Generated heat within power cable sheaths per unit time and volume

An assessment of the generated heat per unit time and volume within cable sheaths is required to determine the corresponding temperature distribution through the domains with underground power cable systems. If the sheaths of a cable line, laid in a flat formation, are bonded and earthed at both ends of an electrical section, and if conductor currents form a balanced three-phase system, the generated heat per unit time and volume within solid sheaths can be accurately evaluated using: i) the filament method in the case of the cables laid in either touching or close arrangements, ii) both the filament method and the simple analytical IEC (International Electrotechnical Commission) relations associated with sheath losses in the case of spaced formations. By using the filament method, the modeling of the ground return path for sheath currents is not a mandatory task, regardless of the cable spacing.

► Heat per unit time and volume within solid sheaths can be assessed by the IEC relations for spaced flat cable formation.
► Use of the filament method is suggested for touching flat cable formation.
► Modeling of the ground return path using filament method is not a mandatory task.