Effective radial thermal conductivity for bundles of identical insulated single core cables

The effective radial thermal conductivity of cable bundles is an important parameter for the thermal design of electrical systems. This paper presents a novel model for calculating the effective thermal conductivity of bundles of identical, insulated singl e-core cables. The model incorporates radiative heat transfer between adjacent cables in addition to conductive heat transfer through air-filled cavities and cable materials. Lichtenecker’s logarithmic mixture formula is applied to derive an effective conductivity for the entire bundle. The proposed model has been validated experimentally by measurements on cable bundles with varying numbers of cables. The results show a good agreement between the measured thermal conductivities and those calculated with the model.