Researchers from RMIT University have developed a fault detection system that can alert electricity companies of discharges on powerlines, reducing the chances of starting bushfires.
“The technology is designed to detect what we call 'departure discharge' originated on the overhead equipment. If it’s not detected early it can eventually lead to bushfires,” said RMIT associate professor, Andy Wong, who led the project along with associate professor Wayne Rowe.
“The wooden pole can actually catch on fire. There are incidents in Australia and around the world where those pole-top fires eventually spread to the surrounding area and lead to bushfire or forest fire. In Western Australia there were incidents where pole-top fire actually caused the start of a bushfire.”
The NSW Rural Fire Service investigations into the NSW mid-north coast bushfires in October last year suggested they were caused by powerlines sparking. The Royal Commission into the 2009 Victorian bushfires found that five major fires were caused by powerlines.
“Discharges are most likely caused by pollution on the insulator, or a faulty insulator," Wong said. "Heat or high temperature and humidity can also cause discharge. Normally you see high discharge occur in the warmer months of the year.”
The real-time continuous monitoring system devised by Wong and Rowe can be installed on the top of a power pole. Inspired by the behaviour of electric fish, the system uses electromagnetic sensors to register discharges on an electrical powerline, as well as determine the line's condition.
The sensor has no direct contact with the powerline, which means its installation doesn't interrupt electricity distribution.
“We have a system that can cover 10 kilometres of powerline with just two units sitting on either side of the line," Wong said. "So you can have hundreds of power poles sitting in between, and the system will monitor that particular span 24/7 to detect any discharges.”
Some of the algorithms used to process the data are implemented in the sensor system's hardware using field-programmable gate arrays (FPGA).
“The benefit of doing that is we can achieve high-speed or almost real time processing capability," Wong said.
“Every second there are millions of data points coming into our sensors, so we need to process all of that before the next second. That’s where FPGA comes into play. Even a standard software program would take longer than FPGA.”
Data is relayed from the powerline monitor back to remote servers via Telstra’s 3G network.
The computer servers and data are managed by IND Technology, a company that Wong established with private investors to commercialise the system. Reports are produced monthly or weekly for utility companies. In the case of a major event, instantaneous alerts are issued. Last year, the company signed its first contract with a major power distribution company in Victoria.
The system has the potential to not only reduce the risk of bushfires occurring but also to help utility companies avoid financial penalties from electrical outages, Wong said.
“For any unplanned outages, there’s a [financial] penalty that’s applied to the company [by the government] if it exceeds a certain number of minutes of power outage. The whole idea is to avoid that, even 20 per cent by taking a proactive approach in maintenance with the help of this technology will save them lots.”
Wong and Rowe are currently exploring how the system can be applied in other industries such as transport. Wong said he has received an enquiry from a company in Asia interested in applying the system to a high-speed rail network.
“All of the rail networks nowadays run on electricity with overhead lines, so they do have similar infrastructure [to powerlines for electricity distribution]. Especially for a rail system you can’t afford to have power outages.”
He said he is also looking into how it could help companies in the mining, oil and gas industries.
“In the mining industry, for example, most of the mine sites have their own electricity distribution network because it normally sits in a remote area. There is lots of electrical infrastructure in harsh environments. So our system is capable of picking up all the signs of degradation, ageing.
“For oil and gas, normally they are in a high saline environment; lots of salt content will accelerate the ageing of that equipment.”