A review of wind turbine maintenance management procedures

Wind energy is one of the fastest growing sources of renewable energy in Europe as well as on a global scale. In order to increase the competitiveness of wind power against other competing energy sources there is a profound need to optimise the operational and maintenance costs of wind turbines. The most efficient way of reducing these costs is through an evolution to predictive maintenance procedures based on condition monitoring of key turbine components. Condition monitoring allows early detection of degradation of the actual health of various components such as the gearbox, brake system, blade, tower, etc., facilitating a proactive response, minimising downtime, and maximising the overall annual capacity of wind farms. Due to the importance of condition monitoring for the wind energy industry and the need for future research, a substantial amount of research has been carried out in the field of wind turbine condition monitoring. This paper summarises this state of the art, describing different maintenance models, condition monitoring techniques and algorithms, and highlights the importance of the NIMO's system integrated concept. A qualitative evaluation using fault tree analysis has also been carried out to identify future research opportunities for fault diagnostics.