Transmission Equipment Ratings
The owners of the electricity assets provide AEMO with ratings of their equipment. The ratings may be provided as static data for use under specified conditions, telemetered dynamic real time data for use in dispatch timeframe, or may be hand dressed by AEMO in urgent circumstances. Equipment ratings are used in AEMO’s energy management system (EMS) and constraint equations.
Rating data used by AEMO uses equipment identifiers, a number of rating application levels, and rating application rules. How ratings are used in constraint equations is detailed in the Constraint Implementation Guidelines.
The structure used by AEMO in modelling the electricity network includes provision for multiple ratings on any transmission element. The modelling allows for the application of a rating at both ends of the element and allows for flow in both directions. The network modelling also allows for a number of rating levels that can be used under different operating scenarios.
Two files are published by AEMO. The “altlimits.zip” file contains the complete list of ratings used in AEMO’s EMS, this file is updated when the network model is updated (normally every two weeks). The “PUBLIC_TER_DAILY.zip” file contains the ratings used in constraint equations and the ID used in the right-hand of the constraint equations – it is updated on change (generally every few minutes).
The data on this webpage and linked documents is provided subject to this Disclaimer.