Conductor Temperature Monitoring of High-Voltage Cables Based on Electromagnetic-Thermal Coupling Temperature Analysis

As a key state parameter of high-voltage cables, conductor temperature is an essential determinant of the current carrying capacity of cables, but in practice, this is difficult to measure directly during the operation of high-voltage cables. In this paper, the electromagnetic-thermal coupling analysis model of a 110 kV high-voltage cable is established using the finite element analysis software COMSOL. By analyzing the temperature distribution law of high-voltage cables under different load currents and ambient temperatures, the relationship between the change in the high-voltage cable surface temperature and the conductor temperature is deduced, which allows the monitoring of the high-voltage cable conductor temperature. Taking the 110 kV cable of the Yanzhong line in Shanxi Province as an example and using the electromagnetic-thermal coupling temperature field analysis method, the conductor temperature of the high-voltage cable can be measured using the data obtained from the cable surface temperature, which is measured by the self-developed Raman Distributed Temperature Sensor (RDTS) system with a maximum measurement error of about 2 degrees C. The method is easy to use and can achieve the accurate measurement of the conductor temperature without damaging the cable body.