The GISmonitor builds on more than 20 years of experience in online PD monitoring on rotating machines, transformers, cables, and especially GIS systems. It combines proven technology of the ICMmonitor with new processor technology and embedded hardware capabilities. The hardware core of the system has been 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 calculated in real-time and, therefore, an effective PD and alarm detection is given.
Each 8-channel acquisition plug-in board operates fully stand alone, but can be combined with a virtually unlimited number of units, to monitor all PD sensors in one or even multiple GIS in parallel. A full 19" sub-rack carries 64 channels. A remote computer reads all data of the instruments via the high speed fiber optic LAN ring, providing communication redundancy. The GISmonitor indicates with on-board LED’s internal states and alarm conditions.
Cabinets are used to accommodate all instruments and the industrial type PC. Each cabinet comes with a standard 19” frame, an uninterruptible power supply, a network switch as well as temperature controlled cooling and heating. Cabinets for indoor applications feature a protection class of IP54, while cabinets for outdoor applications reach a protection class of IP65.
The GISmonitor is designed to suit all currently available UHF sensors for GIS PD monitoring. This includes embedded and external retrofit UHF sensors. A special input protection unit (IPU2) blocks strong transients (VFT). The preprocessing unit FCU2 demodulates UHF signals into a lower frequency band.
The user interface software panel of the GISmonitor monitoring system is installed on the local industrial PC and can be installed additionally on any remote computer for data evaluation and diagnosis. Using an administrative setup allows configuring the system and the embedded service program.
This service program takes care of reading data and alarm conditions from the instruments in a predefined time schedule. The service starts as soon as the computer has been turned on and, hence, a valid login on this machine is not mandatory to continue the data acquisition.