PWS Transient Stability Implementation

1. PWS Transient Stability Implementation PowerWorld Program Users Work Group August 23, 2011 Presented by John Gross Phone: 509-495-4591 Email: john.gross@avistacorp.com

2. Practical Use of PowerWorld Transient Stability • Don’t get distracted… • What are the Transmission Planner requirements? • The old way of doing things • Simple example of PWS Transient Stability • The new way of doing things (possibilities are unbounded) • Examples

3. Requirements – Why Transient Stability Studies? • Demonstrate through valid assessment… • TPL-002 - Category B.2: Transmission Circuits, Avista simulates • 115 kV lines - 70 x 2 • 230 kV lines - 26 x 2 • 12 cases = 2304 • Evaluate WECC Criteria • Document results! • Files? – do you have enough • Plots? – how did they wiggle • Tabular? – flag violations

4. The Old Way (PSLF) • Create switch files for each contingency • Maintain list to call each contingency • Separate “simulation” and “results processing” routines • User written code • Provides flexibility • Lacks uniformity and structure – planning vs. coding • Avista wrote programs to: • Evaluate WECC criteria • Implement arming RAS and RAS functioning • 6 months of two staff members time to implement

5. Example Switch File

6. Example Contingency List File All of this just to get channel files – still need to evaluate Criteria!

7. Worst Case Analysis Program • Separate file for each contingency • Summary file for contingency list • Difficult to summarize for system assessment • User written program could be modified to give desired result…

8. Example PSLF File and Results • D:\2011\PWPUWG\PSLF

9. Using PowerWorld Simulator Transient Stability • Familiar dialogue – not user written code • Simple navigation - easy to view models and parameters • Quickly define contingencies • Single aux file can contain: • Contingency definitions • Plot descriptions • Solution and results storage settings • Avista provided many requirements for TS features

10. Easy to Get Started • Open a case… nothing new here • Read dynamics data • Did you check for errors with other program? • PowerWorld makes it easier to check errors but time is limited... • Validate/AutoCorrection typically works good enough • Define what you want to simulate • Pick what you want to save • Run Simulation and look at results • Show Double Palo Verde Example

11. Using PWS for Compliance Studies • Apply consistent contingency definitions and settings • Monitor WECC Criteria using Transient Limit Monitors • Documentation • Save all “channel” files – shows you did something • How much data do you save? • Plots – automatically saved for each contingency • Export Transient Limit Monitor Violations – is this enough? • Document the contingencies you study • Internal policy or procedure • Aux file containing contingency definitions

12. Demonstrate Using PWS TS Features

13. Example of WECC Criteria Monitor Documentation • Actual compliance documentation will show results for: • Several cases • Hundreds of contingencies • Category B, C, and D criteria • Possibly internal criteria