# ECE 476 POWER SYSTEM ANALYSIS Lecture 24 Transient

- Slides: 10

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

Announcements l l 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 10 pm here (218 Ceramics). l l Final is comprehensive, with more emphasis on material since exam 2. Three notesheets allowed (e. g. , ones from previous two 1 exams and one new notesheet)

2007 CWLP Dallman Accident l 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). l l l 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 2

Dallman After the Accident 3

Outside of Dallman 4

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 = 0. 1. Use Dt=0. 01 second. Ea 5

Transient Stability Example, cont'd 6

Transient Stability Example, cont'd 7

Transient Stability Example, cont'd 8

Exciter Block Diagram Example • Consider again the Example 11. 10 case, with an IEEE T 1 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 = 2. 9135 and Vt = 1. 0946 9