Marine power cables are used to connect various electrical equipment in the Marine grid to transmit electrical energy or electrical signals. With the continuous improvement of the degree of electrification and automation of ships, the variety and consumption of Marine power cables are increasing. Marine cables are basically divided into power cables, communication cables and special high-frequency cables three categories, of which power cables are used for power, lighting and other systems, is the most used cable on board. For power cables, carrying capacity is an important technical index. The size of the current carrying capacity generally depends on the temperature resistance grade of the cable insulation material. Under the same laying conditions, the higher the temperature resistance level. The greater the carrying capacity. If the ambient temperature is high, and the selected cable insulation temperature resistance level is low, so that the allowable temperature rise caused by current heating is very low, it is not economical. The sheath of Marine cable should have the properties of moisture resistance, oil resistance, fire resistance and heat aging. Commonly used sheathing materials are neoprene rubber, chlorosulfonated polyethylene and polyvinyl chloride, in addition to lead sheathing.
Under normal circumstances, Marine power cable from the inside to the outside for the conductor (cable core), insulation layer (insulation can withstand the voltage of the grid), filling and shielding layer (made of semiconductor or metal materials), protective layer (to maintain the insulation performance of the cable) and other main parts, its insulation performance will directly affect the integrity of the entire electrical system and stable operation, therefore, International standards such as IEEE and IEC/TC18 have clearly defined the performance of cables.