Time-domain reflectometry based temperature monitoring on MVAC cables: experience from field and laboratory experiments

This work presents a study on the impact that temperature variations have on propagation speeds in MVAC cables using time-domain reflectometry. A multi-scale approach is adopted, beginning with a proof-of-principle experiment on a micro-network containing a short coaxial cable, followed by controlled laboratory measurements on a mini-network consisting of a 207 metre PILC cable drum, and concluding with an active in-service circuit of comparable length and identical cable type. Temperature-induced changes in propagation speed have been reliably detected and confirm the well-defined linear relationship between changes in propagation speed and temperature for PILC cables. Applying this calibration to field measurements and adjusting for baseline offsets, yields relative temperatures that…