Increasing the ampacity of underground cable lines by optimising the thermal environment and design parameters for cable crossings

Abstract

The problem of optimising the thermal environment and design parameters of under-ground cable lines for cable crossings with the aim of increasing the ampacities of cablesis considered in this paper. Particle swarm optimisation (PSO) algorithm, formulated asa continuous non-linear optimisation problem with constraints, for solving this hot spotproblem is applied. It is found, using the PSO algorithm, that there are a suitable size ofcable bedding and an arrangement of cables within that bedding, which can eliminate orsignificantly mitigate the hot spot effect without the use of any additional cooling equip-ment. In this manner, the ampacities of both crossing cable lines increase by about 15%on average with respect to the case of a similar crossing with installation parameters com-monly used. In addition, it is shown how the cross-sectional areas of the conductors andmetal screens and the metal screen bonding methods affect the optimal solution.