Why power networks need a 'smoke alarm' system

Scientists at RMIT University have designed an early fault detection system (EFD) for powerlines that has been adopted in North America, Europe and Australia.

The system helps to prevent bushfires and blackouts by detecting and locating faults before they escalate. “You can think of it like a smoke alarm for the power network,” said lead RMIT researcher Professor Alan Wong.

“If you place enough sensors across the network, these sensors or alarm system will send out an alert when it thinks there’s a certain risk in the network.”

The EFD system is included in several wildfire mitigation plans in the US and Canada.

Wong is CEO of Melbourne-based company IND Technology, which has commercialised the invention and is seeking funding from the Australian Government to assist with rolling out the EFD system across all single-wire earth return (SWER) networks around the country over the next decade. This amounts to about 200,000 km of powerlines.

Professor Alan Wong.

With 2500 units installed worldwide, the technology now monitors over 12,500 km of powerlines and has prevented more than 750 failures and potentially saved lives, according to RMIT. The technology can cover up to 5 km of powerlines with two units.

“According to a report by Adept Economics that we commissioned, every dollar spent on the EFD technology would generate $4.70 in expected benefits for Australia, in terms of the benefits from preventing bushfires and blackouts,” Wong said.

Wong described the system as “a passive-listening device”.

“It listens to radio frequency signals travelling up and down powerlines. Some of these radio frequency signals are generated by failing assets on the powerlines. The EFD system uses the radio frequency information collected by the sensors to work out where and which equipment is failing.”

The patented sensing method and data processing algorithm can identify the precise location of expected faults down to a 10 m section of a powerline, Wong said, enabling more proactive and cost-effective management of electricity network assets.

Network owners can use the technology to monitor every network asset 24/7, including during extreme weather when asset failures are likely to first appear.

On 7 February 2009, the town of Marysville in Victoria was devastated by bushfire. The fire was allegedly caused by a break in an electrical conductor on a power pole near a local sawmill.

Jenny Pullen, a Marysville fire survivor, said she welcomed technology that could help prevent bushfires. “We went to so many funerals,” she said.

“The bushfire took a huge toll and there’s still people who are trying to get over it and who will never get over it.”

During a trial of the technology, the EFD system developed by Wong’s team identified a failing conductor on Michael Thorne’s property in Victoria’s Porcupine Ridge.

“When I’m driving around the property, I’m looking at the stock or at the pasture; I’m not looking up at the powerline which is well above me, and it would be pretty hard to spot a broken strand even if you were paying a reasonable amount of attention,” Thorne said.

“The risk is that the powerline breaks, drops to the ground and starts a grass fire. Grass fires can move very quickly, faster than a bushfire typically because the wind’s not interrupted as it flows across the grass and the fire could have swept up to the house, through the sheds and then beyond to adjacent farms very rapidly.

“In addition to the houses lost in a major fire, there’s the lives lost and lives disrupted. Fire can rip apart communities; it can destroy so much that matters,” Thorne said.

“The idea of a fire ripping through my community is obviously deeply distressing and … I’m keen to celebrate any tools that we have that can help reduce the risk of the kind of devastation we have seen across towns like Marysville and others in Victoria.”

Wong was pleased that his team had been able to discover the failing conductor on Thorne’s property, thus preventing a potentially catastrophic fire.

“We always tell people that this technology can potentially save lives and prevent fires. I think in Michael’s example it captured all this essence,” he said.

 

Top image caption: Michael Thorne with the EFD system on his property at Porcupine Ridge, Victoria.