Rotational synchronous extremum seeking control for a wind energy system: Vibration suppression evaluation via small-scale experiments

Extremum seeking control (ESC) can be utilized as a maximum power point tracking (MPPT) method that optimizes the operating point of a wind energy system by adjusting the wind turbine's rotor speed according to the change in the wind speed. Although ESC has a tracking ability and quick response capability that is better than those of the conventional MPPT methods, it increases the mechanical vibration of the wind turbine generator system due to the perturbation signal used in the ESC algorithm. To overcome this issue, rotational synchronous ESC wherein the perturbation signal is synchronized with the rotor angle of the wind turbine has been proposed. In this research, we evaluate the amount of mechanical vibration in an actual machine experiment using DC motors that are controlled by rotational synchronous ESC.