On 19 September 2017 the Australian Energy Market Commission (AEMC) made a final rule that clarifies the scope and level of detail of model data that registered participants and connection applicants are required to submit to the Australian Energy Market Operator (AEMO) and network service providers.

The final rule complements and is part of a broader package of system security related projects, including the Managing power system fault levels rule change. By allowing AEMO and network service providers to access accurate model data, the final rule will support these parties in fulfilling their obligations for maintaining system strength.

The final rule amends the NER frameworks related to the provision of model data to:

• clarify the range of parties who are required to provide model data to AEMO and network service providers
• clarify when this model data must be provided to AEMO and network service providers, including for the purposes of meeting system security obligations
• require AEMO to consider specific principles when developing the power system model guidelines. 

Background

Model data is a mathematical representation of the operation of power system equipment, such as generation equipment or network assets. It is an input into power system studies, which are used by parties including AEMO, generators and network service providers to examine how the power system will function under different conditions. These studies then inform how the power system is planned and operated, and how generators are connected.

Changes in power system conditions are making it more difficult to undertake accurate power system studies, particularly decreases in system strength in many parts of the grid. As system strength reduces, the interactions between grid connected equipment become more complex. This means that the simpler kinds of model data that have historically been used in power system studies may no longer be accurate and more detailed model data inputs may be required to maintain the effectiveness of power system studies.

This final rule is designed to provide AEMO and network businesses with access to the detailed model data that is needed to support effective power system studies in a changed power system environment.

The final rule amends the existing frameworks in the National Electricity Rules (NER) to clarify the circumstances and conditions under which parties must provide model data to AEMO and, where relevant, network service providers. The final rule requires AEMO to set out, in the model guidelines and data sheets, the technical and operational details of what model data will be required by participants and the specific circumstances or conditions under which that model data will be required.

The final rule also sets out principles that AEMO must consider when it develops the guidelines and data sheets including:

• having regard to the costs faced by participants in providing model data,
• the protection of confidential model information, and
• the specific needs of network businesses with regards to receiving model data, where this is needed to fulfil their NER or jurisdictional electricity legislation obligations. 

Rule change request overview

On 31 October 2016 the AEMC received a rule change request from AEMO in relation to the provision of modelling data.

A key aspect of AEMO’s proposed rule was the introduction of a specific obligation on generators to provide AEMO with model data required to perform specialised electromagnetic simulation analysis. The proposed rule specified that this data would be provided in circumstances such as where a generator was connected through power electronic interfaced technologies.

AEMO also proposed to be able to request this data from any generator in those situations where, in AEMO’s reasonable opinion, the generating system would adversely affect other network users, power system security, or quality or reliability of supply of the power system.

On 15 March 2017 the AEMC published a consultation paper on the rule change request. 13 submissions were received to the consultation paper.

On 20 June 2017 the AEMC published a draft determination and a draft rule on the rule change request. Ten submissions were received to the draft determination.

On 12 September 2017 the AEMC extended the period of time for making a final determination under section 107 of the NEL until 19 September 2017 for the Generating System Model Guidelines rule change request (a time extension of one week). This extension was due to the complexity of the issues and also the interdependency with the Managing power system fault levels (ERC0211) rule change.