Review of Fault Detection and Diagnosis Methods including Failure Root Causes of Major Components of Hydraulic Pitch System for Wind Turbines-Part-II

The hydraulic pitch system is a critical component of modern wind turbines, responsible for both power regulation and safety mechanisms. Ensuring the reliability and availability of this system is essential for optimal turbine performance. This study focuses on the reliability of less active yet essential components within the hydraulic pitch system, including the pump, accumulator, relief valve, hose, and hydraulic oil. The hydraulic oil in the analysis has been treated as a component also. Employing a comprehensive Fault Tree Analysis (FTA), this study identifies the failure modes, effects, and root causes of these components. Key findings indicate that contamination and inadequate maintenance are primary contributors to failures. The study discusses various fault identification and condition monitoring algorithms, including those based on artificial intelligence and machine learning, which are effective in post-processing data for fault detection. Physics-based models, such as observer methods like the Kalman Filter, show potential for real-time implementation. The findings underscore the importance of stringent filtration, regular inspections, and proactive maintenance strategies, including monitoring accumulator pre-charge pressure and using appropriate hydraulic oil. Addressing these root causes can significantly enhance the reliability and longevity of hydraulic pitch systems, thereby improving the overall performance and safety of wind turbines.