds to a simplification of the first one, and allows a reduction of the calculation time associated to the predictions stage of the algorithm and, at the same time, avoids the use of weighting factors in the cost function. This allows to simplify the implementation of the control system, obtaining the same dynamic performance as with the first strategy. Experimental and simulation results verify the validity and effectiveness of the two proposed control schemes for SynRM drives. Furthermore, a state-of-the-art control technique like direct torque control is also considered in the paper, for performance comparison purposes.
- An encoderless high-performance synchronous reluctance motor drivePublication . Hadla, Hazem; Cruz, Sérgio; Oliveira, Álvaro; Cavaleiro, Diogo; Branco, RicardoThis paper presents an encoderless high-performance synchronous reluctance motor drive for traction applications. The control system is based on the active flux concept and a hybrid rotor position estimation algorithm is used, being this algorithm based on the injection of high-frequency signals at low speeds and on the position of the active flux vector for medium and high-speeds. A smooth transition algorithm between the two rotor position estimation methods is provided. Moreover, in order to improve the efficiency of the overall drive system, a loss minimization algorithm is proposed in order to reduce the motor copper losses when operating in steady-state. Experimental results obtained in the laboratory confirm the validity and adequacy of the proposed algorithms for the developed drive system.
- Células de Combustível : Uma Tecnologia Para a Geração DistribuídaPublication . Santos, Fernando; Jorge, Humberto Manuel Matos; Santos, Fernando António Castilho Mamede dosEsta comunicação visa o estudo de sistemas de produção de energia eléctrica a partir de combustíveis hidrogenados e toda a sua envolvente como forma de contribuir para apresentação de soluções técnicas que conduzam ao desenvolvimento sustentado. Muito embora esta forma de produção de energia esteja ainda numa fase de investigação, foi possível, através deste estudo, observar-se um conjunto de resultados importantes para o conhecimento, escolha e utilização adequada da mesma. Neste trabalho é definido o enquadramento da produção de energia eléctrica tendo como base a economia do hidrogénio e o seu “estado da arte”. É abordado um conjunto de questões técnicas relacionadas com as células de combustível, nomeadamente o seu desempenho. Recorre-se à utilização de dois tipos de células de combustíveis de forma a efectuarem-se ensaios de curvas características, curvas de potência e perdas, ensaios para a validação da lei de Faraday e rendimentos.
- Conversor DC/DC para Interligação de Armazenamento e Produção de Energia com Origem em Fontes RenováveisPublication . Santos, Fernando; Cruz, Sérgio; Jorge, Humberto Manuel MatosO trabalho de investigação aqui reportado tem como objectivo último a integração de diferentes módulos de produção e armazenamento de energia, com várias cargas eléctricas, por intermédio de um barramento DC, estando este interligado com a rede eléctrica de forma a optimizar, do ponto de vista económico, as trocas de energia entre esta e tal barramento. Em concreto, este trabalho de investigação centra-se nos conversores de potência necessários à interligação dos diferentes módulos produtores e de armazenamento de energia eléctrica ao barramento. De forma a compatibilizar os equipamentos de diferentes fabricantes, com diferentes tensões de funcionamento, torna-se necessário implementar conversores DC/DC que permitam a ligação destes ao barramento DC, com elevado rendimento e possibilitando a gestão da energia eléctrica fornecida/pedida por cada módulo. Este artigo expõe o dimensionamento e explica o funcionamento dos conversores DC/DC que serão usados no sistema laboratorial implementado para o efeito. Após o bom dimensionamento destes será possível interligar o barramento DC à rede, através de um rectificador PWM, sendo possível gerir de forma eficiente o fluxo de energia entre o barramento DC e a rede de distribuição de energia eléctrica. A partir desse ponto pode ser feita uma análise económica do mercado da energia e do impacto destes sistemas no diagrama de carga da rede.
- ENERGY MANAGEMENT ALGORITHM FOR END INSTALLATIONS WITH RENEWABLE PRODUCTION AND STORAGEPublication . Santos, Fernando; Hadla, HazemThis paper presents an algorithm to manage different renewable energy sourceswith storage. The objective of this algorithm is to regulate and control the outputcurrents of the DC-DC converters, which are directly connected to both the DC bus andthe inverter. Here, the inverter allows exchanging the energy between the DC bus andthe AC grid. The implementation of the proposed algorithm to end facilities in aliberalized market is also presented and tested. In addition, the benefits of suchimplementation, using eight dispatches, to the operators of the grid is demonstrated.The algorithm considers several situations of the consumption, energy production,various storage capacities, grid manager's demands, forecasts of production andconsumption loads. The results, which are obtained by the proposed algorithm, show agood regulation and control of the currents of the DC-DC converters, therefore a betterenergy management is achieved being this supported by an extensive theoretical analysis.
- Performance Comparison of Field-oriented Control, Direct Torque Control, and Model-predictive Control for SynRMsPublication . Hadla, Hazem; Santos, FernandoSimulation studies of three synchronous reluctance motor (SynRM) control strategies are presented: field-oriented control (FOC), direct torque control (DTC), and finite-set model-predictive control (FS-MPC). FOC uses linear controllers and pulse-width modulation to control the fundamental components of the load voltages vectors. In contrast, DTC and FS-MPC are nonlinear strategies wherein the voltage vectors are directly generated in the absence of a modulator. Theoretical operating principles and control structures of these control strategies are presented. Moreover, a comparative analysis of the static and dynamic performance of the control strategies is conducted using Matlab/Simulink to identify their advantages and limitations. It is confirmed that each of the control strategies has merits and that all three of them satisfy the requirements of modern high-performance drives.
- Predictive Torque Control of SynRM Drives with online MTPA Trajectory Tracking and Inductances EstimationPublication . Hadla, Hazem; Cruz, Sérgio; Varatharajan, AnantaramThis paper proposes a new predictive torque control algorithm for synchronous reluctance motor drives with the ability to track online the maximum torque per ampere trajectory. An additional term is included in the cost function of the predictive control algorithm which uses an adaptive weighting factor to improve the dynamic behavior of the drive system. As the derivative of torque with respect to the current angle depends on the values of the apparent and incremental inductances, the apparent inductances are estimated online based on the values of the flux linkage and current components while the incremental inductances are estimated using a recursive least squares (RLS) algorithm. Experimental results validate the proposed control algorithm and demonstrate a remarkable performance both in steady-state and during transients, as well as a reduction of the current ripple and audible noise.