1. Review of After-the-Fact (ATF) Tagging Criteria Scheduler’s Meeting May 24, 2016
Raymond will ask the audience what their expectations are in regard to ATF tagging presentation. What do they want to learn or clarify?
RAYMOND r. VOJDANI, PE

2. Review of ATF Tagging Criteria
Background
ATF Transactions Has Been Getting a Lot of Publicity
There Is a Movement to Limit or Eliminate ATF Changes All together
There is Confusion as when ATF Transaction is needed or warranted
Purpose
Review the ATF Tagging Guideline
Provide Education and Guidance on When ATF Tagging Should be Used
Background - Raymond will review the number of ATF transaction in recent years and emphasize the necessity to eliminate or minimize the number of ATF tags.
Purpose – Raymond will articulates the purpose and goal of this presentation

3. Review of ATF Tagging Criteria
REASON
2016
2015
2014
2013
2012
Incorrect Path or Sched Entity 3 66 56 82 72
Scheduling or Adjusting Error 21 20 16 36
System Error 12 27
Generation/Meter Adjustment 6 50 40 26 31
Incorrect Source / Sink 2 13
203 11
Curtailment Error
Incorrect PSE 1 8 5
RSG Tag Error 9 18
Integration Error 4
Tag Type Correction 49
Incorrect Tag 68
WIT not match OATI Tag
Oversold
Unknown
No Original Tag
TOTAL 28
236
383
199
231
Originally Reported 88 87
Current MW
749
5840
22662
1679
12896
Changed to MW 84
2301
9614
1365
7691
Total MW Change
665
3539
13048
314
5205

4. Review of ATF Tagging Criteria
Rule of Thumb as When ATF Tag Should be Used
To accurately reflect what had occurred during the real-time
What Did the BA Control to
What transmission path/s were used
To Correct a Critical Issue Which Was Not Caught Real Time
When ATF Tag Should NOT be Used
To eliminate energy imbalance or generation imbalance within a BA
When Creation of ATF Tag creates Inadvertent Interchange for the BA

5. Review of ATF Tagging Criteria
Introduction
Overview of Some Basic Definitions
Balancing Authority
Interchange
Interchange Transaction
E-Tag
Interchange Schedule
Dynamic Schedule
Automatic Generation Control (AGC)
Area Control Error (ACE)
Inadvertent Interchange
Western Interchange Tool (WIT).
Raymond will go over some basic definition used in electric power system

6. Review of ATF Tagging Criteria
How Does an e-tag Become a Schedule
A RFI (Request for Interchange) Is Created by One of the PSEs
The WECC Interchange Authority Distributes the e-tag to All Affected Parties
The RFI Goes Through Appropriate Approval by Affected Parties
PSEs, TSPs, BAs, and Sometimes SEs
Once the e-tag is Approved, hen a Schedule Is Created in WIT
The WIT Schedule Is Reflected in All Impacted BAs (From Source BA to the Sink BA)
The BAs use the Schedule and Control Their EMS and AGC Based on the Their Net Schedule Interchange (sum of all schedules)
Any Subsequent Changes to WIT Schedule Has to be Done By Modifying an Existing e-tag, Creating a New e-tag, or Deleting the Schedule in WIT

7. Review of ATF Tagging Criteria
Synopsis of a Scheduling Issue and ATF Clean up
One BA (BA1) has load in another BA (BA2), the load is dynamically scheduled
There was a transmission outage in BA2, so BA1 had to arrange with alternative transmission provider and create a new e-tag using the new TSP
The BA1 submits an emergency tag, all parties approve the tag
The BA1 realizes that they have made an error and they submit a withdraw request (denied), submit an adjustment (denied), so the original tag stays in place
BA1 not realizing that their withdrawal request and adjustment request is denied, submits a new Dynamic tag
Now we have two tags in effect, distorting the situation
ATF Efforts to zero out one of the schedules (WIT Request Change) goes nowhere (one of the affected BAs, BA3, refuses to sign the WIT Change Request Form)
Meanwhile, the Primary Inadvertent Interchange is reflecting a wrong value and both BA1 and BA2 and paying back inadvertent which was calculated based on a wrong NSI
Ultimately, the Dynamic Tag was Adjusted to Zero to correct the situation (many days later)

8. Review of ATF Tagging Criteria
Purpose of ATF Tag
There was no tag (schedule) for the interchange as agreed by the affected BAs
Reserve Sharing Tags
Emergency Situation
Energy Emergency, transmission loading issues
There was a tag but the tag had incorrect information
To allow BAS, TSPs, and PSEs to accurately reflect a schedule which was coordinated and controlled by a BA’s EMS and AGC system during real time system operations but was not properly tagged
Missing or Incorrect Balancing Authority, TSP, Scheduling Entity
Missing Adjacencies or incorrect POR or POD - Incorrect POR or POD could be changed in the e-schedule.
Emergency situation when WIT is down
The key criteria is to match the tagging system or schedules to what really happened during the real time operation (what did the BAs control to)

9. Review of ATF Tagging Criteria
General Principals for Creating an ATF tag
There was no tag created
Entities can create a new ATF tag up to 7 days later from the start time
Close BA coordination between affected entities is required
No Peak RC intervention or submittal of a Form is needed
There was a tag but it contain incorrect information
If the original schedule needs to be deleted, then, lead BA is to complete the form and coordinate with affected entities for approval
If the original schedule needs to be modified (increase MW) then a new ATF tag can be created

10. Review of ATF Tagging Criteria
Logistics of creating an ATF Tag/Schedule
Call and/or all parties involved on the tag when an ATF tag is needed and gain agreement to proceed.
Coordinate changes needed within the timeframe for processing/submitting the ATF tag.
Route WIT Schedule Change Request Form to all parties for signatures.
Submit the WIT Schedule Change Request Form to the WIT Administrator and copy all parties involved.
After WIT Administrator responds that the changes have been completed, all parties should verify that the changes were made properly in the WECC Interchange Tool (WIT).
Submit the ATF tag by 2:00 p.m. (MST) on the same day that the WIT Administrator makes the changes to WIT, inform all involved parties that the tag is out for approval and reference the new tag number.
The lead BA will follow up that ATF tag was approved.
Each entity will update its in-house scheduling software to reflect the changes (adjust or zero MW on the original tag schedule) and if necessary verify that the resultant Net Schedule Interchange matches with WIT for that particular hour.

11. Review of ATF Tagging Criteria

12. Review of ATF Tagging Criteria
Questions ?

13. NERC Definition of Terms
Balancing Authority – The responsible entity that integrates resource plans ahead of time, maintain load-interchange- generation balance within a Balancing Authority Area, and supports Interconnection frequency in real time
Interchange – Energy transfers that cross Balancing Authority boundaries
Interchange Transaction – An agreement to transfer energy from a seller to a buyer that crosses one or more Balancing Authority Area boundaries
E-Tag – An electronic document which details of an Interchange Transaction required for its physical implementation
Interchange Schedule – An agreed-upon Interchange Transaction size (MW), start and end time, beginning and ending ramp times and rate, and type required for delivery and receipt of power and energy between the Source and Sink Balancing Authorities involved in the transaction
Dynamic Schedule – A telemetered reading or value that is updated in real time and used as a schedule in the AGC/ACE equation and integrated value of which is treated as a schedule for interchange accounting purposes. Commonly used for scheduling jointly owned generation to or from another Balancing Authority Area.
AGC – Means equipment that automatically adjusts a Balancing Authority's generation from a central location to maintain its interchange schedule plus Frequency Bias
Area Control Error (ACE) – Means the instantaneous difference between net actual and schedule interchange, taking into account the effects of Frequency Bias including correction for meter error.
Inadvertent Interchange – The difference between the Balancing Authority’s Net Actual Interchange and Net Scheduled Interchange
WIT – Western Interchange Tool – A consolidated Scheduling Software which is used by all the Balancing Authorities in the Western Interconnection to coordinate and document interchange