2013 Wind Conference
Congestion
Management &
Communication
Processes
CJ Brown
Section 1
CONGESTION MANAGEMENT
3
Congestion Management Overview
•
Transmission Loading Relief (TLR)
•
Congestion Management Event (CME)
•
Security Constrained Economic Dispatch (SCED)
•
Manual Directives
•
CLIPs
4
Congestion Management
•
We manage congestion in one of two ways:
–
TLR (Transmission Loading Relief) event if there are
curtailable (>5%) impacts other than SPP EIS Market
impact
–
Congestion Management Events (CME) if there are no
curtailable external impacts
5
Typical Event Sequence to Mitigate Congestion
Communication
•
The Reliability Coordinator (RC) contacts BA and or TO to confirm the SOL
limit and the Real Time Loading of the flow gate
Issue TLR in IDC
•
The Reliability Coordinator (RC) calls a TLR event in NERC IDC. The TLR
event triggers a calculation by NERC IDC to determine who needs to curtail
Tags (transactions) and who needs to re-dispatch to what amount to
accomplish enough relief to lower the real time loading of flow gate
Curtailments
•
NERC IDC will send out curtailment instructions and relief obligations to
entities that need to take action
Monitor
•
The Reliability Coordinator (RC) monitors the flow gate loading. The
loading should go down because of the Tag Curtailments and re-dispatch by
Markets (typically a 15-20 minute delay)
Re-issue TLR in IDC
•
The Reliability Coordinator (RC) will request more relief in NERC IDC if
necessary
•
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SPP Market will accomplish its relief through Security Constraint Economic
Dispatch (SCED)
6
Typical Event Sequence – TLR Event
1.
2.
3.
4.
5.
6.
7.
8.
9.
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Flow approaches or exceeds flowgate limit
Reliability Coordinator calls TLR and requests relief from IDC
NERC IDC prescribes Tag, Network and Native Load (NNL), and/or
Market Flow curtailments as appropriate
Constraint Manager and CAT receive Target Market Flow from IDC
SPP RC accepts TLR event in Constraint Manager and verifies that
the effective limit is appropriate
SPP CAT will calculate appropriate schedule adjustments for those
schedules not curtailed by IDC and send to RTOSS
Flowgate is activated in next Security Constrained Economic
Dispatch (SCED)
Market System will run SCED, attempting to keep flowgate flow
below effective limit
RC continues to monitor flowgate flow and ask for additional relief
as necessary
7
Transmission Loading Relief (TLR) Event
Tag Curtailments
Target
Market Flow
to SPP CAT
1
NERC IDC
RC Issues TLR
8
Market Flow sent
To NERC IDC every
15 minutes
ETAGGING
3
SPP
CAT
Adjusted
every 15 minSchedules
Effective Limit
of Constraint
Sent to MOS
2
Target
Market Flow
to SPP Constraint
Manager
Market Flow
Calculator
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2
2
4
SPP
Constraint
Manager
5
NLS
RTOSS
scheduling
6
SPP MOS SCED
SFT Topper / SPD
Runs every 5 min
SPP RC accepts TLR
Dispatch Instructions and NSI values
7
8
Congestion Management Event (CME)
•
A CME is issued in the SPP EIS Market System by the
SPP RC through activating a defined flowgate and
setting a Target flow limit (typically SOL) for the SPP
EIS Market System to maintain the flow on or below
through Secure Economic Constraint
9
Typical Event Sequence – CME
1.
2.
3.
4.
5.
6.
7.
Note:
Flow approaches or exceeds flowgate limit
Reliability Coordinator verifies in NERC IDC that there are no
curtailable Tags or Market relief from other Entities
SPP RC calls a CME event in Constraint Manager and sets effective
limit
SPP CAT will calculate appropriate schedule adjustments for those
schedules not curtailed by IDC and send to RTOSS
Flowgate is activated in next Security Constrained Economic
Dispatch (SCED)
Market System will run SCED, attempting to keep flowgate flow
below effective limit
RC continues to monitor flowgate flow and ask for additional relief
as necessary (lower effective limit in Constraint Manager)
CME = Congestion Management Event. It only results in re-dispatch by SPP Market.
It can result schedule curtailments if Market is providing counter flow to support financial schedules.
CME is only allowed if there are no Tags to curtail in IDC and no Market relief from other Markets.
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10
CME EVENT
Congestion Management Tools
used by SPP Reliability Coordinator
CME = Congestion Management Event
Only results in re-dispatch by SPP Market
and schedule curtailments if Market is
providing counter flow to support financial
schedules
ETAGGING
4
SPP CAT
OATI
Adjusted
every 15 minSchedules
NERC IDC
OATI
3
CME event
Send to CAT
Effective Limit
of Constraint
Sent to MOS
7
2
Market Flow sent
To NERC IDC every
15 minutes
Market Flow
Calculator
Alstom 15min
RC Issues CME
1
Constraint
Manager
NLS
RTOSS
Scheduling
OATI
5
SPP MOS SCED
SFT Topper / SPD
Runs every 5 min
Dispatch Instructions and NSI values
6
11
Security Constrained Economic Dispatch (SCED)
•
Once a flowgate is activated in constraint manager, the
SPP EIS market will redispatch all available generation
to provide market flow relief
•
EIS market runs a SCED every 5 minutes for a 10
minute out target
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Manual Directives
•
When the TLR/CME/SCED processes do not
provide enough relief or if the relief cannot be
provided in a timely manner, the SPP Reliability
Coordinator (RC) will issue manual directives to
manage congestion on the bulk electric system
13
Section 2
CLIP
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What is a CLIP?
•
Capacity Limit Implementation process (CLIP) is a
communication process in which the SPP RC will
electronically communicate a deployment to a specific
Non-Dispatchable Resource (NDR), which reflects a
reliability output limit for that Resource.
•
This would be comparable to a security constrained
dispatch instruction provided to dispatchable
Resources
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Why change?
•
Current communication of output limits for these
types of Resources consists of an onerous, timeconsuming process in which the deployment takes the
form of a directive from the RC
•
The purpose of CLIP is to communicate these same
output limitations in the form of an electronic
message that is acknowledged and monitored for
implementation and efficacy
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Advantages
•
Reduce Operator/minutes consumed during the
curtailment process over the current manual verbal
process
•
Greater flexibility in the issuance and release of
limitations
•
Greater focus on overall system reliability
17
Process
•
Entry into the RC logging system will include a list
of NDR entity names (could be common Resource
names, MP names, or any common reference) that
are linked to a specific email address for the realtime operational function of that resource
–
The required information is entity name, MW limit, and
date/time
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Process (cont.)
•
When the form is completed, RC will click on a
“send email” button which will send a pre-worded
email message including the required information
to the email link for that entity
•
RC will initiate a pre-recorded blast call (or
individual calls depending on volume to be called)
to notify all impacted entities that a CLIP
notification message has been sent.
– Using the existing Msg911 communication tool
– Text and/or computer generated voice message
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Process (cont.)
•
NDR operating entity will review and comply with
the message, by first replying to the received CLIP
email message and then implementing the output
limitation
•
RC shall monitor replies from recipients and
ensure real-time data is consistent with the limits
communicated within a timely manner (time
period TBD)
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Process (cont.)
•
If RC is unable to obtain a reply, or has obtained a
reply but cannot verify the resource has complied
with the deployment, RC shall contact that
resource and, if appropriate, issue a curtailment
directive to that entity (to ensure compliance)
•
Amendments and terminations to the output
limitation will be made in the same manner as the
initial limit – log, send, and verify
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Development and Implementation
•
Teams formed to address various aspects of NDR
curtailment concerns
•
CLIP project team progress:
–
Prototype logging pages have been developed, subject to
changes based on stakeholder input
–
Coding is completed based on current version of logging page
–
Msg911 is being populated with NDR points of contact for
control of their respective NDR (CLIP account)
–
Expected completion by end of July, depending on when final
design is set (could be earlier)
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Questions
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