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NPRR1034

Summary

Title Frequency-Based Limits on DC Tie Imports or Exports
Next Group
Next Step
Status Approved on 02/09/2021

Action

Date Gov Body Action Taken Next Steps
02/09/2021 BOARD Approved
01/27/2021 TAC Recommended for Approval Revision Request Consideration
01/14/2021 PRS Recommended for Approval Revision Request Consideration
12/10/2020 PRS Deferred/Tabled Impact Analysis Consideration
11/11/2020 PRS Recommended for Approval Impact Analysis Consideration
08/13/2020 PRS Deferred/Tabled Language Consideration

Voting Record

Date Gov Body Motion Result
02/09/2021 BOARD to approve NPRR1034 as recommended by TAC in the 1/27/21 TAC Report Passed
01/27/2021 TAC to recommend approval of NPRR1034 as recommended by PRS in the 1/14/21 PRS Report as amended by the 1/25/21 ERCOT comments. Passed
01/14/2021 PRS to endorse and forward to TAC the 12/10/20 PRS Report and Impact Analysis for NPRR1034 with a recommended priority of 2021 and rank of 3280 Passed
12/10/2020 PRS to table NPRR1034 Passed
11/11/2020 PRS to recommend approval of NPRR1034 as amended by the 10/22/20 SCT comments Passed
08/13/2020 PRS to table NPRR1034 and refer the issue to ROS Passed

Background

Status: Approved
Date Posted: Jul 22, 2020
Sponsor: Southern Cross Transmission
Urgent: No
Sections: 4.4.4 and 4.4.4.3 (new)
Description: This Nodal Protocol Revision Request (NPRR) creates new Protocol Section 4.4.4.3, Frequency-Based Limits on DC Tie Imports or Exports to allow ERCOT to establish import or export limits on Direct Current Ties (DC Ties) to avoid the risk of any unacceptable frequency deviation that may be identified in the event of an unexpected loss of one or more DC Ties when importing or exporting. Revisions to Section 4.4.4, DC Tie Schedules, would allow ERCOT to curtail DC Tie Schedules on a DC Tie on a last-in-first-out basis when necessary to address this risk. The last-in-first-out curtailment methodology is consistent with current practice documented in the ERCOT DC Tie Operating Procedure Manual. ERCOT would be required to post on the Market Information System (MIS) Public Area the operating conditions and associated limits that it would expect to use.
Reason: Regulatory requirements: This NPRR is proposed in accordance with the May 23, 2017, order of the Public Utility Commission of Texas (PUCT) in Project No. 46304, Oversight Proceeding Regarding ERCOT Matters Arising Out of PUC Docket No. 45624 Relating to DC Tie Project Proposed by Southern Cross Transmission, LLC, which requires ERCOT to address a number of issues as a condition for the energization of the DC Tie project proposed by Southern Cross Transmission LLC (“Southern Cross Transmission”). As proposed, the Southern Cross DC Tie would be capable of importing 2,000 MW or exporting 2,100 MW. The PUCT’s Directive 9 in the order requires ERCOT to “evaluate what modifications to existing and additional Ancillary Services, if any, are necessary for the reliable interconnection of the Southern Cross DC tie.” ERCOT’s studies evaluating the potential need for Ancillary Services associated with the Southern Cross DC Tie identified a risk of unacceptable frequency overshoot in the event of the loss of the Southern Cross DC Tie when exporting above certain levels under certain operating conditions. ERCOT’s evaluation further identified likely future procurement of incremental Ancillary Services as a means to address the frequency overshoot concern. Southern Cross Transmission proposes this NPRR as a more efficient solution for the entire market by establishing limits on certain DC Tie transfers when necessary to address the risk of frequency overshoot, rather than requiring procurement of additional Ancillary Services.

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