2013 Wind Conference

Congestion Management & Communication Processes

CJ Brown

CONGESTION MANAGEMENT Section 1

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Congestion Management Overview

• Transmission Loading Relief (TLR)

• Congestion Management Event (CME)

• Security Constrained Economic Dispatch (SCED)

• Manual Directives

• CLIPs

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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

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Typical Event Sequence to Mitigate Congestion

• The Reliability Coordinator (RC) contacts BA and or TO to confirm the SOL limit and the Real Time Loading of the flow gate

• 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

• NERC IDC will send out curtailment instructions and relief obligations to entities that need to take action

• 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)

• The Reliability Coordinator (RC) will request more relief in NERC IDC if necessary

• SPP Market will accomplish its relief through Security Constraint Economic Dispatch (SCED)

Communication

Issue TLR in IDC

Curtailments

Monitor

Re-issue TLR in IDC

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Typical Event Sequence – TLR Event1. Flow approaches or exceeds flowgate limit2. Reliability Coordinator calls TLR and requests relief from IDC3. NERC IDC prescribes Tag, Network and Native Load (NNL), and/or

Market Flow curtailments as appropriate4. Constraint Manager and CAT receive Target Market Flow from IDC5. SPP RC accepts TLR event in Constraint Manager and verifies that the

effective limit is appropriate6. SPP CAT will calculate appropriate schedule adjustments for those

schedules not curtailed by IDC and send to RTOSS 7. Flowgate is activated in next Security Constrained Economic Dispatch

(SCED)8. Market System will run SCED, attempting to keep flowgate flow below

effective limit9. RC continues to monitor flowgate flow and ask for additional relief as

necessary

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Transmission Loading Relief (TLR) Event

NERC IDCRC Issues TLR

SPPCATevery 15 min

SPPConstraintManager

SPP MOS SCEDSFT Topper / SPD Runs every 5 min

RTOSSscheduling

TargetMarket Flowto SPP CAT Adjusted

Schedules

Effective Limitof ConstraintSent to MOS

TargetMarket Flowto SPP ConstraintManager

Tag Curtailments

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2

5

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7Dispatch Instructions and NSI values

SPP RC accepts TLR

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Market FlowCalculator

Market Flow sentTo NERC IDC every 15 minutes

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ETAGGING NLS

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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

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Typical Event Sequence – CME 1. Flow approaches or exceeds flowgate limit2. Reliability Coordinator verifies in NERC IDC that there are no

curtailable Tags or Market relief from other Entities3. SPP RC calls a CME event in Constraint Manager and sets effective

limit4. SPP CAT will calculate appropriate schedule adjustments for those

schedules not curtailed by IDC and send to RTOSS 5. Flowgate is activated in next Security Constrained Economic

Dispatch (SCED)6. Market System will run SCED, attempting to keep flowgate flow

below effective limit7. RC continues to monitor flowgate flow and ask for additional relief

as necessary (lower effective limit in Constraint Manager)Note: 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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Congestion Management Tools used by SPP Reliability Coordinator

NERC IDCOATI

RC Issues CME

SPP CATOATIevery 15 min

ConstraintManager

SPP MOS SCEDSFT Topper / SPD Runs every 5 min

RTOSSSchedulingOATI

AdjustedSchedules

Effective Limitof ConstraintSent to MOS

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2

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6Dispatch Instructions and NSI values

1Market FlowCalculatorAlstom 15min

Market Flow sentTo NERC IDC every 15 minutes

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ETAGGING NLS

CME EVENT

CME event Send to CAT

CME = Congestion Management EventOnly results in re-dispatch by SPP Marketand schedule curtailments if Market isproviding counter flow to support financial schedules

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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

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CLIPSection 2

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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, time-consuming 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

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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 real-time 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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