The Research On Loss Of Metallic Sheath And Armored Layer In High Voltage Submarine Cable

This article embarks from the basic equations of maxwell electromagnetic field,derives the differential equation of vortex field and the loss, then gives the definitecondition of vortex field and boundary value problem, studies the conditions offunctional of the two-dimensional vortex field and the finite element analysismethod.Using the active uniform transmission line model to calculate the workingparameters, then derives the loss of metallic sheath in different grounding state. Andusing the analytical method calculates the loss of metallic sheath and armored layerwhen metallic sheath is in different grounding state, then compare the results of loss,finding that the current in the middle of armored layer, the loss of metallic sheath andarmored layer and the total loss are approximately equal.The boundary and boundary conditions should be determined firstly when usingthe finite element method to calculate the loss of submarine cable, the analyticalmethod is adopted to calculate the value of boundary here. Due to the magneticconductivity of the sheathed steel wires, the magnetic field lines of single submarinecable are mainly distributed in armored layer, but the distribution in nonmagneticconductivity materials is less. Separating the armored layer, then compares with theresults of analytical method, and gets that the application of magnetic separation canreduce the total loss in the armored and sheath, and the more magnetic separationuses, the more the total loss in the armored and sheath is reduced. Because the vortexfield was not taken into consideration in analytical method, so the vortex field andnonlinear all should be taken into consideration when using the finite elementmethod to calculate the loss again, and compare the results with the other twomethods. The calculation result shows that after considering the nonlinear of steelwires in armored layer, the loss in armored layer is decreased obviously, the total loss is also decreased, and the results is more accurate than not considering the nonlinear.In short, the loss is related to many factors, when analysising and calculating the loss,should be according to the actual situation.