NERC Congestion Management

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NERC Congestion Management

• Congestion Management
• Option 3
• Vendor Meeting
• Julie Pierce NERC IDCWG Chair

2
Objectives

• History of EI Congestion Management
• Overview of IDC functionality
• Overview of NERC TLR Procedure

3
Congestion- What is it?

• A Few Power System Operator Answers
• Overloading the Transmission System
• Lines are on Fire
• Too Much Generation for the Load
• Too Many MWs on the Lines
• for the given Topology

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Congestion Management

• Basic Methods Available
• Re-Dispatch
• Moving generation to change the flow of energy on
  the transmission system
• Reconfiguration
• Changing the topology of the transmission system
  to create the desired system flow

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Transmission Flow - MWs
Maximum Output 500 MW
Generator A
Generator to Load MWs for BA(s) (Not in MISO or
PJM)
Interchange Transactions (E-Tags) Market Flow
for MISO and PJM
Parallel Flow Caused by the Tags and GN to Ld
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History NERC Congestion Mngt

• Prior to NERC Regional Congestion Management
• Localized Congestion Management Procedures used
  to mitigate the overloading of lines
• Minimal number of operating agreements between
  NERC Reliability Regions
• No visibility of Parallel Flows caused by all the
  MW transactions and local load serving taking
  place on the Eastern Interconnect

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History NERC Congestion Mngt

• Visibility of Parallel Flows was increased with
  implementation of Electronic Tagging of MW
  transfers from on balancing area to another.
• Implementation of E-tagging and NERC Policy 3
• In conjunction with this effort was the NERC
  Regional Congestion Management proof of concept

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History NERC Congestion Mngt

• Idea was that Congestion Management should be
  done on a larger regional basis due to the
  interconnection characteristics and parallel
  flows present on the system
• Assigning responsibility to those entities that
  were causing parallel flows was necessary to
  maintain reliability and equity during loading
  events

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History NERC Congestion Mngt

• Transmission Loading Relief Procedure (TLR)
• NERC Policy 9 and associated Appendices
• Procedure defines several levels of transmission
  loading and mechanisms to remove MWs from the
  system.
• Goal is to maintain reliability while removing
  MWs from the system in an equitable manner

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History NERC Congestion Mngt

• Transmission Loading Relief (TLR)
• Implemented in 1999
• Interchange Distribution Calculator (IDC) created
• Adopted and used heavily by the majority of the
  Eastern Interconnect
• Created Visibility of Eastern Interconnect MW
  Impacts due to Industry day to day business
• Provided a useful analysis tool for Control Areas
  and Reliability Entities for Emergency and
  Non Emergency situations

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Interchange Distribution Calculator

• Basic Functionality
• Impact Calculation of MW Transfers
• Generation to Balancing Area Load
• Scheduled Transfers from one Balancing Area to
  another
• Define Responsibility For Loading events
• Whos MWs are on the transmission line(s) of
  interest
• How Much Relief is Required? Operator Input
• Prescription for achieving relief using TLR
  Process Rules

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Interchange Distribution Calculator

• Basic Functionality (Continued)
• Communications
• Transmit Responsibilities and Relief
  Prescriptions to affected parties
• Accept and display feedback
• Allow Visibility and Transparency into the impact
  of potential MW transfers and actual taking place

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IDC System Flow Diagram
Request for Relief
Flowgate Definition
Prescription for relief
Model of System
IDC
Current Outages
Software
Users Reliability
Market Flow from MISO/PJM
Authorities and
Balancing Areas
ETAG Transactions
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Transmission Loading Relief

• Summary of TLR Levels
• 1 - Warning
• 2 - Hold
• 3A - Reallocate Non-Firm
• 3B - Curtail Non-Firm/Halt Non-Firm Starting/Inc
• 4 - Reconfigure
• 5A - Reallocate Firm
• 5B - Curtail Firm
• 6 - Emergency
• 0 - TLR End

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Congestion Management and Option 3
Calculating Impacts Of Visible Transfers
Assigning Event Responsibility
Option 3 Addresses New Method To assign
Responsibility For loading events
Defining Appropriate Relief Prescription
Option 3 Addresses other Alternatives to
Reliably and Economically get MWs off The system.
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Questions ?