Impact of Inertia Control on the Structural Loads of DFIG-based Wind Turbine Connected to Weak Grid

This paper investigates the impact of inertia control on structural loads of doubly fed induction generator (DFIG) based wind turbine connected to weak grid. It is of practical relevance that wind turbine has inertia control and operates in very weak grid. In this situation, the interaction between wind turbine and power grid will be significant and brings about stability and loads problem of wind turbine. By developing a co-simulation platform with GH Bladed and Matlab/Simulink, detailed modeling of blades, drive-train and tower in combination with electrical and control dynamics becomes possible. Factors such as grid strength, inertia control and drivetrain damping filter are considered in the study. The simulation results reveal that the vibrations of drive-train and tower will be severer due to inertia control, and improper selection of inertia control parameters causes sub-synchronous oscillation in a weak grid which hence has a harmful impact on structural load.