In this paper measuring results of partial discharges in power cable accessories are described. For the purpose of measuring simultaneously partial discharge activity in three or more accessories during an acceptance test, a wireless partial discharge detection system was developed. Therefore, each power cable accessory is equipped with either an internal or external sensor to decouple the partial discharge signals. The system uses narrow-band detection and is described in this paper. The computers controlling the measuring units are connected via a wireless network which allows communication between the different units and the main computer situated at the voltage source site. Moreover, effective real time noise-suppression is possible by tuning the system to a noise-free frequency band. Practical examples of this system are shown based on several measurements performed in the field.@en

The VHF/UHF PD detection technique is a non-intrusive method for power cable PD diagnostics. It incorporates a VHF/UHF current probe placed at the grounding of the cable and a spectrum analyzer connected to the probe. This technique however is very difficult to calibrate due to different factors affecting the frequency response of the measuring setup. In this paper the calibration procedure is described and discussed. Furthermore two examples of on-site calibration are presented, before the actual PD measurements take place. In these examples the sensitivity of the technique is also studied.@en

This paper introduces a new advanced partial discharge detection system for detecting partial discharge activity in the accessories of power cables during the acceptance test. The system consists of three autonomous PD measuring systems which communicate via a wireless communication network with one main computer. As a result, the measured data of each measuring unit can be displayed and analyzed at one single point near e.g. the voltage source which makes easy communication between the measuring technician and test engineer possible. Based on several field measurements performed in Europe on different 380kV and 150kV cables systems aspects of measurement and data processing are discussed.@en