Robust Performance Analysis of Wind Turbine Control Systems

In this paper, a framework for robustness analysis of wind turbine control systems is proposed. This framework is employed to examine and compare the robust performance of ${{\mathcal{H}}_\infty }$ and PI blade pitch controllers designed to maintain the turbine’s generated power at its rated value in Region 3 of the turbine operation. In this framework, a turbulent wind model based on the Kaimal characterization of turbulence is added to the closed-loop wind turbine model obtained by linearizing the nonlinear model at different mean wind speeds. The framework utilizes the theory of Integral Quadratic Constraints (IQCs), whereby IQCs and signal IQCs are used to perform the analysis. The proposed framework results in an improved characterization of the system’s performance. The analysis results are validated via extensive high-fidelity simulations.