OTEM - detects and localizes partial discharges in gas-insulated switchgear

Detection of partial discharges with optoelectronic sensors

Detecting partial discharges in gas insulated switchgear is the primary purpose of the optical partial discharge system. As a result, considerable damage up to the worst-case scenario, the so-called "blackout", can be avoided. The optical partial discharge system also eliminates the need for time-consuming localization efforts by precisely identifying the affected gas compartment within the switchgear. As such, our optical systems can be a valuable addition to your existing monitoring systems.

The OTEM partial discharge monitoring system reliably monitors the condition of your GIS and enables you to take preventive action. This allows affected components to be replaced or repaired at an early stage without causing a failure or major damage (e.g. due to the development of an arc fault) to the system.

OTEM is particularly suitable if your GIS already is equipped with light sensors. In this case, the switchgear can be upgraded cost-effectively and efficiently. For systems without a dedicated light sensor, the system can be installed on standard glass windows (e.g. available on the disconnectors) . This makes the system suitable for new and existing installations, particularly in the high-voltage sector.

Use cases:
  • Testing / commissioning of the GIS/GIL
  • Monitoring of the GIS/GIL
  • Maintenance / repair of the GIS/GIL
OTEM system installed on gas-insulated switchgear

Schematic view of the OTEM system:
All optoelectronic sensors are connected to the local control cabinet

Mobile OTEM system for testing gas-insulated switchgear

Schematic view of the mobile OTEM system:
The test can be performed at any time

The advantages of the optoelectronic detection of partial discharge can be seen in all operational phases (diagnosis/operation/maintenance):
  Precise detection down to the individual gas compartment
  Exact diagnosis of the specific fault
  Suitable for DC and AC voltage systems
  Insensitivity to electromagnetic interference from various sources (e.g. UHF signals, radio/TV, mobile radio, electrical machines)
  Diagnostics also possible during operation (especially during switching operations)
  Specifically engineered for switchgear in high-voltage environments
  Easy installation and operation
Sensor partial discharge on SF-6 isolated system

The optoelectronic sensor (OTEM module) can also be retrofitted to existing systems

Partial discharge sensor on gas-insulated switchgear

OTEM is connected to a light sensor

Signal recording and visualization

The optical patterns of the partial discharges are comparable to the signal patterns of conventional IEC and UHF methods, allowing reliable detection and verification with an independent technology.

Due to the virtually interference-free signal recording, no further filtering of the signals by the operator is required.
Figure 1 - hopping particle

Figure 1 - hopping particle

Figure 2 - Peak on the inner conductor

Figure 2 - Protrusion on the inner conductor (HV-Potential)

Figure 3 - Protrusion on housing (earth potential)

Figure 3 - Protrusion on housing (earth potential)

Figure 4 - Electrode with floating potential

Figure 4 - Electrode with floating electrode

Figure 5 - Particle on insulator

Figure 5 - Particle on insulator

Individual inspection and test solutions for your switchgear

Permanent monitoring of the condition of the GIS

As a permanently installed solution, server for the OTEM can be installed in standardized racks or as a standalone solution in order to save space. The unit is robust and resistant to external influences. In particular, the entire system is insensitive to electromagnetic interference. The modular system also allows for additional gas compartments to be installed at any time without interfering with the existing system in operation. In summary, the fixed installation of our OTEM system for monitoring partial discharges is the best option for accurately assessing the condition of your GIS at any time.

Permanent monitoring of the condition of the high-voltage switchgear

If the OTEM system is permanently installed, the status can be monitored at any time via a user interface

Mobile testing for partial discharges

As an alternative to the fixed installation, the testing of your GIS for partial discharge can also be carried out at intervals as a mobile test. The test itself is carried out by our qualified personnel. After completion of the switchgear´s test, you will receive an insightful test report, which you can use to accurately assess the condition of the high-voltage system. The mobile test method is also carried out independently of electromagnetic interference signals (e.g. from cellphones, radio traffic, electrical devices, etc.). The result is always accurate and precise.

Mobile testing of a high-voltage switchgear for partial discharges

As part of the on-demand test for partial discharges, you will receive a comprehensive diagnosis of your GIS