Gridded‐based LPV control of a Clipper Liberty wind turbine

Abstract

This paper proposes a linear parameter varying (LPV) control design for a Clipper Liberty C96 2.5 MW wind turbine to operate in all wind conditions. A standard approach is to use multiple single-input, single-output loops for control objectives at different wind speeds. This LPV controller instead takes these objectives into a uniformed multi-input, multi-output design framework. The key difference is that the LPV controller is specifically designed to smoothly transition from Region 2 to Region 3 operation. Reducing structural loads is another major concern in the design. Synthesis of the controller relies on a gridded-based LPV model of the turbine, which is constructed by interpolation of linearized turbine models at different wind speeds. To overcome the conservativeness in the design, parameter varying rates will be considered based on turbulent wind conditions. The performance of the LPV controller is evaluated using a high fidelity FAST model provided by Clipper. The LPV controller is directly compared with the baseline controller currently operating on the turbine. Simulations and analysis show that the LPV controller meets all performance objectives and has better load reduction performance.