The Network Model Management System By Joel Koepke ERCOT, Network Model Engineer

1. The Network Model Management System By Joel KoepkeERCOT, Network Model Engineer EMS Users Conference 1 September 23rd – 26th

2. AGENDA • About ERCOT • NMMS Overview • ERCOT CIM • Submission of Model Updates • ERCOT as the Registration Authority EMS Users Conference 2 September 23rd – 26th

3. About ERCOT • Grid covers 75% of Texas’ land and serves 85% of Texas’ load • 38,000 miles of +60kV transmission lines • 750 miles of 345kV lines added since 1999 • 70,000 MW of total resources • 26,000MW of generation added since 1998 • 63,056 MW peak load (8/17/2006) • 5400 Bus Model ERCOT EMS Users Conference 3 September 23rd – 26th

4. Market Redesign – Going Nodal! Zonal Market • Insufficient price transparency • Resources grouped by portfolio • Indirect assignment of local congestion • 5 CMZ Zones Nodal Market • Improved price signals • Improved dispatch efficiencies • Direct assignment of local congestion • 4000 Nodes EMS Users Conference 4 September 23rd – 26th

5. The Network Model Management System

6. NMMS The Network Model Management System • What is it? • The system that will perform all modeling functions in the Nodal market. • Submission of modeling changes • Storage and validation of the model data (Operations and Planning) • Creation of all required models for downstream applications • Why? • The Nodal Protocols contain requirements which significantly change ERCOT’s current modeling process • Need “Future” models • Modeling should be consistent (Operations vs. Planning) • Must accept CIM inputs and produce CIM outputs EMS Users Conference 6 September 23rd – 26th

7. NMMS - Overview EMS Users Conference 7 September 23rd – 26th

8. NMMS - Key Features • Incremental Changes– All model updates are stored as a packet of database modification commands • Effective Date– Each incremental change is given an energization date • Future Models – Applying dated incremental changes to a base model creates a model representing a future date Time-Based Modeling EMS Users Conference 8 September 23rd – 26th

9. Time Based Modeling Example – Part 1 A time based model as it appears on February 15th. Wanted: A set of models that represent April 1st through April 30th. EMS Users Conference 9 September 23rd – 26th

10. Time Based Modeling Example – Part 2 First, build a base model representing April 1st. Second, gather all incremental changes during the desired date range. EMS Users Conference 10 September 23rd – 26th

11. Time Based Modeling Example – Part 3 EMS Users Conference 11 September 23rd – 26th

12. NMMS Future Model Creation • Creating an Operations Model • The model is created by applying all the incremental changes that occur between the current and future dates to the base model • Creating a Planning Model • An Operational model is created for the future date • This model is passed through a “topology processor” to change the breaker/switch model into a bus/branch Planning model • Planning incremental changes are then applied to the model to make it reflect the future date • Consistent Data – Converting an Operational model guarantees consistency EMS Users Conference 12 September 23rd – 26th

13. NMMS Common Information Model (CIM) • What is it? • An information model that describes real-world objects and their interrelations within the electric power industry • A format for exchanging information • Why is it important? • Provides a standard way of depicting data • Enables the integration of multiple applications and vendors • Facilitates bulk and incremental model exchange EMS Users Conference 13 September 23rd – 26th

14. NMMS – Detailed Overview EMS Users Conference 14 September 23rd – 26th

15. Questions? EMS Users Conference 15 September 23rd – 26th