A robust control strategy for a self-excited induction generator wind turbine system

Abstract

In this paper, a new control strategy of a variable speed based SEIG wind energy conversion is presented. Nonlinear control strategy is proposed to extract maximum available energy from the wind turbine and regulate the rotor flux magnitude of SEIG and the DC-link voltage in the generator side as well as the load voltage magnitude in the inverter load side under wind speed, load and rotor/stator resistances variations. The proposed nonlinear adaptive controller is robust given its insensitivity to SEIG variation of the rotor and stator resistances. The global convergence and stability analysis taking into account the interconnections between the stator electrical angular position, the rotor flux and rotor resistance estimators and the nonlinear controller have been proved by using the separation principle. Another contribution of this paper is the robustness of the proposed method with respect to the variation of the driven speed and relatively low wind speed operation. Thus, the proposed stand-alone variable speed based SEIG wind energy conversion system can be used in remote and isolated areas where the mean value of the wind speed profile is relatively low.