2. ITP20 Flowgate Selection Introduction
Timothy Miller
July 21st, 2010 TWG Teleconference

3. Flowgate Simulation Impact
In the economic simulations flowgates are the only flow control mechanism
Line limits are not heeded by default
Penalties associated with an overload provide control
Manage the economic dispatch
Key to a reasonable economic solution
Background warm-up information – why it’s important
Flowgate list will be longer than that of the NERC IDC
270 monitored by Operations
500 needed by ITP processes
Not related to the annual review – not even close
Don’t dwell on economics

4. Selecting Reasonable Flowgates
Staff is developing flowgates based upon the ITP 20 Year Assessment Scope document
Preferred outcomes
Spreadsheet listing the flowgates
Charts summarizing the simulated data
Maps showing congestion
The reason we are here today

5. Flowgate Selection Criteria

6. Flowgate Selection Criteria
Starting Point
NERC Book of Flowgates
Additional criteria
345 kV Contingencies
115+ kV Monitored Elements
Evaluate 8,760 hours
From the ITP scope:
The initial flowgate list will be the then-current NERC Book of Flowgates (BoF)
Flowgate studies will be run over 8760 hours (1 year)
Flowgate studies will be performed on each future case
For the flowgate analysis, contingencies 345 kV and up in SPP, including autotransformers stepping down from 345 kV and up, will be selected
For the flowgate analysis, monitored elements 115 kV and up in SPP will be selected
A minimum of one iteration will be performed in the flowgate study
Unless other information is available, the flowgate ratings will be selected based upon the Rate A (normal rating) and Rate B (emergency rating) in the powerflow model.
This analysis will focus on a 2030 economic model

7. Flowgate Selection Criteria
Additional criteria
SPP devices and tie-lines
60 hour threshold
Rate A & Rate B unchanged
Three iterations
From the ITP scope:
The initial flowgate list will be the then-current NERC Book of Flowgates (BoF)
Flowgate studies will be run over 8760 hours (1 year)
Flowgate studies will be performed on each future case
For the flowgate analysis, contingencies 345 kV and up in SPP, including autotransformers stepping down from 345 kV and up, will be selected
For the flowgate analysis, monitored elements 115 kV and up in SPP will be selected
A minimum of one iteration will be performed in the flowgate study
Unless other information is available, the flowgate ratings will be selected based upon the Rate A (normal rating) and Rate B (emergency rating) in the powerflow model.
This analysis will focus on a 2030 economic model

8. Unique Operational Flowgates

9. Unique Operational Flowgates
SPP-SPS interfaces
Staff recommends redefining flowgate as individual OTDF flowgates due to extensive upgrades in place by 2030.

10. Unique Operational Flowgates
GGS Stability Interface
Staff recommends continued use of this interface

11. Example Flowgate Simulation Data

12. Flowgate Example Results
Violations avoided by flowgate definition
Before & After
By Area
By month

13. Effect of Adding Flowgates
Not Normalized for the number of lines in each area

14. Flowgate Example Results
Flowgate congestion
Limit is respected
Prices change
Violations should be minimized by adding flowgates

15. Congestion by Shadow Price Impact
Data to be provided by SPP

16. Next Steps Staff to provide TWG draft results:
Top 10 congested flowgate summary
Exhaustive flowgate spreadsheet
Hours Congested & Avg. Shadow Price
Results of contingency scans
Requesting TWG endorsement of flowgates in August teleconference

17. Timothy Miller Planning Engineer 501-614-3357 tmiller@spp.org