# Technological Advances on Fault Diagnosis in Wind Turbines: A Patent Analysis
## 4 Conclusions  
Wind power is a renewable energy widely used worldwide, and its rapid advances raise concerns, especially relating to safety and reliability. Based on the results of this work, it was possible to observe that fault diagnosis for wind turbines is very important, and the development of new technologies is still necessary. This can be seen by taking into account the increasing evolution in patent filings over the years. Furthermore, it can be observed that of the 636 patent documents found, most reported the development of new methods or new devices for identifying potential faults and defects in wind turbines and their components, especially in the blade components. In addition, it was possible to retrieve patents for a used model, improving an already used technique. This technological prospection focused on patent documents has highlighted the important growth in the development of inventions of new methods and techniques used for the accurate detection of faults in wind turbines through non-destructive methods. The findings pointed out the main applicants of the technologies, as well as the main inventors, highlighting Vestas Wind SYS As and Wang, Rui-ming, respectively. In evidence, the world leader in the wind power market is China, which has a total of 373 patent documents and is also the main market for these applications. The results found in this study make clear that artificial intelligence and database analysis are the future strategies for improving the methods already used, especially in view of the peculiarities involved in the maintenance and viability of wind turbines. All the results observed in this prospection can directly contribute to possible investments in research and development on fault diagnosis techniques, identifying potential saturated fields and also the ones that present possible technological trends. Furthermore, by identifying the main areas and countries, companies can use this technological research to help in their decision-making when needed. They could also use the findings to target new possible technologies of interest and focus their efforts on the development of their own inventions while identifying gaps that can be converted into new discoveries. Additionally, this work could directly support the identification of market needs, which may be the target for research and development of novel inventions based on the application of different fault diagnosis techniques, combining traditional techniques with advanced mathematical models, such as artificial intelligence and deep learning, especially considering the increased importance for the worldwide development of renewable and sustainable energy. This research may present some limitations, which may be similar to any other technological prospection using patent analysis. The limitations may be related to the search strategy, which limited access to documents related to the selected keywords. However, it is important to point out that the keywords proposed in this analysis allowed the presentation and discussion of a cohesive and robust form regarding the diagnosis of wind turbine failures, exposing, especially, the challenges of this sector. Continued research is needed to contribute to clarifying the issues within this area. Conceptualization, N.B.B., D.D.G.N., A.A.B.S. and B.A.S.M. ; Data Curation, D.D.G.N. ; Formal Analysis, N.B.B., D.D.G.N., A.A.B.S. and B.A.S.M. ; Investigation, N.B.B., D.D.G.N. and B.A.S.M. ; Methodology, N.B.B., D.D.G.N., A.A.B.S. and B.A.S.M. ; Project Administration, A.A.B.S. and B.A.S.M. ; Software, D.D.G.N. ; Supervision, B.A.S.M. ; Validation, A.A.B.S. ; Visualization, N.B.B. ; Writing--Original Draft, N.B.B. and D.D.G.N. ; Writing--Review and Editing, A.A.B.S. and B.A.S.M. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. All research data were reported in the manuscript.