Selectivity of inductive coupling for partial discharge measurement in MV cables

The aim of this article is to verify the possibility of using inductive coupling for the on-line measurement of partial discharges MV cables. At its principle, inductive coupling records partial discharges that cause current changes over this coupling only. This natural selectivity can be used within on-line measurement, and, therefore, to restrain other partial discharges sources that can be found in MV system. That is why a new detection system based on the inductive coupling principle was designed and tested in laboratory conditions. In order to verify sensitivity and recording availability, basic partial discharges models (corona, surface, and internal) were prepared, and verifying measurement with standard PD Smart detecting system was realized. Based on measured and analyzed data, it is possible to state that this newly developed system has, at its disposal, parameters suitable for partial discharges detection.