HomeSystem ReliabilityM12577Evidence
Topic/Matter Intersection

Topic:"System Reliability" in M12577

Matter: North American Electric Reliability Corporation (NERC) - Third Quarter 2025  - Application for Approval of Reliability Standards
45 passages 5 documents

System Reliability across all matters →

N-1Application 30 passages
BEFORE THE NOVA SCOTIA ENERGY BOARD OF THE PROVINCE OF NOVA SCOTIA p. p. 34
BEFORE THE NOVA SCOTIA ENERGY BOARD OF THE PROVINCE OF NOVA SCOTIA North American Electric Reliability ) Corporation ) THIRD QUARTER 2025 APPLICATION FOR APPROVAL OF RELIABILITY STANDARDS OF THE NORTH AMERICAN ELECTRIC RELIABILITY CORPORAT...

AI summary The document is an application for the approval of reliability standards by the North American Electric Reliability Corporation (NERC) before the Nova Scotia Energy Board. It outlines a proceeding related to reliability standards in the third quarter of 2025.

November 25, 2025 p. p. 34
November 25, 2025 I. NOTICE AND COMMUNICATIONS 3 II. REQUEST FOR APPROVAL OF RELIABILITY STANDARDS 3 A. B. C. 1. BACKGROUND: NERC QUARTERLY FILING OF PROPOSED RELIABILITY STANDARDS 3 OVERVIEW OF NERC RELIABILITY STANDARDS DEVELOPMENT PROCE...

AI summary The document outlines an application by the North American Electric Reliability Corporation (NERC) for the approval of new reliability standards in the third quarter of 2025. It includes background information on NERC, the reliability standards development process, and descriptions of proposed standards such as PRC-024-4 and EOP-012-3.

A. Background: NERC Quarterly Filing of Proposed Reliability Standards p. p. 34
eview process for considering 4 See Memorandum of Understanding between Nova Scotia Utility and Review Board and North American Electric Reliability Corporation (signed Dec. 22, 2006). 5 See Memorandum of Understanding between Nova Scotia...

AI summary The NSUARB has established a process for reviewing NERC's proposed reliability standards, requiring FERC approval before processing applications. The NSUARB does not require approval for Violation Risk Factors and Severity Levels but will accept them as guidance.

B. Overview of NERC Reliability Standards Development Process p. p. 34
B. Overview of NERC Reliability Standards Development Process NERC Reliability Standards define the requirements for reliably planning and operating the North American BPS. These standards are developed by industry stakeholders using a bal...

AI summary This section outlines the process by which NERC develops reliability standards for the North American bulk power system. These standards are created through an open, inclusive, and fair process managed by the NERC Standards Committee, involving industry stakeholders. Standards are approved by stakeholders through a balloting process and then adopted by the NERC Board of Trustees and relevant governmental authorities.

Reliability Standards p. p. 34
Reliability Standards Reliability Standard Effective Date Protection and Control (PRC) PRC-024-4 10/1/2026 PRC-029-1 10/1/2026 Emergency Preparedness and Operations (EOP) EOP-012-3 10/1/2025 \ At the time of this filing, the standards mark...

AI summary The document outlines reliability standards for the electricity sector, including Protection and Control (PRC-024-4 and PRC-029-1) and Emergency Preparedness and Operations (EOP-012-3), with effective dates of 10/1/2026 and 10/1/2025, respectively. These standards have been approved by FERC and are set to become mandatory in the future.

1. PRC-029-1; PRC-024-4 - Inverter-based Resource (IBR) Ride-through Reliability Standards p. p. 34
Planning and Operational Studies Requirements for all IBRs (completion: November 4, 2026). Reliability Standards PRC-024-4 and PRC-029-1 relate to Generator Ride-through and are part of Milestone 2. Reliability Standard PRC-029-1 establish...

AI summary The document outlines the requirements for Planning and Operational Studies for Inverter-based Resources (IBRs) under Reliability Standards PRC-024-4 and PRC-029-1. These standards focus on generator ride-through performance, ensuring IBRs maintain reliability during disturbances and defining criteria for synchronous generators and wind units.

2. EOP-012-3 p. p. 34
2. EOP-012-3 On September 18, 2025, FERC issued an order approving Reliability Standard EOP-012- 3 as well as the associated implementation plan,18 Violation Risk Factors and Violation Severity Levels, and the revised definition of the ter...

AI summary On September 18, 2025, FERC approved Reliability Standard EOP-012-3, which addresses the effects of extreme cold weather on generating units by requiring Generator Owners to implement mitigation plans. This standard replaces EOP-012-2 and includes revised definitions and risk factors.

Revised definition of Generator Cold Weather Constraint: p. p. 34
Revised definition of Generator Cold Weather Constraint: FERC also approved a revised definition of Generator Cold Weather Constraint that is defined as: "Any condition that would preclude a Generator Owner from implementing freeze protect...

AI summary FERC approved a revised definition of Generator Cold Weather Constraint, which includes measures to ensure generators can implement freeze protection during cold weather. The new standard, EOP-012-3, includes nine requirements, including a periodic review of constraints every 36 months.

III. CONCLUSION p. p. 34
III. CONCLUSION NERC respectfully requests that NSEB approve the Reliability Standards as specified herein. Respectfully submitted, /s/ Sarah P. Crawford Lauren Perotti Assistant General Counsel Sarah P. Crawford Senior Counsel Alain Rigau...

AI summary NERC requests that NSEB approve the Reliability Standards as specified. The submission includes legal counsel from NERC and contact details for the involved parties.

Exhibit A-1 p. p. 34
Exhibit A-1 Reliability Standards Applicable to Nova Scotia, Approved by FERC in Third Quarter 2025

AI summary This exhibit lists the reliability standards applicable to Nova Scotia, which were approved by the FERC in the third quarter of 2025.

Exhibit A-2 p. p. 34
Exhibit A-2 Informational Summary of Reliability Standards Applicable to Nova Scotia, Approved by FERC in Third Quarter 2025

AI summary This exhibit provides an informational summary of reliability standards applicable to Nova Scotia, approved by the FERC in the third quarter of 2025. It outlines the standards relevant to the region's electricity grid and operations.

Exhibit A-2: Informational Summary of Reliability Standards Applicable to Nova Scotia, Approved by FERC in Third Quarter 2025 p. p. 34
Exhibit A-2: Informational Summary of Reliability Standards Applicable to Nova Scotia, Approved by FERC in Third Quarter 2025 Purpose Applicability Reliability Standard PRC-024-4 To assure that protection of synchronous generators, type 1...

AI summary Exhibit A-2 outlines three reliability standards (PRC-024-4, PRC-029-1, and EOP-012-3) approved by FERC in 2025. These standards ensure the protection of generators, wind resources, and synchronous condensers during frequency and voltage excursions, and address reliability impacts of extreme cold weather on generating units.

A. Introduction p. pp. 34-40
A. Introduction 1. Title: Frequency and Voltage Protection Settings for Synchronous Generators, Type 1 and Type 2 Wind Resources, and Synchronous Condensers 2. Number: PRC-024-4 3. Purpose: To assure that protection of synchronous generato...

AI summary The document outlines the purpose of PRC-024-4, which is to ensure that the protection settings for synchronous generators, type 1 and type 2 wind resources, and synchronous condensers do not lead to unnecessary tripping during frequency and voltage fluctuations that impact the Bulk Power System (BPS).

4.2. Facilities2: p. p. 34
4.2. Facilities2: - 4.2.1 Frequency, voltage, and volts per hertz protection (whether provided by relaying or functions within associated control systems) that respond to electrical signals and: (i) directly trip the generating resource(s)...

AI summary This section outlines specific protection requirements for frequency, voltage, and volts per hertz in the Bulk Electric System (BES), including protections for synchronous generators, transformers, and wind resources. It also specifies exemptions for auxiliary equipment and references an implementation plan for PRC-024-4.

Violation Severity Levels p. pp. 34-57
Violation Severity Levels Violation Severity Levels R2. N/A N/A N/A The Generator Owner or Transmission Owner failed to set its applicable voltage protection so that it does not trip according to Requirement R2.

AI summary The document outlines a violation related to voltage protection settings, where the Generator Owner or Transmission Owner failed to set the applicable voltage protection to prevent tripping as required by R2.

This Variance adds a VSL for D.A.5 and modifies the VSL for R2 as follows: p. p. 34
This Variance adds a VSL for D.A.5 and modifies the VSL for R2 as follows: Violation Severity Levels R # Lower VSL Moderate VSL High VSL Severe VSL D.A.2. N/A N/A N/A The Generator Owner or Transmission Owner failed to set its applicable v...

AI summary This Variance modifies the Violation Severity Levels (VSL) for D.A.5 and adds a VSL for D.A.2, outlining different levels of severity for violations related to voltage protection settings and the designation of strategic power plants by the Planning Coordinator.

Table 1: Frequency Boundary Data Points - Eastern Interconnection p. p. 34
Table 1: Frequency Boundary Data Points - Eastern Interconnection High Frequency Duration Low Frequency Duration Frequency (Hz) Minimum Time (Sec) Frequency (Hz) Minimum Time (sec) ≥61.8 Instantaneous10 ≤57.8 Instantaneous11 ≥60.5 10(90.93...

AI summary Table 1 presents frequency boundary data points for the Eastern Interconnection, specifying thresholds and durations for high and low frequency conditions, including formulas and continuous operation parameters. It notes that areas outside the 'No Trip Zone' are not 'Must Trip Zones.'

Table 2: Frequency Boundary Data Points – Western Interconnection p. p. 35
Table 2: Frequency Boundary Data Points – Western Interconnection High Frequency Duration Low Frequency Duration Frequency (Hz) Minimum Time (Sec) Frequency (Hz) Minimum Time (sec) ≥61.7 Instantaneous11 ≤57.0 Instantaneous11 ≥61.6 30 ≤57.3...

AI summary Table 2 presents frequency boundary data points for the Western Interconnection, detailing the minimum time durations for various high and low frequency thresholds. This data is critical for understanding frequency stability and operational requirements within the bulk-power system.

PRC-024 — Attachment 2 (Voltage No-Trip Boundaries – Eastern, Western, and ERCOT Interconnections) p. pp. 37-38
PRC-024 — Attachment 2 (Voltage No-Trip Boundaries – Eastern, Western, and ERCOT Interconnections) Figure 5: Voltage No-Trip Boundaries – Eastern, Western, and ERCOT Interconnections

AI summary This document provides a visual representation of voltage no-trip boundaries for the Eastern, Western, and ERCOT interconnections, which are critical for ensuring grid reliability and stability in power systems.

Table 6: High Voltage Boundary Data Points – Quebec Interconnection p. p. 40
Table 6: High Voltage Boundary Data Points – Quebec Interconnection High Voltage Duration for all Synchronous Generators and Condensers High Voltage Duration for strategic Power Plants Voltage (per unit) Minimum Time (sec) Voltage (per uni...

AI summary The text presents two tables detailing high and low voltage boundary data points for the Quebec Interconnection, including voltage thresholds and minimum durations for synchronous generators, condensers, and strategic power plants. It also references an attachment providing voltage boundary clarifications.

B. Requirements and Measures p. pp. 40-57
shall also retain evidence of actual disturbance monitoring (i.e., sequence of event recorder, dynamic disturbance recorder, and fault recorder) data to demonstrate that the IBR failed to Ride-through during a phase jump of greater than or...

AI summary The document outlines requirements for Generator Owners to ensure IBR voltage performance during voltage excursions, specifying that tripping should not occur unless necessary, with exceptions for documented hardware limitations. It also emphasizes the need for evidence of disturbance monitoring and coordination with reliability entities.

Attachment 2: Frequency Ride-Through Criteria Table 3: Frequency Ride-through Capability Requirements p. p. 40
Attachment 2: Frequency Ride-Through Criteria Table 3: Frequency Ride-through Capability Requirements System Frequency (Hz) Minimum Ride-Through Time (sec) > 61.8 May trip > 61.2 299 ≤ 61.2 and ≥ 58.8 Continuous < 58.8 299 < 57.0 May trip...

AI summary Attachment 2 provides frequency ride-through capability requirements for the Bulk-Power System. The table outlines minimum ride-through times for different system frequency ranges, with specific measurements taken at the high-side of the main power transformer.

Preamble p. pp. 40-57
- 2. Frequency is measured over a period of time (typically 3-6 cycles) to calculate system frequency at the high-side of the main power transformer. - 3. Instantaneous or single points of measurement may not be used in the determination o...

AI summary The text outlines frequency ride-through requirements for IBR, specifying that frequency is measured over multiple cycles, instantaneous measurements are not used, and IBR must ride-through unless the duration exceeds specified limits. These requirements are cumulative over disturbances within a 10-minute period.

C. Compliance p. p. 57
nt implementation plan. "Good faith" in this context refers to a sincere intention to comply with Reliability Standard EOP-012-3 regarding all requirements based on the calculation of the Extreme Cold Weather Temperature for each applicabl...

AI summary The text outlines the implementation plan for compliance with Reliability Standard EOP-012-3, emphasizing 'good faith' efforts by entities to comply with requirements related to Extreme Cold Weather Temperature calculations. Entities are required to participate in compliance monitoring activities by the CEA and submit requested documentation.

Case-by-case Determinations of Generator Cold Weather Constraints p. p. 57
- 2. The implementation of a specific freeze protection measure would exceed a manufacturer's design limitation and the exceedance is expected to functionally impair or degrade the effective operation of the impacted component or system. -...

AI summary The document outlines conditions under which freeze protection measures for generators may not be implemented, including when they exceed design limitations, are technically infeasible, or negatively impact system reliability. These determinations are based on engineering analysis, operating experience, and reliability considerations.

List of Currently Effective NERC Reliability Standards p. p. 57
List of Currently Effective NERC Reliability Standards BAL-001-2 Real Power Balancing Control Performance BAL-001-TRE-2 Primary Frequency Response in the ERCOT Region BAL-002-3 Disturbance Control Standard – Contingency Reserve for Recover...

AI summary The document lists currently effective NERC Reliability Standards, focusing on power balancing, frequency response, cyber security, and communication protocols for the Bulk Electric System (BES). These standards ensure reliability and security in the electricity grid.

Change History p. p. 57
Change History The first three sections identify all terms that have been adopted by the NERC Board of Trustees for use in continent-wide standards; the Regional definitions section identifies all terms that have been adopted by the NERC B...

AI summary This section of the document outlines the Change History, explaining how terms were adopted by the NERC Board of Trustees for use in continent-wide and regional standards, including the development of Version 0 standards and subsequent additions following board adoption, FERC filing, and final approval.

Any comments regarding this glossary should be reported to the NERC Help Desk. Select "Standards" from the "Service" drop-down menu and "Other" from the Standards Subcategory drop-down menu. p. p. 57
Any comments regarding this glossary should be reported to the NERC Help Desk. Select "Standards" from the "Service" drop-down menu and "Other" from the Standards Subcategory drop-down menu. Subject to Enforcement Continent-wide Term Link...

AI summary The text provides definitions and details related to electric reliability standards, including terms such as 'ACE Diversity Interchange' and 'Actual Net Interchange,' along with their adoption dates, FERC approval dates, and effective dates. These standards are subject to enforcement and are managed by entities like NERC.

Section 477 p. p. 57
2 FERC approved the WECC Tier One Reliability Standards in the Order Approving Regional Reliability Standards for the Western Interconnection and Directing Modifications, 119 FERC ¶ 61,260 (June 8, 2007). In that Order, FERC directed WECC...

AI summary FERC approved the WECC Tier One Reliability Standards in an order dated June 8, 2007, directing WECC to address inconsistencies between regional definitions and the NERC Glossary in developing permanent replacements.

WECC Regional Definitions p. p. 57
3 FERC approved the WECC Tier One Reliability Standards in the Order Approving Regional Reliability Standards for the Western Interconnection and Directing Modifications, 119 FERC ¶ 61,260 (June 8, 2007). In that Order, FERC directed WECC...

AI summary FERC approved the WECC Tier One Reliability Standards in 2007 and directed WECC to address inconsistencies with NERC Glossary definitions. Replacement standards were filed in 2009. The document includes definitions related to reliability standards, such as 'Secondary Inadvertent Interchange' and 'Security-Based Misoperation'.

101073Board Decision Letter 3 passages
Preamble p. pp. 0-2
Furthermore, NERC is requesting revisions to the Glossary of Terms Used in NERC Reliability Standards (NERC Glossary), which is provided as Exhibit C in the application. The Document: 327362 request includes the revised definitions for gen...

AI summary The document discusses the approval of revised NERC Reliability Standards and the NERC Glossary by the Board, following input from NS Power and IESO Nova Scotia. The Board confirms the importance of the standards for system reliability and recommends their approval with specified effective dates in Nova Scotia. The transition of NERC roles between NS Power and IESO Nova Scotia is noted, with a call for collaboration.

LIST OF STANDARDS APPROVED p. p. 2
LIST OF STANDARDS APPROVED Reliability Standard Description NERC Effective Date (m/d/y) Nova Scotia Effective Date (m/d//y) Protection and Control (PRC) PRC-024-4 Frequency and Voltage Protection Settings for Synchronous Generators, Type 1...

AI summary This document lists reliability standards approved for implementation in Nova Scotia, including PRC-024-4 and PRC-029-1 related to frequency and voltage protection settings and ride-through requirements for various resources, and EOP-012-3 concerning extreme cold weather preparedness and operations. These standards are effective in July 2026, though some are not yet effective at the time of filing with the Board.

LIST OF RETIRED STANDARDS p. pp. 3-4
LIST OF RETIRED STANDARDS Reliability Standard Nova Scotia Retirement Date (m/d//y) PRC-024-3 July 1, 2026 EOP-012-2 July 1, 2026

AI summary The document lists two retired reliability standards in Nova Scotia, PRC-024-3 and EOP-012-2, both set to be retired on July 1, 2026.

100614Comments - NSPI 4 passages
Section 5 p. p. 2
- In its application dated November 25, 2025, the North American Electric Reliability Corporation - (NERC) applied to the Nova Scotia Energy Board (NSEB, Board) for approval of the following - new NERC Reliability Standard approved by the...

AI summary The North American Electric Reliability Corporation (NERC) has applied to the Nova Scotia Energy Board for approval of new NERC Reliability Standards and definitions, including PRC-024-4, PRC-029-1, EOP-012-3, and revised definitions related to Generator Cold Weather Constraint and Ride-through.

Revised Reliability Standards p. pp. 2-4
Revised Reliability Standards 29 30 31 32 By letter dated November 26, 2025, the NSEB requested comments from Nova Scotia Power Incorporated (NS Power, Company) on NERC's Application by December 23, 2025. On December 17, 2025 NS Power requ...

AI summary The NSEB requested comments from NS Power on NERC's revised reliability standards, with NS Power requesting an extension for its response. NS Power notes that NERC's applications include effective dates for reliability standards in the U.S., but not in Nova Scotia, and requests clarification from the NSEB. NS Power also highlights that its recommendations for NERC standards do not include VRFs and VSLs, and discusses the transition of NERC roles to the IESO-NS.

1 p. pp. 6-7
1 Reliability Standard PRC-029-1 (Frequency and Voltage Ride-through Requirements for Inverter-based Resources) Group Protection and Control (PRC) Current version in Effect in Nova Scotia New Standard, no version in effect in Nova Scotia A...

AI summary The document outlines the proposed implementation of the PRC-029-1 reliability standard in Nova Scotia, including its applicability, FERC approval, and NS Power's recommendation for its effective date. The standard is new and not currently in effect in Nova Scotia.

DATE FILED: January 16, 2026 Page 11 of 12 p. pp. 10-11
DATE FILED: January 16, 2026 Page 11 of 12 1 5.0 CONCLUSION 2 3 In summary, NS Power has reviewed the NERC Application and recommends the NSEB: 4 5 (a) Approve Reliability Standard PRC-024-4, PRC-029-1 and EOP-012-3 effective as set out 6...

AI summary NS Power recommends that the NSEB approve specific NERC reliability standards and related definitions, while retiring older standards. The implementation of PRC-029-1 may require action from the IESO-NS in Nova Scotia.

100616Comments - IESO NS 5 passages
Section 4
21 4 (Frequency and Voltage Protection Settings for Synchronous Generators, Type 1 22 and Type Wind Resources, and Synchronous Condensers), (2) PRC-029-1 23 (Frequency and Voltage Ride-through Requirements for Inverter-Based Resources) 24...

AI summary The document references several reliability standards approved by FERC, including PRC-029-1 and EOP-012-3, which pertain to frequency and voltage ride-through requirements and extreme cold weather preparedness, respectively. No other standards were approved for Nova Scotia in the third quarter of 2025.

28
28 Reliability Standard Effective Date Protection and Control (PRC) PRC-024-4 10/1/2026 PRC-029-1 10/1/2026 Emergency Preparedness and Operations (EOP) EOP-012-3 10/1/2025 29 30

AI summary The document outlines the effective dates for several reliability standards, including PRC-024-4 and PRC-029-1 under the Protection and Control category, and EOP-012-3 under Emergency Preparedness and Operations. These standards are set to take effect in 2025 and 2026.

Section 6
31 By letter dated November 26, 2025, the NSEB requested comments from Nova Scotia Power (NS 32 Power) and the Nova Scotia Independent Energy System Operator (IESO Nova Scotia) on NERC's 33 Application by December 23, 2025. NS Power subseq...

AI summary The NSEB requested comments from Nova Scotia Power and IESO Nova Scotia on NERC's application. NS Power requested an extension to submit comments, which was granted. IESO Nova Scotia is a not-for-profit corporation established under the More Access to Energy Act, with a mandate to maintain the reliability of the bulk power system and facilitate a competitive electricity market.

1 NS Power Recommendations Re: M12436 – NERC 2025 Q2 Application for Approval of Reliability Standards, October 20, 2025, p.5.
1 NS Power Recommendations Re: M12436 – NERC 2025 Q2 Application for Approval of Reliability Standards, October 20, 2025, p.5. 52 generation interconnection functions. Accordingly, IESO Nova Scotia will provide its comments 53 on the NERC...

AI summary IESO Nova Scotia recommends that the NSEB confirm effective dates for NERC reliability standards in Nova Scotia and notes that VRFs and VSLs are not included in their approval recommendations. The document references historical approvals and the transition from the NSUARB to the NSEB.

84 2.1 PRC-024-4
84 2.1 PRC-024-4 Reliability Standard Group Current version in Effect in Nova Scotia Applicability PRC-024-4: Frequency and Voltage Protection Settings for Synchronous Generators, Type 1 and Type Wind Resources, and Synchronous Condensers...

AI summary The document discusses the implementation of the PRC-024-4 Reliability Standard, which pertains to frequency and voltage protection settings for synchronous generators, wind resources, and synchronous condensers. The standard is applicable to Generator Owners and Transmission Owners, though IESO-NS does not perform these roles. The FERC approved the standard in Order No. 909, and the NERC effective date is set for October 1, 2026.

101073Board Decision Letter 3 passages
Preamble p. pp. 0-2
Furthermore, NERC is requesting revisions to the Glossary of Terms Used in NERC Reliability Standards (NERC Glossary), which is provided as Exhibit C in the application. The Document: 327362 request includes the revised definitions for gen...

AI summary NERC is requesting revisions to its Glossary of Terms and Reliability Standards, which have been approved by FERC. The Board has received comments from NS Power and IESO Nova Scotia, who support the approval and recommend effective dates for the revised standards in Nova Scotia. The Board agrees and incorporates these recommendations into its Order.

LIST OF STANDARDS APPROVED p. p. 2
LIST OF STANDARDS APPROVED Reliability Standard Description NERC Effective Date (m/d/y) Nova Scotia Effective Date (m/d//y) Protection and Control (PRC) PRC-024-4 Frequency and Voltage Protection Settings for Synchronous Generators, Type 1...

AI summary The document lists reliability standards approved for implementation in Nova Scotia, including PRC-024-4 and PRC-029-1 related to frequency and voltage protection settings, and EOP-012-3 concerning extreme cold weather preparedness. These standards are effective in July 2026, with some not yet effective at the time of filing but approved by FERC.

LIST OF RETIRED STANDARDS p. pp. 3-4
LIST OF RETIRED STANDARDS Reliability Standard Nova Scotia Retirement Date (m/d//y) PRC-024-3 July 1, 2026 EOP-012-2 July 1, 2026

AI summary This document lists two retired reliability standards in Nova Scotia, PRC-024-3 and EOP-012-2, both set to be retired on July 1, 2026. The standards are related to reliability in the electricity sector.

Disclaimer: These summaries were generated by AI from the filings they describe. We take care to make them accurate, but errors are possible - and they aren't advice. Only the filings themselves are the record: if you're relying on something here, confirm it against the source documents or the Nova Scotia Energy Board's own record. Full disclaimer →