Study of Soil Temperature and Moisture Changes in a Physical Model of an Underground Cable Line

The ampacity of power cables is highly dependent on the thermal resistivity of the soil in which they are laid. The lower it is, the higher this ampacity. The thermal resistivity of the soil decreases as its moisture increases. Therefore, it is preferable that the soil around the cables has high moisture. Unfortunately, the heat generated in heavily loaded cables causes the migration of moisture from the surrounding soil, which adversely affects the ampacity of these cables. However, it turns out that it is possible to stop the migration of moisture from the immediate vicinity of the cables. The paper presents the results of a long-term experiment (soil/betonite temperature and moisture measurements), which proves that proper protection of the medium around the cables makes it possible to stop the migration of moisture. This has a positive effect on the ampacity of the cables and, thus, on the level of transmitted power.