1. ECE 476 POWER SYSTEM ANALYSIS
Lecture 24
Transient Stability
Muhammad Abdul Retha lefte Al-Badri
Department of Electrical and Computer Engineering

2. Announcements Be reading Chapter 11 and Chapter 12 thru 12.3
HW 10 is 11.4, 11.7, 11.10, 11.19, 11.20; due Dec 1 in class.
Project is due Thursday Dec 1 either in class or under my office door (343 Everitt)
Final exam is as given on the UIUC website. That is, Tuesday Dec 13 from 7 to 10pm here (218 Ceramics).
Final is comprehensive, with more emphasis on material since exam 2.
Three notesheets allowed (e.g., ones from previous two exams and one new notesheet)

3. 2007 CWLP Dallman Accident
In 2007 there was an explosion at the CWLP 86 MW Dallman 1 generator. The explosion was eventually determined to be caused by a sticky valve that prevented the cutoff of steam into the turbine when the generator went off line. So the generator turbine continued to accelerate up to over 6000 rpm (3600 normal).
High speed caused parts of the generator to shoot out
Hydrogen escaped from the cooling system, and eventually escaped causing the explosion
Repairs took about 18 months, costing more than $52 million

4. Dallman After the Accident

5. Outside of Dallman

6. Transient Stability Example
A 60 Hz generator is supplying 550 MW to an infinite bus (with 1.0 per unit voltage) through two parallel transmission lines. Determine initial angle change for a fault midway down one of the lines. H = 20 seconds, D = Use Dt=0.01 second. Ea

7. Transient Stability Example, cont'd

8. Transient Stability Example, cont'd

9. Transient Stability Example, cont'd

10. Exciter Block Diagram Example
Consider again the Example case, with an IEEE T1 exciter with Tr = 0, Ka = 100, Ta = 0.05, Vrmax = 5, Vrmin = -5, Ke = 1, Te = 0.26, Kf = 0.01 and Tf = 1.0. Determine the initial states. Initial value of Efd = and Vt =