Directory#1 Design and Operation of the BPS
TFCP and TFCO
Response to Open Process Comments
August 18th, 2015:
The NPCC Task Force on Coordination of Planning (TFCP) and Task Force on
Coordination of Operation (TFCO) Response to Comments Received during the Open
Process Posting of Directory #1 Design and Operation of the Bulk Power System.
The TFCP and the TFCO would like to thank those who provided comments on the
proposed revisions to Directory #1 posted from May 28th, 2015 through July 12th, 2015.
The Task Force responses to individual comments are provided below.
Comment #1:
Comment – New York State Reliability Council (NYSRC):
The Third Open Process Posting of NPCC Directory#1 has a revised Introduction as shown
below:
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
Comment – New York State Reliability Council (NYSRC):
Two comments are offered on the proposed revision to the Introduction, "If an entity
becomes aware1 of a contingency not on a bulk power system element that results
in a significant adverse impact outside of the local area, that entity must design
and/or operate the system to respect that event." The above phrase could be
interpreted to address contingency testing to determine BPS elements within NPCC
control areas and the comments below address that interpretation.
Note that bolded words in the proposed revision are NPCC defined terms also used in
NPCC Document A-­‐10, "Classification of Bulk Power System Elements", and that the
term "local area" is an NPCC defined term and should have been bolded.
Comment #1
"If an entity becomes aware1 of a contingency...." is too loose even with the
"strive to meet" footnote. NPCC member's interpretation of the word "strive"
can differ and result in uneven application of Directory 1.
Task Force Response to NYSRC Comment#1:
Thank you for the comment.
Comment not accepted.
TFCP has considered this comment and notes that the purpose of the subject language
……"If an entity becomes aware1 of a contingency…. is to ensure that a non BPS
contingency once identified and known to impact the BPS is evaluated in accordance
with the criteria.
Furthermore, the inclusion of the footnote addresses the risk of the language in the
objective being misinterpreted as a requirement to test all non-BPS contingencies.
TFCP also would like to emphasize that the sentence immediately prior to the subject
sentence obligates each Full Member to ‘at a minimum’ apply recognized contingency
events on the BPS and likewise monitor the performance requirements on the BPS,
thereby ensuring that each Full Member adheres to the reliability principles of the
document in its entirety.
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
Comment #2
"......of a contingency not on a bulk power system element that results in a
significant adverse impact outside of the local area, that entity must design and/or
operate the system to respect that event." is confusing since a contingency on an
element that results in a significant adverse impact outside of the local area makes
that element a bulk power system element by definition if it is tested per NPCC A-­‐10
procedures.
The key idea is to ensure that testing confirms existing BPS elements and identifies
new BPS elements. However, the footnote does not affirmatively require testing of
every potential BPS element and therefore may omit elements that can have a
significant adverse impact outside of the local area.
It is, in any case, redundant because NPCC Document A-­‐10, "Classification of Bulk of
Bulk Power System Elements", requires testing to determine, "elements being added to
or removed from existing lists", underline added.
Task Force Response to NYSRC Comment#2:
Thank you for the comment.
Comment not accepted.
TFCP agrees that the A-10 testing methodology is used to determine the scope of the
BPS by confirming existing BPS elements and identifying new BPS elements.
However, TFCP also recognizes that certain contingent elements may not be identified
as BPS facilities during the A-10 testing methodology and could potentially impact the
BPS. The subject language addresses these scenarios and ensures that such
contingencies are considered for their impact on the BPS.
TFCP will also undertake a review of the A-10 methodology once its effort on Directory
#1 has been concluded.
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
NYSRC Recommendation:
Strike the proposed revision, "If an entity becomes aware1 of a contingency not on a
bulk power system element that results in a significant adverse impact outside of the
local area, that entity must design and/or operate the system to respect that event."
and its footnote from Directory 1, Rev 3.
Replace it with, "An entity shall also design and operate the system to meet the
reliability objectives in this document for any contingency outside of NPCC Control
Areas if that contingency results in a significant adverse impact outside of the local
area."
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
Comment #2:
Comment – Nova Scotia Power Inc.
Section 3.0, NERC ERO Reliability Standard Requirements, adding a list of NERC ERO
Reliability Standards containing requirements for the BES introduces requirements
that may not be approved by the NSPI Regulator.
It is recommended that the NPCC members, though C07/CP11 or TFCP review the
implications of including NERC requirements for the Bulk Electric System in a criteria
document for the Design and Operation of the NPCC Bulk Power System.
NSPI cannot recommend to its Regulator the acceptance of a criteria document for its
BPS that contains requirements for the BES that may never be adopted in NS.
Task Force Response to Nova Scotia Comment:
Thank you for the comment.
Comment accepted.
NPCC will introduce a proposal to the Regional Standards Committee to revise the
existing language in each NPCC Directory for the section of the documents that lists the
ERO Standards from:
(Existing)
The NERC ERO Reliability Standards containing requirements that are associated with this
Directory include but may not be limited to:
(Revised)
The NERC ERO Reliability Standards containing requirements associated with this Directory,
but not necessarily enforceable in all NPCC areas, include but may not be limited to:
Additionally the proposal to the RSC will include a recommendation to move the list of
ERO standards in each Directory into a separate Appendix within each document.
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
Comment #3:
Comment 1 – United Illuminating Company
The United Illuminating Company, referred to as “UI” throughout this document,
respectfully submits comments on the 3rd Open Process Posting of Directory 1, posted on
May 27th, 2015.
UI appreciates the opportunity to submit these comments. UI’s comments are on the red-line
version of the Directory.
•
P. 9 – R.12
UI believes reference to “Special Protection Systems” or “SPS” should be updated to
meet NERC’s new definition and term of “Remedial Action Schemes” or “RAS”.
Task Force Response to UI Comment#1:
Thank you for the comment.
Comment not accepted.
NPCC is monitoring the ongoing NERC efforts and regulatory approval milestones
surrounding the revision to the definition of Remedial Action Schemes (RAS) and the
existing PRC standards that govern Special Protection Systems.
Subsequent to industry and regulatory approval of the revised definition and standard
(PRC -012-2), NPCC will review all of its documents to insure that its criteria is not
inconsistent with the ERO standards.
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
Comment 2 – United Illuminating Company
•
Table 1 – P.1 – Category I

Contingency Event 6: “Simultaneous fault on two adjacent transmission circuits on a
multiple circuit tower”

Fault Type: “Phase to ground faults on different phases of each circuit, with normal
fault clearing”
In UI’s experience of Double Circuit Tower (DCT) testing, this condition cannot easily
(if at all) be done using commonly used simulation software for stability analysis. This
results in Transmission Planners making assumptions in modeling (either testing (a)
simultaneous 3-phase faults which is deemed too conservative, (b) testing simultaneous
DLG faults as an approximation, or (c) testing simultaneous SLG faults though not
specified on different phases).
These inconsistencies could occur throughout several entities within a common area.
Thus UI would like to request a revision on this requirement for ease in modeling,
consistency across areas, and avoiding over- or mis-interpretation of the requirement for
modeling purposes.
UI does not have a proposal as to the type of fault to be studied; however UI would
appreciate it if the modeling perspective was also taken into account when possibly
modifying this requirement.
Task Force Response to UI Comment#2:
Thank you for the comment.
Comment accepted.
TFCP and TFSS will undertake to provide guidance on this issue.
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
Comment 3 – United Illuminating Company
•
Table 1 – P.3 – Performance Requirements for the contingencies defined in Table 1
– Footnote iv

Voltages and loadings shall be within applicable emergency limits for postcontingency conditions except for small or radial portions of the system as
described in ii.
UI believes the term “emergency” should be kept in order to avoid the possibility of
incorrectly measuring voltages and loadings against “Normal” limits for postcontingency conditions. UI believes this term provides further clarity that could later
avoid confusion if removed.
Task Force Response to UI Comment#3:
Thank you for the comment.
Comment not accepted.
TFCP considers the applicable limit to include the emergency limit.
Comment 4 – United Illuminating Company
•
Table 1 – P.3 – Performance Requirements for the contingencies defined in Table 1
– Footnote vii

Regarding contingency no 6, if multiple circuit towers are used only for station
entrance and exit purposes and if they do not exceed five towers at each station,
then this condition is an acceptable risk and therefore can be excluded. Other
similar situations can be excluded on the basis of acceptable risk, provided that the
Reliability Coordinating Committee specifically accepts each request for exclusion.
(See Appendix E.)
The new NERC TPL-001-4 (footnote 11 on P.12) states DCT’s 1 mile or less can be
excluded. UI believes this should also be addressed in this Directory 1 requirement,
by adding a statement such as “regardless of distance of the multiple circuit towers”
in the first sentence. By doing so, this would make it clear to the planner that this
requirement supersedes NERC’s requirement for DCT testing exclusions.
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS
Task Force Response to UI Comment#4:
Thank you for the comment.
Comment not accepted.
The exclusion is only for station entrance and exit purposes.
TFCP/TFCO Response to Comments on Directory #1 Design and Operation of the BPS