| dc.description.abstract | The renewables sector is currently experiencing a rapid growth and wind turbines are no exception. They are increasing exponentially in their numbers and the nameplate power production capacity has crossed the double-digit megawatt line. In short, thousands of valuable power plants are going to be built and operated for decades. As with any other heavy industry independent integrity management will play a major role in how productive the turbines will be and how long they will last. The proper collection and treatment of asset performance data will also pave way for better and smarter designs of turbines. Oceaneering IMDS has as an integrity management advisor explored several well-established principles on how to best approach this challenge and the potential gains are significant. This study aims to develop a generic maintenance plan for onshore, offshore bottom fixed and offshore floating wind turbines. Specifically, it investigates a risk-based approach including failure rates and risk priority number (RPN) evaluations of the different concepts through failure mode, effects, and criticality analysis (FMECA).
The main objective of the thesis was to develop realistic and functioning maintenance plans for each of the wind turbines. A mixed-method research combining qualitative and quantitative research was used as it contributed to a more reliable discussion and conclusion. At first it was important to collect reliable and valid literature and data from relatable articles and papers. As there is a lack of developed wind power standards, it was also important to utilize oil and gas data and standards such as OREDA, ISO and NORSOK where it was applicable as there are many correlated systems and routines between the industries. Secondly, a semi-structured interview with an experienced maintenance company within wind power, Espeland Energi AS, contributed to improvement of the outcome of the thesis and provided precise details to the maintenance plans. The construction of technical-, and functional hierarchies and FMECA was based on expert judgements and necessary competence from Oceaneering. They also contributed with important information and knowledge when the authors performed the consequence classification and the redundancy levels were assigned.
Use of risk-based methods to ensure availability of the system was provided by use of NORSOK Z-008. The detailed and mature procedures provided by Oceaneering was the main enabler to achieve that. The result was three detailed maintenance plans for onshore, offshore bottom fixed and offshore floating wind turbines with focus on the four most critical subsystems of the different turbines: rotor, gearbox, protection and switchgear, and tower (including substructure for offshore). From this result, it was concluded that a risk-based approach to wind turbine maintenance work should be conducted to ensure availability by mitigating failures on critical components.
An additional objective of the thesis was to discuss possibilities within spare part transportation
using artificial intelligence, which was achieved by utilizing Oceaneering’s ROV and AGV fleet
by expanding their Freedom ROV with an additional trunk that can transport the spare part. A
complete spare part transportation plan was developed by further utilization and development of
existing technology within Oceaneering to enhance the lead time and substantiate availability of
the offshore wind turbines. | |