Efficient and Effective

Overhead Line Fault Location Concept and Directional Earth Fault Passage Indication

Project Data

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End date:





The scope of the project is to address time spent searching for overhead line faults; the duration of the outage; and the inability, currently, to detect developing faults. The scope of the project is 11kV overhead lines, which may or may not be fitted with existing visual Fault Passage Indicators (FPIs) and automatic sectionalising links (ASLs), but where fitted these devices do not report in via SCADA to our control room.

What is the project about?

The project aims to further reduce search times by identifying that permanent faults as being down a particular spur, or locating them to a particular location between sectionalisation points on the main line. Secondly, it aims to demonstrate that developing or “incipient” faults can be reliably detected.

How we’re doing it

The project will develop functionality to detect faults, determine their direction whether upstream or downstream of the sensors, and estimate the location of the fault using the following equipment and techniques. It will be carried out in the following phases:

Phase 1a:

Tollgrade’s LightHouse Power Sensors and additional Fault Passage Indicators which report via SCADA into our control room will be installed. Where possible, existing items of equipment (existing remote terminal units (RTUs) which can be upgraded) will be modified to report estimates of distance to a fault.

Phase 1b:

Tollgrade will enhance the LightHouse SMS software and LightHouse Power Sensor firmware to report directionality of fault events based on the phase angle of the captured faults. Software and firmware deployed during phase 1a will be remotely upgraded. As fault events are detected, the enhanced solution will demonstrate the reporting of the direction of fault current from each sensor location. The location of faults in the upstream or downstream direction will be confirmed by associated UK Power Networks records following outage resolution.

Phase 2: Fault Library and Fault Location

Tollgrade will enhance their LightHouse SMS software to calculate distance to fault based on the readings from the LightHouse Power Sensors. In addition, the LightHouse Power Sensors will capture, time stamp and communicate critical measurements and event waveforms back to the LightHouse SMS software. This will allow UK Power Networks and Tollgrade to evaluate the reliability with which these are representative of developing or incipient faults, and to configure alarms via text or email to assigned personnel. The data will remain in the LightHouse SMS software as a repository, where it will also be used to understand whether it is possible to recognise the type of event or failure from the data captured.

What makes it innovative

The main learning that will be shared with other DNOs is expected to include:

  • The reliability with which the equipment can distinguish the correct spur and estimate location of the fault;
  • The reliability of detecting developing or “incipient” faults;
  • Whether capturing the waveform can provide any further clues about the nature of the fault; and
  • What policies needed to be developed to install and make use of the equipment.
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