Exploring the Limits in Individual Pitch Control

Abstract

Individual pitch control (IPC) is an advanced wind turbine control method for fatigue load reduction. The conventional IPC algorithm (cyclic pitch control) aims at achieving 1p blade load reduction by mitigating the static rotor tilt and yaw moments. Besides these existing IPC methods, this paper presents a novel application of IPC: rotor balancing. Imperfections in the blades lead to aerodynamic and/or mass unbalance that result in variations at the rotational frequency 1p in the rotor tilt and yaw moments. The new IPC algorithm compensates for such rotor unbalance by adding quasi-steady offsets to the blade pitch angles. As a second contribution, an anti-windup߿ݠIPC implementation is proposed for dealing with blade actuator limitations. Detailed nonlinear simulations are used to validate the proposed IPC algorithms.