WECS Optimal Control with Mixed Criteria

Abstract

The idea of conveniently sizing a trade-off between energy efficiency and increasing the service lifetime of WECS by alleviating fatigue loads is continuously being paid special attention, even when employing classical controllers like PI or PID. Inside the control loop aiming at keeping the operating point on the optimal regimes characteristic (ORC), a control requiring a drastic fulfilment of the performance criteria will induce significant stress due to important torque variations. In contrast, reasonably diminishing control performance may result in reducing the torque variations without altering the energy performance (see the results of case studies reported in Sections 5.3.3 and 5.3.4). However, this approach does not allow a rigorous control design in order to perform a fine tuning of the trade-off between the energy performance and the reliability demands.