The AEMC has made a final rule to manage power system fault levels by requiring networks to maintain minimum levels of system strength to keep the system stable.

System strength is stronger or weaker in different places depending on the generation mix. It is a localised problem and is measured by the fault level at specific points in the network. More non-synchronous generation like wind and solar in a region makes the system relatively weaker.

This final rule makes networks provide services necessary to meet minimum levels of system strength at key locations in the power system when shortfalls are identified by AEMO. It also requires new connecting generators to pay for remedial action if they are going to negatively impact on minimum system strength levels.

This rule change is part of the AEMC’s broader package of system security work which includes a range of measures to help AEMO and networks manage a transforming power system with reduced inertia and system strength.

Media: Prudence Anderson, Communications Director, 0404 821 935 or DL (02) 8296 7817.


A package of final rules was released today to deliver a stronger, more stable power system:

  • Managing power system fault levels – keeping the system stable by making networks maintain minimum levels of system strength at key locations, and requiring new generators to pay for remedial action if they impact system stability
  • Managing the rate of change of power system frequency – enabling better frequency control by making networks provide minimum levels of inertia and, with AEMO approval, enabling networks to contract with suppliers to provide inertia substitutes 
  • Generating system model guidelines – requiring generators and networks to provide more detailed information about how their equipment performs so AEMO and networks have the right data to efficiently plan and operate the system