1. PRC-012-1 and SPSs in ERCOT RAS Workshop May 9, 2016

2. Agenda Existing SPSs and their new Classification Review Draft NPRR Review Draft NOGR Review Draft PGRR Talk through Next Steps

3. RESTRICTED Following Generation runback or trip related SPSs are RAS –Barney Davis SPS –Baytown Energy Center SPS –Eskota Switching Station SPS –Horse Hollow Generation Tie SPS –Monticello Switching Station SPS B –Morgan Creek Switching Station SPS –Permian Basin Switching Station SPS –Stryker Creek Switching Station SPS Following Series Reactor insertion or Line trip related SPSs are not RAS –Allen Switch Station SPS (Series Reactor Insertion) {exclusion (f)} –China Grove Switching Station SPS (Series Reactor Insertion) {exclusion (f)} –Elkton Switching Station SPS (Line trip) {exclusion (e)} –Monticello Switching Station SPS Mining (Line trip) {exclusion (e)} NERC Glossary RASs in ERCOT 3

4. RESTRICTED Draft NPRR 4 Section 2 –Remove Special Protection Systems and Add Remedial Action Scheme (RAS) A summarized version of the NERC RAS definition and exclusions. Full exclusion list is outlined in Operating Guide Section 11.2(2). –Add Automatic Mitigation Plan (AMP) [New type of CMP] Some exclusions identified in NERC RAS definition may be used for mitigating reliability concerns, –Ex-1. Monitor Element(s) during non fault conditions and de-energize these to prevent damage –Ex-2. Switch series reactors by monitoring quantities in same substation Automatic transmission scheme (which cannot be called a NERC-RAS) that automatically monitors and protects Transmission Element(s) Section 3.10.7.4 –RASs, AMPs must be submitted to ERCOT for review and approval. Submitted RASs, AMPs will be shared with market within 5 Business Days of receipt. Approved RASs, AMPs will be shared with market at least 2 Business Days before implementation. –Approved RASs, AMPs will be modeled * Modeled RASs, AMPs will be included in ERCOT’s Network Security Analysis tools. Draft RAS NPRR

5. RESTRICTED Draft NOGRR 5 Section 6.2.3 –RASs, AMPs Misoperations shall be documented and reported to ERCOT, TRE. Sections 11, 11.1, 11.2 –New email distribution list for CMP, RAS submittals (ras_cmp@ercot.com).ras_cmp@ercot.com –RAS, AMP design, implementation be coordinated with all affected Facilities owners/operators –RAS, AMP shall provide SCADA/ICCP telemetry for status, arming, tripping, etc. –RAS proposal, modification and retirement shall be reviewed and approved by ERCOT. To facilitate RAS submittals, added Attachment K in Section 8. Removed reference to ERCOT’s review procedures; added study timelines in 11.2(5) ERCOT will review existing RASs once every 5 years. –AMPs proposal, modification and retirement shall be reviewed and approved by ERCOT. Review process envisioned to be similar to RAPs. ERCOT will review existing AMPs annually as part of the Annual CMP review. –RASs, AMPs Operations shall be documented and reported ERCOT. Sections 11.3, 11.4, 11.5 –Added language to clarify that RAPs, MPs, PCAPs may not include Generation re-dispatch Draft RAS NOGRR

6. RESTRICTED Draft PGRR 6 Section 6.2.3 –Upon request, RAS owner shall provide dynamics data to simulate RAS actions. Existing language; Replace SPS with RAS. Section 6.4.1 –Transmission projects that only consists of RAS or AMP may be excluded from being modeled in the current set of steady state base cases. Existing language; Replace SPS with RAS, AMP. Draft RAS PGRR

7. RESTRICTED PRC-012-1 & RAS DefinitionRAS Definition Will be effective April 1, 2017. Project Webpage 7 A scheme designed to detect predetermined System conditions and automatically take corrective actions that may include, but are not limited to, adjusting or tripping generation (MW and Mvar), tripping load, or reconfiguring a System(s). RAS accomplish objectives such as :  Meet requirements identified in the NERC Reliability Standards;  Maintain Bulk Electric System (BES) stability;  Maintain acceptable BES voltages;  Maintain acceptable BES power flows;  Limit the impact of Cascading or extreme events. The following do not individually constitute a RAS: a.Protection Systems installed for the purpose of detecting Faults on BES Elements and isolating the faulted Elements b.Schemes for automatic underfrequency load shedding (UFLS) and automatic undervoltage load shedding (UVLS) comprised of only distributed relays c.Out-of-step tripping and power swing blocking d.Automatic reclosing schemes e.Schemes applied on an Element for non-Fault conditions, such as, but not limited to, generator loss-of-field, transformer top-oil temperature, overvoltage, or overload to protect the Element against damage by removing it from service f.Controllers that switch or regulate one or more of the following: series or shunt reactive devices, flexible alternating current transmission system (FACTS) devices, phase-shifting transformers, variable-frequency transformers, or tap- changing transformers; and, that are located at and monitor quantities solely at the same station as the Element being switched or regulated

8. RESTRICTED PRC-012-1 & RAS DefinitionRAS Definition Will be effective April 1, 2017. RAS FAQ 8 A scheme designed to detect predetermined System conditions and automatically take corrective actions that may include, but are not limited to, adjusting or tripping generation (MW and Mvar), tripping load, or reconfiguring a System(s). RAS accomplish objectives such as :  Meet requirements identified in the NERC Reliability Standards;  Maintain Bulk Electric System (BES) stability;  Maintain acceptable BES voltages;  Maintain acceptable BES power flows;  Limit the impact of Cascading or extreme events. The following do not individually constitute a RAS: g.FACTS controllers that remotely switch static shunt reactive devices located at other stations to regulate the output of a single FACTS device h.Schemes or controllers that remotely switch shunt reactors and shunt capacitors for voltage regulation that would otherwise be manually switched i.Schemes that automatically de-energize a line for a nonFault operation when one end of the line is open j.Schemes that provide anti-islanding protection (e.g., protect load from effects of being isolated with generation that may not be capable of maintaining acceptable frequency and voltage) k.Automatic sequences that proceed when manually initiated solely by a System Operator l.Modulation of HVdc or FACTS via supplementary controls, such as angle damping or frequency damping applied to damp local or inter-area oscillations m.Sub-synchronous resonance (SSR) protection schemes that directly detect sub-synchronous quantities (e.g., currents or torsional oscillations) n.Generator controls such as, but not limited to, automatic generation control (AGC), generation excitation [e.g. automatic voltage regulation (AVR) and power system stabilizers (PSS)], fast valving, and speed governing

9. RESTRICTED PRC-012-2 Final Draft Introduces the concept of “Limited RAS” –A RAS designated as limited impact cannot, by inadvertent operation or failure to operate, cause or contribute to BES Cascading, uncontrolled separation, angular instability, voltage instability, voltage collapse, or unacceptably damped oscillations. All RASs to be reviewed by Planning Coordinator at least once every 5 full calendar years. “Limited” designation to be ratified during each review. Functional Test to be performed by RAS Entity for Limited RASs at least once every 12 full calendar years and for all (other) RASs at least once every 6 full calendar years. Introduces many Attachments/Checklists for submission and review. Project Webpage 9