Rule Change: Open
This rule change request from the Australian Energy Market Operator (AEMO) proposes to introduce a mandatory obligation for all scheduled and semi-scheduled generating units to help to control power system frequency.
AEMO’s rule change request states that:
- AEMO is increasingly unable to control frequency in the NEM under normal operating conditions, due to reduced frequency responsiveness from generation.
- The tools currently available to AEMO cannot effectively control frequency on an ongoing basis, and are increasingly resulting in power system outcomes that AEMO now regards as inconsistent with prudent industry practice
AEMO’s objectives for this rule change are to:
- Re-establish effective control of power system frequency in line with international practice.
- Increase the resilience of the power system to disturbances.
- Improve the predictability of frequency response from generation to power system disturbances, to support power system planning and modelling.
AEMO recognises that the proposed rule represents a significant change to the frequency control arrangements that have been in place in the NEM since 2001. However, AEMO considers that there is an urgent need to restore effective frequency control in the NEM.
The Commission intends to progress this rule change request in the shortest reasonable time frame, balancing the requirement for appropriate consultation with the need for AEMO to have adequate tools to control power system frequency.
Related rule change requests
This rule change request is one of three rule change requests that the AEMC has received in relation to primary frequency response and frequency control in the national electricity system.
The other related rule change requests are:
• ERC0263 – Removal of disincentives to primary frequency response
• ERC0277 – Primary frequency response requirements
On 19 September 2019 the AEMC published a consultation paper seeking stakeholder feedback on the proposal.
This consultation paper addresses the issues raised in all three of the rule change requests relating to primary frequency response. Submissions on the consultation paper closed on 31 October 2019.
On 17 October 2019 the AEMC published a revised version of AEMO’s proposed Primary frequency response requirements, which were submitted to the AEMC along with AEMO’s rule change request. In the revised version, AEMO seeks to address concerns that have been raised in discussions with stakeholders. Marked-up and clean copies of the revised document can be found below.
The revised Primary frequency response requirements document was submitted to the AEMC by AEMO. The AEMC did not have input into the document.
On 16 August 2019 the AEMC received a rule change request from AEMO to introduce a mandatory requirement for all scheduled and semi-scheduled generating units to help to provide primary frequency response.
This rule change request relates to part of the Frequency control work plan that sets out actions the Commission, AEMO and the Australian Energy Regulator (AER) will take to support the stable and secure operation of the power system in relation to frequency control. The frequency control work plan was published in July 2018 as part of the final report for the Commissions Frequency control frameworks review.
This rule change request also follows AEMO’s investigation into the power system disturbance that occurred on 25 August 2018. As part of its operating incident report, AEMO recommended:
“increasing the provision of primary frequency control from capable generation to arrest the decline in system resilience to larger contingency events and maintain frequency closer to 50 Hz.”