Circuit-breaker innovation to prevent bushfires
The deadly Black Saturday bushfires in Victoria, Australia, triggered a significant innovation: The world’s fastest circuit-breaker that can react in 10 milliseconds to prevent sparks from faulty power lines or traditional pole fuses. With the risk of wildfires increasing due to the climate crisis, the impact of this invention will be felt by communities worldwide.
By Garry Barker
Fire has been Man’s friend and servant since the beginning of human life, but also an enemy with which we have always battled, increasingly in recent times.
Wildfires – huge, lethal outbreaks in forests and bushland – have been growing more frequent and more intense in many countries, in Australia, and California in the US most notably, but also in Greece, Spain, Portugal, Brazil, Indonesia and elsewhere, and their ferocity is increasing.
Climate crisis fuels bushfire inferno
Global heating has undeniably exacerbated the wildfire problem with temperatures and winds that have parched forests, and turned undergrowth and grasslands into tinder. High winds and lightning storms added to the fury.
The bushfires thus produced in Australia, particularly eastern Victoria, have brought tragedy and devastation. The worst occurred on 7 February 2009, later dubbed ‘Black Saturday’; 180 people lost their lives and 414 more were injured as whole towns were wiped out.
In total 3,500 buildings, including more than 2,000 houses, were destroyed and it is estimated that more than 1 million wild and domesticated animals died. Nearly 500,000 hectares of the Victorian landscape were burned; the cost has been estimated at more than AUS$1 billion (US$ 690 million) in 2009 money.
This was by far the greatest toll so far from bushfires in Australia.
Witnessing the devastation of communities
On 8 February 2009, I drove with a team of telecom engineers to the remains of the tiny fruit-growing hamlet of Strathewen about 10 kilometers from Kinglake to report on the fire and its aftermath for the Melbourne daily The Age.
Here 27 of the 170 residents died, trapped by flames soaring as high as 100 meters suddenly bursting on all sides, denying escape. Houses were heaps of still-hot ash. Blackened smoldering tree trunks spread across the landscape. The school’s huge rainwater tank was a mound of melted plastic on earth burned bright orange by temperatures estimated to have reached 1,500 degrees Celsius.
The ugly smell of the burning lay heavily on the air. In the long valley running to the south, a line of pylons supporting high voltage power lines stood starkly, as if recognizing that the network was to be a major point of interest in the inquest that was to come.
Learning from the Black Saturday disaster
On that day the temperature in Melbourne hit 46.4 degrees Celsius, then the hottest ever recorded in the city, and humidity dropped to 2 percent, as hot dry northwesterly winds reaching more than 100 km/h roared in from the torrid Red Centre of Australia.
The Victorian Government, alarmed by the ferocity and extent of the fires, appointed a Royal Commission to investigate the causes of the disaster and the preparedness, management and performance of fire-fighting and other agencies. Improving and modernizing the network should “substantially remove one of the primary causes of catastrophic fires in Victoria,” the report said. “We need to learn from the experiences of Black Saturday and improve the way we prepare for and respond to bushfires.”
The Commission found that failures in Victoria’s ageing electricity network were responsible for igniting three of the fires, including the original outbreak at Kilmore East, about 80 kilometers north of Melbourne, where hurricane winds ripped down a dilapidated wooden power pole supporting a SWER (single-wire earth return) power line that had been incorrectly rigged.
Distribution grid identified as one of the causes
Sparks from the broken wire ignited dry undergrowth and, fanned by the gale, the fire moved swiftly to Kinglake, 60 kilometers north east of Melbourne, causing 120 deaths and destroying more than 1,200 homes. Other fires to the east caused more devastation. The report concluded that the network had to be urgently upgraded and made safe.
Powercor, the electricity distribution company operating throughout Western Victoria and parts of suburban Melbourne, was given five years until 2021 to make its network safe on time, or be hit with significant financial penalties.
Similar conditions were imposed on AusNet, the other big Victorian distributor that operates mainly in eastern Victoria, as well as on the several “minnow” suppliers, where they applied. “Each company has a variety of challenges and we are working with them to solve their varied and complicated problems,” said Jonathan Granger, head of communications at Fire Safe Victoria.
Collaboration to prevent bushfires
“When it came to fulfilling the Royal Commission’s recommendations, Powercor was looking for a partner with a solution that met the mandated requirements and allowed for time and cost-efficient installation,” said Dene Ward, Powercor’s manager of network safety and bushfire mitigation. “Siemens was willing to work with us.”
The task united Siemens and Powercor in the joint endeavor to prevent further bushfires caused by power line failures. Powercor had run trials of the original Siemens Fusesaver unit to “save fuses” for transient faults, but wanted reclose functionality added.
Development and tests over nine months produced the world’s lightest and fastest vacuum in-line circuit breaker with a single reclose capacity. Siemens’ Fusesaver has a clearing time of 10 milliseconds, compared with between 30 and 50 milliseconds for other such units.
Australian-produced innovation for global bushfire-prevention
Energy Safety Victoria, a government agency, said traditional pole fuses could expel molten material during operation and should be removed from high-risk bushfire zones. Their report suggested Fusesaver was capable of “fully eliminating this risk.”
Siemens opened a new factory in Yatala, Queensland, to support the growing global demand for Fusesaver, a product that is helping to eliminate up to 80 percent of sustained electricity outages on rural networks in more than 30 countries and counting.
The current and future investment in the new factory, totaling about AUS$25 million (US$ 17.3 million) across five years (2018–2022), will support local research and the manufacturing of Australian-made smart infrastructure products for energy utilities worldwide.
Meanwhile, summer temperatures continue to rise. This year’s maximum in Melbourne mounted to 47.5 degrees Celsius.
As countries all over the world are having to adapt to the challenges that global heating brings, communities will certainly face further natural disasters that are beyond human intervention. Innovations like the Fusesaver will help to eliminate some of the preventable ones and make communities less vulnerable.
Fusesaver has an exceptionally small footprint and light weight, allowing for quick, low-cost installation, fast commissioning and enhanced operator safety. It is self-powered from ultra-low line current and has capability for multi-phase fault clearance for both transient and permanent faults. It is controlled by a smart system providing wireless connectivity for remote access and is easily integrated into SCADA (supervisory control and data acquisition) networks by a remote control unit.
Powercor will install more than 1,000 of the units on its network which measures 90,000 kilometers and which, with its sister company Citipower’s 157 square kilometers of distribution network in Melbourne, provides electricity to more than 1.2 million metropolitan and rural customers in Victoria.
By August 2019, 732 sites had been fitted with Fusesavers and Powercor says it is confident of completion by 2020, a year ahead of the deadline.
Author: Garry Barker is a technology editor based in Melbourne.
Picture credits: Siemens / gettyimages / Austockphoto
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