Analysis of underground cable ampacity considering non-uniform soil temperature distributions

• An analytical model for the assessment of cable ampacity due to non-uniform underground temperature distribution is developed.
• The underground temperature distribution is obtained by solving the heat equation with the respective boundary conditions.
• The cable ampacity reduction is calculated as a function of the surface temperature distribution and the cable depth of burial.
• The model is validated and several numerical results are obtained for different installation conditions.

An analytical model for the assessment of cable ampacity due to non-uniform underground temperature distribution is presented. The uneven underground temperature is usually caused by a non-uniform surface heating (e.g., a street or parking crossing, etc.), which is extended for certain length along the cable installation and in depth. The underground temperature distribution is obtained by solving the heat equation with the respective boundary conditions. The cable ampacity reduction is calculated as a function of the surface temperature distribution and the cable depth of burial. The model is validated and several numerical results are obtained for different installation conditions.