Dynamic performance improvement of DFIG-based WT using NADRC current regulators

• An advanced NADRC for RSC of DFIG to improve its dynamic performance is proposed.
• The NADRC treats the internal and external dynamics as a generalized disturbance.
• The NADRC actively rejects the disturbine and enhances the FRT capability of DFIG.
• One-parameter tuning technique simplifies the design of multi-parameter controller.

In this paper, to improve the dynamic performance of DFIG-based WT, a NADRC technology is proposed. The proposed NADRC can actively estimate and compensate the plant internal dynamics and external disturbances in real time. Therefore, it improves the tracking performance of the rotor current without any overshoot and steady-state error, and enhances the fault ride-through capability of DFIG-based wind turbine. Compared with the proportional PI control, the proposed NADRC during grid fault can significantly suppress the peak values of stator and rotor currents and DC-link voltage, and decrease the oscillation time of electromagnetic torque. Moreover, the proposed NADRC has a characteristic of one-parameter tuning by using the parameterization technique of controller, and parameter tuning of NADRC is only determined by the rise time of the system step response. A series of simulations for various cases on a 1.5-MW DFIG-based wind turbine are implemented, and the results validate the stability of the proposed NADRC and the strong robustness against the plant internal dynamics and external disturbances.