The main task of the GISmonitor partial discharge monitoring system is to detect internal partial discharge (PD) in the insulation system of gas-insulated switchgear (GIS). The system's hardware has been optimised for parallel, real-time PD acquisition on multiple channels.
Each 8-channel acquisition plug-in board operates independently, but can be combined with a nearly unlimited number of units to monitor all PD sensors, in parallel, in one or multiple GIS systems. The unit detects and digitises any ultra-high frequency (UHF) signals within microseconds. Therefore, no PD activity is left undetected. A separation of PD events from external disturbances or internal switching pulses is calculated in real-time; this provides automatic, effective PD detection and alarm.
The GISmonitor is designed to suit all currently available UHF sensors for GIS PD monitoring, including embedded and externally retrofitted UHF sensors. A special input protection unit (IPU2) blocks strong transients (VFT). The pre-processing unit FCU2 demodulates UHF signals into a lower frequency band for easy transmission over longer distances.
The common software interface allows you to easily monitor PD activity on the entire GIS system without interrupting its operation. All data is collected, stored, and automatically analysed in one central server and a database of typical PD failures is provided (ICMexpert software). External interfaces to IEC 61850, SCADA, or other overall monitoring systems are available on request.
Certain features set the GISmonitor apart in its abilities as a specific PD monitoring system for GIS. These differentiating features include:
The unit accommodates a customised system layout for each installation. Flexible system design due to frequency conversion -> up to 80 m of sensor cabling.
Advanced software features for sensitivity verification and high voltage testing.
High levels of redundancy and self-monitoring.
Highest cyber security standards (hardened system, encrypted communication, user authentication, integration to superordinate systems).
Continuous and parallel PD measurement on all channels -> no PD pulse gets lost.
All PD measurement data is saved, facilitating an in-depth review and analysis.
More features often necessitate more hardware. When choosing between multiple PD monitoring systems for your GIS, look closely at the prospective systems' specific capabilities to ensure they are comparable.
The continuous data acquisition, storage, and analysis provide a complete overview of the development of PD activity within your switchgear. You can track ageing mechanisms and evaluate the urgency of taking action based on continuous data acquisition.Furthermore, a permanent PD monitoring system provides an instant indication in case PD activity occurs. Manual measurements with a portable instrument can be weeks or months apart, possibly delaying detection after PD's inception.
The GISmonitor is based on a scalable architecture. The number of channels can be increased by adding more acquisition cards and, if required, more Partial Discharge Monitoring Acquisition Racks (PDMAR). With this approach, systems with more than 1000 channels are possible, and a system design customised and optimised for a specific GIS can be provided.
The detection of the problem is done by the GISmonitor system autonomously. You will not be required to determine if there is PD activity. The software algorithm continuously analyses all measured data and detects whether PD activity is present. Regarding a deep analysis of a PD defect, our ICMexpert software comes with a database of known defects. The software automatically takes the phase resolved partial discharge (PRPD) that triggers an alarm, compares it to a database of known defects, and finds the best match within our database. Accordingly, it will give you an indication of the most likely type of defect you are facing.