Report on the heat resistance of the bedding material 110kV cable (Kremeni pijesak Pjescara Jerovec)

Abstract

The transmission power and lifespan of energy cables, and thus the quality and reliability of the consumer’s power supply, directly depends on the ability of the environment to dissipate the heat that develops due to Joule and dielectric losses in the cable. The overtemperature of the underground power cable is proportional to the specific thermal resistance of the environment in which the cable is laid. For common geological environments, the thermal resistance ranges from 40 Kcm/W to 400 Kcm/W. A well-chosen and dimensioned cable bed can significantly improve heat dissipation from the surface of the cable and thus extend its life, just as a bad bed can lead to its overheating and premature destruction. Therefore, it is necessary to investigate the thermal characteristics of the bedding material before application. The thermal resistance of the tested sample usually depends on its moisture content and compaction (density). A fully wet compacted sample (16.4% water) shows a thermal resistance of 92 K cm/W, and a dried compacted sample around 340 K cm/W. A moderately dry sample (about 7% water) has a resistivity of about 150 K cm/W.

Stanko Milun

Full Professor

Faculty alumnus with a research focus in the development of measurement methods in high-voltage systems, signal analysis in electrical power systems, and the application of geoelectrical methods in energy infrastructure. Prof. Milun has been involved in numerous scientific projects, including those related to the optimization of grounding systems for high-voltage plants and the development of transient measurement methods. He has authored 38 scientific papers and over 150 professional studies.

Goran Petrović

Full Professor | Department of Electrical Measurements

Prof. dr. sc. Goran Petrović is a full professor at the Faculty of Electrical Engineering, Mechanical Engineering and Architecture in Split. His research interests include measurement of electrical and process quantities, analysis of geoelectrical and geothermal features of the soil, instrumentation for smart grids, measurement and application of synchrophasors. He is the author of numerous papers published in top-tier scientific journals and contributed to valuable international and national scientific projects.