Designed to accurately locate faults even in the most challenging environment

The MetrySense-5000 (MS5000) Fault Detector & Analysis features patent-pending sensors and algorithms, which rely on high frequency signals for the detection and localization of high impedance faults. The sensors embed algorithms for reliable fault detection both in distribution power grids with solidly earthed neutral and in distribution grids with a Petersen coil compensated neutral.

MetrySense-5000 sensors are deployed on the conductive wire using a grip-all hot stick. The sensors detect different events, including:

  • A trip of a recloser. The sensors detect this event by sensing current drop and electric field drop, and autonomously reports the event to the central controller.
  • Crossing a predefined current threshold. The threshold can be configured from the server.
  • A predefined change due to sudden current increment.
  • A drop of electric field.
  • Increment of harmonics.
  • A presence of an arc.

MetrySense-5000 sensors are constantly sampling and recording current and electric field signals at a typical sample rate of 1kHz and up to 500kHz for high frequency applications. When an event happens, the waveforms are copied to an internal log in the sensor. The data is processed for further event analysis. The raw data waveform and the results of the data processing can be retrieved by the server by polling the sensors via the radio network or by receiving an autonomous event from the sensor.

The following figure is a waveform of a load current captured from three sensors:

1

In addition, the sensors compress the measured data, save it to a local database, and sends it to the server, where it is visualized and analyzed.

The MetrySense-5000 analytic module provides the following information:

  • RMS current
  • RMS electric field
  • Total harmonic distortion
  • High frequency current and electric field information
  • Power factor
  • Power sags
  • Power surges
  • Voltage swell (voltage rise)
  • Harmonics information.

MetrySense-5000 sensors and analytics include unique patent pending algorithms for detection of high-impedance faults and the presence of arcs in the high voltage power grid. This capability is essential for better detection of faults, which are sometimes not detected by the protection system.

Fault detection field tests utilizing deployed MetrySense-5000 sensors

his is an example of a field test conducted on a 13kV rural distribution power grid in Brazil.

The first test dealt with a fault that was generated by connecting the live high voltage line to the ground via two grounding rods:

Metrycom_rural_area_fault_detection

The second test dealt with a high impedance fault that was generated by connecting a ring to the live high voltage line and placing it on a dry ground. The resulting current was only 2 Amperes:

Metrycom_rural_area_fault_detection_1

Both faults were successfully detected by the MetrySense-5000 sensor, which was deployed several kilometers from the location of the fault.

Metrycom_rural_area_fault_detection_2