Comparing Wave Propagation Characteristics of MV XLPE Cable and Covered-Conductor Overhead Line using Time Domain Reflectometry Technique

In this paper, the wave propagation characteristics of single-phase medium voltage (MV) cross-linked polyethylene (XLPE) cable are determined using time domain reflectometry (TDR) measurement technique. TDR delivers the complex propagation constant (attenuation and phase constants) of lossy cable transmission line as a function of frequency. The frequency-dependent propagation velocity is also determined from the TDR measurements through the parameters extraction procedure. The TDR measurement results for MV XLPE cable and covered-conductor (CC) overhead line are compared and it is proved that CC line has lower attenuation and higher propagation velocity than power cable. The measurement results can be used to localize the discontinuities in XLPE power cables and for PD detection to monitor falling trees on the MV CC overhead lines.