Evaluation of Strategies for Inertial Control in Wind Turbines and Their Effect on Blade Dynamics

Modern wind energy conversion systems (WECS) can emulate the inertial response of conventional generators by implementing additional control loops. Inertial control methods, such as Optimized Power Point Tracking (OPPT) and its variants, and Torque-Limited Inertia Control (TLIC), control the kinetic energy of the rotating masses in the wind turbine, allowing WECS to assist in frequency regulation in contingency events. These inertia control methods modify the operating point of the wind turbine to provide frequency support without the need for energy storage systems. This causes the blades to be subjected to forces that can reduce their useful life. This article analyzes wind turbine rotational speed time series obtained from simulations of contingency events in power systems with a high participation of wind generation. WECS implements inertial control systems based on OPPT, OPPT Extended, and TLIC. The power system simulation environment is MATLAB/Simulink. Finally, the possible impact on the forces acting on the wind turbine blades was evaluated based on the time series of the rotor speed obtained with and without these frequency control strategies using the transient structural analysis in ANSYS Workbench.