PD-Guard/UHF

• For use on GIS or other UHF applications (e.g. transformers)

• Automatic default setting (attenuation, filters ...) in the PD Guard after a power interruption before the network communication to the data acquisition server is re-established
• no mechanical moving parts (no hard disks, no fans)
• PD signal and low frequency synchronisation signal on same signal path (only one cable needed)
• Built-in alarm function with pre-defined alarm level (PD magnitude, PD repetition rate or PD current), threshold level and threshold time can be adjusted individually

Signal processing:

• PD signal resolution: 12 bit bipolar
• Accuracy at 50/60 Hz: 0.3 degree
• PD measuring range: up to 700 mV, attenuation in 2 dB steps up to 62 dB
• PD frequency range: 100 MHz .... 1000 MHz
• Pulse repetition frequency: 50 kHz
• FPGA based digital signal processing
• Input filter for PD signal
• Amplifier adjustable in linear operation
• Pre-configured digital filter
• Embedded RTOS-Computer, Linux-based
• Peak detection, clipping recognition
• Processing unit for generation of:
  • upeak, phi, U-List
  • amplification factor for auto-ranging
  • cycle time for each measured period

Communication:

• each PD Guard is addressed with an IP-Address for communication with the server
• IP-Address for identification of incoming data and for the jobs to do for each PD Guard, controlled by the data acquisition server
• Configuration of the PD Guards via monitoring software PD GUARD "TIMER"
• Simple alarm adjustment for each monitoring device and each channel
• Alarm output: optical in the monitoring software and via email (adjustable)
• Alarm criterions: PD level and PD repetition rate (adjustable)

• Ethernet-In-/Output (RJ-45 - 10/100 Mbps)
• Trigger sources: internal, external
• 4 PD inputs (TNC-connectors)
• Status-LED's for network activity and data communication

Software interfaces:

• ActiveX Control
• DCOM-Interface (Distributed Component Object Model)

Case:

• Designed for wall mounting in any position
• Stable, compact and light-weight construction
• IP65 for all industrial surroundings
• Weight: 6 kg
• Environment: +5°C to + 40°C

• PD Sensor Typ A - inductive line coupler, ungrounded type
• Active UHF-PD-Sensor DN-50- For decoupling of electromagnetic PD Signals from the inner of an oilpaper insulated transformer
• Active UHF-PD-Sensor DN-80- For decoupling of electromagnetic PD signals from the inner of an oilpaper insulated transformer
• LDC-7/UHF - External Calibrator for functional check of the complete UHF PD detection circuit, only for UHF-version of PD-Guard
• Relay Box-Interface, to control external alarms (lights, buzzers etc.)
• PD Guard-Interface allows access to PD Guard data on PC level for integration purpose in Host (SCADA) system.

• Prospect PD GUARD/UHF