Nonlinear control of dynamic voltage restorer to improve lvrt capability in wind turbine systems

Abstract

This paper proposes a nonlinear control of dynamic voltage restorer (DVR) based on a feedback linearization (FL) theory to improve a low-voltage ride-through (LVRT) capability of a doubly fed induction generator (DFIG) wind turbine system. First, the nonlinear model of the system including LC' filter is obtained in the d-q synchronous reference frame. Then, the controller design of the linearized model is performed by the multi-input multi-output feedback linearization. The simulation results for the 2 MW-DFIG wind turbine system with the DVR compensation at grid faults gives as good performance as those without grid faults.