Load analysis and impacts on fatigue behaviour in offshore wind turbines

Real-time adaptive control strategies are a key challenge in improving the longevity and performance of wind turbine systems. Frequent start-stop cycles and excessive downregulation significantly accelerate fatigue damage, primarily due to operations under off-design conditions characterized by transient loads and reduced aerodynamic damping. Derating, while useful in specific scenarios such as adverse weather or sustained drops in power demand, can increase structural stress, particularly on turbine blades. In this study, fatigue analysis was focused on a critical component of an offshore wind turbine, namely the blade root. The results show that, compared to normal operation, derating can lead to greater fatigue loads on the blades. These findings underscore the need for advanced control systems capable of dynamically adjusting power output while safeguarding structural integrity. Specifically, smoother and more targeted strategies, such as gradual or modulated power reductions, are crucial to minimizing structural transients and reducing wear on critical components.