Design and validation of power-frequency magnetic field conductive shielding for underground cables

In this paper a systematic cost-effective procedure is presented to assist in the optimal 2D design of conductive shielding for underground high voltage power cables. A 2D shape optimization algorithm based on gradient methods is used. It was found, surprisingly, that the optimal shielding shape, for a given weighted combination of magnetic energy and dissipated energy in the shielding material can result in a complex structure, presenting high shielding efficiency. A process of experimental validation at reduced scale was applied and a practical approximation was verified.