Nonlinear robust control to maximize energy capture in a variable speed wind turbine (original) (raw)
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2009 IEEE International Conference on Systems, Man and Cybernetics, 2009
The emergence of wind turbine systems for electric power generation can help satisfy the growing global demand. To maximize wind energy captured in variable speed wind turbines at low to medium wind speeds, a robust control strategy is presented. The proposed strategy simultaneously controls the blade pitch and tip speed ratio, via the rotor angular speed, to an optimum point at which the efficiency constant (or power coefficient) is maximum. The control method allows for aerodynamic rotor power maximization without the restrictions of exact wind turbine model knowledge. A series of numerical results show that the wind turbine can be controlled to achieve maximum energy capture.
IET Control Theory & Applications, 2012
In this study, an optimum seeking-based robust non-linear controller is proposed to maximise wind energy captured by variable speed wind turbines at low-to-medium wind speeds. The proposed strategy simultaneously controls the blade pitch angle and tip-speed ratio, through the turbine rotor angular speed, to an optimal point at which the power coefficient, and hence the wind turbine efficiency, is maximum. The optimal points are given to the controller by an optimisation algorithm that seeks the unknown optimal blade pitch angle and rotor speed. The control method allows for aerodynamic rotor power maximisation without exact knowledge of the wind turbine model. A representative numerical simulation is presented to show that the wind turbine can be accurately controlled to achieve maximum energy capture.
Backstepping nonlinear control to maximize energy capture in a variable speed wind turbine
International Journal of Electrical and Computer Engineering (IJECE)
We are considering the problem of maximum power point tracking MPPT in wind energy conversion system (WECS). The paper proposes a new control strategy to maximize the wind aerodynamic energy captured in variable speed wind turbine with a separately excited DC-Generator and transformed to the battery through a controlled DC-DC converter. The proposed strategy controls the stip speed ratio via the rotor angular speed to an optimum point at wich the power coefficient is maximal. The controller is designed using the backstepping technique. A formal analysis based on lyapunov stability is developed to describe the control system performances. In addition to closed-loop global asymptotic stability, it is proved that the controller actually meets the MPPT requirement. The above results are confirmed by simulations.
2020
This paper deals with the problem of maximizing the extracted power from a wind turbine in the presence of model uncertainties and input saturation. An adaptive second-order integral terminal sliding mode speed control method is utilized to address this problem. The presented method benefits from the advantages of several control techniques, i.e., adaptability, robustness, finite-time convergence, and the capability of coping with the input saturation. The robust nature of the designed controller causes its high performance in facing the uncertainties in the wind turbine model. In this paper, to compensate for the effect of input saturation, an auxiliary dynamic variable is added to the tracking error and also an adaptation law is designed so that the finite-time convergence of the closed-loop system can be achieved. Moreover, to reduce the mechanical stresses which are the result of the chattering phenomenon, a second-order sliding surface is employed. The finite-time convergence o...
Nonlinear Power Control Strategies for Variable- Speed Wind Turbines
International Journal of Renewable Energy Research, 2017
These last years, several important researches are about the controls of a variable-speed wind turbines. The objectives of these controls are the optimization of power in the zone of lows winds and the regulation of the power in the zone of intense winds and reduction of the mechanical constraints applied to the wind turbines. The productivity of the wind turbines is limited by available linear controls. In this paper, we will have developed nonlinear controls that satisfy the control objectives of variable-speed wind turbines. The nonlinear controls are tested and compared between them for lows and intense winds. The simulation results on Matlab software show that the nonlinear controls satisfy the desired objectives.
Robust Active Disturbance Rejection Control Approach to Maximize Energy Capture in Variable-Speed Wind Turbines, 2013
This paper proposes an alternative robust observer-based linear control technique to maximize energy capture in a 4.8 MW horizontal-axis variable-speed wind turbine. The proposed strategy uses a generalized proportional integral (GPI) observer to reconstruct the aerodynamic torque in order to obtain a generator speed optimal trajectory. Then, a robust GPI observer-based controller supported by an active disturbance rejection (ADR) approach allows asymptotic tracking of the generator speed optimal trajectory. The proposed methodology controls the power coefficient, via the generator angular speed, towards an optimum point at which power coefficient is maximum. Several simulations (including an actuator fault) are performed on a 4.8 MW wind turbine benchmark model in order to validate the proposed control strategy and to compare it to a classical controller. Simulation and validation results show that the proposed control strategy is effective in terms of power capture and robustness.
Maximizing the performance of variable speed wind turbine with nonlinear output feedback control
Procedia Engineering, 2012
In this paper, the problem of designing an output feedback regulation control scheme of variable speed wind energy conversion system with rotor speed measurement is addressed. The controller consists of the combination of a linear control for blade pitch angle with a nonlinear H ∞ torque control and a finite-time convergent Super-Twisting Observer. This strategy does not use the wind velocity and avoid the chattering phenomena. The nonlinear H ∞ torque control take into account the nonlinear dynamic aspect of the wind turbine and the turbulent nature of the wind, also mitigate the effects of external disturbances that occur at the input and output of the system. The controller exhibits better power and speed regulation when compared to classic linear controllers. In order to validate the mathematical model and evaluate the performance of proposed controller, we used the National Renewable Energy Laboratory (NREL) aerolastic wind turbine simulator FAST. Simulation and validation results show that the proposed control strategy is effective in terms of power and speed regulation.