This project will trial a new type of fault indicator (Metrysense 5000) which will help locate faults in a shorter time compared to a full line patrol, therefore reducing operational costs, the number of customers off supply and Customer Minutes Lost (CMLs). This will also decrease the time a live conductor could potentially be on the ground, and therefore will reduce the risk to members of the public.
Metrysense 5000 is a fault indicator suitable for the arc suppression coil network arrangement, which can offer detailed information to a DNO’s control centre on the fault location. This has been used successfully in other countries for similar network configurations but at higher voltage levels. This technology has never been tested in the United Kingdom.
Metrysense 5000 will send real time data once integrated into UK Power Networks’ and WPD’s SCADA system. As part of the project, the fault indicator will be tested first at the Power Networks Demonstration Centre (PNDC) in a simulated network environment. If the testing is successful, it will be followed by training of operational staff, integration into the SCADA system, equipment installation and commissioning across five 11kV feeders in EPN and 10 33kV feeders from a Bulk Supply Point (BSP) in the South West.
The project aims to:
- Trial the Metrysense 5000 fault indicator
- Demonstrate how this unit can be utilised to improve the fault location in case of ASC earthing configurations, therefore helping to keep Peterson coils network arrangements commissioned safely
- Analyse how reliable, robust and cost effective the new protection/monitoring system is
- Demonstrate how operational costs and CMLs can be reduced on trial feeders if the technology is successful
- Assess the safety improvement following the deployment of the units
The project is currently in-flight; however, the following have been observed so far:
• The outcome of the tests and simulation at PNDC determined that the sensors could successfully detected 100% of the faults, including high impedance faults, which were tested under different scenarios and had secure and reliable communication and connection.
• Following the successful testing UK Power Networks carried out familiarisation training with the teams required for the installations. This highlighted the ease of the installation: each sensor was installed with a short stick or a hot glove procedure, and approximately 10 minutes installation time was required for each gateway in accordance with distribution safety regulations and HV live manual.
• Performance of these units is also vital to the long term BaU strategy to continue to employ Arc Suppression Coil (ASC) earthed systems going forward.
The following lessons were learnt through the project delivery:
- Real time digital simulation testing can offer high quality information on device performance in a relatively short time period and can provide a good alternative when lacking the ability to install and test sensors;
- Units of this size offer advantages in terms of installation time and techniques available within the distribution safety regulations as both hot glove and short stick methods can be used by operational teams giving more flexibility;
- It is beneficial to check cellular network at the specific sites, especially for remote areas of installation to ensure reliable communication; and
- A key learning outcome from the installation phase of the project is to determine a consistent sign convention for power flow prior to the sensor installations.