Roll on to 2024, and several factors are transforming networks, including net-zero emissions goals, the desire for greater energy efficiency and security and lower bills, and the introduction of technologies such as EVs and heat pumps. “The dynamics of how we use energy have entirely shifted in the last decade,” says UK Power Networks senior technology transfer engineer Peter Lang.

“Our networks were originally designed for a single flow of power in one direction, which made consumer profiling easier. Most households were pretty similar. Based on demographics, you could model demand.”

But things have changed. “Now because of the adoption of cleaner energy sources and the drive to net zero,” Lang says, “we are seeing that a) generation is distributed and b) usage is highly unpredictable.”

This means understanding loads on networks and demand for electricity requires new technologies that can monitor the grid and report back to the DNO. SSEN now employs low-voltage monitoring technology from Lucy Electric as part of its ongoing work in RIIO-ED2. UK Power Networks has also introduced Lucy devices for improving the visibility of its LV network, including GridKey and Synaps technology.

Benefits of LV monitoring

Monitoring allows load profiles and electricity demand to be assessed in near real time. GridKey (which SSEN has been using for low-voltage monitoring since 2016) is a system for low-voltage substation monitoring that sees sensors fitted on each phase of a feeder. The sensors are connected to a metrology and communications unit that processes data and generates and logs substation loading and conditions.

This information is relayed to a data centre, where it’s securely stored and analysed. It can then be accessed graphically via an online portal or incorporated into the operator’s own networks.

Synaps, meanwhile, is a deep learning-based artificial intelligence system for the detection of intermittent faults in underground cables using a proprietary algorithm [see case study]. Synaps uses hardware installed at local substations to collect data from intermittent faults and then runs an AI algorithm against a digital twin of the distribution grid. This enables the type of fault to be classified, identifies its location, and allows planned maintenance.

From reactive to proactive

The two technologies help minimise customer minutes lost and the prospect of financial penalties as a result. Understanding the load profile on parts of the low-voltage network also helps overcome technical losses and theft and ensures power quality standards are maintained. GridKey and Synaps help plan reinforcement of the network and asset replacement by understanding load and voltage profiles.

For UK Power Networks, the system is a far cry from waiting for a customer to call reporting a loss of power, as Lang explains. “Our biggest challenge has been moving from being reactive when a fault occurs on any of our networks. Where traditionally we would wait for customers to call saying supply has been lost, the Lucy Electric technology allows us to monitor the LV feeder.”

The Synaps algorithm detects disturbances on the network that are too small to cause the fuse to operate but provide a warning that a fault is developing, Lang explains. The machine learning allows a location to be determined. “This allows us to use other techniques to pinpoint it,” Lang says.

This is very different from an undesirable cycle of waiting for a fuse to blow, replacing it, the fuse blowing again, and replacing it again, which can mean multiple interruptions in supply for the customer. “That sequence can recur until the fault becomes permanent. It’s only once it’s permanent that some of our techniques for fault location can be used. That’s why we’ve introduced technology such as reclosers, where you don’t have to physically replace the fuse, and you can get customers back on supply in 40 to 60 seconds.”

Reclosers have meant huge improvements. “We’ve gone from an annoying two-hour outage to an outage of less than a minute. Now using Synaps, even when a fault hasn’t occurred, we know when there is a defect on the circuit – and the location.”

The technology works by measuring voltage and current on low-voltage feeders and sampling waveforms at a very high frequency. Defects cause the waveform to deviate from the norm. As the system collects information about the defect, it is able to identify the fault and say where it is.

The system is currently being trialled on several UK Power Networks circuits, Lang explains, and the early results are promising. “Being able to predict when a defect is going to become a permanent fault is still a bit of challenge, but when we are warned about an event that is about to occur, we can be proactive and avoid the customer interruption.”

GridKey and Synaps are helping UK Power Networks adapt to the demands of the evolving network, he adds. “They are allowing us to be supportive of new low-carbon technologies. When a customer relies on the electricity network to charge up their EV or heat their home, or export surplus power from their solar panel, we are proactive in repairing defects before they cause a supply interruption.

“It is better for everybody.”