Research on UV fluorescence-based localization for insulating fluid leakage and underwater sealing repair method for SCFF submarine cable

Self contained fluid filled (SCFF) submarine cables remain widely employed in long-distance, large-capacity, high voltage(HV)/extra-high voltage(EHV) AC/DC transmission systems, owing to its superior insulation properties and proven operational reliability. However, damage to the cable sheath in complex sub-sea environment may lead to insulating oil leakage, threatening cable integrity and marine ecology. Locating such leaks in long cables spanning tens of kilometers or longer is extremely difficult and time-consuming with conventional methods. Moreover, traditional repair approaches involving cable sectioning and jointing face operational complexities, weather dependencies, and exorbitant costs.