Online PD monitoring system for MV cable connections with weak spot location

A unique measuring system is presented for the online monitoring of partial discharges (PDs) in medium-voltage power cables. The system is able to locate the origin(s) of PDs by using two inductive sensors, each at one cable end. The measuring system is called PD-OL, which stands for PD detection On-line 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. The Control Center at KEMA collects data from all the PD-OL measuring systems for final presentation and interpretation, which can be made visible on a secured web-site for the network owners. This paper discusses the basics of PD-OL and some first measurement results.