The Network Assets Project is making substantial upgrades to Victoria’s high voltage powerline network in hazardous bushfire risk environments across rural and regional areas of Victoria.
The three parts of the project are:
- Installing Rapid Earth Fault Current Limiters (REFCLs) on 22 kilovolt powerlines at 45 zone substations across Victoria to detect and supress faults.
- Installing Automatic Circuit Reclosers (ACRs) on all 12.7 kilovolt, single-wire earth return (SWER) lines in Victoria.
- Provide community education and raise awareness of changes to power supplies that arise because of these bushfire risk mitigation strategies provided through the Network Assets Project.
Rapid Earth Fault Current Limiters (REFCLs)
Rapid Earth Fault Current Limiters (REFCLs) are a smart technology. They rapidly reduce the threat of arcing and igniting bushfires, by lowering the energy release in certain types of powerline faults (multi-wire and wire-to-earth faults) within milliseconds. Power is restored immediately if the fault clears.
REFCLs are a class of Ground Fault Neutralisers (GRNs). They have been identified as a new safety device for bushfire risk mitigation. Originally operating in Europe since the early 1990’s, they have been used to improve supply reliability on mainly underground cable networks.
The Victorian Government invested $5.5million in a series of world-first trials during 2014-15. The trials proved REFCLs are 10-times more effective in reducing bushfire risk than existing best practice safety infrastructure.
Amended regulations introduced from 1 May 2016, ensure that electricity distribution businesses invest in REFCLs as part of a staged roll out to be completed by May 2023.
REFCLs are being installed in a staged rollout in the following bushfire risk locations:
|Tranche 1||April 2019|
|Tranche 2||May 2021|
|Tranche 3||May 2023|
Frequently Asked Questions
REFCLs rapidly limit energy release in certain types of powerline faults on multi-wire (not SWER) powerlines. They act like a safety switch to stop energy flow to the affected line almost instantly when a fault occurs.
Unlike standard powerline technology, REFCLs allow the electricity distribution system to continue operating for a short time, instead of cutting power off altogether when a fault is detected. This avoids unnecessary downstream power outages if the fault is temporary. If the fault persists, the REFCL then shuts down the power to the affected line.
- Fire protection – REFCLs will save lives as they reduce the risk of powerlines starting bushfires.
- Optimal safety setting – the use of REFCLs also reduce supply disruptions as faults can be isolated allowing supply customers on other phases on the faulted powerline to remain unaffected.
- Value for money – REFCLs are a cost-effective measure to increase safety and reduce the risk of bushfires started by powerlines benefiting all Victorians and particularly those who live in high fire risk areas.
During Total Fire Ban and Code Red days, REFCLs operate at greater sensitivity and may shut down a section of the network where a fault occurs. This reduces the risk of a fault starting a fire, responding to the high consequence of fires on these days. This may mean customers are more likely to experience outages on Total Fire Ban and Code Red days.
Automatic Circuit Reclosers (ACRs)
Automatic Circuit Reclosers (ACRs) are next generation network protections devices. They immediately detect and turn off power at a fault on high fire risk days on 12.7 kilovolt single-wire earth return (SWER) powerlines.
ACRs have been installed across rural and regional areas where SWER lines are primarily situated, replacing existing Oil Circuit Reclosers (OCRs). Older OCRs are set manually while ACRs allow enhanced reclose settings to be made remotely to respond to changing bushfire risk conditions.
CSIRO estimates ACRs reduce the likelihood of ignition on bare-wire SWER lines by nearly half (45.7%) under worst case bushfire risk conditions.
As of February 2020, AusNet Services and Powercor have installed more than 2,100 ACRs across their SWER networks. As a result, the entire Victorian SWER network (30,000 kilometres) is now protected with this new-generation technology.
Frequently Asked Questions
Energy Safe Victoria has directed electrical distribution businesses to replace older Oil Circuit Reclosers (OCRs) with more advanced models of ACRs in areas of highest risk. These areas have been identified by the PBSP bushfire risk analysis and modelling.
ACRs can quickly reconnect power after an outage. If for example, vegetation or some other obstruction falls across powerlines causing an outage, an ACR will immediately attempt to reconnect power.
During summer, electricity businesses modify their ACR safety settings on Total Fire Ban or Code Red days to reduce the risk of bushfires. As recommended by the Victorian Bushfires Royal Commission, they will not automatically reconnect power after a fault. The electrical distribution businesses will send a truck out to inspect the line to ensure there is no risk of a fire start once the power is reconnected. This may delay restoring power after an outage.
The installation of ACRs will improve power reliability in the areas they service. The ACR settings are remotely changed from the central control room, rather than having to be manually adjusted. This will allow for more efficient management of the power network.
Public information - Prepare for Power Outages
On Total Fire Ban and Code Red days, electricity businesses are required to modify their powerline safety settings to reduce the risk of a fire starting after a fault. This may cause more power failures and a delay in restoring power if a fault occurs.
PBSP has produced a guide, Prepare for Power Outages, with valuable information to keep you safe and comfortable during a power outage of any length. It is shared each summer to advise peri-urban, regional and rural communities about the impact of enhanced electricity protection safety settings on power reliability and to be prepared of a power failure during extreme summer weather conditions.
It’s key safety message and call to action is – It only takes a few simple things to prepare for a power outage.
Page last updated: 04/08/20