SP Energy Networks has successfully trialled the “world’s first” real-time fault level measurement system on a section of its network.
The distribution network operator (DNOs) said the device developed by Outram Research achieved an error margin of less than 1 per cent at 11kV, “far outperforming” the 5 per cent margin it was originally targeting.
Fault level refers to the amount of current that flows through a network in the event of a short circuit. Network operators must ensure that their assets have sufficient capacity to handle this current to prevent damage during a fault.
These levels have historically been estimated based on modelling of networks and connected loads, but the increasing complexity of their configuration has made these calculations more difficult.
“One of the core issues that we have is that with increasing levels of embedded generation and new low-carbon technologies connected onto the grid, that causes the fault level to vary across the network,” explained Scott Mathieson, director of network planning and regulation at SP Energy Networks.
He continued: “The problem is that if you can’t actually monitor this you have to make conservative assumptions about how you operate the network because you can’t afford for that failure. That will mean that you might be planning for a 1-in-100, 1-in-200, 1-in-1000 type circumstance that may happen.”
Back in 2010, SP Energy Networks undertook a project with Outram Research to develop a device capable of directly measuring fault levels using natural disturbances on the network. However, Mathieson said this system, which became available in 2011 and is now used by all of the DNOs in Great Britain, can take several days to deliver a result.
The new device, which has now undergone testing at the Power Networks Demonstration Centre (PNDC), is able to measure faults levels in real-time by using an in-built disturbance generator to send small pulses of energy through the network.
“We’ve always believed this technology will be a real gamechanger, so we’re pleased to have it validated by the PNDC,” said Mathieson. “SP Energy Networks is leading the way by supporting the development of innovative solutions like this, which have the potential to revolutionise the industry in the future.
“The real-time fault level monitoring technology will enable new connections, such as renewable energy generators, to be added to the network at a much lower cost – making this technology a key enabler for a just transition to net zero.”
John Outram, managing director at Outram Research, said “We are pleased to have further, independent confirmation of the accuracy of the fault level measurement algorithm used in all of our fault level monitoring devices, both in the real-time units and those using natural disturbances to derive results.
“Less than 1 per cent error for both peak and RMS fault level results at 11kV is a real testament to the hard work involved but also to the high levels of support we have received from SP Energy Networks whilst achieving it.”
By minimising the reinforcements needed to connect new generation safely to the power grid, Mathieson said the device could save £35 million over the RIIO ED2 price controls if deployed out across its license areas and £150-200 million if deployed across the whole of Great Britain.
UK Power Networks has now joined the project through the Energy Innovation Centre which is managing collaboration. The DNO will help to begin national rollout of the technology.
Rob Greenoak, innovation programme manager at UK Power Networks said: “Collaboration is vital if the whole of the UK is to reach net zero by 2050.
“We’re looking forward to coming together with other key players in the industry with the common goal to enable more low carbon technologies to connect to the network. This new technology is facilitating net zero whilst improving reliability and efficiency of the network.”