Failure modes analysis and reliability enhancement of wind turbines

What is it about?

The transition of the global energy system to affordable, reliable and clean sources is an important target of several international climate change accords and conferences such as the United Nations Framework Convention on Climate Change (UNFCCC) and its Conferences of parties (COP), Kyoto protocol and the UN Sustainable Development Goals (SDGs). The wind power is at the heart of these energy systems transformation and climate change mitigation. Indeed, the global capacity of wind turbines has seen tremendous growth, especially, during the past two decades which has made wind energy the fastest growing renewable source in the world. Nevertheless, the problem of premature failures and low-reliability level of wind turbines have been increasingly noticed. This paper presents a new systematic analytical approach for failure modes and reliability analysis of wind turbines. The approach is a combination of three aspects which are qualitative and quantitative analysis using the fault tree method, reliability assessment as well as lifetime estimation and enhancement. Firstly, the various failure modes are presented. Then, mathematical modeling and reliability evaluation have been developed and simulated. Afterward, the actions that can be considered to improve the reliability and, consequently, the lifetime of wind turbines have been presented and analyzed. The results of the developed approach revealed that major reliability improvements, failure rate reduction and lifetime extension can be achieved, leading to a better return on investment, reduced maintenance as well as a safer and more reliable clean energy production.

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Photo by insung yoon on Unsplash

Photo by insung yoon on Unsplash

Why is it important?

Despite the booming developments and trends of wind energy; the low reliability level of wind turbines is considered as a major concern that has become a very active and challenging area of research. In this paper, a systematic analytical approach for failure modes analysis, reliability assessment, lifetime estimation and improvements were developed. For this end, firstly, the different failure modes were presented and modeled using the fault tree method, then qualitative and quantitative analysis were conducted in order to identify the different failure paths, the distribution of failure causes, reliability and lifetime estimation. The analysis found that the control system is the most vulnerable part of the wind turbine (29.4% of the failure causes distribution). The calculated lifetime (19.2 years) was in accordance with data published in several related papers (20 years). Subsequently, the improvement actions have been introduced and evaluated. The results of the presented approach reveal that the wind turbine's reliability can be increased considerably, the failure rate is dropped by 24% and the lifetime is extended by 31%. Achieving such reliability improved level not only thrives the transition toward affordable, reliable and clean sources, but also drives operations and maintenance, assets management, returns on investment as well as energy production by: • Maximizing the useful life of the wind turbine, • Reducing maintenance cost since the failure rate is less, • Improving operational efficiency, • Minimizing the life cycle cost, • Ensuring more safe and reliable production, • Minimizing replacements capital cost.