2. – 1Texas Nodal Texas Nodal Electrical Buses

3. – 2Texas Nodal Electrical Bus Definition as Proposed in NPRR 63 Electrical Bus A physical transmission element defined in the Network Operations Model that connects, using breakers and switches, one or more Loads, lines, transformers, generators, capacitors, reactors, and phase shifters to the ERCOT Transmission Grid where there is negligible impedance between the connected transmission elements. All Electrical Buses are designated by ERCOT and TSPs for modeling the electrical topology of the ERCOT Transmission Grid.

4. – 3Texas Nodal Example 1: Simplified Ring Bus Lines Disconnects Breakers No Electrical Buses

5. – 4Texas Nodal Example 2: Slightly More Complicated Ring Bus Lines Disconnects Breakers Electrical Buses

6. – 5Texas Nodal Example 3: Another Ring Bus Not Electrical Buses Electrical Buses

7. – 6Texas Nodal Example 4: Breaker and a half Not Electrical Buses Electrical Buses

8. – 7Texas Nodal Example 5: Tap with disconnects Electrical Bus

9. – 8Texas Nodal Example 6: Tap without Disconnects No Electrical Buses

10. – 9Texas Nodal Example 7: The Real World Electrical Buses

11. – 10Texas Nodal Example 8: The Real World Electrical Buses

12. – 11Texas Nodal Example 9: The Real World Electrical Buses

13. – 12Texas Nodal The End? Questions?

14. – 13Texas Nodal Electrical Buses and the Outage Scheduler Section 3.1.5.1- ERCOT Evaluation of Planned Outage and Maintenance Outage of Transmission Facilities 1. A TSP shall request a Planned Outage or Maintenance Outage for any Transmission Element in the Network Operations Model that requires the Transmission Element to be removed from its normal service. Proposed Transmission Planned Outage or Maintenance Outage information submitted by a TSP in accordance with this Section constitutes a request for ERCOT’s approval of the Outage schedule associated with the Planned Outage or Maintenance Outage. ERCOT is not deemed to have approved the Outage schedule associated with the Planned Outage or Maintenance Outage until ERCOT notifies the TSP of its approval under procedures adopted by ERCOT. ERCOT shall evaluate requests under Section 3.1.5.11, Evaluation of Transmission Facilities Planned Outage or Maintenance Section 2 - Definitions and Acronyms Transmission Element: A physical transmission facility that is either a Electrical Bus, line, transformer, generator, load, breaker, switch, capacitor, reactor, phase shifter, or other similar device that is part of the ERCOT Transmission Grid and defined in the ERCOT Network Operations Model.

15. – 14Texas Nodal Electrical Bus Definition as Proposed in NPRR 63 Electrical Bus A physical transmission element defined in the Network Operations Model that connects, using breakers and switches, one or more Loads, lines, transformers, generators, capacitors, reactors, and phase shifters to the ERCOT Transmission Grid where there is negligible impedance between the connected transmission elements. All Electrical Buses are designated by ERCOT and TSPs for modeling the electrical topology of the ERCOT Transmission Grid.

16. – 15Texas Nodal Outage Scheduler – Line Associations Choose this line Station A Station C Station B

17. – 16Texas Nodal Outage Scheduler – Line Associations Choose this line Station A Station C Station B

18. – 17Texas Nodal Outage Scheduler – Transformer Associations Choose this Transformer Station A Station C Station B

19. – 18Texas Nodal The End? Questions?