Automated Model Builder (AMB) and AFCs Presented By: Nate - PowerPoint PPT Presentation

2008 ITO LG&E/KU Stakeholder Meeting Automated Model Builder (AMB) and AFCs Presented By: Nate Schweighart TVA Transmission Reliability Engineering 1

AFC Methodology-Modeling Process AFC Methodology-Modeling Process • Every day TVA creates a large number of transmission models • 48 – Next 48 hourly cases every hour • 146 – hourly cases four times a day • 35 – daily cases four times a day • 18 – monthly cases once a day • Total 1894 cases per day 2 Transmission Reliability Engineering

AMB – Automated Model Builder AMB – Automated Model Builder MMWG based cases Generation Outages, Generation Dispatch, Load Forecast, Tag AMB Dump, Path definitions, Flowgate Definitions, etc… Transfer Distribution Initial AFCs Factors TVA FTP Site 3 Transmission Reliability Engineering

Case Conditioning Case Conditioning • Updating topology • Removing any transmission outages, Fixing N.O line list • Removing generation outages • Correcting interchange • Account for base case transactions in the process • Equivalize DC bubbles, superfluous areas • Correcting Control Area numbering • Making cases solve AC for applicable horizons • Making sure bus naming matches IDC • Checking log files 4 Transmission Reliability Engineering

Input Data Input Data • Transmission Outages – Comes from SDX and updated every hour – Includes all LGEE neighbors • TVA, AEP, OVEC, CIN, SIGE, BREC, EKPC, CE – plus select tier 2 entities • Generation Outages – Comes from SDX and updated every hour – Includes all LGEE neighbors • TVA, AEP, OVEC, CIN, SIGE, BREC, EKPC, CE – plus select tier 2 entities • Load Forecast – Comes from SDX and updated every hour – Includes all LGEE neighbors • TVA, AEP, OVEC, CIN, SIGE, BREC, EKPC, CE – plus select tier 2 entities • Tags – Comes from NERC Tag Dump file and generated every hour • Path Definitions – Static file changes only when paths change 5 Transmission Reliability Engineering

Input Data Input Data • Flowgate Definitions – Updated to reflect flowgate definition changes • Generation Block Dispatch – Updated to reflect changes in generation dispatch • Base cases • Flowgate monitor files • Area subsystem files • Normally open line list • Base case transaction static files 6 Transmission Reliability Engineering

Calculating AFCinit and TDFs Calculating AFCinit and TDFs • Make topology changes – line outages, generation outages • Use generation dispatches or scale load in areas to match load forecast • Solve cases • Calculate all areas’ generation to load impact on flowgate list to obtain Initial AFCs – Initial AFCs: the remaining flowgate capacity considering base case flows from the case creation process • Use Path Definition file to determine distribution factors for all Path combinations on all flowgates 7 Transmission Reliability Engineering

AFC Data Exchange AFC Data Exchange • Initial AFC’s and TDF’s for all product types and horizons are exchanged daily for a total data transfer of 491MB of data • The hourly non-firm process data which is exchanged hourly covering the next 48 hours makes up over 406MB of the total data transfer 8 Transmission Reliability Engineering

AFC Derivation AFC Derivation • AFC are derived from the flowgate rating. • AFC = flowgate rating – base case flow impacts – TRM – CBM – Existing Transmission Commitments (ETC) impacts. TVA’s Part • ATC = Most limiting (AFC / Associated TDF) 9 Transmission Reliability Engineering

Non-Firm Scheduling Horizon Non-Firm Scheduling Horizon Noon Noon Midnight Noon Noon Midnight Midnight Schedules Reservations 1 pm Reservations Schedules 6pm Reservations Schedules 4 am Reservations Schedules Noon Reservations Schedules 1 pm At 12 noon daily, non-scheduled transmission capacity is released by using schedules instead of reservations. Reservations are used beyond midnight of the next day. 10 Transmission Reliability Engineering

TVA AFC Process Enhancements TVA AFC Process Enhancements • Switched to new AMB engine called TARA created by PowerGem – New engine has more robust solution methods – Cases can be created and solved much quicker – Vendor continues to upgrade software as new enhancements are created 11 Transmission Reliability Engineering

Transmission Reliability Engineering Questions? Questions? 12