The submarine cable is affected by the complex marine environment in the process of operation. Once the fault occurs, it will cause serious economic loss and social impact. Firstly, this paper analyzes and classifies the causes of the submarine cable fault. Then, based on the history data of faults, the static reliability model with the change of submarine cable length is established, which reduces the calculation error for the long-term reliability evaluation of the power grid. Then, based on this static reliability model, an improved dynamic reliability model with time-varying failure rate is proposed, which provides a computational basis for short-term reliability evaluation. Finally, the practicability and accuracy of the method are verified by an example of submarine cables in an offshore oilfield power grid.

Submarine cable,Dynamic reliability model,Marine environment,Time-varying failure rate