Remote voltage synchronization for wireless Partial Discharge diagnostics

The main objective of this paper is the assessment of the exact phase angle displacement of each Partial Discharge, PD, pulse with respect to the voltage reference waveform. Such problem also referred to as 'synchronization' is relevant when the cable is not accessible and the PD measure is carried out in wireless mode. It is well known, that the angle phase shift, due to the propagation phenomenon on the transmission line, can be calculated knowing the line type and length and typical operating conditions of the transmission line. The setup comprises a customized electronic device, the 'Phase check', a server to collect remote measurements and a Look up table to provide corrections to the measured phase shift values. To evaluate the voltage phase shift introduced by a transmission line, different simulations have been carried out in PSCAD. Then, to prove the correctness of simulated results and verify the 'Phase check' precision, experimental measurements have been carries out on three transmission lines in Sicily, Italy. The experimental measurements prove that the proposed setup is effective and quite useful to provide precise assessment of voltage phase shift for PD wireless diagnosis.