Final rule: managing the rate of change of power system frequency

19 September 2017

The AEMC today made a final rule to manage the rate of change of power system frequency by requiring networks to provide minimum levels of inertia.

The generation mix is changing. As more non-synchronous generators like wind and solar come in, and synchronous generators like coal retire, the power system has less inertia. Less system inertia means frequency may become less stable. If frequency changes too fast then the system is at risk of going black.

This final rule will equip the system to manage frequency changes by requiring networks to make minimum levels of inertia available when needed to help stabilise the frequency. For example, they can install synchronous condensers on their networks or contract with suppliers to provide inertia substitutes like fast frequency response from batteries or demand response, with AEMO’s approval.

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.

Explainer

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

  • 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 
  • Managing power system fault levels – keeping the system stable by making networks provide minimum levels of system strength at key locations, and requiring new generators to pay for remedial action if they impact system stability
  • 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