Partial Discharge Monitoring

Real-time on-line detection of partial discharge events
Optional feature to SENSeOR’s monitoring platform for electrical equipment

An easy-to-implement and cost-effective partial discharge indicator option for DSO’s, TSO’s, and end-users of critical electrical assets
Continuous partial discharge monitoring, early warnings and trend analysis to trigger maintenance inspections, only when necessary but before important damage occurs
Get the maximum value out of SENSeOR’s monitoring platform to exploit your assets to their maximum, minimizing life-cycle costs and downtime!


Main features

  • Non-contact UHF (Ultra-High Frequency) detection of PD events
  • Remote real-time surveillance of PD activity – enabling alarms and trend analysis over equipment lifetime
  • Cost-effective solution for first level diagnosis, covering a wide range of PD discharge events, triggering deeper PD analysis and the required maintenance actions only when necessary
  • Exclusive design of the antenna/UHF sensor, compact, optimized for SAW sensors and PD detection in switchgear cubicles
  • Dedicated high-performance algorithms and interrogation methods for robust and reliable operation in RF-challenging environments like metallic cavities
  • Modbus-RTU communication protocol (over RS485 wired network through RJ45), Ethernet prepared, to interface with control systems (SCADA, HMI) or the SENSeOR’s supplied GUI (MS/Windows)
  • Wireless link to control room on request
  • Compact, DIN-rail mounting transceiver (installed in the low-voltage compartment of AIS switchgears)
  • Option to SENSeOR’s integrated monitoring platform for wireless passive SAW temperature sensors (including ambient temperature, humidity, analog inputs/outputs, connectivity options, data storage, GUI)
  • Suited for Medium-Voltage Air-Insulated Switchgears (metal-clad AIS), power transformers, GCB, GIS, bus ducts etc.
  • Compatible with retrofit installation or factory-mounted, OEM version available

Operation overview

PD are a consequence of local electrical stress concentrations in insulation or on the surface of insulation. PD activity is observed in all types of high- & medium-voltage power equipment.
There are several main types of PD: external/in air and internal/in equipment. External PD takes place outside of the power equipment, for example in overhead lines or on armature. Internal PD occurs inside the high- or medium-voltage power equipment, like switchgears.
Examples of PD:

  • Surface discharge, which occurs on interfaces of dielectric material
  • Cavity (void) discharge, which occurs in solid or insulating materials
  • Corona discharge, which occurs on metallic sharp edges.

Such electrical discharges appear as various forms of voltage and current impulses, having a very short duration (Nanoseconds).These events radiate electromagnetic energy with a specific spectral signature for which UHF detection is well suited, enabling high levels of refresh rate and accuracy.
SENSeOR’s specific antenna(s) (aka UHF sensors) for PD monitoring is/are installed in the cubicle, typically in the cable compartment. The same antenna(s) is/are used to monitor the temperature with the wireless passive SAW temperature sensors and SENSeOR’s transceiver/concentrator.
The PD indicator functionality operates simultaneously to the SAW temperature monitoring system, using the same communication protocol and the results are sent to the same GUI or customer HMI/SCADA. 
The ambient noise in nominal operation of the equipment is measured at system installation. PD events are separated from this ambient noise in real-time thanks to SENSeOR’s specific hardware and exclusive high-performance algorithms (optimized phase-resolved analysis and IEC60270 rules translation to UHF method). Several frequency bands are scanned to qualify and ascertain the presence of a PD activity.
Alarms levels can be set for notifications in the GUI based on the evolution of partial discharge activity (amplitude, occurrence).
With input of optional sensors, ambient temperature, load and humidity levels can be integrated into the calculation of alarm levels and trending data.

Contact SENSeOR

French Headquarters
505 route des Lucioles, Navigator B
06560 Valbonne – Sophia Antipolis

SENSeOR Offices
c/o Temis Innovation
18 rue Alain Savary
25000 Besançon

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SENSeOR Profile

SENSeOR exploits Surface Acoustic Waves (SAW) to conceive unique-patented wireless passive temperature sensors. SENSeOR is a 10-year old start-up spirit French company, part of WIKA Group since 2012. Its expert engineer team provides field-engineering services and customized developments in addition to its standard sensor portfolio, in a simple and comprehensive monitoring platform, for Industry and Energy applications. SENSeOR is a member of the French association “Think Smartgrids, French solutions for smart grids” and is part of "La French Tech - Clean Tech".