On-line Partial Discharge Monitoring of MV Cables

A new measuring system for the on-line monitoring and location of partial discharges (PDs) in medium-voltage power cables.

Many grid owners indicated the need for an on-line PD measuring system, i.e. while the cable connection remains in-service. This need has been expressed already for years, both for hv and mv cables. The system uses two inductive sensors, each at one cable end. The measuring system is called PD-OL, which stands for PD detection Online with Location. A pulse injection system is used for the time synchronization of the data intake at both cable ends and for the on-line calibration. PD data is send via internet to the KEMA Control Center for interpretation and final presentation, made visible on a secured web-site for the network owners. This paper discusses the basics of PD-OL and a number of measurement results.