Transcript SOS Seminar Interface and SPS

FRCC
INTERFACE OPERATIONS
SPS OVERVIEW
- TRAINING FRCC SYSTEM OPERATOR
SEMINAR
Spring 2006
OBJECTIVES
• Review of the Florida / Southern Interface
• Studies and Limits
• Facilities that make up the Interface
• Florida / Southern Interface Reductions
• FL / SOCO Planned and Unplanned Outage
Coordination Procedure
• Overview of FRCC SPS Installations
• Loss of Multiple Interface Elements
• Questions…
FLORIDA / SOUTHERN INTERFACE
Atlantic
Ocean
Gulf Of Mexico
Summer 2006
Import Limit
3600 MW
FLORIDA / SOUTHERN INTERFACE
- “OUR TIES TO THE NORTH” -
• Planning and Operations across the Interface
coordinated by Florida / Southern Coordinating Group
(FSCG).
• The various facility owners coordinate changes and set
Interface Limits annually via the Transfer Capability
Study
• FSCG Provides the FRCC RC with the additional
procedures to manage and allocate loading on the
interface
Interface Limits are Based
on Annual …
Planning Studies
TTC
FLORIDA / SOUTHERN INTERFACE
• Operational Standards
established by NERC and
the FRCC require that
flows across this
interface be Limited
• Limits preserve Reliability
and provide for stable
operations using the
(N-1) Criterion
• Capability of the Interface
is much higher than the
limits
• These Limits Protect the
interconnected reliability
of the FRCC Bulk Electric
System as well as
protecting facilities from
potential damage
resulting from unplanned
outages.
• Shown Next is a simplified
Diagram of the Facilities
that Make up the Interface
FLORIDA / SOUTHERN INTERFACE
Southern
S. Bainbridge
Callaway
Thalmann
Ktl Creek
Scholz
TAL
Hatch
Kingsland
Pine Grove
Sub 20
Hopkins
500 kv
230 kv
Suwannee
Jasper
Duval
115 kv
* Underlying 69 kv
transmission NOT shown
FRCC (w/out TAL)
Florida/Southern Interface
Owners and Allocation
• The Florida/Southern interface is comprised
of several Transmission owners on both sides
of the interface.
• Florida - FPL, PEF, JEA, TAL
• Southern - SOCO, MEAG, GTC, Dalton
• Both Florida and Southern allocate their
respective side of the interface according to
transmission ownership.
FLORIDA SIDE
INTERFACE ALLOCATION
• Florida allocations determined by ownership agreement
• Jacksonville Electric Authority (JEA)
• Florida Power and Light (FPL)
• Progress Energy of Florida (PEF)
• City of Tallahassee (TAL)
• All of these entities utilize a single OASIS site to post
their individual allocations of the SOCO/FLA interface.
• Here, the respective import limit is determined by
equipment thermal ratings and location of any outages.
They can also change according to system load.
SOUTHERN SIDE
INTERFACE ALLOCATION
• Southern allocations are determined according to the
Interconnected Transmission System (ITS) agreement.
• This is an agreement where the transmission system
in the State of Georgia is co-owned by four entities:
• Southern Company (SOCO),
• Georgia Transmission Company (GTC),
• Municipal Electric Authority of Georgia (MEAG),
• City of Dalton.
• SOCO, GTC, and MEAG operate their own OASIS sites
and post their respective allocations on these sites.
FLORIDA SIDE ALLOCATION
OF CURRENT REAL-TIME IMPORT / EXPORT LIMITS
• PRO-RATA – Allocation is based on current REAL-TIME
•
•
•
•
Import Limits with NO Assignable Problems
Joint Ownership Party Agreement (JOP) –
JEA / FPL
Allocation Based on Assignable Reduction to FPL &
JEA for Outages in Florida of the DUVAL/HATCH and
/or DUVAL/THALMAN 500KV Lines
PEF (FPC) –
Allocation Based on Assignable Reduction to PEF for
Outages of the of the SUWANNEE / PINE GROVE 230KV
Line
TAL Assigned 200 MW : The Limit Goes to Zero for
Planned / Unplanned Outages of BAINBRIDGE / SUB 20
230 KV Tie Line
INTERFACE LIMITING CONDITIONS
• SOCOs .. Hatch / Thalman 500 kV Line Outage
• There is no stability limit
• Target an import limit of 3300 / 200 MW
• The 3300 MW is the flow into the Florida peninsula and the 200
MW is the flow into Tallahassee on their Bainbridge 230 kV tie.
• RC Will Adjust once CA solves for a higher or lower number.
• FRCCs … Duval / Hatch or Duval / Thalman 500 kV Line
Outage
• There is no stability limit below 3900 MW
• Target an import limit of 1100 / 200 MW
• Contingency Analysis should be used to set operating
limits.
• Remember these import limits must be achieved ASAP
and within 30 minutes to satisfy IROL mitigation
requirements.
FLORIDA SIDE vs SOUTHERN SIDE
INTERFACE ALLOCATION MIS-MATCH
• Net result = Allocations don’t match on both sides.
• This lead to conflicts as to what schedules are curtailed
• Planned Outages : Next Day RC coordinates
• Both sides post individual allocations
• Un-planned Outages : Real Time RC’s coordinate
• Most restrictive numbers will always apply
– First two (2) hours
– After first two hours each side re-allocates if
necessary
• The following procedure was developed as a guideline
for these situations.
PLANNED OUTAGE IN FLORIDA
RELIABILITY AREA & TIE LINES
Fla Owner coordinates outage
w/FRCC RC
FLA
FRCC RC Calc. & notifies
SCA Reliability Eng. of new
FRCC TTC capability
SOCO
FRCC RC notifies the Fla. Interface
Owners of new FRCC TTC and of the
Interface allocation ownership
capability using Fla. procedures
SCA Reliability Eng. notifies
Interface Owners in SCA of
the outage & new FRCC TTC
Fla. TTC will be changed on
the FLOASIS based on
Fla. allocations
OASIS postings in SCA are
reviewed & adjusted to
reflect SCA TTC
FRCC RC will post the
FRCC TTC on the
FLOASIS site
SCA Interchange Desk
will notify the affected
FLA Interface Owners
of schedule changes
PLANNED OUTAGE IN SOUTHERN
RELIABILITY AREA & TIE LINES
SCA Owner or ITS Operator
coordinates with SCA
Reliability Engineer
SOCO
FLA
SCA Reliability Engineer
calculates & notifies
FRCC RC and ITS Interface
Owners of new SCA TTC
FRCC RC notifies Fla.
Interface Owners of the new
SCA TTC and ITS Owner allocation
As well as SOCO breakdown of
ownership
FLOASIS postings are reviewed
and adjusted to reflect the
FRCC TTC based on Fla
allocations (If necessary)
SCA TTC are changed on all
affected OASIS sites in SCA
based on new ITS allocations
UN-PLANNED OUTAGE IN FLORIDA
RELIABILITY AREA & TIE LINES
FLA
FRCC and Southern Reliability Coordinators
will agree on an interface limit. If Fla &
Southern determine different limits
the lower limit will be Used
SOCO
FRCC RC will notify the Fla Interface
Owners of the outage, FRCC
TTC and allocate ownership
based on Fla Procedure
SCA Reliability Coordinator will
Notify the Interface Owners in SCA
of the outage and new FRCC TTC
FRCC TTC will be changed immediately
on each affected FLOASIS page based
on new allocations provided
by FRCC RC
After the remaining event hour + 2 hrs, the
various TTC OASIS Postings in SCA will be
reviewed & adjusted to reflect SCA TTC
based on the ITS Allocations
FRCC RC will also post the
FRCC TTC on the FLOASIS
site
SCA Interchange Desk will notify
affected Fla Owners of schedule
changes
All FRCC Entities will notify SCA Interchange Desks of any schedule changes
via phone & ETAG message system
UN-PLANNED OUTAGE IN SOUTHERN RELIABILITY
AREA (NOT TIE LINES)
FLA
FRCC & Southern RC’s will agree
on an interface limit. If FRCC and Southern
determine different limits, the lower limit
will be used
FRCC Reliability Coordinator will notify
the Interface Owners in FLA of the
outage and the new TTC
SOCO
SCA Reliability Coordinator will notify
the Interface Owners in SCA of the new
TTC and their allocation based on
SCA procedures
After the remaining event hour + 2 Hrs,
the Various TTC FLOASIS pages will be
reviewed & adjusted to reflect FRCC
TTC based on FLA allocations. (If necessary)
SCA TTC will be changed immediately on
each affected OASIS site in SCA based on
new allocations by SCA
All FRCC Interchange Desks
will notify the affected SCA
owners of schedule changes
All SCA entities will notify the
FRCC Interchange Desks of any
schedule changes via phone & ETAG
message
NORMAL OPERATIONS
Import ~ 3200 MW
LOSS OF LINE - IROL
NO-SOLVE CONDITION
Thermal
Overload
REDUCED IMPORT
Import ~ 1250 MW
REDUCED IMPORT
QUESTIONS ….?
What Happens IF ….?
We Lose Multiple Interface Lines…
at the same time…
at the wrong time (high state import)…
Overview of FRCC SPS
Installations
• Most SPS are automatic systems that
respond to overloads or unstable conditions
by operating circuit breakers to change
transmission configuration or to drop load or
generation.
• SPS are generally developed after grid
studies identify a outage event/operating
scenario where the resulting grid conditions
are not sustainable and there is not enough
time for System Operator intervention.
• The SPS used in Florida are islanding
schemes (out of step) and load shedding
schemes (FALS).
Special Protection Schemes
aka - SPSs
• NERC Operating Criteria?
• Operate to single contingency (CA)
• No Uncontrolled Cascading or Islanding for
Credible Multiple Contingencies (SPSs)
• These are the Design Basis of our SPSs
Purpose Of SPS
• Prevent uncontrolled islanding or cascading
• Provide Automatic Corrective Action where there is
insufficient time to implement manual measures before
cascading occurs
• Prevent Damage to Equipment
“A special protection system (SPS) or remedial action
scheme (RAS) is designed to detect abnormal
system conditions and take pre-planned, corrective
action (other than the isolation of faulted elements)
….
to provide acceptable system performance.”
• SPS actions include:
• Changes in demand (e.g., load shedding),
• Changes in generation,
• Changes in System Configuration
• In order to maintain system stability,
acceptable voltages, or acceptable facility
loadings.
• SPS installations must meet the requirements
defined in section PRC of the NERC Reliability
Standards along with the FRCC Regional
Coordination Requirements.
NERC Standards Require the FRCC to have a Documented
SPS Design and Review Process
…and an FRCC SPS
Database (ROG Site)
As a Result we Have a
Handbook Procedure…
Reliability Standard that Requires
Individual TOPs … Coordinate SPSs…
NERC Reliability Standards
• Reliability Standards have detailed list of outage type
and allowed level of transmission performance along with
Regional coordination and documentation requirements
Category
A
Contingency
Allowed Performance
No Outages
Loadings & Voltages within rating
presumably normal ratings
B
Single Contingency
Loadings & Voltages within rating
could be emergency ratings
C
D
Multiple contingency
No cascading, Loadings & Voltages
(e.g. double circuit tower)
within emergency ratings
Severe multiple contingency (e.g. Study and assess consequences
loss of all lines on common r.o.w.) No action required
What are Credible Multiple
Contingencies?
• Loss of Transmission Lines on Same
Structure
• Loss of Transmission Lines on Same Right
of Way
• Loss of an Entire Plant Site
Are SPS Only for Multiple Contingencies ?
No !!!!!!!!!
What are NOT SPSs…
• Under Frequency Load Shedding Schemes
•
Steps Set by FRCC for Florida
•
Sheds Load Before Units Are Damaged
•
Official First Step (59.7Hz) FPL (59.82Hz)
• Under Voltage Load Shedding Schemes
•
FPL, TAL (temporary)
• Schemes are Not Technically SPSs
(Not Listed in FRCC SPS Database)
• Schemes May be Used in Conjunction with SPSs
• Underfrequency and Undervoltage load shedding
are not considered to be SPSs and are governed
by separate sections of the NERC Reliability
Standards
• Other types of protection and control systems
that are not considered to be SPS include;
• Out-of-step relays when not used in
conjunction with other detection relays and
their trip or block function is limited to the
circuit they monitor.
• Automatic synchronizing relays
• Capacitor controls and Other Reactive
compensation switching systems.
• SPS schemes currently installed
within the FRCC region fit into the
following three categories:
• Transmission separation schemes
• Load shedding schemes
• Overload protection schemes
Purpose of Schemes
DUVAL OUT-OF-STEP
FAST ACTING LOAD SHEDDING (FALS)
Protects Florida/Southern Interface Against
Cascading for Loss of Multiple Generating
Units or Loss of Both 500kV ties
Out of Step is for Unstable Situation where
Separation Occurs
FALS for Stable Situation with High
Transmission Overloads or Generators
Beyond Reactive Capability ( Most Likely)
Characteristics
• Out of Step Schemes
• A) Instantaneous Separation
• B) Provides Control of Where
• C)
• D)
• E)
• F)
• G)
Separation / Islanding Occurs
Intended to Prevent Uncontrolled
Cascading
Separation of FRCC will Cause
Local Frequency Decay in FRCC
Scheme Relies on Under-Frequency
Load Shed Action
Frequency Recovers after Load Shed
Auto-Synch Restoration if Available
Corridor SPS
Out-of-Step or Corridor FALS
Protect for Loss of Specific Corridors
E.X. Poinsett-Martin & Poinsett Midway
Out of Step for Unstable Situations where
Separation Occurs
CFALS for Stable But Overloaded
FRCC SPS Transmission Separation Schemes
• TS1 Transmission Separation Scheme 1
Controlled separation for outage of Duval North 500 kV right-of-way
• TS2 Transmission Separation Scheme 2
Controlled separation for outage of Duval South 500 kV right-of-way
• TS3 Transmission Separation Scheme 3
Controlled separation for outage of Poinsett North 500 kV right-of-way
• TS4 Transmission Separation Scheme 4
Controlled separation for multiple generating units outages
• TS5 Transmission Separation Scheme 5
Controlled separation for outage of Poinsett South 500 kV right-ofway (TS5 is new and has been added to the 2005 SPS database)
Transmission Separation Scheme 1 (TS1)
Controlled separation for loss of Duval North 500kV Corridor
• The sudden loss of the DuvalHatch & Duval Thalman lines when
carrying more than 1300 MW, can
cause low voltage & loss of
synchronism in and around Ft.
White and Kingsland.
• Out of Step & undervoltage relays
at Ft. White, Kingsland, &
Columbia will detect these
conditions and will initiate special
tripping at these facilities.
•
For Sou-Fla flows < 1300 MW, there
may be low voltages at Kingsland & Ft.
White. There may not be any line
overloads other than Pinegrove-Jasper
115 kV.
Hatch
Pinegrove
Kingsland
Thalman
V
Duval
Suwannee
Normandy
5
7
Columbia
6
LEGEND
Firestone
Baldwin
Bradford
Out-Of-Step Relay
Deerhaven
V
JEA
Undervoltage Relay
Trip Point
Black
Creek
Switzerland
Seminole
1
Ft. White
2
LOGIC AT FT. WHITE
V
3
Rice
Sampson
R1
R2
R3
R4
4
OR
AND
Split Ft. White
V
Millcreek
Newberry
LOGIC AT KINGSLAND
Tocoi
Putnam
R5
AND
V
Silver
Sp.N.
Open KingslandDuval 230 kV
Bunnell
LOGIC AT COLUMBIA
R6
Silver Sp.
Open Columbia-Suwannee 115kV
Volusia
LOGIC AT DUVAL
R7
Central Fl Deland W
Poinsett
Figure 1 - Transmission Separation Scheme 1
Controlled Separation for Outage of Duval-Hatch & Duval-Thalmann
Open Duval-Kingsland 230 kV
Notes
• Both Ft. White and Kingsland have out of step supervised low
voltage tripping schemes. The out of step relays are used to
sense heavy power swings. If they pickup for a power swing,
tripping will be initiated if the 230 kV voltage drops below 80%
(184 kV).
• At high imports (~ 3600 MW), the Kingsland scheme may not
operate due to limitations in the swing detector relay. In this
case, there is an out of step relay at Duval that will open the
Duval end of the Kingsland circuit.
• After Kingsland and Ft. White trip, the import power will get
dumped on to the Columbia-Suwannee 115 kV circuit which
will quickly go out of step. An out of step relay at Columbia
will open the Columbia end.
• Relative to other possible island situations, this one is mild.
Operation of the 59.82, 59.7, and perhaps the 59.4 hertz UFLS
steps should be enough to restore Fla frequency to 60 hertz.
• There is an automatic synchronization relay scheme at Ft.
White which will most likely tie the system back together.
Simulation of Duval North
ROW outage
2003 Summer peak load,
Sou-Fla = 3600 MW
Frequency dips to
59.6 hertz
Recovers to 60 hertz
after 3895 MW
dropped by UFLS
SPS TS1 Actuation History - Example
Nov. 3, 1987 - Fault on Duval-Thalmann 500 with single
end trip at Hatch, Sou-Fla = 2600 MW Split at Ft. White &
Kingsland
~ 2200 MW UFLS, Hatch recloses via auto synch after 2
seconds
August 20, 1989 - Fault on Duval-Hatch, single end trip of
Thalmann ckt. Sou-Fla = 3136 MW, Split at Ft. White,
Kingsland, & Columbia
~ 3082 MW of UFLS, Ft. White recloses via auto synch
after 2 min.
Transmission Separation Scheme 2 (TS2)
Controlled separation for loss of Duval South 500kV Corridor
• The sudden loss of the
Duval-Rice & DuvalPoinsett lines when
carrying more than 2100
MW, can cause low voltage
& loss of synchronism in
the vicinity of
Ft. White
and either North or South
of Putnam.
Loss of Synchronism South of Putnam
For low voltage & loss of synchronism at Ft. White & South of Putnam the separation
point would to split the bus at Ft. White, Open the Bradford-Deerhaven line, Black Creek
Firestone line, Putnam Volusia line, and the Bunnell-Volusia line.
Loss of Synchronism North of Putnam
For low voltage & loss of synchronism at Ft. White & North of Putnam the
separation point would be Split the bus at Ft. White, open the BradfordDeerhaven line, Bradford-Rice, Duval-Seminole, & Millcreek Sampson.
Transmission Separation Scheme 3 (TS3)
Controlled separation for loss of Poinsett North 500kV Corridor
• The sudden loss of the
Poinsett-Rice & PoinsettDuval lines when carrying
more than 2400 MW, can
cause low voltage & loss
of synchronism in the
vicinity of Ft. White and
Putnam.
• Controlled separation for
this condition consists of
Out of Step (OST)
Schemes at Putnam, Silver
Springs North, & at Ft.
White.
•
•
Silver Springs North OST scheme opens terminals at Silver Springs North on the Seminole #1 & #2
lines
Ft. White OST scheme opens breakers 5061,5063, & 930 at Ft. White. This ties the Newberry, Archer
lines to the North & the High Springs 69kv to the South.
Putnam OST scheme opens the Putnam terminal on the Putnam-Volusia 230kv, Bunnel terminal on
the Bunnel-Volusia 230kV, & Bradford terminal on the Bradford-Deerhaven 138kV. This effectively
leaves the Putnam plant connected the North.
Transmission Separation Scheme 4 (TS4)
Controlled separation for loss of Generation
• The loss of multiple
generators, e.g. both St.
Lucie units will severely
depress the 500 kV
voltages if it occurs
during high import
conditions.
• Controlled separation is
initiated by
undervoltage & OST
relays at Duval, Ft.
White, Poinsett, &
Columbia.
• Separation occurs at
Duval, Columbia, & Ft.
White.
Transmission Separation Scheme 5 (TS5) NEW
Controlled separation for loss of Poinsett South 500kV Corridor
• The sudden loss of the
Poinsett-Martin &
Poinsett-Midway lines
when carrying more than
2400 MW, can cause low
voltage & loss of
synchronism in the
vicinity of Orange River &
Malabar.
• Controlled separation is
initiated by the OST
scheme at Orange River,
Okeelanta, & Malabar.
• Separation is
made by the
Orange River
terminal of the
Andytown 500kV
& Alva 230 kV
lines.
• Additionally the
Okeelanta
terminal of the
OkeelantaHendry line
opens
FRCC SPS Load Shedding Schemes
• LS1 Load Shedding Scheme 1
FALS – Load shedding for multiple generating units outages
• LS2 Load Shedding Scheme 2
CFALS – Load shedding for 500 kV right-of-way outages
• LS3 Load Shedding Scheme 3
Brookridge FALS
• LS4 Load Shedding Scheme 4
East Clearwater FALS
Overload Protection Schemes
• OL1 Overload Protection Scheme 1
Split Central Florida 230 (to reduce loading on Central Florida
500/230 autotransformer
Characteristics
Computer Schemes
• Designed to Prevent Separation or Islanding
• React in Seconds to Minutes Timeframes
• Protect for Severe Overloads or Low
Voltages
• Rely on Computer Shedding of Either
Transmission or Feeder Loads
Load Shedding Scheme 1 (LS1) FALS
Load Shedding for loss of multiple generating units
• LS1 responds to stable but overloaded conditions
caused by the outage of multiple units.
• Drops load in Southeast FL which unloads the
transmission system and arrests voltage decline.
• Total initial load dropped is at least 800 MW and is
dependent on system conditions.
• FALS requires a command from the Control center be
sent in addition to specific under-frequency relays
being operated.
Load Shedding Scheme 2 (LS2) CFALS
Load Shedding for 500kV corridor outages
• LS2 responds to stable but overloaded conditions
caused by the outage of the corresponding lines
• 5 CFALS logic matrices for the 500kV corridors
•
•
•
•
•
LS2a - CFALS Poinsett North/Duval South Corridor
LS2b - CFALS Poinsett South Corridor
LS2c - CFALS Martin Corridor
LS2d - CFALS Andytown North Corridor
LS2e - CFALS Andytown South Corridor
• Decides between 3 load areas where load will be
dropped & sheds between 800 to 1000 MW.
Load Shedding Scheme 3 (LS3) CFALS
Brookridge FALS Load Shedding
• Designed to prevent potential
blackout of PEF’s Suncoast area
due to loss of the Brookridge
corridor.
Load Shedding Scheme 4 (LS4) FALS
Clearwater FALS Load Shedding
•
•
Designed to prevent potential
blackout of PEF’s Suncoast area
due to loss of East Clearwater
transmission Corridor.
Scheme operates under-frequency
relays at 7 substations in the the
South Suncoast area to stabilize
voltage and relieve overloading.
Overload Protection Scheme (OL1)
• To protect Central FL 500/230
kV tx’s from severe overload if
one is out of service.
• Splits the Central FL 230 kV
bus
Situational Awareness
• 1) …
Review SPS if Anyone Takes Any 500kV
On Clearance
• 2) …
Review SPS Following Any 500kV Line
Trip
• 3) …
Review SPS for Any CA Output Showing
Loading >130% for loss of Any 500kV
Line
• 4) …
Not All Double Contingencies are
Covered
Check ALL FALS Alarms
• 5) …
Questions ?