Thermal-Electrical Co-Simulation of Underground Cables in Smart Cities: A Multiphysics Approach for Enhanced Grid Reliability

Fatima H.  Faris

Authors

Fatima H. Faris Department of Electrical Engineering, University of Technology, Baghdad, Iraq

Keywords:

Underground cables, multiphysics simulation, smart cities, thermal-electrical coupling, IEC 60287, digital twin

Abstract

This paper presents the development of coupled electromagnetic-thermal finite element model for underground power cables, which is of great importance in smart city applications. The model accounts for temperature-dependent material properties of the cable and incorporates the IEC 60287 thermal resistance networks. The electromagnetic part importantly models the heat generation in the different materials using COMSOL Multiphysics and validates against analytical calculations, achieving a deviation of 2.9% in the conductor temperature prediction. The thermal network predicts the temperature of the soil and the thermal resistances from the cable to the soil. It shows improvement in accuracy of 9.2% when compared the uncoupled models, especially with depth being of consideration as well. As first step towards smarter cables in smart cities, get complimentary soil thermal resistivity characterization for more accurate ampacity. In implementing IoT monitoring systems, thermal resistivity of local soil is significant for predicting ampacity and to ensure predictive maintenance in smart grid infrastructure, which predicts the condition of underground cables, estimating the life cycle of cables.

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