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In this article, the problem of tracking control for variable speed induction generator–wind energy conversion system is investigated using nonlinear predictive control. A rotor speed predictive control algorithm has been designed to control the angular speed of the machine in order to allow the wind energy conversion system to operate with maximum power extraction. The generator torque and uncertainties are estimated and injected into the control law to improve the tracking performance. Control action is carried out assuming that all the states are known by measurement. Then, a state observer is implemented and Lyapunov method is used to prove the global stability of the complete continuous control scheme. Simulation is carried out to verify the performance of the proposed control system.

Control system developed for hybrid wind diesel system (HWDS) operating as standalone power system is presented. The HWDS consists of a permanent magnet synchronous generator (PMSG) based wind turbine generation system and a diesel generation system (DGS) with synchronous machine. Control system developed for both machine side and load side power converter is simulated. A maximum power point tracking (MPPT) control system is developed and simulated for machine side power converter to track the optimum rotor shaft speed for achieving maximum power extraction through wind turbine. The transition from wind-diesel to wind-only mode of operation is simulated. A dynamic model of HWDS is developed to study the system operating behavior under standalone condition. The complete HWDS is modeled and simulated in MATLAB Simulink environment. Simulation results to validate the performance of developed control system are presented.

In this paper, a power electronics circuit is proposed to control the rotational speed of a wind turbine. This interface is based on two DC-DC converters, where a buck converter is used to control the speed and a boost converter is used to maintain a constant voltage for the load. The power electronics circuit is implemented on a small laboratory size wind turbine and experimentation is carried out to show its capability of speed control.

An automatic power management system, to monitor the distribution of power to a set of load banks, is presented in this paper. The required power is generated from a laboratory-size pitch-controlled wind turbine experimental workstation. The management system is a sequence of logic expressions, based on the generated power, a profile of the banks’ states provided by the supervisor and the banks’ priorities, to obtain an optimal behavior of the system and to ensure the load requirement. A modified PI pitch angle control is proposed to regulate the generated power for tracking the power reference in order to maintain a consistent brilliance of the load’s LEDs, to reduce the activity of the pitch actuator and to deal with fluctuation problems. Experimental results are provided to show the effectiveness of the proposed automatic power management system for load banks supplied by a pitch controlled wind turbine. Keywords: automatic switching; load banks; pitch angle control; power management; wind turbine

A control strategy developed for hybrid wind-diesel system (HWDS) is presented in this paper. The proposed system consists of the induction generator based wind turbine generation (WTG) system, IGBT based power electronics converters, diesel generator (DG) unit and dump load (DL) system. Developed control strategy shares the required power generation between the WTG and DG unit. The control system operates the wind turbine to achieve maximum power extraction using maximum power point tracking (MPPT) scheme, and simultaneously controls the dump load to absorb excessive power generation, in turn regulates the frequency of power supply. The DG unit is controlled for supplementing the generated power from WTG to supply the complete load power demand. The complete system is modeled and simulated using SimPowerSystems toolbox from Matlab-Simulink software package.

A pitch controlled wind turbine experiment workstation is presented in this paper. This laboratory size system can be used for research purpose, where various control strategies can be achieved through the pitch angle actuator/control for variable load. Mathematical models of the major components of the wind turbine and the configuration of the load, based on LED, are presented. Pitch angle control strategies are discussed and experimental results for controlling power, rotor speed and voltage are provided to show the capabilities of the wind turbine.