Final report - NTESMO Amendment of the Secure System Guidelines – System Frequency Control

Date of notice: 12 September 2025

This Notice of Expedited Rules Consultation (Notice) informs all relevant parties including:

Northern Territory Electricity Market (NTEM) participants
NT Utilities Commission
Persons who identify themselves to NT Electricity System Market Operator (NTESMO) as interested in the Power System Controller (Consulted Persons), that NTESMO is conducting a consultation (Consultation) on the amendments to the Secure Systems Guideline (SSG).

The Consultation is being conducted under clause S3.5.2 of the System Control Technical Code, Version 7.0, 14 February 2024 , consistent with the expedited rules consultation procedure presented in the National Electricity Rules as in force in the Northern Territory – v125 – Chapter 8.9.3 .

The amendments to the Secure Systems Guideline (SSG) include the following:

Reformatting of the SSG to align with the formatting of the System Control Technical Code (SCTC) and other procedures and guidelines.

A set of discussion papers that further explain amendments regarding frequency control, including:

Reformatting of the SSG to align with the formatting of the System Control Technical Code (SCTC) and other procedures and guidelines.
A discussion paper responding to all written submissions received during the consultation process.
Final reference materials for licensed generator participants and the UC specific to accreditation examples for generators.

Matters under consultation

The changes (Changes) proposed (Proposal) are to:

Reformat the SSG consistent with the format of the SCTC, update all cross references, and structure the SSG into themed sections:
- Guidelines for System Frequency
- Guidelines for System Adequacy
- Guidelines for System Voltage
- Guidelines for Power System Operations
- Registration Thresholds
- Related Records
- Document History
Amend the Guidelines for System Frequency to include:
- Operational Application of Frequency Operating Standards
- Frequency Control Ancillary Services (FCAS) and their application

Consultation outcome

The consultation process is now complete. SSG version 5 will take effect on 1 November 2025.

NTESMO thanks participants and interested parties for their written submissions. NTESMO has made final amendments to the SSG version 5 that align with recommendations received during the consultation process.

The following documents are available for reference:

NTESMO proposed changes to secure system guidelines - final amendments PDF, 325.72 KB

Read NTESMO’s response to Territory Generation’s submission on proposed amendments to the Secure System Guidelines (SSG).

NTESMO Secure System Guidelines Version 5 PDF, 750.55 KB

Read version 5 of the Secure System Guidelines, outlining principles for maintaining power system stability and reliability.