Full-scale case study of a road crossing thermal bottleneck in buried MV cable installation

Abstract

Infrastructures such as road crossings, are often limiting the ampacity of a cable link due to poor thermal properties. In order to fully utilize the true loading capacity of the cable, thermal modelling with correct input parameters should be applied. In this work, a full scale artificial road crossing have been constructed and characterized, and temperature measurements have been compared with calculations performed according to IEC 60287 and finite-element analysis (FEA). It was found that calculations according to IEC provide a good fit to measured temperature profiles by adjusting the unknown mean thermal resistivity of the material layers outside the pipe. The thermal properties of road construction materials can be challenging to measure, and in order to provide accurate ampacity calculations further work should be focused on this.