Some 31,000 km of high-voltage powerlines in Victoria are now protected by Rapid Earth Fault Current Limiters. Photo: AUSNET.
One of the findings from the royal commission into the tragic 2009 Black Saturday bushfires in Victoria was that many of the fires in which 173 people were killed north and northeast of Melbourne were caused by downed powerlines that had come loose during high winds and extreme heat.
As a result of these findings, under its Powerline Bushfire Safety Program (PBSP) the Victorian Government undertook to install Rapid Earth Fault Current Limiters (REFCL) on many of the state’s major powerlines as an efficient and cost-effective measure to reduce the risk of fires being caused by downed powerlines.
On 3 November, the Government announced that the 45th and final REFCL had been installed at Benalla in the state’s north on one of the state’s longest powerlines, completing a decade-long, $750 million project that covers some 31,000 km of high-voltage lines.
REFCLs work like a giant safety switch, effectively reducing power to a downed line within a 10th of a second from when it is detected as having hit the ground. This reduces the chance of ignition of dry grass or tree branches by up to 70 per cent without disrupting the flow of power on the two other parallel lines.
REFCLs are installed in substations where the high-voltage powerlines originate. They detect when there is a fault on one of the three wires that make up a high-voltage powerline, and compensate for this by rapidly limiting the energy released into the fault to such a magnitude that a fire is unable to be ignited. If the fault persists, it will then instruct a circuit breaker to switch power off to the powerline.
The technology was proven in the 2019/20 Black Summer fires where REFCLs were reportedly triggered 33 times on total fire ban days, each of which could have caused a major fire. It has now been picked up in California, which is experiencing similar increases in bushfire activity as eastern Australia in recent decades.
The program was rolled out in three tranches, all of which were successfully delivered in 2019, 2021 and 2023 respectively.
“REFCLs are a life-saving technology that act as a giant safety switch when powerlines come into contact with vegetation, reducing the risk of bushfires igniting,” Victorian Minister for Energy and Resources Lily D’Ambrosio said.
“Bushfire-prone areas around the world, including in California, are now looking to Victoria’s leading use of this important technology to better protect their own communities.”
Member for Northern Victoria Jaclyn Symes added: “As climate change continues to drive an increase in the frequency and intensity of catastrophic bushfires, REFCLs will play a critical role in reducing the risk to communities across the state.”
