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TOP and BA Responsibilities
SPP Wind WorkshopMay 30, 2013
Context
Sunflower and Mid-Kansas will give overview of their activities as example of how TOs and BAs operate in SPP
Other TOs and BAs encouraged to speak up with their own examples.
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Sunflower and Mid-KansasWho We Are
Sunflower is an electric G&T in western Kansas owned by six member cooperatives
Mid-Kansas is owned by five of the Sunflower member cooperatives, plus one additional member that is a wholly-owned subsidiary of the sixth Sunflower member
Mid-Kansas holds physical and contractual assets, but has no employees – agreement with Sunflower to operate and maintain all assets
Sunflower has assumed all compliance responsibility for Mid-Kansas and the member cooperatives
Sunflower and Mid-Kansas operate in a combined balancing area (SECI)
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Sunflower and Mid-Kansas Service Territory
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Sunflower and Mid-Kansas Transmission Facilities
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Sunflower(miles)
Mid-Kansas(miles)
Total(miles)
115-kV Line 1,009 733 1,742
138-kV Line 0 86 86
230-kV Line 0 193 193
345-kV Line 222 0 222
Total Transmission 1,231 1,012 2,243
Sunflower(number)
Mid-Kansas(number)
Total(number)
Substations 27 49 76
Sunflower and Mid-Kansas Statistics
SECI peak load – 1,156 MW (June 27, 2012)
Sunflower and Mid-Kansas owned generation – 980 MW
Sunflower and Mid-Kansas wind contracts – 280 MW (nameplate)
Wind installed in SECI footprint – approximately 1,445 MW (nameplate)o Over 900 MW of new wind added in last year within the SECI BA
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SECI Balancing Area
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Sunflower Registered Functions –Typical for SPP TOs
Balancing Authority
Transmission Owner
Transmission Operator
Generator Owner
Generator Operator
Distribution Provider
Load Serving Entity
Resource Planner
Purchasing Selling Entity
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Balancing Authority ResponsibilitiesHow Sunflower Meets
Balance resources with load to control frequencyo Monitor and control Area Control Error (ACE)o Ensure adequate Regulation Reserves (up and down) are maintainedo Meet NERC Control Performance Standards (CPS1 and CPS2)o Sunflower balances 445 MW (nameplate) of wind in the SECI BA
• 280 MW from contracts• 165 MW from balancing agreements• Other wind in SECI BA is pseudo-tied out• Typically carry 10 MW of up regulation and 10 MW of down regulation
Respond to disturbances to restore frequencyo Meet NERC Disturbance Control Standard requirementso Ensure adequate Contingency Reserves (spinning and supplemental) are
maintainedo Sunflower compliance met through participation in the SPP Reserve Sharing
Group
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Balancing Authority Responsibilities
Respond to capacity and energy emergencieso Maintain adequate capacity at all times to cover load and reserve
requirementso Develop and implement plans to address capacity and energy shortfallso Sunflower monitors capacity position each hour to ensure firm capacity
position is maintained above load plus operating reserves minus wind generation
Plan to meet voltage and/or reactive power limits, including the deliverability/capability for any single contingency
Upon implementation of SPP Integrated Marketplace, BA responsibilities will shift to SPP
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Transmission Owner Responsibilities
Develop and implement facility connection requirements
Develop and implement vegetation management program
Develop and implement facility rating methodologyo Operating time frame Sunflower Facility Ratings:
• Operate indefinitely below Normal Rating
• Operate for up to four hours between Normal and Emergency Rating
• Operate for no more than 30 minutes above Emergency Rating
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Transmission Owner Responsibilities
Implement an Underfrequency Load Shedding System (UFLS) per SPP RTO requirements
Set relays per SPP and RTO requirements
Develop and implement maintenance and testing program for Protection Systems, UFLS, Undervoltage Load Shedding Systems, and Special Protection Systems
Identify misoperations associated with Protection Systems and Special Protection Systems and develop corrective action plans
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Transmission Operator Responsibilities
Establish and communicate System Operating Limits
Monitor and control voltage levels and real and reactive power flows
Operate within all identified operating limits (IROLs and SOLs)
Operate to prevent the likelihood that a disturbance, action, or inaction will result in an IROL or SOL violation
Operate the transmission system to ensure instability, uncontrolled separation, or cascading outages will not occur as the result of the most severe single contingency
Take actions as required to alleviate operating emergencies including curtailing transmission service or energy schedules, operating equipment, and shedding load
Coordinate outage requests with other TOPs
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Shared BA and TOP Responsibilities
Coordinate current-day, next-day, and seasonal operations with neighboring BAs, TOPs, and the RC
Plan to meet forecasted load, system configuration, generation dispatch, interchange scheduling, and demand patterns
Plan to meet unscheduled changes in system configuration and dispatch (at a minimum N-1 contingency planning)
Conduct current-day, next-day, and seasonal studies to determine SOLs and update studies as required to reflect current system conditions
Plan to operate below all SOLs and IROLs (N-1 Contingency planning)
Comply with reliability directives issued by the RC
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Shared BA and TOP Responsibilities
Sunflower completes current-day, next-day and seasonal BES Studies and on an as-needed basis due to real time system changes, to identify N-0 and N-1 thermal overloads and voltage violations within the Sunflower/Mid-Kansas footprint
Results of studies are used to identify the need for mitigation plans to address any identified issues
Sunflower utilizes the SPP real time contingency analysis as an additional tool to monitor and evaluate N-1 overloads on Sunflower and Mid-Kansas facilities based on a pool-wide assessment of current operating conditions
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Example Study and Mitigation Plan
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NERC Alert
and Impact in SPP
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Facility Rating NERC Alert
APPLICABLE TO ALL SPP TOsOn October 7, 2010 NERC issued a facility ratings alert to transmission facility owners to evaluate actual field conditions vs. original design conditions in the determination of Facility Ratings
Alert included a requirement for each entity to assess whether actual field conditions conform to design tolerances specification in the conformance with entity’s Facility Rating Methodology
Facility assessments were to be prioritized over a three-year period with assessment of the highest priority facilities to be completed by the end of 2011, medium priority facilities by the end of 2012, and low priority facilities by the end of 2013
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Facility Ratings NERC Alert
Assessments should identify situations where actual conductor clearances are not within design tolerances and do not meet code clearances
Such findings should be coordinated with the RC and an interim mitigation plan should be developed to address the findings and identify actions required to maintain reliabilityo Such actions could include de-rating of the impacted facility until the
problem is fixedo Consideration should be given to optimizing the overall robustness and
reliability of the bulk power system during the remediation period o Remediation that takes more than one year after identification requires
approval from the Regional Entity
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System Constraints in SPP“Perfect Storm”
20
Discrepancies found during NERC Alert inspections result in de-rates to Facility Ratings and constrain the system more than normal
Outages required to remediate NERC Alert findings change system topology which may further constrain the system
Multiple Transmission Owners completing NERC Alert inspections and remediation activities simultaneously add further potential for system constraints
Outages to support previously planned construction work associated with projects identified through the SPP planning process and generation interconnection and transmission service, as well as Member and third party delivery point requests add additional constraints
Large amount of wind generation added over past year adds to loading on already constrained transmission facilities (pseudo-ties help with balancing, but not physics)
Following slides show how SECI deals with congestion
What can we do as BAs? As TOs? As a region?
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“Perfect Storm” – Now What?
Congestion Management Processfrom Sunflower’s Perspective
Risk for congestion is highest when wind output is high during low load periods
When congestion occurs, Congestion Management Events (CMEs) are utilized by SPP to redispatch online dispatchable resources through the market system
o Market Locational Imbalance Prices (LIPs) have experienced significant volatility as wind has been added to the system
o Most of Sunflower’s gas resources are typically dispatched to minimum load, so redispatch that involves reducing output from these resources is often not possible or effective
o Sunflower’s Holcomb 1 coal-fired unit, which has historically experienced very little dispatch movement as a base load resource, has experienced significant cycling over the past several months as a result of CMEs and LIP volatility
SPP’s remaining tool – out of market curtailments 22
Holcomb 1 Dispatch
23
Other Elements of Perfect Storm
Generator interconnection and transmission service study processes may not identify all system loading issueso In interconnection studies, upgrades not assigned to Customers
for all wind on at 100% nameplateo Studies start with “system intact” before running ‘n-1’. (no
maintenance outages accounted for)o NERC alerts may not be accounted foro Should studies be changed?
24
Other Elements of Perfect Storm
No load / Light load o High voltageo Lack of voltage control when wind generation is not producingo No reactive control/capabilityo May require opening of interconnection to control network
voltage Effects of generator outages due to EPA rules FERC Separation of Functions Rules
o Constrain communication/collaboration among TOs and generatorso Using SPP to coordinate is key
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NEXT STEPS
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How Do We Minimize Wind Curtailments?
Investigate ways to speed up process for reducing wind output to protect reliabilityo Change from proactive N-1 mitigation to reactive? Can this be done
short of implementing Special Protection Systems?
Reconsider process for reviewing and approving transmission facility outageso Should pre-contingent curtailment of wind continue to be an acceptable
mitigation for violations identified when studying planned outage impacts?
Find a better way to coordinate required NERC Alert work from a SPP region-wide perspective to minimize wind impacts while continuing to protect reliabilityo Would require more input from SPP (FERC Separation of Functions
Rules)
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How Do We Minimize Wind Curtailments?
Investigate ways to factor in economic impact of wind curtailmento On generation owners – loss of PTCo On Project off-takers - potential make whole paymentso How and can this be incorporated into CME process?
Moving projects from NDVER to DVERo Are projects capable?o What are the potential costs?o Are there control system changes required?o What is the required time frame to convert?
How will this change with Integrated Market? What else?
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