Optimal tuning of individual pitch control using economic goal-oriented objectives

Individual pitch control (IPC) is a method developed to cope with fatigue loads, which works by actively changing the pitch angles of each blade based on feedback. While beneficial for fatigue damage, the use of IPC leads to some reduction in yield and an increase in pitch activity, which can influence operation and maintenance (O&M) costs. Tuning of the IPC parameters plays a significant role, as different settings could result in different trade-offs among lifetime, yield, and O&M costs. In this paper, an optimal parameter tuning method for IPC for existing turbines is proposed. The effects of IPC on competing objectives, i.e. energy production, pitch system wear, and fatigue life are utilized to maximize the long-term profit based on given constraints. The proposed approach is demonstrated in a simplified scenario, where the tower is the only critical component that requires damage reduction to achieve a target lifetime. The performance of the proposed approach is compared to a standard tuning that targets load reductions in terms of d- and q-axis components. Results indicate that the proposed optimal tuning approach provides IPC gains that meet the desired lifetime of the component, and that improve profit compared to the standard approach.