Fixing major faults on powerlines can be a costly and sometimes dangerous task, so it’s essential to find problems early on before they get worse. Thermal imaging equipment is one tool helping utilities to identify deteriorating connections on networks before they become full-blown failures.
In preparation for the upcoming summer, utilities are starting to survey their networks to make sure there are no hidden faults that could become dangerous during bushfire season.
Ausgrid is one of the electricity companies currently identifying potential bushfire risks and undertaking maintenance on its network, which includes 132,000 volt powerlines running through New South Wales’s Central Coast, stretching from Killingworth in the lower Hunter Valley to Berowra in Sydney’s north.
Besides regular inspection techniques including land-based patrols of poles and powerlines, general maintenance of equipment and the clearing of tree branches, Ausgrid is also using thermal imaging cameras to scan powerlines from helicopters and locate hotspots on the network.
These hotspots are connection points between powerlines that are operating above their normal temperatures, which is an early sign that the connection is deteriorating.
Identifying these points as early as possible makes them easier to fix and improves the efficiency of maintenance procedures.
Ausgrid General Manager Network Services, David Pengilly, said thermal imaging equipment is the most efficient way to locate these hotspots on the network.
“We use this technology to identify potential faults on joints between lengths of powerlines. These show up as hotspots in the images allowing our maintenance crews to head out and make repairs before problems occur,” Mr Pengilly said.
Thermal imaging cameras provide a snapshot of the condition of powerline and electricity assets at a certain point in time. The technology is non-invasive and able to be operated at a safe distance away from live lines. Network hotspots are also not visible to the human eye so thermal images are able to locate potential problem areas that wouldn’t be found by regular patrols.
While Ausgrid carries out thermal surveying throughout the year, the hotspot patrol prior to bushfire season is an annual survey that specifically focuses on 132kV sub-transmission powerlines, as these high-voltage lines are the backbone of the region’s electricity supply.
Ausgrid uses a helicopter to cover more than 100km of powerlines in Berowra and Mt. Kurin-gai, Somersby, Gosford, Ourimbah, Berkeley Vale, Tuggerah, Vales Point, Morisset, Eraring, Awaba, Rathmines and Killingworth. The survey takes three days to complete and the infrared cameras are also used to inspect substations.
An Ausgrid spokesperson said these surveys and the use of thermal imaging equipment is an essential part of its powerline maintenance program.
“Locating these hotspots is an essential maintenance task which allows our crews to assess the condition of the network and fix any potential problems before they occur. It means we know the network is safe and we can be efficient and targeted with our fieldwork.”