View all consultations

System Strength Requirements Methodology and System Strength Impact Assessment Guidelines amendments consultation

30/09/2022
Market National Electricity Market
StageFinal Report
ConvenorAEMO NEM
Initiated10/02/2023
Accepting submissions?No

Consultation timeline

  • Issues Paper published
    26 April 2022
  • Submissions due on Issues Paper
    1 June 2022
  • Draft report published, including a draft SSRM and PSSG
    29 July 2022
  • Submissions due on Draft Report for draft SSRM and PSSG
    19 August 2022
  • Final Report published, including the final SSRM and PSSG
    30 September 2022
  • Draft report published, including a draft SSIAG
    12 January 2023
  • Submissions due on Draft Report for draft SSIAG
    10 February 2023
  • Final Report published, including the final SSIAG
    15 March 2023
  • SSIAG minor amendments proposal published (Stage 3)
    11 May 2023
  • Submissions due on SSIAG minor amendments proposal
    25 May 2023
  • Final updated SSIAG published
    6 June 2023

Overview

AEMO has concluded the consultation on:

  1. System Strength Requirements Methodology (SSRM) and Power System Stability Guidelines (PSSG), consistent with the requirements in clauses 5.20.6 and 4.3.4; and
  2. System Strength Impact Assessment Guidelines (SSIAG), consistent with the requirements in clause 4.6.6.

The consultation process was completed in accordance to rule 8.9 of the National Electricity Rules (NER).

Background

AEMO sees system strength as the ability of the power system to maintain and control the voltage waveform at any given location in the power system, both during steady state operation and following a disturbance.

In October 2021, the Australian Energy Market Commission (AEMC) released its final determination on the efficient management of system strength on the power system. This introduced new rule requirements for the System Strength Requirements Methodology (SSRM) and System Strength Impact Assessment Guidelines (SSIAG), as well as consequential changes to the Power System Stability Guidelines (PSSG).

In April 2022, AEMO released an issues paper to begin consultation on amendments to all three documents. Due to the number and complexity of issues raised in the Issues Paper consultation, and following discussions with several participants and market bodies, AEMO subsequently decided to progress consultation on the SSIAG amendments separately from the SSRM and PSSG.

In July 2022, AEMO opened the second stage of consultation on the draft SSRM and the draft PSSG. In September 2022, AEMO published the final SSRM and final PSSG.

Key changes - SSRM

The key changes to the SSRM are to introduce a new power system standard comprising a minimum fault level requirement for power system security, and a requirement for stable voltage waveforms at connection points to host forecast levels of inverter-based resources. The amendments to the PSSG are consequential, with the addition of a system strength and converter stability definition.

Key changes - SSIAG

The existing system strength assessment only requires remediation if the connecting plant presents an adverse system strength impact, affecting the stable operation of the power system.

The new assessment also requires remediation if the connecting plant reduces the available fault level at the connection point, irrespective of whether it is affecting the stable operation of the power system.

As a result, the SSIAG required amendments to address the co-ordination and demand side elements of the Amending Rule.

The Draft SSIAG was published for second stage of industry consultation on 12 January 2023 with the submission closing on 10 February 2023. AEMO published the final SSIAG document on 15 March 2023.

SSIAG Minor Amendment

AEMO identified that applying the system strength quantity (SSQ) formula as drafted in NER 6A.23.5, could significantly overstate the quantity of system strength required for a connection.

AEMO published guidance for calculating system strength quantities in the NEM that sets out a methodology for calculating the SSQ for a relevant NEM connection that, in AEMO’s view, better aligns with the intended outcomes expressed in the final determination of the National Electricity Amendment (Efficient management of system strength on the power system) Rule 2021. 

The revised SSIAG v2.1 was published following the minor amendment consultation, removing the reference to SSQ and instead referring to the component elements of SSQ, as per NER 6A.23.5(j). 

System Strength Framework webinar

AEMO hosted a webinar on 15 June 2023  to provide interested parties with an overview of the new System Strength Framework and an opportunity to ask questions. The webinar covered both the System Strength Impact Assessment Guidelines (SSIAG) and the System Strength Requirements Methodology (SSRM).

AEMO has prepared a Frequently Asked Questions fact sheet to address questions related to the Efficient System Strength Framework being implemented from 2022-23. The FAQ document is located on the SSIAG webpage. 

The presentation pack and webinar recording are available below for those who were unable to attend.

For more information, email ssiag@aemo.com.au.

  • First stage
  • Second stage
  • Final stage
  • SSIAG Minor Amendment

Meetings for first stage of consultation

AEMO met with the following stakeholders:

  • Clean Energy Council 
  • Powerlink Queensland
  • Tesla

A summary of the outcomes of these meetings is provided below.

First stage documents

Other documents

First stage submissions

Late first stage submissions

Meetings for second stage of consultation for the SSRM and PSSG

AEMO met with the following stakeholders:

  • CPSA
  • DIgSILENT

A summary of the outcomes of these meetings is provided below.

Second stage documents for the SSRM and PSSG consultation

Second stage submissions for the SSRM and PSSG consultation

Late second stage submissions for the SSRM and PSSG consultation

Second stage documents for the SSIAG consultation

Second stage submissions for the SSIAG consultation

Late second stage submissions for the SSIAG consultation

Final documents

Final determination

Final documents

Stakeholder comments

Consultation documents

ConsultationsNational Electricity Market
X
Cookies help us improve your website experience.
By using our website, you agree to our use of cookies.
Confirm