Reliability Modelling of Marine Hybrid Power and Propulsion System Considering Operation Profile

This paper focuses on the reliability modelling of a marine hybrid power and propulsion system. In order to ensure the accuracy of the reliability model, its operation profile is introduced by the multi-phase Markov method. The reliability modelling is based on a particular vessel. The reliability after introducing all the operation modes is figured out and compared with the individual reliability of each specific mode. In addition, the survival functions are also obtained by setting the repair rates as zero. The results show that Dynamic Positioning A mode has the lowest reliability while Transit A and ECO A modes have the highest reliability. In addition, different operation modes have different levels of Mean Time To Failure (MTTF). The differences among MTTFs can reach nearly 4000 operation hours, even though the differences in reliability are quite small. This can further influence maintenance strategies, which may not be apparent from the reliability calculation. Therefore, it is necessary to consider operation profiles for reliability modelling in the design and operation planning phase.