Integral variable structure control for grid connection of double-fed wind generator

With combination of integral variable structure control (IVSC) and field-oriented vector control technique, a control strategy is presented for smooth no-load grid connection of variable-speed constant-frequency double-fed wind-power generator. In order to get strong robustness to many kinds of disturbances in global range and excellent dynamic performance, the control system consists of two current controllers using IVSC and one voltage deviation controller based on variable integration rate. The saturation function is employed in switch control, which can decrease the chattering of rotor current and reduce the harmonic distortion rate of stator voltage.