MonthlyTCR Calculation

DRAFT 3James J. Teixeira

05/11/02Also 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 Queries VB

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

Process Overview

• Outage Scheduler• PSSE Version 26.2.3 (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 4.02.02 (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 Group 1

Outage Group 2

Beginning of Month

End of Month

Study both periods, select group with most impact on OC0 - CSC TTC.

Line 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 7.5.2.2)

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 AdjustmentERCOT 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 7.5.2.2)

n

1iii AWSF)](SF*[L Where:

n = total number of load busesL i = MW load at bus iSF i = ind. shift factor at bus IAWSF = corresponding zonal shift factor for bus i

TCR Calculation Results

COMMERCIALLY SIGNIFICANT CONSTRAINT #1 - GRAHAM TO PARKER

COMMERCIALLY SIGNIFICANT CONSTRAINT #2 - SANDOW TO TEMPLE

COMMERCIALLY SIGNIFICANT CONSTRAINT #3 - STP TO DOW

COMMERCIALLY SIGNIFICANT CONSTRAINT #4 - PARKER TO GRAHAM

Zonal Flow Direction WEST TO NORTH SOUTH TO NORTH SOUTH TO HOUSTON NORTH TO WEST

Limiting Element1624 LEON 138 1640 LNGLVL M 138 1

3430 SANDOW 138 3675 ROGERS 138 1

42500 DOW345 5 345 42510 DOW138 8 138 A1

1640 LNGLVL M 138 1641 STPHVIL 138 1

Contingency

GRAHAM-PARKER & GRAHAM-PARKER 3247

TEMPSSLT-SANDOW & TEMP SS-SANDOW 3443

P_H_R_ 5-DOW345 5 & DOW345 5-WAP_C710 3715

GRAHAM-PARKER & GRAHAM-PARKER 3247

Zonal ATC 1380 -462 -1674 245Ties TTC 1130 792 1421 366OC0 - CSC TTC -double circuit line flow - MW 726 638 756 237delta CSC - adjustment for Settlement Calculation 57 -46 -54 -57total TCR (following Protocols) 783 592 702 180

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 WWW.ERCOT.COM/Participants/CSC/

Questions?