Auto-disturbance rejection control for the stator voltage in a stand-alone DFIG-based wind energy conversion system

The second-order nonlinear state equations are established to describe the dynamic behavior of the stator voltage. Then the direct stator voltage control based on the second-order auto-disturbance rejection control (ADRC) is proposed for the rotor side converter. The total disturbance is observed and compensated in real time by ADRC; and the constant amplitude and frequency of stator voltages are maintained. The dynamic response and steady-state performance of the system has been greatly improved. The simulation results verify the correctness and feasibility of the proposed control scheme.