Detectability of Degraded Joint Discontinuities in HV Power Lines Through TDR-Like Remote Monitoring

Remote Monitoring of Joints Status on In-Service High-Voltage Overhead Lines

“…The principle underlying the monitoring technique presented in [21] for OoS power grids is the direct application of a voltage pulse, through a pulse generator owned by TERNA, at specific accessible line terminations, and then the detection of the total voltage at the same point. This voltage is a temporal combination of the injected and reflected signals due to changes of impedance, such as the line end and/or defected joints.…”

“…In reference [21], a real 220 kV power line managed by the TERNA TSO was considered. This is the same line as that considered in the present study.…”

“…Figure 1a shows the longitudinal layout and Figure 1b shown the types of towers and the conductor cross section. The implementation of the real TDR test bench and the measurement activities are reported in [21] and therefore are not repeated here. The effectiveness of this technique is shown by the agreement of the results obtained from a circuit simulation and the measured results as reported in Figure 2.…”

“…An interesting tentative strategy to apply the TDR technique to power lines was proposed in [21][22][23], where, thanks to a close collaboration with the Italian National TSO (namely, TERNA S.p.A.), the reflections of some types of artificial defects were successfully detected [21] and also types related to the intrinsic variations of the line impedance, such as transpositions [23]. The principal issue of the presented results consists in the necessity to set the power line out-of-service (OoS), which is a very important for the TSO, making the approach unaffordable for concrete real-time monitoring.…”

“…The aim of this work is to set-up a strategy to extend the basic approach presented in [21][22][23] toward in-service (IS) power lines, thus making the TDR technique more appealing from an application point of view.…”