The new design of the GISmonitor builds on 12 years experience in online PD monitoring on rotating machines, transformers, cables, and especially GIS systems. It combines proven technology of the ICMmonitor, as it is installed now on more than 400 objects, with new processor technology and embedded hardware capabilities. The hardware core of the system has been fully redesigned and optimized for parallel, real time PD acquisition on multiple channels. Any UHF signal can be detected and digitized within micro seconds. A separation of PD events from external disturbances or internal switching pulses is provided by the advanced GISmonitor software.
Each acquisition unit operates fully stand alone to monitor all PD sensors in one GIS PD monitoring system in parallel. A remote computer reads all data of the instruments via the high speed fiber optic LAN.
The key features of this GISmonitor concept are:
- Real time parallel PD acquisition on all channels
- Parallel reading of PD peak values, PD scope amplitudes, and PD patterns
- Parallel 8x8x16bit colored PD pattern acquisition
- Automatic noise separation techniques via intelligent software analysis
- Separate gating input channel
- Automatic alarm detection system via software
- PD trending and PD pattern information available with the remote computer
- User friendly software panel including a customized GIS overview diagram indicating all sensors and its current activities
- Additional analysis and trending panel displaying Qp, NQS, scope, and pattern information of each channel at every time stamp
- Alarm event list indicating peak levels, PD patterns and trend information
- Direct access to all history files and to current readings
- Typical PD failure database provided (ICMexpert software)
- System redundancy in storage and LAN
- Wide temperature operation range
- External interfaces to IEC61850 or other overall monitoring systems available on request
- Low maintenance and user friendly monitoring system
- Extensibility and scalable
This online PD monitoring system has been designed to fit to all currently known UHF sensors available on the market for GIS systems. Embedded UHF sensors are as well suited as retrofit external ones. Strong transients will be blocked by a special input protection unit (IPU2B). All other common UHF signals are converted into lower frequencies by a special pre-processing matching unit (FCU2 – frequency converter unit).