Hot spot temperature inversion for the single-core power cable joint

Highlights: • The authors propose a novel approach to invert temperature of cable joint. • Indirect temperature measurement of conductor of the cable joint is realized. • The verification experiment was carried out. • Inversed results match with measured ones, and the relative errors do not exceed 6%. - Abstract: Monitoring temperature inside the power cable joint is of great meaning to the safety of power distribution, while measuring it directly is infeasible. In this paper, the authors propose a new method to invert real-time hot spot temperature of conductor in the single-core power cable joint. This method consists of two parts, the radial-direction temperature inversion (RDTI) in the cable and axial-direction temperature inversion (ADTI) in the conductor. With this method, hot spot temperature of conductor in the cable joint could be figured out with the surface temperatures of the cable nearby the cable joint and load current, both of which are measurable. Then, the authors carry it out on an actual power cable joint in the laboratory, and the inversed temperatures are compared with experiment data, which come from the indoor experiment platform, to validate the availability of this method. The maximum error of this method is 6%, and it shows that this method for temperature inversion is feasible in laboratory scale.