Underground Cable
The use of underground power distribution has grown significantly over the years with the rapid increase in demand for electric energy and the trend for large infra-structures and vast expansion of highly-populated metropolitan areas. Traditional methods of cable ampacity calculations are all based on the analysis which approximates the cable circuit configuration and assumes uniform soil conditions around the cable. Such approximations and assumptions lead to inaccuracies in the calculations and often force cable engineers to use un-necessarily large safety factors and overly conservative designs, this paper presents an improved technique using the finite-element method to calculate the steady-state temperatures at various points of the cable ampacity corresponding to a specified maximum conductor temperature. An application to a cable system in the QATAR GENERAL ELECTRICTY & WATER CORPORATION (Q.G.E.W.C) network is also presented.