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Robust control algorithms may improve the efficiency of wave power conversion systems since they present intrinsic nonlinear dynamics and the system uncertainties. Sometimes, the generators that can operate al variable speed (e.g. double feed induction generator) are used at wave power generation plants, since they may improve the system efficiency to generate power when compared to fixed speed generators...
Electromobility lies on the crossroad between mobility and energy systems. The individual heterogeneous behaviours, and especially the spatial distribution and dynamism of the system make it a complex one. In this work, it is proposed an agent-based model to reflect this complexity and create a bottomup model which addresses specifically driving and charging behaviours of the individual agents. The...
The control of plasma in nuclear fusion has been revealed as a promising application of Control Engineering, with increasing interest in the control community during last years. In this paper it is developed a control-oriented linear model for the control of plasma current. For this purpose, it is provided a summary of the background necessary to deal with control problems in tokamak-based nuclear...
The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a robust control for variable speed wind power generation that incorporates a doubly feed induction generator is described. In the presented design it is applied the so called vector control theory. The proposed control scheme uses stator flux-oriented control for the...
The structure and behaviour of Electrical Grids share many of the properties of Complex Computer Systems, with microgrids and other decentralised electrical systems attached to them, so they can be interpreted as Systems of Systems. Furthermore, the evolution of future electrical systems will bring a higher degree of decentralisation, especially concerning production and control. To deal with this...
As a consequence of the continued increase in the worldwide demand of energy the need to achieve new sources of power has come out as a very important issue. In this sense, nuclear fusion has arisen to be a promising source of energy which has entailed an increasing interest in solving the different control problems existing in the nuclear fusion reactors such as tokamaks. The aim of this manuscript...
Modern wind turbines are capable to work in variable speed operations. These wind turbines are provided with adjustable speed generators, like the double feed induction generator. One of the main advantage of adjustable speed generators is that they improve the system efficiency compared to fixed speed generators because turbine speed is adjusted as a function of wind speed to maximize output power...
The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a robust control for variable speed wind power generation that incorporates a doubly feed induction generator is described. The electrical systems incorporates a wound rotor induction machine with back-to-back three phase power converter bridges between its rotor and the...
With eyes focused on simulation the authors review some of the main topics of hybrid renewable energy systems (HRES). Then they describe an object oriented model of a simple example of one of such systems, a micro-grid, oriented to designing a decentralized supervisor control. The model has been implemented using AnyLogic.
The design of fractional order-holds (FROH) of correcting gains beta isin [-1, 1] (potentially and possibly including zero-order-holds, ZOH with beta = 0, and first-order-holds, FROH with beta = 1) is discussed related to achieving output deviations being close with respect to its sampled values. A squared error time- integral between the current output and its sampled values is minimized to yield...
This paper presents an indirect adaptive stabilization scheme for first-order continuous-time systems under saturated input which is described by a sigmoidal function. The singularities are avoided through a modification scheme for the estimated plant parameter vector so that its associated Sylvester matrix is guaranteed to be non-singular and then the estimated plant model is controllable. The modification...
In this paper the performance of the Wells turbine has been improved, studying its stalling behaviour when the flow coefficient reaches a specific characteristic value. The generator increases its velocity when the flow coefficient of the turbine is approaching the critical point at which the turbine losses power.
Nowadays there exists a need of carrying out new features and improvements in the existing and future Tokamak devices as ITER or DEMO. The present capabilities of the control engineering and the development of fusion technologies allow the achievement new plasma configurations. These aspects, jointly with the increased performance of the computer hardware and the advances in plasma modelling and control,...
The current worldwide increasing demand of energy has pointed out the need to develop new sources of power. Nuclear fusion has turned out to be a promising source of this power which has lead to an increasing interest in finding solutions for the different tokamak control problems. In order to find suitable controllers, several kind of models have been developed and studied. In this paper, some of...
The control of plasma in nuclear fusion has been revealed as a promising application of Control Engineering, with increasing interest in the control community during last years. In this paper it is outlined a control-oriented linear model for the control of plasma current. For this purpose, it is firstly provided a summary of the background necessary to deal with control problems in tokamak-based...
This paper focuses in the design of an adaptive sliding mode control (SMC) for induction motor drives, that reduces the high frequency chattering that usually appears in the SMC schemes. The proposed design consist of a sliding mode control law that incorporates an adaptive switching gain. This adaptive switching gain avoids the need of calculating an upper limit of the system uncertainties as it...
Nuclear fusion is nowadays one of the newest and most promising clean energies, composing a new application area of Control Engineering, with new and interesting challenges for the control community. In this sense, this paper deals with the modeling of tokamak nuclear fusion reactors. In order to control the creation of unstable modes in fusion processes, it is necessary to derive numerical models...
The design of a speed sensorless PWM robust control scheme for an induction motor drive in order to control the rotor speed is proposed. The proposed design is divided in two parts. In the first one it is designed a speed estimator to estimate the rotor speed. In the second one it is developed the proposed robust control. This robust control comprises two parts, the so called inverse dynamic technique...
This paper presents a new variable structure control law that improves the performance of the control law presented in our previous work [2]. The new smoothed control law reduces the chattering phenomenon of the previous one, and therefore implies less activity control and diminish the mechanical fatigue of the system. The proposed design employs the so called vector (or field oriented) control theory...
This paper presents a new proposal of speed vector control of induction motors based on robust adaptive VSC (variable structure control) law and its experimental validation. The presented control scheme incorporates the SVPWM (space vector pulse width modulation) instead of the traditional current hysteresis comparator. The SVPWM improves the quality of the stator currents, reducing the harmonics,...
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