Measurement of Soil Thermal Properties by Spherical Probe
Abstract
The thermal resistivity of the soil surrounding a power cable is a very important factor in evaluating the load-carrying capability of underground cable. This paper presents a method for measurements of soil thermal properties with spherical probe along the cable installation routes. On the base of two port network analysis equations for temperature response of hollow spherical probe are obtained. The paper offers a mathematical model for calculation the soil thermal parameters including the related standard deviations using the least square method. Propagation time of thermal flux is calculated and it is shown that transient stage of spherical probe can be used for measurements in infinite as well as limited samples of soil. Thermal self capacity and contact thermal resistance between probe and surroundings are taken into calculations. Realization of probe with electrical heater and temperature detector as well as additional measuring devices are described.
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.
Tomislav Kilić
Full Professor | Department of Electrical Measurements
Full professor at the at the Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture in Split, with professional reserch focus on power quality, signal analysis in electrical power systems, and measurement of process variables, alongside a significant role in the academic and administrative life of the University of Split.
