Sliding Mode Control Strategy for Wind Turbine Power Maximization

Abstract

The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a sliding mode control for variable speed wind turbine that incorporates a doubly fed induction generator is described. The electrical system incorporates a wound rotor induction machine with back-to-back three phase power converter bridges between its rotor and the grid. In the presented design the so-called vector control theory is applied, in order to simplify the electrical equations. The proposed control scheme uses stator flux-oriented vector control for the rotor side converter bridge control and grid voltage vector control for the grid side converter bridge control. The stability analysis of the proposed sliding mode controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory. Finally simulated results show, on the one hand, that the proposed controller provides high-performance dynamic characteristics, and on the other hand, that this scheme is robust with respect to the uncertainties that usually appear in the real systems.

Modeling and Design Optimization of Variable-Speed Wind Turbine Systems

“…One of them is to optimize the capture of energy from the wind utilizing effective control strategies [4][5][6][7]. The contributions of these studies include new control structures, even for the aeroturbine mechanical part [4,6,7] and the electrical components [5][6][7] that overcome some of the drawbacks of existing control methods. For the mechanical part control, the control design is generally based on a local linearized model of the WTS around its operating points [4].…”

“…For the mechanical part control, the control design is generally based on a local linearized model of the WTS around its operating points [4]. Some nonlinear controllers were also proposed assuming that the wind turbine operates under steady state conditions [6,7]. For the generator, a doubly fed induction generator (DFIG) with a power converter is a common and efficient configuration to transfer the mechanical energy from the variable speed rotor to a constant frequency electrical grid [6].…”

“…The stator is directly connected to the grid while the rotor is fed through a variable frequency convertor. In order to produce electrical active power at constant voltage and frequency, the active power flow between the rotor circuit and the grid is controlled both in magnitude and direction by controlling the stator flux and rotor current of the asynchronous generator using standard nonlinear [5,6] and/or adaptive control techniques [7,8].…”

Operation and Power Flow Control of Multi-Terminal DC Networks for Grid Integration of Offshore Wind Farms Using Genetic Algorithms

“…The most important technical aspects are the choice of HVDC converter topology [11][12][13][14], the necessity of dc/dc converters [15,16], the need for protection schemes [17][18][19], dynamic stability issues [20][21][22], and power-flow control strategies [23][24][25][26].…”

Super-twisting controllers for wind turbines

“…In previous works (e.g., [2]), it has been proposed the use of classical sliding mode control for WT control. Such approaches deal efficiently with the power regulation objective and provide the advantage of robustness against system uncertainties and perturbations but its well-known drawback has been the discontinuous behavior of the computed control inputs that may derive into a high-frequency oscillation known as chattering.…”