GISmonitor - Partial Discharge Monitoring System

When it comes to Partial Discharge (PD) monitoring, Power Diagnostix’s GISmonitor is the perfect choice for the job. The main task of the GISmonitor is to provide the user with a reliable Partial Discharge Monitoring System (PDMS) capable of detecting defects hidden inside the Gas Insulated Switchgear (GIS) such as hopping particles, floating potential, cracks in insulators, protrusion or other degradation in the insulation system. The system’s hardware has been optimised for continuous, parallel and real-time PD acquisition in order to record each signal coming from the pre-installed UHF sensors inside the GIS enclosure, no PD activity is left undetected. The Frequency Converter Units (FCU2) pick up the UHF signal from the embedded UHF sensor and demodulates it into a lower frequency band for easy transmission over longer distances. Special Input Protection Units (IPU2B) placed at the output of the UHF sensors block strong signals, such as very fast transients (VFT), and protect the PDMS. Each UHF sensor is connected to an acquisition cabinet (PDMAR) that process the data before sending it to the control cabinet (PDMCR): each of these acquisition units can be connected up to 120 UHF sensors. With very few acquisition cabinets, Power Diagnostix’s GISmonitor can therefore cover even the largest GIS and thanks to its modular approach it is highly extendable in case of future extension of the switchgear. The acquired and processed data is sent through fiber optic ring network to the control unit (PDMCR) where the user can directly operate and have a complete overview of the status of the GIS. In order to ensure that a proper analysis of the measured PDs can be conducted, the GISmonitor software provides the user with a various set of features and options. Through a monitoring mode the operator can access to the historical and live analysis of years of measured data in just a click while also checking the PD event list that summarizes the most critical acquired signals. All the data is collected, stored and automatically analysed in one central server and a database for automatic recognition of particular defects is provided (ICMexpert). Dedicated features for pre-energization activities are part of the GISmonitor software. A Sensitivity Verification mode, with CIGRE TBA 654 compliancy, reduces to a minimum the requested time for the commissioning of the PDMS and automatically generate a report for the customer. The sensible HV Test that is performed before the energization of a GIS is supported by a dedicated HV Test mode that allows the user to record PD levels and applied voltage simultaneously creating therefore a replay that can be viewed anytime: this constitutes a fingerprint of the substation at the moment of the test. The PDMS generates and forwards alarms to the subordinated system, such as SCADA, in the exact moment as they are raised, through different interfaces such as potential-free relays or IEC61850 communication protocol. In case the GIS to monitor is not provided with embedded UHF PD sensors, Power Diagnostix can offer also a series of accessories and external sensors optimized for retrofitting. To receive software updates or user guides, please contact support.pdix@megger.com or call +49 241 74927. Please have your device serial number ready or state your reason for interest.