Development of a new program to estimate the conductor temperature of underground transmission cables in the buried ducts

Tokyo Electric Power Co. and the Japan Research Institute, Ltd. have jointly developed a new conductor temperature estimation program that makes use of the finite element method, as a tool for calculating at high precision the transmission capacity of a cable installed in a buried duct. This program newly incorporates seasonal changes in air and ground temperature, ground-surface boundary conditions for sunlight and radiation, and temperature changes in the depth direction. Heretofore it has been impossible to vary the load current, but this time it was possible to obtain more realistic simulation results than by the previous stationary-current analysis, by allowing transient-current analysis to which daily and seasonal fluctuations are added. And by employing the finite element method, it has become possible to calculate the temperature even for locations other than the cable conductor temperature (example: the cable surface temperature).