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Santos, Fernando Miguel Soares Mamede dos Santos
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- 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.
- DESIGN OF A MULTIFUNCTIONAL FLYBACK DCDC CONVERTER WITH CURRENT CONTROLPublication . Santos, Fernando; Jorge, Humberto; Cruz, SérgioThis paper proposes a set of design techniques to build a DC-DC converter for the interconnection of different sources of renewable energy with storage elements and flexible load profiles. This type of multifunctional DCDC converter is essential to provide the dispatch of energy generation to storage connected to the DC bus or allow energy exchange with the AC network, with different decision modes as a function of the state of charge of batteries, with the forecast of the consumption of a house with renewable production. This work emphasizes the application of a method to design switched mode flyback converters with current control capabilities on the output side. The paper discusses in detail the design of the different parts of the converter: the power circuit, the control signals and the auxiliary power supply. The experimental results obtained with the prototype of the DC-DC converter built validate the theoretical analysis and the proposed design techniques. Moreover, the results demonstrate the good dynamic performance of the converter, which exhibits a good current control capability on the output side, being able to follow closely the reference value in a very short period of time, and ensuring at the same time a stable steady-state response.
- 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.
- 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.
- Parameter Identification for Simplfied Set Current Predictive Control of SynRM DrivesPublication . Hadla, Hazem; Santos, FernandoIn this work, a simplified finite set current predictive control (FS-CPC) is presented for the synchronous reluctance motor (SynRM) drive due to its fast response and simplicity. However, the prediction model of this control is obtained from a mathematical model of the motor which contains many parameters, and thus any parametric uncertainly might lead to inaccuracies of the predictive algorithm. Therefore, the online identification of the stator resistance, and inductances of the motor are implemented using the recursive least square (RLS) technique. The identification method is built in Matlab/Simulink, and the obtained simulation results reveal its strong accuracy and effectiveness. Thus, the estimation technique is seen as a good option to be selected and combined with the simplified FS-CPC of the SynRM.