Project 2010-13.2 Phase 2 Relay Loadability: Generation
Related Files

 

Status:
PRC‐023‐3 became effective on October 1, 2014.
PRC-025‐1 became effective on October 1, 2014. 


Background:
The March 18, 2010, FERC Order No. 733, approved Reliability Standard PRC-023-1 – Transmission Relay Loadability. In this Order, FERC directed NERC to address three areas of relay loadability that include modifications to the approved PRC-023-1, developing a new Reliability Standard to address three areas of relay loadability that include modifications to the approved PRC-023-1, developing a new Reliability Standard to address generator protective relay loadability, and another Reliability Standard to address the operation of protective relays due to power swings. This project’s SAR addresses these directives and establishes a three-phased approach to standard development.

Phase 2 is focused on developing a new Reliability Standard, PRC-025-1 – Generator Relay Loadability, to address generator protective relay loadability. This Reliability Standard establishes requirements for the Generator Operator functional entity to set protective relays at a level such that generating units do not trip during system disturbances that are not damaging to the generator thereby unnecessarily removing the generator from service.

Phase 1 was focused on making the specific modifications to PRC-023-1 and was completed in the approved PRC-023-2 Reliability Standard, which became mandatory on July 1, 2012. Phase 3, which will follow this project, will focus on developing requirements that address protective relay operations due to stable power swings.

Purpose/Industry Need:
During analysis of many of the major disturbances in the last 25 years on the North American interconnected power system, generators have been found to have tripped for conditions that did not apparently pose a direct risk to those generators and associated equipment within the time period where the tripping occurred.   This unnecessary tripping has often been evaluated to have extended the scope and/or duration of that disturbance.   This was noted, in detail, to be a serious issue in the August 2003 “blackout’ in the northeastern North American continent.

During the recoverable phase of a disturbance, the disturbance may exhibit a “voltage disturbance” behavior pattern, where system voltage is widely depressed.   In order to support the system during this phase of a disturbance, this standard establishes criteria for setting load-responsive relays such that individual generators may provide Reactive Power within their dynamic capability during transient time periods to help the system recover from that voltage disturbance.   Premature or unnecessary tripping of generators during this period can deepen the severity of the voltage disturbance due to removal of dynamic Reactive Power, and change the character of the disturbance such that it is less recoverable.

Draft Action Dates Results Consideration of Comments

 

Draft 4

PRC-023-3
Clean | Redline to Last Posting |  

Redline to Last Approved


Implementation Plan
Clean | Redline

Final Ballot

Info>>

 

Vote>>

09/04/13 - 09/13/13

(closed)​

Summary>>

 

Ballot Results>>

 

Draft 5
 
PRC-025-1
Clean | Redline to Last Posting (Redline Corrected 08/05/13) 
 
Supporting Materials:

Guideline and Technical Basis

Clean | Redline to Last Posting
 

Final Ballot
Updated Info>>

 

Vote>>

08/02/13 - 08/12/13

(closed)

 

 Summary>>

Ballot Results>>

Draft 4
 
Implementation Plan
Clean | Redline to Last Posting
 
Guideline and Technical Basis
Clean | Redline to Last Posting
 
Draft 3
 
Implementation Plan
Clean | Redline to Last Posting
 
Supporting Materials:
Unofficial Comment Form (Word)
PRC-025-1
PRC-023-3
 
VRF/VSL Justification for PRC-025-1
Clean | Redline to Last Posting
 
 
 
Successive Ballot and Non-binding Poll for PRC-025-1
 

Vote>>

07/10/13 – 07/19/13
(Closed)

Summary>>

 

Ballot Results>>

 

Non-binding Poll Results>>​

 
30-day Comment Period for PRC-025-1
 
06/20/13 - 07/19/13
(Closed)
Comments Received>> Consideration of Comments>>​
Initial Ballot for PRC-023-3 Info>>
 
Vote>>

07/26/13 - 08/08/13

(closed)​

 
Summary>>
 
Join Ballot Pool>> 06/20/13 - 07/19/13
(Closed)​
45-day Comment Period for PRC-023-3
 

06/20/13 - 08/08/13

(closed)​

Consideration of Comments>>

Draft 3

PRC-025-1

Clean |

Redline to Last Posting

Implementation Plan

Clean | Redline to Last Posting

Guideline and Technical Basis

Clean | Redline to Last Posting

Draft 2

PRC-023-3

Clean |

Redline to Last Posting

Implementation Plan

Clean | Redline to Last Posting

Supporting Materials:

Unofficial Comment Form (Word)  

 

VRF/VSL Justification for PRC-025-1

Clean |

Redline to Last Posting

Consideration of Issues and Directives for PRC-025-1

VRF/VSL Justification for PRC-023-3

Successive Ballot and Non-binding Poll for PRC-025-1

 

Updated Info>>

 

Vote>>

05/15/13 - 05/24/13

(closed)​

 

Summary>> 

Ballot Results>>

 

Non-binding Poll Results>>

 

Comment Period for PRC-025-1 and PRC-023-3

 

Info>>


04/25/13 - 05/24 13

(closed)​

Comments Received>>​ Consideration of Comments>>​

Draft 2
PRC-025-1
Clean | Redline to Last Posting

Implementation Plan
Clean | Redline to Last Posting

Guideline and Technical Basis
Clean | Redline to Last Posting

VRF/VSL Justification

Consideration of Issues and Directives

Draft 1

Supplemental SAR for Relay Loadability
Order 733 to revise PRC-023-2


PRC-023-3
Clean | Redline to Last Approved

PRC-023-3 Implementation Plan

Supporting Materials:

Unofficial Comment Forms (Word)
PRC-025-1
Supplemental SAR
Cost Effectiveness

Initial Ballot and Non-binding Poll

Info>>

Vote>>
03/01/13 - 03/11/13
(closed)​
Summary>>

Ballot Results>>

Non-binding Poll Results>>
Comment Period

Info>>

Submit Comments
01/25/13 - 03/11/13
(closed)​

 

Pilot CEAP Report

Comments Received:
PRC-025-1
Supplemental SAR

Consideration of Comments:

PRC-025-1>>

Supplemental SAR>>

RSAW Industry Comment Period

PRC-025-1 RSAW>>

RSAW Feedback Form>>

Please send RSAW Feedback Forms to:
RSAWfeedback@nerc.net
01/25/13 - 03/11/13
(closed)​

 

Join Ballot Pool>>

01/25/13 - 02/25/13

(closed)​

  Draft 1

PRC-025-1

 

Implementation Plan

Clean

 

 
Supporting Materials:
SAR for Relay Loadability
Modifications and Additions

 

 

Unofficial Comment Form (Word)

SAR for Relay Loadability
PRC-023-2
Draft SAR Version 1

 

 

  Comment Period​

Info>>

 

 

 

 

10/5/2012 - 11/5/2012
(Closed)
Comments Received>> Consideration of Comments>>
 

All comments should be forwarded to sarcomm@nerc.net