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Efficient and Effective


Arc-Aid is trialing new fast-acting sensors on overhead lines that could allow our control engineers to detect faults faster, improving efficiency and getting power supplies back on quickly and safely.

Project-on-a-Page summary

Project data

Start date: 03/02/2020
End date: 30/11/2021
Budget: £446,000

To serve our 20m customers in London, the South and South East of England, we distribute energy through more than 46,000km of overhead electricity lines, more than enough to wrap around the earth. Most of these overhead lines are in rural areas like Suffolk or the South and cover very long distances, while in urban areas much of the electricity network is buried underground.

While our network is 99.9% reliable, with such a large number of cables high above the ground ‘faults’ which cause power cuts sometimes happen. This is particularly possible during extreme weather where, for example, high winds can on rare occasions cause cables to break or cause poles to topple.

Arc-aid is aiming to help our network control engineers identify and detect these faults much more quickly by installing innovative new sensors which alert our engineers should a fault occur.

This new fault indicator – the Metrysense 5000 – can use a variety of ways to communicate (such as radio) with software that will be integrated into our state-of-the-art network management system. Should a fault occur on either our 11kV or 33kV overhead networks, the devices can send a signal with the location and timing of the fault to our control team. With that information to hand, our control staff can dispatch a field team to quickly and safely repair the fault – getting the power back on faster for any affected customers in that area.

Fixing faults faster can also help to improve safety in general – the quicker power supplies can be securely restored, the better.

The devices, produced by technology experts Metrycom Communications, are effective on overhead wires which have a legacy device known as an ‘arc suppression coil’ (ASC) fitted, which gives the project title its “Arc” in “Arc-Aid”.  Arc suppression coils were previously fitted to help us keep power flowing for our customers, but as technology has advanced we no longer fit them.

The Metrysense 5000 devices have never been trialed before on electricity networks in England. As part of the trial, we’ll work with Metrycom Communications to make sure our control software can securely and effectively integrate with the software used by the fault indicators.

Before we test the devices on our network, we’ll work with the Strathclyde University’s Power Networks Demonstration Centre (PNDC) to test the devices in conditions that replicate the real electricity network.

We’ll also train our field engineers on how to install these units for the first time, and our control staff to view and understand the results.

Arc-Aid aims to prove that the devices can help to shorten the duration of power cuts (which we measure in aggregated scores for ‘Customer Minutes Lost’, or ‘CMLs’) and understand whether they can help us to create a more reliable, robust and efficient network.

Throughout the project we’ll assess the real benefits delivered by the Metrysense 5000 devices and analyse whether they could provide benefits for our customers if rolled-out more widely across our network.

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