Analysis of Geometric and Material Parameters in the Modal Stability of Wind Turbine Brakes Using the Complex Eigenvalue Method

Abstract

Wind energy is a sustainable and forward-thinking investment, harnessing the vast power of the wind to generate electricity. Recent decades have seen significant advancements in floating offshore wind turbines (FOWTs), which hold great potential for expanding offshore wind energy infrastructure. While wind power has grown in popularity, it has raised questions about the operations and maintenance of wind turbines, particularly those located in remote and challenging environments. Offshore wind energy offers optimal wind conditions and construction flexibility, but FOWTs face complex marine conditions, including turbulent forces, wind variations, and unpredictable weather events. Emergency Mechanical Braking (EMB) is commonly used to swiftly stop wind turbines during adverse conditions, but frequent use can lead to structural oscillations, mooring failures, and blade damage. These issues can result in emergency situations, increased downtime, and higher maintenance costs. One significant challenge in understanding wind turbine brake system instability is the cost of experimental studies. To address this, our work introduces an iterative method that establishes correlations between brake component properties (like Young’s modulus and friction coefficient), geometric and operational parameters, and key instability factors such as frequency and intensity. Using finite element analysis and complex eigenvalue analysis, this approach focuses on reducing vibration instability and optimizing braking performance. Our study yielded intriguing results, including the observation that reducing brake pad thickness, whether through design choices or natural wear, decreases total unstable points but shifts instabilities to lower frequencies. Ultimately, our research highlights the importance of various parameters in wind turbine brake system instability.