Analysis of Insulation Electric Field After Extrusion Deformation of 500kV Oil-Filled Submarine Cable
The working environment of submarine cable is complex,which is not only eroded by seawater for a long time,but also may be subject to a series of injuries such as anchor damage,wave impact,and rock fall,resulting in extrusion deformation.This deformation will cause electric field distortion of the insulation layer,which may lead to insulation breakdown failure.In this paper,a finite element model of the AC 500kV self-contained oil-filled subma-rine cable is established to solve the electric field distribution of the submarine cable insulation layer under different longitudinal compression rates.According to the standard of cable factory test,the electric field distortion before and after cable deformation is compared to determine whether there is a risk of partial discharge or even breakdown of the insulation layer,and the equations of the field strength and longitudinal compression ratio of the cable in each direc-tion are fitted.The results show that the insulation ellipticity is caused by the extrusion deformation of the cable,and the deformation can be represented by the elliptic longitudinal compression rate.At 525kV,the risk of cable break-down occurs when the longitudinal compression rate reaches 15％,and the insulation layer is completely broken when the longitudinal compression rate is 31％ .The results can provide theoretical and data reference for the electrical characteristics evaluation of submarine cable after extrusion deformation.
Oil-filled submarine cableExtrusion deformationInsulation electric fieldFinite element
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