HVPD Multi™ Permanent 16-Channel PD Monitor

The monitoring system comprises of one or more HVPD Multi™ Monitor modules installed in the MV switchgear room. Each HVPD Multi™ Monitor module hosts up to 16x HVCC/HFCT/TEV electromagnetic PD sensors, and up to 16x Airborne Acoustic sensors installed within the central switchgear line-up. The system is capable of complete monitoring coverage of the entire MV network, providing an 'early warning' against insulation degradation within the switchgear, cables, and connected Motors, Generators and Transformers. The HVPD Multi™ Monitor is recommended by HVPD for use in Phase 4 of the HVPD 4-Phase Integrated PD Test and Monitoring Solution.

Features Include

• Local and remote access to data via on-board HTML web interface (shown right).
• Continuous, 24/7 on-line PD monitoring technology for monitoring each phase of the MV power cable/rotating machine/transformer and the metal-clad switchgear.
• Each monitor node features 16x sensor channels for HVCC/HFCT/TEV sensors, and 32x AA sensors, suitable for monitoring 4x machine feeders or more.
• Economical network PD monitoring for detection of incipient faults and PD trends.
• Suitable for wall-mounting in MV substations.
• Measures and logs PD Peak Level, Cumulative PD Activity and PD Count to provide a measure of the PD 'Criticality' i.e. PD 'badness' factor from 0-100.
• Installation and commissioning performed by HVPD engineers or HVPD-approved service partners.

Application Testing

Medium Voltage plant that can be 'Monitored' for PD with the HVPD Multi™:

• Cables and cable accessories (terminations and joints)
• Switchgear (solid insulated, air insulated and gas insulated)
• Motors and Generators

Key Functions

PD signals are measured sequentially from the attached HFCT, HVCC, and TEV sensors and are processed with the unit's SmoothSurvey© PD analysis software. PD measurements per channel are made at regular time intervals (typically every 20 minutes) with the PD data captured at a high sampling rate (100 MS/s). This allows the PD pulses to be analysed and classified based on their true wave-shapes. The system works by acquiring a single 50/60 Hz power cycle of data at the high sampling rate and the impulsive waveforms within the power cycle are then extracted by the unit's software. Pulses are then separated automatically by the knowledge-based pulse analysis software into the following three categories:

• 'Cable PD' (PD signals in the frequency range of 100 kHz to 4 MHz from the cable or cable accessories)
• 'Local PD' (high frequency PD signals in the frequency range 4 MHz to 80 MHz from the local switchgear/plant)
• 'Noise' (switching noise and RF radio interference)

Logged data in time can then be viewed and indications of rising PD trends, intermittent PD activity and incipient faults detected. The HVPD Multi™ Monitor has an HTML user interface that can be accessed via the unit's web browser. The same user interface can also be accessed remotely if the device has a network connection either with the inbuilt 10/100 LAN or USB GPRS modem. Warning messages are generated when critical PD levels and activity are detected. The system's warning signals can also be integrated into a customer's SCADA system through simple, dry-contact output relays.

Data Sheet