Submarine Cable Detection Method Based on Multisensor Communication

Submarine cable is widely used in today’s oil industry, and it is a much hidden large-scale industrial facility, which vigorously promotes the development of people’s lives. With the widespread use of submarine cables based on multisensor communication, as far as the current situation is concerned, this paper makes a report and summary on the research of submarine cable detection method in shallow sea area (sea area within 200 m). According to the implementation of the project and the way of controlling variables, the current common detection modes are planned, fault prediction, fault diagnosis, fault analysis and summary, and experimental data comparison, and then, we can use Brillouin radio frequency to prevent the occurrence of submarine cable fault, and when the fault occurs, we can detect the fault at the first time. The feedback value range of TTSL electromagnetic detection is very stable, and the Brillouin scattering frequency is within the normal fluctuation range. In deep-sea exploration, TTSL electromagnetic detection can detect faults for submarine cables and will not affect the fault in all aspects of waveform and wavelength. Finally, the best path and future development trend of submarine cable detection method are obtained by analyzing and summarizing the detection data, and a complete scheme plan such as some preventive measures and repair technology is put forward.

Transient overvoltage characteristics in submarine cables of multi-terminal flexible HVDC transmission system

The overvoltage transient characteristics of submarine cables are one of the key technologies for submarine power transmission. This article takes the submarine cable of Zhoushan Multi-terminal Flexible HVDC Transmission Project as the research object. The MMC-HVDC simulation models at both ends of converter stations are built in PSCAD. The parameters and equivalent models of the flexible HVDC cables are determined, and the submarine DC cable operating overvoltage is calculated by using statistical methods. The simulation results show that the maximum overvoltage of the submarine cable, that is, the maximum overvoltage of the conductor to sheath, the sheath to the armour, and the armour to the ground are 400 kV, 7.27 kV and 0.45kV respectively. The maximum overvoltage when it occurs faults on grid-side or valve-side appears in the middle of the submarine cable. Maximum overvoltage of HVDC single pole grounding fault appears at the connection point of land cable and submarine cable. The simulation results and the discovery of features in this article provide reference in the design, selection, and testing of submarine power transmission equipment.

Research on Improving the Working Efficiency of Hydraulic Jet Submarine Cable Laying Machine

The anchoring and hooking of ships, bedrock friction and biological corrosion threaten the safety and stability of submarine cables. A hydraulic jet submarine cable laying machine manages to bury the submarine cables deep into the seabed, and effectively reduces the occurrence of external damage to the submarine cables. This machine uses a hydraulic jet system to realize trenching on the seabed. However, the hydraulic jet submarine cable laying machine has complicated operation and high power consumption with high requirements on the mother ship, and it is not yet the mainstream trenching method. In this paper, a mathematical model for the hydraulic jet nozzle of the submarine cable laying machine is established, and parameters that affect the trenching efficiency are studied. The effects of jet target distance, flow, angle and nozzle spacing on the working efficiency of the burying machine are analyzed by setting up a double-nozzle model. The results of the theory, numerical simulation and experiment show that the operational efficiency of the hydraulic jet submarine cable laying machine can be distinctly improved by setting proper jet conditions and parameters.

Legal regime regulating the laying and protection of submarine cables in the Republic of Croatia

One of the strategic development priorities of the Republic of Croatia is the development and construction of a modern telecommunications network and the availability of high-speed Internet throughout its territory, especially in rural areas and on islands. To enable this, it is important to build a reliable and resilient communication infrastructure. With the cooperation of all stakeholders in the construction, from telecom operators to local and state administrations responsible for the maritime demesne, and with efficient legislation, it is possible to achieve sustainable development of submarine cable infrastructure. The paper provides an overview of the legal aspects of submarine optical cable infrastructure design and application at the national and international levels. Special attention is dedicated to the analysis of a national legal regime regulating the protection and sustainable use of submarine cables. Thus, the authors will provide critical analysis of a kind of dualism present in the application of the Ordinance on the Register of Concessions and the Ordinance on the Register of Concessions on the Maritime Demesne and offer suggestions for potential improvements of a national legal framework pertaining to the right of laying and legally protecting submarine cables.