@article {85, title = {Active and Reactive Power Control for Wind Turbine Based on a MIMO 2-Sliding Mode Algorithm With Variable Gains}, journal = {Energy Conversion, IEEE Transactions on}, volume = {28}, year = {2013}, month = {Sept}, pages = {682-689}, abstract = {

This study proposes a power control strategy for a grid-connected variable-speed wind turbine, based on a doubly-fed induction generator (DFIG) with slip power recovery. The control objectives vary with the zones of operation (dependant on the wind speed), aiming to maximize the active power in the partial load zone and to limit it when operating within the full load zone, while regulating the stator reactive power following grid requirements. The control design, based on the second-order sliding modes (SOSM) and Lyapunov, uses a modified version of the super-twisting algorithm with variable gains which can be applied to nonlinear multiple inputs-multiple outputs (MIMO) systems. The well-known robustness of the sliding techniques, the simplicity of the algorithm, and the adaptive characteristic of its gains are used together in this study to obtain a controller able to deal robustly with the exacting challenges presented by these systems. An additional benefit of the proposal lies in the smoothness of the control action, an important issue regarding applied mechanical efforts. Representative results obtained by simulation of the controlled system are shown and discussed.

}, keywords = {asynchronous generators, control design, DFIG, doubly-fed induction generator, energy conversion, full load zone, Gain, Lyapunov method, Mathematical model, MIMO, MIMO 2-sliding mode algorithm, MIMO communication, nonlinear multiple inputs-multiple outputs system, partial load zone, Power control, power generation control, power grid-connected variable-speed wind turbine, power grids, reactive power control, Rotors, second-order sliding modes, second-order sliding modes (SM), slip power recovery, SOSM, stator reactive power control strategy, Stators, super-twisting algorithm, variable gains, variable structure systems, Wind power generation, Wind speed, wind turbines}, issn = {0885-8969}, doi = {10.1109/TEC.2013.2272244}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6582571}, author = {Evangelista, Carolina A. and Valenciaga, Fernando and Puleston, Pablo F.} } @article {88, title = {Lyapunov-Designed Super-Twisting Sliding Mode Control for Wind Energy Conversion Optimization}, journal = {Industrial Electronics, IEEE Transactions on}, volume = {60}, year = {2013}, month = {Feb}, pages = {538-545}, abstract = {

This work explores an adaptive second-order sliding mode control strategy to maximize the energy production of a wind energy conversion system (WECS) simultaneously reducing the mechanical stress on the shaft. Such strategy successfully deals with the random nature of wind speed, the intrinsic nonlinear behavior of the WECS, and the presence of model uncertainties and external perturbations acting on the system. The synthesized adaptive controller is designed from a modified version of the super-twisting (ST) algorithm with variable gains. The suitability of the proposed strategy is proved by extensive computer-aided simulations employing a comprehensive model of the system emulating realistic conditions of operation, i.e., considering variations in the parameters and including external disturbances. Additionally, a second controller based on the traditional ST algorithm is also designed and simulated. Results are presented and discussed in order to establish a comparison framework.

}, keywords = {adaptive control, adaptive second-order control strategy, Algorithm design and analysis, CAD, Computational modeling, control system synthesis, Control systems, direct energy conversion, extensive computer-aided simulations, external disturbances, external perturbations, Generators, intrinsic nonlinear behavior, Lyapunov methods, Lyapunov-designed super-twisting sliding mode control, mechanical stress reduction, model uncertainties, Sliding mode control, ST algorithm, suitability strategy, super-twisting (ST), system emulating realistic conditions, Torque, variable gains, variable structure systems, WECS, wind energy conversion optimization, wind power, Wind power generation, Wind speed, wind turbines}, issn = {0278-0046}, doi = {10.1109/TIE.2012.2188256}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6153362}, author = {Evangelista, Carolina A. and Puleston, Pablo F. and Valenciaga, Fernando and Fridman, Leonid M.} } @conference {100, title = {Active and reactive power control of a brushless doubly fed reluctance machine using high order sliding modes}, booktitle = {Electrical Machines, 2008. ICEM 2008. 18th International Conference on}, year = {2008}, month = {Sept}, abstract = {

This article develops a decoupled active and reactive power control for a variable-speed constant-frequency (VSCF) power generation system based on a brushless doubly fed reluctance machine. This machine is a forthcoming low cost candidate for applications with limited variable speed requirements such as pumping and wind generation. Basically, it allows the use of a partially rated power electronic converter and, at the same time, offers a reliable and maintenance-free operation because of its brushless feature. The control design is approached through second order sliding mode techniques. This theoretical framework permits to deal with systems described by perturbed nonlinear dynamic models, obtaining simple controllers with a finite time reaching phase and a chattering free behavior. The controller performance is assessed through exhaustive simulations.

}, keywords = {active power control, brushless doubly fed reluctance machine, brushless machines, chattering free behavior, Converters, Costs, high order sliding modes, machine control, perturbed nonlinear dynamic models, Power conversion, power electronic converter, Power electronics, Pumps, reactive power control, reluctance machines, Sliding mode control, variable structure systems, variable-speed constant-frequency power generation system, Wind energy generation, Wind power generation}, doi = {10.1109/ICELMACH.2008.4799959}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=4799959}, author = {Valenciaga, Fernando} } @article {108, title = {Power control of a solar/wind generation system without wind measurement: a passivity/sliding mode approach}, journal = {Energy Conversion, IEEE Transactions on}, volume = {18}, year = {2003}, month = {Dec}, pages = {501-507}, abstract = {

This paper deals with the control of the output power of a solar/wind stand-alone system. The control system regulates the generation of the wind subsystem in order to satisfy, jointly with the photovoltaic generation subsystem, the load and battery charge power demand. The controller is designed using a theoretical framework that unifies passivity and sliding mode techniques. The resultant control law does not need wind measurement and only relies on rotational speed and current measurements. An analysis of the acceleration estimate error is carried out and a countermeasure to compensate its effects is proposed. Finally, the performance of the controller is assessed through computer simulation, using a comprehensive nonlinear model of the plant.

}, keywords = {acceleration estimate error, angular velocity measurement, Battery charge measurement, Computer Simulation, control law, Control systems, controller design, Current measurement, current measurements, effects compensation, electric current measurement, hybrid power systems, nonlinear model, output power control, passivity/sliding mode approach, photovoltaic generation subsystem, photovoltaic power systems, Power control, power demand, Power generation, power generation control, Power measurement, rotational speed measurements, Sliding mode control, sliding mode techniques, Solar power generation, solar/wind generation system, stand-alone system, variable structure systems, Wind energy generation, wind generation subsystem control, Wind power generation, wind turbines}, issn = {0885-8969}, doi = {10.1109/TEC.2003.816602}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1247775}, author = {Valenciaga, Fernando and Puleston, Pablo F. and Battaiotto, Pedro E.} } @article {72, title = {Dynamical sliding mode power control of wind driven induction generators}, journal = {Energy Conversion, IEEE Transactions on}, volume = {15}, year = {2000}, month = {Dec}, pages = {451-457}, abstract = {

This paper concerns power regulation of variable-speed wind energy conversion systems. These systems have two regions of operation, depending on the tip speed ratio of the wind turbines. They are distinguished by a minimum phase behavior in one of these regions and a nonminimum phase one in the other. A sliding mode control strategy is proposed that assures stability in both regions of operation and imposes the ideally designed feedback control solution in spite of model uncertainties. Moreover, power regulation by the proposed sliding control in the minimum phase region is completely robust to wind disturbances and parameter uncertainties

}, keywords = {asynchronous generators, Control systems, dynamical sliding mode power control, feedback, ideally designed feedback control solution, Induction generators, machine control, minimum phase behavior, minimum phase region, model uncertainties, nonminimum phase region, parameter uncertainties, Power control, Power generation, power regulation, Power system modeling, Robustness, Sliding mode control, stability, tip speed ratio, variable speed gear, variable structure systems, variable-speed wind energy conversion systems, wind disturbances, wind driven induction generators, Wind energy, Wind energy generation, Wind power generation, wind turbines}, issn = {0885-8969}, doi = {10.1109/60.900507}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=900507}, author = {De Battista, Hern{\'a}n and Mantz, Ricardo J. and Christiansen, Carlos F.} }