Abstract—In this paper present a sensorless maximum wind power extraction for variable speed constant frequency (VSCF) wind power generation systems with a doubly-fed induction generators (DFIG), to ensure stability and to impose the ideal feedback control solution despite of model uncertainties , using the principles of an active and reactive power controller (DPC) a robust sliding mode power control has been proposed to guarantees fast response times and precise control actions for control the active and reactive power independently. The simulation results in MATLAB/Simulink platform confirmed the good dynamic performance of power control approach for DFIG- based variable speed wind turbines. Keywords—Doubly fed induction generator , sliding mode control, maximal wind energy capture, MRAS estimator I. INTRODUCTION IND energy conversion systems are becoming increasingly popular because of the demand on renewable energy resources ,as a consequence wind power generation technique is being developed rapidly, The wind energy systems using a doubly-fed induction generator (DFIG) have some advantages due to variable speed operation and four quadrant active and reactive power capabilities compared with fixed speed induction generators, variable speed constant frequency doubly fed wind power generator presents noticeable advantages such as, it can keep the optimum tip-speed ratio to get maximum wind-power during a low wind speed and improve the flexibility of the drive system by releasing or saving some energy during high wind speed. In the first method, the stator active and reactive powers are regulated by controlling the rotor current vector using either stator voltage or field oriented control, based on rotational transformations and linear controllers (proportional– integral controller), has so far proved to be the most popular control technique, although it is clear that its drawbacks are its linear nature and lack of robustness when faced with changes in operational conditions.The problem in the use of PI controller is the tuning of the gains and the cross-coupling on DFIG Hicham Serhoud is with Institute of Science Technology , Departement of Electrotechnics University Center of EL-Oued, Algeria.e-mail: hichamser_39@yahoo.f r Djilani Benattous is with Institute of Science Technology , Departement of Electrotechnics University Center of EL-Oued, Algeria.e-mail: dbenattous@yahoo.com terms in the whole operation range, sensitive characteristics to the parameter variation and interference. DPC control strategy for a DFIG-based wind energy generation system was proposed in [5] [17],.The control method is based on the, the converter switching states were selected from an optimal switching table based on the instantaneous errors between the reference and estimated values of active and reactive power, DPC is robust with respect to the change of machine parameters and to perturbations. However, it has some drawbacks: it exhibits high active and reactive power ripples, and current ripple [4]. In order to achieve the maximum power point tracking (MPPT) the control strategies for DFIG mainly include the cutting-in control, the maximal power point tracking with it the knowledge needed speed of the machine. A MRAS observer for standalone DFIG operation was presented by the authors in [1] [2] [3] [4],based is a well known method for the sensorless control of cage induction machines. Compared with these sensor-less methods, this paper proposes the method realize MPPT with/without wind speed measurements it is usually rotor speed observervation ,therefore it can improve the control system reliability and energy conversion efficiency and The due to both the nonlinear nature and parameters variations of DFIG, This paper presents a very robust approach control of doubly fed induction generators. The control method is based on the variable structure control associated to the flux oriented control technique, the extensive simulation study in the beginning validated all the control algorithms. II. MATHEMATICAL MODEL OF DFIG The equivalent two-phase model of the symmetrical DFIG, represented in an arbitrary rotating (d-q) reference frame is: [3,6,14,15]. ⎪ ⎪ ⎪ ⎪ ⎩ ⎪ ⎪ ⎪ ⎪ ⎨ ⎧ − + + = − − + = + + = − + = dr s r qr qr qr qr s r dr dr r dr ds s qs qs s qs qs s ds ds s ds dt d i Rr V dt d i R V dt d i R V dt d i R V ψ ω ω ψ ψ ω ω ψ ψ ω ψ ψ ω ψ ). ( . ). ( . . . . . (1) Hicham Serhoud, Djilani Benattous Sensorless Sliding Power Control of Doubly Fed Induction Wind Generator Based on MRAS Observer W World Academy of Science, Engineering and Technology International Journal of Electrical and Computer Engineering Vol:5, No:8, 2011 1021 International Scholarly and Scientific Research & Innovation 5(8) 2011 ISNI:0000000091950263 Open Science Index, Electrical and Computer Engineering Vol:5, No:8, 2011 publications.waset.org/10425/pdf