Proposal: rename Temporary AAR Exceptions

[getorymckeag]

There's been a formal request from SPP to GE Vernova to rename Temporary AAR Exceptions to a term that better aligns with the FERC order, based on stakeholder feedback. AAR exceptions are probably a better term for what GEV's product calls AAR Exemptions, which is not a term needed in the TROLIE spec.

The proposed name is "temporary alternate Transmission Line Ratings". That's probably too long, and we should consider an alternative.

I move that we also do this in a backward compatible way, such that new media types are created in parallel and existing Temporary AAR Exception APIs are still supported, but marked as deprecated.

[getorymckeag]

Based on TAC meeting today:
We are considering the proposal. Need to decide on a new name for Temporary AAR exceptions. How about Temporary Alternate Rating? Seems to be the best alignment to the wording in the order. The words "transmission line" make it kind of long, and these ratings can also apply to transformers, causing confusion. Another possibility is simply "Temporary Rating", skipping the "Alternate" keyword. This does not match the order as precisely, but may be more common operational nomenclature.

[tggiles]

It's unfortunate there isn't a clean defined term. I'd suggest "Temporary Derate" or Override, as common language, but the order uses neither term. I think "temporary exception" is precise, but the order consistently uses "exception" interchangably with "exemption" which is a permanent, NOT temporary attribute of non-ambiently limited equipment that requires review every 5 years. In contrast the order refers to "temporary alternate ratings" as short-term:

We do not specifically require a periodic re-evaluation of temporary alternate ratings, as we expect such ratings to be used over relatively short timeframes. However, we note that temporary alternate ratings may only be used during periods in which the transmission provider determines that they are necessary under the “System Reliability” section of pro forma OATT Attachment M

the “System Reliability” section of pro forma OATT Attachment M:

System Reliability: If the Transmission Provider reasonably determines, consistent with Good Utility Practice, that the temporary use of a Transmission Line Rating different than would otherwise be required by this Attachment is necessary to ensure the safety and reliability of the Transmission System, then the Transmission Provider may use such an alternate rating. The Transmission Provider must document in its database of Transmission Line Ratings and Transmission Line Rating methodologies on OASIS or another password-protected website, as required by this Attachment, the use of an alternate Transmission Line Rating under this paragraph, including the nature of and basis for the alternate rating, the date and time that the alternate rating was initiated, and (if applicable) the date and time that the alternate rating was withdrawn and the standard rating became effective again.

I concur that temporary-alternate-rating is most in line with the order.

--Tyler Giles, MISO