UK Power Networks trials transformer retrofit to ease low-voltage capacity pressure

UK Power Networks has launched a new innovation project to test whether existing low-voltage transformers can be upgraded to provide more active voltage and phase control as electricity demand becomes less predictable.

The NExT project, delivered with Third Equation, will trial a power-electronic device known as a Network Exchanger, or NEx. The device is fitted to secondary transformers and is intended to manage each phase independently, rather than applying the same voltage adjustment across all three phases.

The technology could prove useful as low-voltage networks are being asked to do more than they were originally designed for – with EV chargers, heat pumps, and rooftop solar all now having an impact on the load profile.

UK Power Networks says the project will begin with the construction and testing of NEx units, alongside preparation of trial sites. The second phase will see five units installed at selected substations and monitored under live network conditions.

The trial will assess whether the technology can increase usable capacity, improve power quality and extend the life of existing assets. UK Power Networks says early expectations suggest the approach could boost capacity by up to 20%, potentially allowing more customers to connect without new network infrastructure.

That claim should be treated carefully until the trial data is available, but if it works it could give UK Power Networks another tool between ‘do nothing’ and ‘reinforce’. After all, reinforcement can be expensive, slow and disruptive. If you need a connection date ASAP, a retrofit device that can actively manage voltage and phase loading could open up that avenue. 

David Francis, Head of Investment Management and Innovation at UK Power Networks, noted, “Keeping electricity supply reliable as demand patterns change is one of our strategic priorities. NExT allows us to explore how smarter, more responsive technology can help manage that in real time, giving more network flexibility and supporting the growth of low‑carbon technologies while maintaining the quality of service our customers expect.”