Monthly TCR Calculation DRAFT 3 James J. Teixeira 05/11/02 Also review ERCOT Protocols Section 7 for more details and additional data

Settlement Adjustment Data Ties Flow CSC Flow TCR.ERCOT.COM Outage Scheduler Query for Study Month to CSV MS Access – Filter outages to be considered PowerWorld Simulator Import RAWD into PowerWorld Simulator Calculate Shift Factors for each bus for each CSC (1 line of DCKT) MS Access Tables and QueriesVB Scripts PSSE SSWG Case Selection Apply IDEV’s Apply Outages Change Zone Numbers to Reflect CM Zone Create PSSE RAWD Create PSSE SAV Case Zonal ATC MS Excel – MON02_AWSF MUST MUST – Load SAV Case Multiple Transfers AC Based FCITC Calculation Monitored Elements Impact Analysis MS Excel – MON02_TTC Shift Factor/Case Data Process Overview

Outage Scheduler PSSE Version (Moving to Version 28) –Apply Outages –Change Zone Numbers to CM Zone Number PowerWorld Simulator Version 8.0 –Calculate raw Shift Factors –Copy/Paste raw Shift Factor and Bus Data to MS Access

Process Overview Cont’d MS Access –Set of Tables, Queries, and VB Scripts –Run VB Scripts to calculate AWSF MUST Version (Moving to Version 5.0) –Calculate First Contingency Incremental Transfer Capability (FCITC) –Monitored Elements Impact Analysis (Ties and CSC flows at FCITC)

Transmission Outage Scheduler Download Transmission Outages from Outage Scheduler –CSV format –Load into MS Access Determine Transmission Outages to use –No Generation Outages or Resource Plan Information Used –Transmission Outage of 5 days or more in Study Month –Group outages to find Period of Month with most/worst concurrent outages

Outage Grouping The modified seasonal base case for a particular month will be based on the most limiting situation within the corresponding month. This analysis takes into account all transmission outages of significant duration and impact … (Protocols )

PSSE Determine PSSE Seasonal SSWG On Peak Base Case to use Apply Applicable IDEV’s to Base Case to apply latest transmission updates to case –Supplied by TDSP’s Apply Selected Transmission Outages to Base Case Change Zone Numbers in Base Case with applied outages to CM Zone numbers Solve, Save, and Create RAWD Case also provides Online Generation Level for AWSF

PowerWorld Simulator Import RAWD into PowerWorld and Save In PowerWorld, calculate a set of raw Shift Factors for each bus for all four CSC’s using TLR Sensitivities –Use Norwood (PSSE Bus #2406) as Transaction Buyer –Calculate raw SF’s for one line of CSC double circuit and multiply by 2 later Copy raw Shift Factors and Bus data to Microsoft Access Tables

PowerWorld TLR Sensitivities

MS Access Run VB scripts to calculate all data found in MON02_AWSF.xls –Summation of Weighted Shift Factors –Average Weighted Shift Factors –Min, Max, Average, Std Deviation In MON02_AWSF.xls, run VB script to move data from Access to Excel

Contingencies/Limits Types Used –48 Phantom Single Multiple modeled elements out for single outage/fault –512 Double Only ones that result in cascade are considered as valid –All Single Branches 130 KV or greater Limits Used –Rate B –105 % if Graham – Parker or Sandow – Temple DCKT is the contingency Based upon TSDP determination –100 % Otherwise

MUST Load previously created PSSE save case into MUST Check/Modify MUST options to use 105% limit for applicable contingencies, 100% otherwise In MUST, run Multiple Transfers AC Based FCITC Calculation –AC is more accurate than DC Set up Study Transfers using Min of Subsystem MaxImport and MaxExport

MUST Cont’d Calculate Study Transfers Examine AC FCITC Multiple Transfers Report to determine lowest AC FCITC where the limiting element is a CRE or the Contingency is a CRE (Protocol 7.5.2) This number is the Zonal ATC found in MON02_TTC.xls

MUST Cont’d Run Monitored Elements Impact Analysis and set Transfer level to Zonal ATC and Contingency number to the corresponding contingency causing the Zonal ATC from the AC FCITC Multiple Transfers Report. Appropriate Ties and CSC Interfaces are defined in file 02cscinterface.mon Post-Shift Base Case flow Impacts on Ties and CSC interfaces are the Ties TTC and OC0 – CSC TTC found in MON02_TTC.xls

MUST Options - Cutoffs

MUST Options - Ratings

Settlement Adjustment ERCOT will determine the total quantity of TCRs for the monthly distribution by adjusting the corresponding modified seasonal base case CSC Limits by the following amount: for each CSC, the sum over all nodes of the product of the expected level of load at each node from the modified seasonal base case multiplied by the difference between the corresponding Shift Factor for that node and CSC and the Zonal Shift Factor. (Protocol ) Where: n = total number of load buses L i = MW load at bus i SF i = ind. shift factor at bus I AWSF = corresponding zonal shift factor for bus i

TCR Calculation Results

Posted Information TCR.ERCOT.COM –PTI PSSE save case and RAWD –MUST configuration files –MON02_AWSF.xls –MON02_TTC.xls –MON02_IM.xls & MON02LoadMappingCMzones.xls CSC Development Information at

Questions?