The AEMC has made a final rule on notification requirements for new tests of system restart ancillary services (SRAS).
Restart services are provided by generators with specialised equipment that allows them to restart after a system-wide blackout without needing electricity from the grid. AEMO recently enhanced the testing regime for these restart services, consistent with the recommendations and findings of the AEMC’s Reliability Panel, the Finkel review, and AEMO’s report on the South Australian system black event.
The new testing regime includes a ‘short notice’ test, where AEMO gives the generator five business days’ notice of the test date.
Under the National Electricity Rules (NER), generators contracted to provide SRAS must give the relevant network service provider at least 15 business days’ notice of any test of connected equipment that would require changes to its normal operation at the connection point.
The new rule exempts generators from this requirement for a short notice test of SRAS capability. Instead, AEMO will work directly with network service providers to plan the test date.
This rule change provides regulatory certainty for SRAS providers by aligning the short notice test requirements and the NER.
The new rule starts on 10 April 2018.
Media: Prudence Anderson, 0404 821 935 or (02) 8296 7817
What happens in a system black event?
A large-scale blackout of the power system is called a system black event. These events are extremely rare.
System black events can occur when a sudden, unexpected loss of a major source of supply causes very rapid changes in system frequency which undermines the security of the electrical system. Generators and networks automatically disconnect or ‘trip’ when there is a very rapid change in frequency in order to protect equipment and personnel from harm.
If supply from the system is lost, most generators are not capable of independently restarting if they have tripped off. They need power from the grid to start running again.
What are system restart ancillary services?
Restart services put energy back into the grid after a power outage so generators can start producing electricity again. Some generators have specialised equipment that allows them to restart without an external ‘kick start‘. These generators provide what are called system restart ancillary services (SRAS). AEMO contracts system restart ancillary services from generators throughout the power system.
Following a system black event AEMO coordinates the restart and restoration process:
- Transmission network companies work with AEMO to establish network paths to generators.
- Transmission network companies work with the distribution network providers to prepare blocks of load to be reconnected progressively.
- Distribution network providers prepare local networks to have power restored and coordinate reconnection with the transmission business.
- AEMO and the transmission and distribution network companies must coordinate the restoration process with each state’s system security coordinator. These are known as jurisdictional system security coordinators.