Thermal analysis for determination of current carrying capacity of PE and XLPE insulated power cables using finite element method

摘要

Transient heat transfer analysis of medium voltage, PE and XLPE insulated underground power cables are investigated by applying finite element modeling developed under a finite element software utilizing principle of virtual temperatures which is the quadratic functional form of the variational formulation of the transient heat transfer equation. Obtained results are compared with and verified by experimental heat transfer data for PE insulated cable. In order to minimize the truncation error arising from the boundary condition choice, two different boundary conditions for the selected boundaries namely Dirichlet and Neumann conditions are applied for different domain dimensions, and, it is shown that appropriate solution domain can be obtained. Then, PE and XLPE insulated cables are compared from the heat transfer point of view. Cable temperature dependency to variations in thermal conductivity of the surrounding medium and loading is investigated. Thus, correction factors given by cable manufacturers regarding cable current carrying capacity are obtained by using the finite element model developed in this study.