A robust adaptive controller for a DFIG wind turbine with grid voltage and frequency support

Abstract

A robust adaptive nonlinear controller is designed for a Doubly-Fed Induction Generator (DFIG) wind turbine connected to a power grid. The controller main objective is to regulate the generator terminal voltage and rotor speed. A model based control design strategy is adopted. The controller structure and equations are obtained following a backstepping control design method using the DFIG reduced order model. Grid parameters are assumed unknown during the design. Therefore, the controller is provided with an adaptation module that automatically readjusts controller parameters when grid conditions change. Simulations are used to assess the proposed DFIG controller effectiveness.