Sliding-mode control of maximum power-point tracking in wind-power system for doubly-fed induction generator

The maximum power-point tracking(MPPT) plays an important role in the wind power system for doublyfed induction generator(DFIG). A sliding mode control(SMC) strategy is proposed based on the theory of SMC and the control principle of the stator magnetic field orientation vector. The principle of stator magnetic field orientation vector control is briefly introduced, and then, an SMC control strategy is propose to realize the decoupling between the active power and the reactive power in DFIG, and carries out the MPPT control. It improves the rate of tracking and enhances the system stability, while capturing more wind energy and realizing the variable-speed-constant-frequency(VSCF) control. Simulation results of controller verified the accuracy and effectiveness of the proposed control strategy.