Wind turbine pitch and active tower damping control using metaheuristic multi-objective bat optimization

Collective pitch control (CPC) is normally combined with an active tower damping control (ATDC) and both control loops are commonly found in the control system of very large wind turbines. Normally, each controller is fine-tuned individually. However, the control loops have a conflict of interest: whereas the CPC keeps the rotational speed constant during overrated wind speed and introduces significant oscillations in the tower subsystem, the ATDC reduces the tower oscillations while detuning the CPC. Thus, the aim of the present contribution is to find an optimal balance where cooperative tuning of both controllers leads to the best possible performance of both controllers with the fewest reciprocal negative effects. In order to achieve the goal, the multi-objective bat algorithm is utilized to obtain all controller parameters. The effectiveness of the methodology is shown by means of a simulation example.