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- Modelo da característica magnética do gerador eléctrico de relutância comutado aplicado a conversores de energia eólicaPublication . Lobato, Pedro; Rafael, Silviano; Pires, A. J.
- An Adaptive PID Speed Controller for an 8/6 Switched Reluctance MachinePublication . Rafael, Silviano; Santos, P. J.; Pires, A. J.This paper presents a classical controller with parameters adaptation capability, in an automatic way. This controller is based on a PID where a parameters adaptation algorithm is used and applied to the switched reluctance motor (SRM) speed control. This PID design do not require any kind of adjustment or calibration from the operator. The parameters adaptation algorithm implemented is based on one fuzzy system with a Takagi-Sugeno inference mechanism with some simplifications. These simplifications had the goal to select the parameters adaptation algorithm contributing for a fast controller response. The developed adaptive PID algorithm was modelled and simulated.
- Load forecasting, the importance of the probability “tails” in the definition of the input vectorPublication . Santos, P. J.; Rafael, Silviano; Pires, A. J.The load forecast is part of the global management of the electrical networks, namely at the transport and distribution levels. This type of methodologies allows to the system operator, to establish and take some important decisions concerning to the mix production and network management, with the minimum of discretionarity. The load forecast in particularly the peak load forecast, represents an important economic improvement in the global electrical systems. Also in certain circumstances, allow reducing the contribution of the non-renewable units, in the daily mixing production. The regressive methodologies specially the artificial neural networks, are normally used in this type of approaches, with satisfactory results. In this paper is proposed a careful analysis in order to define the best-input vector in order to feed the regressive methodology. It was establish careful analyses of the load consumption series. It makes use of a procedural sequence for the pre-processing phase that allows capturing certain predominant relations among certain different sets of available data, providing a more solid basis to decisions regarding the composition of the input vector to ANN. The methodological approach is discussed and a real life case study is used for illustrating the defined steps, the ANN and the quality level of the results.
- Máquina Elétrica de Relutância Comutada (8/6) como motor: do modelo matemático até ao controlo de posiçãoPublication . Rafael, Silviano; Lobato, Pedro; Pires, A. J.
- SRM sensorless for position control based on a frequency modulation systemPublication . Rafael, Silviano; Branco, P. J. Costa; Pires, A. J.This paper presents a study of a system to detect the angular position of the shaft of an 8/6 Switched Reluctance Machine (SRM) for position control. The detection system is independent of the machine circuits and is based on the indirect measurement of the induction coefficient, using a diagnostic coil. This induction coefficient, variable with the angular position, is the variable element of an oscillator, producing a frequency modulation. The intrinsic problems that this indirect position measurement system presents, particularly related with position control, are explained. The influence of the machine temperature, of the rotor speed and of the magnetic circuit saturation are also discussed.