FRCC
Seasonal Transmission
Assessment
&
Operational Seasonal Study
Winter 2012
Objectives
• Purpose
• Review applicable NERC Reliability Standards
• Understand differences between the Seasonal
Assessment and the Operational Seasonal Study
• Understand study methodology
• Review types of contingencies screened
• Review actual coordinated corrective plans
• Understand the review & approval process
• Understand where the report is posted
• Questions?
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Purpose
Assess the adequacy & robustness of the
FRCC Region under expected 2012 winter
load conditions and under anticipated
system conditions (taking into account
generation and transmission maintenance
activities).
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Purpose, cont.
• Potential operating issues identified in advance
• Highlight areas of concern where operating and
system planning personnel need to coordinate
• Coordinate corrective plans where multiple
parties are involved
• Satisfy applicable NERC Reliability Standards
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Applicable NERC
Reliability Standards
NERC Standard
TPL-001-0.1
TPL-002-0b
TPL-003-0a
TPL-005-0
TPL-006-0.1
TOP-002-2b
VAR-001-2
Title
System Performance Under Normal Conditions
System Performance Following Loss of a Single BES Element
System Performance Following Loss of Two or More BES Elements
Regional and Interregional Self-Assessment Reliability Reports
Assessment Data from Regional Reliability Organizations
Normal Operations Planning
Voltage and Reactive Control
For example: TOP-002-2b
R2. Each Balancing Authority and Transmission Operator shall ensure its operating
personnel participate in the system planning and design study processes, so
that these studies contain the operating personnel perspective and system
operating personnel are aware of the planning purpose.
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Assessment vs.Operational Study
Seasonal Transmission Assessment
Analyzes the FRCC transmission system with all
transmission facilities expected to be in-service and with
normal (pre-contingency) operating procedures in effect
during the season. Only performed in Summer and
Winter seasons due to expected peak load conditions.
Operational Seasonal Study
Analyzes the performance of the transmission system
with forecasted generation and transmission outages for
the season. Performed all four seasons (Spring,
Summer, Fall, and Winter).
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Assessment vs. Operational Study, cont.
Seasonal Transmission Assessment
Six cases are developed:
• One case using forecasted Winter peak load flow
(45,890 MW) is run (all facilities in service)
• Five additional cases – each with a large unit off
(aka C3 Gen cases) are developed
• Units outaged include Crystal River #5, Ft Myers
#2, St Lucie #1, Sanford #5, and Stanton #2
• Single contingencies (Category B contingencies)
are run on each of these cases.
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Assessment vs. Operational Study, cont.
Operational Seasonal Study
Six cases are developed:
• Utilizes forecasted load
• Includes generation outages
• Includes transmission outages
• Two cases per month (December,
January, & February)
• The 2 cases for each month are selected
based on quantity and types of outages
during the month
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Study Methodology
• Cases are developed utilizing Siemen’s
PSS/e power flow software
• PSS/e is an integrated , interactive program
for simulating, analyzing, and optimizing
power system performance
• Steady-state analysis is performed using
Siemens’ Managing and Utilizing System
Transmission (PSS/MUST) load flow software
• PSS/MUST enables us to perform a variety of
contingency analysis on multiple cases
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Study Methodology, cont.
• Includes contracted firm interchange
• Includes screening for thermal and
voltage limits
• “No Solves” are referred to the
Stability Working Group (SWG) for
further analysis
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Study Methodology, cont.
• PSS/e Cases include three ratings for each
transmission facility:
Rate A: Continuous (Normal) Rating
Rate B: Long-term Emergency Rating
Rate C: Short-term Emergency Rating
 The amount of time a short-term or long-term
emergency rating is valid is determined by the
owning TOPs facilities rating methodology
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Study Methodology, cont.
• TOPs are responsible for developing and
maintaining all ratings within the PSS/e
cases
• All ratings are developed based on the
individual TOPs facilities ratings
methodology
• Jointly owned facilities and tie-line
facilities’ ratings are coordinated by
applicable TOPs and included in cases
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Study Methodology, cont.
• If the screenings result in a potential overload
on a facility due to a different TOP’s
contingency facility, the TOP with the
overloaded facility is responsible for
contacting the TOP that owns the contingency
facility to coordinate the corrective plan
• TOPs provide internal corrective plans to
applicable screened contingencies
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Study Methodology, cont.
• Each transmission facility’s short term
emergency rating (Rate C) is utilized as a
System Operating Limit (SOL) proxy
• A Rate C screening is performed on each of
the study cases for applicable screened
contingencies
• Pre-contingency corrective plans are
incorporated in the cases for applicable
contingencies that exceed the Rate C SOL
proxy
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Study Methodology, cont.
• Once Rate C screening is complete,
applicable contingencies are run against the
facility’s Rate A (normal continuous rating)
• Screened contingencies resulting in branch
loadings exceeding 100% of the Rate A or
buses outside the general screening criteria
of 95%-105% are sent to entities for review
and possible corrective plan development
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Types of Contingencies Screened
•
•
•
•
Category B - Single Contingency Analysis
All 69kV and above facilities are individually
outaged as a contingency
Performed on all cases
All BES (100kV and above) facilities
exceeding their Rate A and/or their
applicable voltage criteria require corrective
plans
Only 69kV facilities requiring coordination
between entities require corrective plans
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Types of Contingencies Screened, cont.
Category C1 Contingency Analysis
• Models bus section fault contingencies that result in the
loss of two or more transmission system elements.
• Each entity compiles list of C1 contingencies within their
area
• Performed on all cases
• Only BES (100kV and above) facilities exceeding their
Rate A and/or their applicable voltage criteria that need
coordination between entities require corrective plans
• Only 69kV facilities exceeding their Rate A and/or their
applicable voltage criteria that need coordination between
entities require corrective plans
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Types of Contingencies Screened, cont.
Category C2 Contingency Analysis
• Models breaker failure contingencies that result in the
loss of two or more transmission system elements.
• Each entity compiles list of C2 contingencies within their
area
• Performed on all cases
• Only BES (100kV and above) facilities exceeding their
Rate A and/or their applicable voltage criteria that need
coordination between entities require corrective plans
• Only 69kV facilities exceeding their Rate A and/or their
applicable voltage criteria that need coordination between
entities require corrective plans
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Types of Contingencies Screened, cont.
Category C5 Contingency Analysis
• Models the loss of 100kV and above multiple circuit
tower lines (>1 mile) contingencies
• Each entity compiles list of C5 contingencies within
their area
• Performed on all cases
• Only BES (100kV and above) facilities exceeding their
Rate A and/or their applicable voltage criteria that need
coordination between entities require corrective plans
• Only 69kV facilities exceeding their Rate A and/or their
applicable voltage criteria that need coordination
between entities require corrective plans
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Study Results, cont.
The Winter Study documented
specific outages during the
winter season that required
additional coordination.
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Study Results, cont.
Bunnell-Putnam 230kV Line Outage
This line outage showed potential thermal
overloads on various facilities for several
contingencies.
Coordinated Corrective Plan: FPL will
modify the clearance schedule as needed
depending on forecasted load.
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Study Results, cont.
Florahome-Riverview Outage
Contingency: Firestone-Normandy
Potential Overloads:
CECIL FIELD – NORMANDY 138 119%
FIRESTONE 138/69 tx 109%
FIRESTONE 230/69 tx 132%
HAMILTON - RANDALL 69.0 111%
HERLONG - LANE AVE 69.0 132%
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Study Results, cont.
Florahome-Riverview Outage
Coordinated Corrective Plan
Pre Contingency: JEA will open Firestone
breaker 949T3.
Post Contingency: Jax Heights - Firestone
230 kV line will open and load will be dropped
per the pre-approved FRCC Identified IROL
mitigation plan.
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Study Results, cont.
Lake Agnes-McIntosh Outage
Contingency: McIntosh-Teneroc 230kV Line
Potential Overloads:
Larsen E – McIntosh 69kV 107%
McIntosh W-McIntosh E 69KV 115%
McIntosh 230/69 kV 230%
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Study Results, cont.
Lake Agnes-McIntosh Outage
Coordinated Corrective Plan
If McIntosh Unit #3’s net output is > 240MW, LAK will open
breaker P2284 at McIntosh pre-contingency. If McIntoshTeneroc 230kV line trips (identified contingency), McIntosh Unit
#3 will be isolated and subsequently trip offline. No thermal
overloads will actually exist.
If McIntosh Unit #3’s net output is between 150 MW – 240 MW
and contingency occurs, LAK will utilize the McIntosh
autotransformer’s 30 minute emergency rating of 240MW.
Subsequently, LAK will decrease generation at McIntosh and
replace the generation with LAK 69kV generation.
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Study Results, cont.
Poinsett-Holopaw 230kV line outage
SEC, OUC and PEF have agreed to a Local Operating
Plan to mitigate potential contingency overloads on the
OUC’s St. Cloud 69kV transmission system.
Please refer to the Holopaw-Osceola Local Operating
Plan for details.
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Study Results, cont.
Two Local Operating Plans Updated
Handcart Operational Plan
&
Holopaw-Osceola Operating Plan
Local Operating Plans can now be found on
the FRCC website in the BAs/TOPs posting
area under a new folder named “Non-BES
Local Operating Plans”.
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Study Results, cont.
Review actual spreadsheets with contingencies,
impacted facilities, and coordinated corrective
plans:
• Category B Contingencies (Singles & RC
Monitored included)
• C1 Contingencies
• C2 Contingencies
• C5 Contingencies
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Study Results, cont.
The results demonstrate that potential thermal
and voltage conditions exceeding the
applicable screening criteria can be
successfully mitigated under normal
conditions, single contingency events, and
selected multiple contingency events.
The transmission system within the FRCC
Region is expected to perform reliably for the
anticipated 2012 winter season system
operating conditions.
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Review & Approval Process
• Operations Planning Working Group (OPWG) is
responsible for the Seasonal Transmission Assessment
& Operational Seasonal Study
• The OPWG representatives develop and coordinate all
corrective plans
• The FRCC Operations Planning Coordinator (OPC)
assists the OPWG by coordinating the studies, running
contingency analyses, and developing draft reports
• Operating Reliability Subcommittee (ORS) reviews
study and recommends approval by the Operating
Committee (OC) & Planning Committee (PC)
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Posting of Report
Full report is posted on the OPC site
(password protected) within the FRCC
website for Balancing Authority,
Transmission Operator, and Reliability
Coordinator personnel to view.
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Questions?
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