NERC TPL-007-3 Implementation Plan Update for Transmission System Planned Performance

1. May 22, 2019 | Westborough, MA Alex Rost Manager, Transmission Planning New England Implementation Plan for NERC TPL-007-3: Transmission System Planned Performance for Geomagnetic Disturbance Events

2. Certain entities in the region have compliance obligations under the NERC TPL-007-3 standard on Transmission System Planned Performance for Geomagnetic Disturbance (GMD) Events • TPL-007-3 becomes effective on July 1, 2019, and will replace TPL-007-1 • This presentation provides: • Background on the need to update the New England Implementation Plan for meeting NERC TPL-007 • Timelines and information on the updated New England Implementation Plan

3. Background on the Need to Update the New England TPL-007 Implementation PlanOriginal Implementation Plan • In 2017, a New England Implementation Plan was proposed for meeting the requirements of TPL-007-1 • Planning Coordinators (PCs), Transmission Planners (TPs), and Transmission Owners (TOs)/Generator Owners (GOs) with facilities that include power transformer(s) with a high side, wye-grounded winding with terminal voltage greater than 200 kV are the applicable entities under the standard • Additional details on GMD, TPL-007-1, and the original NE Implementation Plan can be found in the March 21, 2017 Reliability Committee (RC) presentation

4. Background on the Need to Update the New England TPL-007 Implementation PlanRequirement Changes Resulting from the Revised Standard • TPL-007-3 recently received approval, and will have phased-in implementation dates for requirements beginning on July 1, 2019 • TPL-007-2 was superseded by TPL-007-3, as discussed at the March 20, 2019 RC • Changes introduced with TPL-007-3 • Five new requirements are added (R8 – R12) • R8, R9, and R10 are new requirements for performing a GMD Vulnerability Assessment, providing Geomagnetically Induced Current (GIC) flow information, and performing transformer thermal impact assessments, respectively, for a “supplemental GMD event” • R11 and R12 are new requirements for gathering GIC monitor and geomagnetic field data, respectively • All previous requirements associated with TPL-007-1 remain (R1 – R7) • For R1, additional responsibilities for PCs and TPs need to be defined for the newly added requirements • For R7, more defined guidelines around the treatment of Corrective Action Plans • NERC implementation plan for TPL-007-3 changes all the requirements’ deadlines

5. NERC and NE Implementation Plan Timelines Table of Timeline

6. NERC and NE Implementation Plan Timelines Table of Timeline, cont.

7. NERC and NE Implementation Plan Timelines NERC Timeline – TPL-007-3 NE Implementation Plan

8. NERC and NE Implementation Plan TimelinesAdditional Considerations • Many of the NE implementation plan due dates are earlier than the NERC TPL-007-3 enforcement dates • Earlier dates for the NE implementation plan are needed to reduce the risk of not meeting the NERC TPL-007-3 requirements’ enforcement dates • This is the first time that NE is going through the complete TPL-007 study cycle, which involves new types of modeling and analyses • The required analyses can be iterative, which means that results obtained in the latter stages of the study cycle may result in the need to re-run study work associated with the early stages of the study cycle

9. NERC and NE Implementation Plan TimelinesAdditional Considerations, cont. • The maintenance of the New England system GIC model is an ongoing effort • The majority of the GIC modeling data needed to perform the required analyses according to the NE Implementation Plan is already included in the maintained New England system GIC model • Limited updates are needed to capture relevant transmission system and resource changes • ISO will notify applicable entities if modeling updates are needed

10. Stakeholder Schedule

11. Alex Rost (413) 540-4282 | arost@iso-ne.com