PD site location in distribution power cables

Abstract

To enable the condition assessment of distribution power cables, advanced onsite PD analysis can be used as a diagnostic tool. If the discharging site can be located, the condition of the power cable can be assessed, enabling maintenance and (partial) replacements to be executed more efficiently. Most location processes of advanced PD analysis techniques are based on the analysis of time-based signals acquired on either one or multiple cable-endings. These techniques, essentially based on the theory of travelling waves, have some limitations when used in practical situations. Where noise and disturbances can be easily suppressed, concurrency of multiple discharging sites form a challenge in the location process. This paper discusses some characteristic cases of time-based signals acquired with advanced onsite PD analysis techniques and discusses the techniques that enable the analysis process to extract the correct discharging sites from these signals.