An incident in Victoria has shown the importance of Early Fault Detection (EFD) systems, with a broken conductor strand being identified before the powerline fell.
The EFD system, installed by Powercor on a 13,000V powerline in a high danger area at Porcupine Ridge near Daylesford, detected the breaking powerline in time for repairs by the company’s line crews.
Dr Alan Wong, CEO of Melbourne-based company IND Technology, which develops and sells EFD systems around the world, explained that the EFD system covering the Porcupine Ridge powerline first picked up indications of trouble in mid-April 2020.
An IND Technology team was able to confirm the breakage when it visited the site in mid-May.
“The company alerted Powercor, which immediately sent a crew to make the conductor safe, so it couldn’t fall or unravel further to create an electrocution risk from hanging strands of wire,” Dr Wong said.
“They came back and fully repaired it two days later.”
The EFD technology uses pole-mounted sensors every 5km.
It continuously monitors powerline networks to detect problems before they create serious safety risks, such as bushfires, locating them accurately within ten metres so crews can go directly to the problem and repair it.
IND Technology developed it with support from Deakin and RMIT Universities.
Local landowner, Michael Thorne, said he was very happy the problem had been found and fixed.
“I often walk through this paddock with the children and we look at the stock and the pasture but never think to look at the powerline above. If that strand had kept unravelling and one of us had walked into it, we could have been killed,” he said.
Mr Thorne is active in the local CFA and is very conscious of the fire risk of fallen powerlines.
“If a fire started under this powerline in the peak of Summer it would likely run up the hill to destroy our property and others further along Porcupine Ridge. An afternoon wind change would then likely drive it into the State Forest only a few hundred metres away. The outcome could be very bad.”
The line had been inspected just a few months earlier and would not have been inspected again until after two more fire seasons.
Broken conductor strands like this one were implicated in Victoria’s worst-ever powerline fire disaster, the Kilmore East Kinglake fire which killed more than 120 people on Black Saturday.
This marks the third powerline at risk of falling that EFD has found in a small-scale government-funded trial, covering less than half a per cent of Victoria’s high fire risk powerlines.
The results of the trial indicated all 30,000km of Victoria’s single-wire powerlines in high fire-risk areas could have EFD monitoring installed for about $30-40 million.
The trial finished 12 months ago in mid-2019, but IND Technology has kept the trial systems running.
Both AusNet and Powercor are taking over ownership of the trial systems on their networks and are committed to keep them running as they consider future use of EFD systems.
NSW network owner Endeavour Energy is installing a small trial of EFD on selected Blue Mountains powerlines.
Power industry research continues to report utility powerline monitoring using visual inspection at multi-year intervals is mainly driven by the incidence of conductor falls and that a reliable and cost-efficient means of assessment of the likelihood of conductor fall is urgently needed.