@article {178, title = {Multiple-input-multiple-output high-order sliding mode control for a permanent magnet synchronous generator wind-based system with grid support capabilities}, journal = {IET Renewable Power Generation}, volume = {9}, year = {2015}, pages = {925-934}, abstract = {This study presents a control design for a grid connected wind energy conversion system based on a gearless PMSG. The generation system structure comprises a three blade turbine, a 2 MW multi-pole PMSG and a full-scale back-to-back frequency converter linked to the utility grid. The proposed control scheme allows following dynamical specifications taking into account operational requirements and ancillary services imposed by the recent grid connection codes, that is, reactive power regulation and fault ride-through (FRT) capabilities. The control actions to be applied during normal grid operation are designed through second-order sliding mode techniques using a two-stage cascade structure. The multi-variable controller designed attains to regulate the active and reactive powers delivered to the grid, minimising the resistive losses into the generator and maintaining important internal variables into the desired range. This controller presents attractive advantages such as robustness against unmodelled dynamics and external perturbations, finite time convergence to the sliding surfaces and chattering mitigation. To endorse the controlled system with FRT capabilities, a switching control scheme based on voltage grid measurements is also proposed. The performance of the whole control approach is analysed through representative simulations which include parameter variations, external perturbations and three-phase voltage dips.}, keywords = {active power regulation, blade turbine, blades, chattering mitigation, control system synthesis, external perturbation, fault ride-through capability, frequency convertors, FRT capability, full-scale back-to-back frequency converter, gearless permanent magnet synchronous generator, grid connected wind energy conversion system, grid support capability, machine control, MIMO systems, multiple-input-multiple-output high-order sliding mode control design, multipole PMSG, multivariable control systems, multivariable controller design, permanent magnet generators, permanent magnet synchronous generator wind-based system, power convertors, power generation control, power generation faults, power grids, power system measurement, reactive power control, reactive power regulation, resistive loss minimization, second-order sliding mode technique, switching control scheme, synchronous generators, variable structure systems, voltage control, voltage measurement, wind power plants, wind turbines}, issn = {1752-1416}, doi = {10.1049/iet-rpg.2014.0417}, author = {Valenciaga, Fernando and Fern{\'a}ndez, Roberto. D.} } @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 {123, title = {Control of a Supercapacitor Energy Storage System for Microgrid Applications}, journal = {Energy Conversion, IEEE Transactions on}, volume = {28}, year = {2013}, month = {Sept}, pages = {690-697}, abstract = {

The proper operation of a microgrid requires storage devices that increase the inertia and avoid instability of the system. This paper presents the control of an energy storage system (ESS) based on supercapacitor in the context of grid-connected microgrids. The ESS is composed of AC/DC and DC/DC converters tied by a dc link. A single sliding mode strategy is proposed to control a bidirectional dc/dc converter, capable of working properly under all operating conditions. The switching devices are commanded by a single sliding function, dynamically shaped by references sent from the microgrid central controller. This feature facilitates the implementation and design of the control law and simplifies the stability analysis over the entire operating range. The effectiveness of the proposed control strategy is illustrated by experimental results.

}, keywords = {AC-DC converter, AC-DC power convertors, bidirectional DC-DC converter control, DC-DC power convertors, distributed power generation, Energy storage systems (ESS), ESS, experimental setup, grid connected microgrid application, microgrid central controller, microgrids, Nonlinear control, Power electronics, power generation control, power grids, power system interconnection, sliding function, Sliding mode control, sliding mode strategy, stability, stability analysis, supercapacitor energy storage system control, supercapacitors, switching convertors, switching device, variable structure systems}, issn = {0885-8969}, doi = {10.1109/TEC.2013.2260752}, author = {Inthamoussou, Fernando A. and Pegueroles-Queralt, Jordi and Bianchi, Fernando D.} } @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.} } @article {134, title = {Reactive Sliding-Mode Algorithm for Collision Avoidance in Robotic Systems}, journal = {Control Systems Technology, IEEE Transactions on}, volume = {21}, year = {2013}, month = {Nov}, pages = {2391-2399}, abstract = {

This brief presents a reactive reference conditioning algorithm for robot collision avoidance based on geometric invariance and sliding-mode (SM) ideas. First, constraints are defined in terms of the measurements given by the robot{\textquoteright}s sensors in order to guarantee that collisions will not occur. Then, a supervisory loop ensures the fulfillment of the constraints modifying the reference trajectory as much as necessary by means of a discontinuous control law. The proposed algorithm activates only when the constraints are about to be violated and, thus, in contrast to conventional SM approaches, there exists no reaching mode to the limit surface of the constraints (sliding surface). The validity and effectiveness of the proposed approach is substantiated by simulation and experimental results using a mobile robot equipped with infrared sensors.

}, keywords = {Collision avoidance, constraint limit surface, constraint violation, discontinuous control law, geometric invariance, infrared detectors, infrared sensors, mobile robot, mobile robots, Motion planning, reaching mode, reactive reference conditioning algorithm, reactive sliding-mode algorithm for collision avoidance in robotic systems, reference conditioning, reference trajectory, robot collision avoidance, Robot sensing systems, robot sensors, Sliding mode control, sliding surface, sliding-mode (SM) control, supervisory loop, trajectory control, variable structure systems}, issn = {1063-6536}, doi = {10.1109/TCST.2012.2231866}, author = {Gracia, Luis and Garelli, Fabricio and Sala, Antonio} } @article {115, title = {2-sliding active and reactive power control of a wind energy conversion system}, journal = {Control Theory Applications, IET}, volume = {4}, year = {2010}, month = {November}, pages = {2479-2490}, abstract = {

This study presents the control of a variable-speed wind energy conversion system based on a brushless doubly fed reluctance machine. The control objectives are the tracking of the maximum power conversion point and the regulation of the reactive power injected by the generation system into the grid. The control design is approached using multi-input second-order sliding techniques which are specially appropriate to deal with non-linear system models in the presence of disturbances and model inaccuracies. The controller synthesised through this theoretical framework presents very good robustness features, a finite reaching time and a chattering-free behaviour. The performance of the closed-loop system is assessed through representative computer simulations.

}, keywords = {2-sliding active power control, 2-sliding reactive power control, brushless doubly fed reluctance machine, brushless machines, chattering-free behaviour, closed loop systems, closed-loop system, control design, control system synthesis, controller synthesis, generation system, grid, maximum power conversion point tracking, multiinput second-order sliding technique, Nonlinear control systems, nonlinear system model, Power conversion, power generation control, reactive power control, reactive power regulation, reluctance machines, representative computer simulation, variable structure systems, variable-speed wind energy conversion system, wind power}, issn = {1751-8644}, doi = {10.1049/iet-cta.2009.0437}, url = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5645800}, author = {Valenciaga, Fernando and Evangelista, Carolina A.} } @conference {212, title = {Low-cost sliding-mode power controller of a stand-alone photovoltaic module}, booktitle = {2010 IEEE International Conference on Industrial Technology}, year = {2010}, month = {March}, abstract = {This work presents a simple and low-cost power electronic system that allows a flexible control of the operating conditions of the photovoltaic module. The system consists of a buck converter with sliding mode control. Control algorithms for maximum power tracking, module voltage and load current regulation are proposed. Moreover, these algorithms can be readily combined to have a complete control of the energy conversion system. The dynamic analysis reveals that there may be regions of instability that are avoided by appropriate switching logics. Operation and main features of the proposed electronic power controller are validated through simulation and experimental results.}, keywords = {Buck converters, Control systems, Current control, electric current control, energy conversion, load current regulation, Logic, maximum power point trackers, maximum power tracking, module voltage control, photovoltaic cells, Photovoltaic systems, Power control, power controller, Power electronics, Sliding mode control, Solar power generation, stand-alone photovoltaic module, variable structure systems, voltage control}, doi = {10.1109/ICIT.2010.5472600}, author = {Inthamoussou, Fernando A. and De Battista, Hern{\'a}n and Cendoya, Marcelo} } @conference {91, title = {Variable gains super-twisting control for wind energy conversion optimization}, booktitle = {Variable Structure Systems (VSS), 2010 11th International Workshop on}, year = {2010}, month = {June}, abstract = {

An adaptive second order sliding mode control strategy is explored in this work, to maximize the energy extracted from the wind in a wind energy conversion system (WECS). It is required to such strategy to deal with the nonlinear nature of the WECS, the randomness of the wind speed, model uncertainties and external disturbances, and also with the need to reduce mechanical loads. The special features of this adaptive technique together with the robustness, relative simplicity and other desirable inherent characteristics of the super-twisting algorithm make the proposed controller an attractive solution. The suitability of the proposed strategy is proved by extensive computer aided simulations employing a comprehensive model of the system.

}, keywords = {adaptive control, adaptive second order sliding mode control, Computational modeling, computer aided simulation, Computer Simulation, control system synthesis, Gain, Lyapunov based controller design, Lyapunov methods, nonlinear systems, optimisation, Programmable control, Robust control, Sliding mode control, Uncertainty, variable gain super twisting control, variable structure systems, Wind energy, wind energy conversion optimization, wind power, Wind speed}, doi = {10.1109/VSS.2010.5544713}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5544713}, author = {Evangelista, Carolina A. and Puleston, Pablo F. and Valenciaga, Fernando and D{\textquoteright}ávila, A.} } @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 {99, title = {High-Order Sliding Control for a Wind Energy Conversion System Based on a Permanent Magnet Synchronous Generator}, journal = {Energy Conversion, IEEE Transactions on}, volume = {23}, year = {2008}, month = {Sept}, pages = {860-867}, abstract = {

This paper presents the output power control of a wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG). It is assumed that the considered wind module integrates a stand-alone hybrid generation system, jointly with a battery bank, a variable ac load, and other generation subsystems. The operation strategy of the hybrid system determines two possible operation modes for the WECS, depending on the power requirements of the load and the wind availability. The paper deals with the design of a combined high-order sliding mode (HOSM) controller for the power control of the WECS on both operational modes. The main features of the obtained controller are its chattering-free behavior, its finite-time reaching phase, its simplicity, and its robustness with respect to external disturbances and unmodeled dynamics. The performance of the closed-loop system is assessed through representative computer simulations.

}, keywords = {chattering-free behavior, closed loop systems, closed-loop system, external disturbances, finite-time reaching phase, High-order sliding mode (HOSM), high-order sliding mode controller, nonlinear systems, permanent magnet generators, permanent magnet synchronous generator, PMSG, Power control, power generation control, stand-alone hybrid generation system, synchronous generators, variable structure systems, WECS, Wind energy, wind energy conversion system, wind power plants}, issn = {0885-8969}, doi = {10.1109/TEC.2008.922013}, author = {Valenciaga, Fernando and Puleston, Pablo F.} } @conference {104, title = {A Geometric Approach for the Design of MIMO Sliding Controllers. Application to a Wind Driven Double Output Induction Generator}, booktitle = {Variable Structure Systems, 2006. VSS{\textquoteright}06. International Workshop on}, year = {2006}, month = {June}, abstract = {

This paper presents a systematic methodology to design controllers for a general class of nonlinear MIMO systems affine in the control in the presence of bounded uncertainties and disturbances. The proposed design method is developed through a theoretical framework based on the combination of a geometric approach and sliding mode techniques. The resulting robust control law guarantees finite time convergence, while chattering reduction is attained by utilising the minimum discontinuous action required to ensure disturbance rejection. The proposed methodology is applied to the control of a grid connected wind energy generation system based on a double output induction generator

}, keywords = {asynchronous generators, chattering reduction, control system synthesis, Control systems, controller design, Convergence, Design methodology, finite time convergence, geometric approach, grid connected wind energy generation system, Induction generators, MIMO, MIMO sliding mode controllers, MIMO systems, Nonlinear control systems, nonlinear MIMO systems, power generation control, Robust control, Sliding mode control, Uncertainty, variable structure systems, wind driven double output induction generator, Wind energy generation, wind power}, doi = {10.1109/VSS.2006.1644503}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1644503}, author = {Valenciaga, Fernando and Puleston, Pablo F. and Spurgeon, Sarah} } @article {65, title = {Comments on "variable-structure PID control to prevent integrator windup"}, journal = {Industrial Electronics, IEEE Transactions on}, volume = {51}, year = {2004}, month = {June}, pages = {736-738}, abstract = {

In the paper by Hodel and Hall, the authors introduce a variable-structure proportional-integral-derivative controller with antiwindup features and compare it with other simple antiwindup methods. It is pointed out here that the conclusions reached from the comparative example are incorrect as the performance of the controllers is not appropriately compared.

}, keywords = {Antiwindup, antiwindup features, Control nonlinearities, Control systems, controllers, Degradation, Furnaces, integrator windup protection, Internet, linear systems, Nonlinear control systems, performance limitations, PID control, Proportional control, proportional-integral-derivative controller, three-term control, variable structure systems, variable-structure systems, Windup}, issn = {0278-0046}, doi = {10.1109/TIE.2004.825205}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1302353}, author = {Mantz, Ricardo J. and De Battista, Hern{\'a}n} } @article {63, title = {Dynamical variable structure controller for power regulation of wind energy conversion systems}, journal = {Energy Conversion, IEEE Transactions on}, volume = {19}, year = {2004}, month = {Dec}, pages = {756-763}, abstract = {

The paper addresses the problem of output power regulation of fixed-pitch variable-speed wind energy conversion systems. Operation is constrained by practical reasons to the low-speed side of the turbine power-speed curve. Unfortunately, this region is characterized by a nonminimum phase dynamics which is an obstacle to perform the regulation task. A dynamical variable structure controller is developed that accomplishes the control objective despite this limitation. The proposed control strategy presents attractive features such as robustness to parametric uncertainties of the turbine and generator as well as to electric grid disturbances.

}, keywords = {65, Aerodynamics, Control systems, dynamical variable structure controller, electric grid disturbance, Electric variables control, Induction generators, Mesh generation, nonminimum phase dynamic, parametric uncertainty, Power control, Power generation, power generation control, power regulation, power supply quality, power system dynamic stability, power system interconnection, speed curve, turbine power, variable structure systems, Wind energy, wind energy conversion system, Wind energy generation, wind power, Wind speed, wind turbines}, issn = {0885-8969}, doi = {10.1109/TEC.2004.827705}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1359955}, author = {De Battista, Hern{\'a}n and Mantz, Ricardo J.} } @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 {68, title = {Variable structure control of a photovoltaic energy converter}, journal = {Control Theory and Applications, IEE Proceedings -}, volume = {149}, year = {2002}, month = {Jul}, pages = {303-310}, abstract = {

The variable structure control of a DC-to-DC converter in photovoltaic applications is presented. The feasibility of establishing stable constant-voltage and constant-current sliding modes is stressed. Further, their ability to satisfy the control objectives, i.e. maximum power tracking or power regulation, is analysed. In addition, different control laws are obtained by combining these sliding motions, thereby improving their individual performances. The capability of these control laws to steer the state trajectories towards the sliding surfaces from any initial condition, as well as the stability of the sliding regimes, is investigated

}, keywords = {constant-current sliding modes, constant-voltage sliding modes, DC-DC power convertors, DC-to-DC converter, maximum power tracking, photovoltaic energy converter, photovoltaic power systems, power convertors, power regulation, state trajectories, Variable structure control, variable structure systems}, issn = {1350-2379}, doi = {10.1049/ip-cta:20020556}, url = {http://ieeexplore.ieee.org/xpl/abstractAuthors.jsp?arnumber=1039154}, author = {De Battista, Hern{\'a}n and Mantz, Ricardo J.} } @article {71, title = {A new approach to reaching mode of VSS using trajectory planning}, journal = {Automatica}, volume = {37}, year = {2001}, pages = {763 - 767}, abstract = {

This work deals with dynamic behavior of variable structure systems operating in reaching mode. Concepts of trajectory planning of differentially flat systems are employed to reach the sliding surface in a point where the sliding mode can be established. An additional control surface is proposed to track the planned trajectory. Then, the system evolves robustly from the initial state to the steady state. Adjusting the control action, undesirable transient behaviors are avoided and the state-space region in which the system operates safely is increased.

}, keywords = {variable structure systems}, issn = {0005-1098}, doi = {http://dx.doi.org/10.1016/S0005-1098(01)00012-7}, url = {http://www.sciencedirect.com/science/article/pii/S0005109801000127}, author = {Mantz, Ricardo J. and De Battista, Hern{\'a}n and Puleston, Pablo F.} } @article {70, title = {Performance analysis of a variable structure controller for power regulation of WECS operating in the stall region}, journal = {International Journal of Energy Research}, volume = {25}, year = {2001}, pages = {1345{\textendash}1357}, abstract = {

This paper deals with power regulation in variable speed wind energy conversion systems. The importance of power control in the stall region is stressed. This mode of operation is characterized by a non-minimum phase behaviour. A variable structure controller is described that provides stability by means of speed feedback and is robust to grid disturbances and model uncertainties. Performance of the controller is investigated. A compromise arises in the design of the speed feedback gain between high and low frequency wind components rejection. Furthermore, a cut-off frequency of the wind velocity measurement is obtained that minimizes the effect of turbulence on power regulation. Simulation results are presented, corroborating the features of the control strategy.

}, keywords = {energy conversion, Power control, variable structure systems, Wind energy}, issn = {1099-114X}, doi = {10.1002/er.758}, url = {http://dx.doi.org/10.1002/er.758}, author = {De Battista, Hern{\'a}n and Mantz, Ricardo J. and Christiansen, Carlos F.} } @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.} } @article {73, title = {Harmonic series compensators in power systems: their control via sliding mode}, journal = {Control Systems Technology, IEEE Transactions on}, volume = {8}, year = {2000}, month = {Nov}, pages = {939-947}, abstract = {

This paper deals with harmonic current compensation in power systems using shunt passive and series active filters. It is shown how constraints of the active filters can notoriously degrade the performance of the compensating system. The use of variable structure system theory is suggested for analysis and design of series active filters. Sliding mode control strategies to improve harmonic rejection are proposed, and active filters with different switching-ripple filters are considered. These control strategies provide robustness to active filter modeling errors and external disturbances

}, keywords = {active filters, compensation, Control systems, Degradation, harmonic series compensation, Power harmonic filters, Power system analysis computing, power system control, power system harmonics, power systems, Robustness, Sliding mode, Sliding mode control, variable structure system, variable structure systems}, issn = {1063-6536}, doi = {10.1109/87.880597}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=880597}, author = {De Battista, Hern{\'a}n and Mantz, Ricardo J.} } @article {74, title = {Sliding mode control of wind energy systems with DOIG-power efficiency and torsional dynamics optimization}, journal = {Power Systems, IEEE Transactions on}, volume = {15}, year = {2000}, month = {May}, pages = {728-734}, abstract = {

Wind turbines with double output induction generators can operate at variable speed permitting conversion efficiency maximization over a wide range of wind velocities. However, random wind fluctuations, wind shear and tower shadow, may excite the oscillation mode of the mechanical system, producing large torque ripple. Consequently, damage to drive train components and power quality problems may occur. In this paper, a sliding mode control is developed which provides a suitable compromise between conversion efficiency and torque oscillation smoothing. The resultant sliding dynamics is completely robust to uncertainties in the electrical variables and parameters. In addition, to prevent windup problems due to saturation, a combined sliding surface that incorporates such limitations is proposed

}, keywords = {asynchronous generators, combined sliding surface, conversion efficiency maximization, double output induction generators, drive train components, electrical variables uncertainties, Fluctuations, Induction generators, large torque ripple, machine control, mechanical system, Mechanical systems, oscillation mode excitation, oscillations, Poles and towers, power efficiency, power generation control, Power quality, power quality problems, power supply quality, random wind fluctuations, resultant sliding dynamics, Sliding mode control, Torque, torque oscillation smoothing, torsion, torsional dynamics optimization, tower shadow, uncertainties robustness, variable speed, variable speed gear, variable structure systems, Wind energy, wind energy systems, wind shear, Wind speed, wind turbines}, issn = {0885-8950}, doi = {10.1109/59.867166}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=867166}, author = {De Battista, Hern{\'a}n and Puleston, Pablo F. and Mantz, Ricardo J. and Christiansen, Carlos F.} }