Simulation and measurement of the steady-state temperature in multi-core cables

• Two analytical thermal models for multi-core cables are reviewed.
• The models are compared using finite element analysis and measurements.
• Results are given for multi-core cables having up to 5 identical cores.
• Simplified models enable fast and accurate determination of cable temperatures.

This paper reviews, adapts and compares two analytical models for computing the steady-state temperature in multi-core cables. Both models are based on the transformation of the complex geometry of a real cable into a new single-core cable having equivalent thermal properties and simplified geometry. The first simulation model is used in the automotive sector for the estimation of temperatures in bundle of wires for road vehicles. The second simulation model is based on the standard of the International Electrotechnical Commission IEC 60287, which is widely used in the industrial sector for determining the rating of electrical cables. However, these two models have never been compared before for multi-core cables having from two and up to five conductors carrying heavy current loads. Solving this problem requires an iterative computation of the heat-equation and allows the estimation of temperatures within the cable as a function of the electric current load. The model predictions are compared with each other, taking results obtained from finite element analysis (FEA) and measurement data as references. Finally, both analytical models are found to give results in good agreement with numerical and experimental analysis.