Utilities operating in Australia face unique geographical and climate challenges with regards to power distribution. With developments in pole-mounted switchgear, however, the obstacles are not as insurmountable as they used to be according to a group of electrical engineers presenting at the annual Australian Protection Symposium.
NOJA Power Australia and Pacific electrical engineer Martin van der Linde said industry can leverage the capabilities of modern Automatic Circuit Reclosers (ACRs) to mitigate bushfire risks – a “headache” for utilities as the weather warms up.
“Australian utilities possess among the longest feeders in the world, and long feeder lines exacerbate the issues presented with power quality and bushfire risk. But Australians are known for innovation, and the utility demands placed on manufacturers have been responsible for some of the greatest steps in switchgear development,” he said.
“Bushfire risk is a fundamental issue of concern for most Australian utilities, with events such as the February 2009 bushfires in Victoria being blamed on a local utility resulting in lengthy court proceedings and fines.
“As responsible DNSPs, all utilities are interested in mitigating their risk of causing fires. Recent developments in recloser technology allows for the simple integration of bushfire risk management strategies.”
Recloser strategy for system reliability relies on interrupting faults and restoring supply after a specified open time at the recloser. A reclose sequence may have multiple different close attempts, but from a bushfire mitigation standpoint the more reclose operations in a sequence, the greater the risk of ignition at a fault point on the feeder. While for low fire risk days a longer recloser sequence will result in less customer lost minutes, the multiple reclose attempts will each increase risk of ignition. This information can be remotely interrogated, retrieved and then manipulated.
“It is possible to reduce and manage the bushfire risk, but the only way to guarantee a continuous improvement in network performance is to embrace the new technology on offer,” Mr van der Linde said.