On-line time domain reflectometry measurements of temperature variations of an XLPE power cable

In this paper an on-line time domain reflectometry system and a four-days measurements sequence are presented. Detected pulse velocity variations are attributed to temperature variations of the cable caused by a load cycling. The changes in the pulse velocity are verified by propagation constant measurements of a power cable at different temperatures in 300 kHz-500 MHz frequency range. Also an influence of temperature dependent semiconducting screens and XLPE insulation to the changes in the cable's capacitance is investigated.