Abstract:Submarine cable long operates in complicated seabed environment. Interruption of the power supply caused by submarine cable fault has a big influence on island. Therefore, its condition must be monitored to avoid power cut. In view of the status of the Weizhou island sea-crossing power system connection project, the existing submarine cable fault detection methods are reviewed. A fast Brillouin frequency shift measurement method is introduced and validated. Based on this, a fast submarine cable temperature and strain monitoring method based on distributed fiber sensing technology is proposed, and at the same time its principle and architecture are introduced. On this basis, a submarine cable operation, insulation and mechanical conditions evaluation and fault diagnosis method based on finite element method and measured fiber temperature, strain is proposed and preliminarily validated. The proposed solution is useful guides for the optic-electric composite submarine cable monitoring system in the Weizhou island sea-crossing power system connection project. It also provides a frame of reference for the realization of similar sea-crossing optic-electric composite submarine cable monitoring system.