Risk assessment of floating offshore wind turbine based on correlation-FMEA

Floating offshore wind turbine (FOWT) is complexly structured by interdependent subsystems and experiences negative impacts in harsh operating conditions. During the risk and reliability analysis, two issues have to be addressed: system failure mode complexity and mutual correlation. We conducted risk assessment through a modified Failure Modes and Effects Analysis (FMEA) method, named correlation-FMEA,to study the connection between failure modes and its effect on the failure probability of the entire system. A series of failure modes with high priority were determined by conventional FMEA, and the corresponding connections were analyzed to obtain the correlation coefficients using the reliability index vector method. The data used in our research comes from field operation in China. Probability Network Evaluation Technique (PNET) was used to get the weakest failure modes set of the system based on those coefficients. With the results, suggestions for floating wind turbine design were provided regarding aspects of safety and reliability.