Anna University Chennai B.E Electrical and Electronics Engineering Be.degree examination, november/december 2009,ee 1003 - power systems transients Question paper

BE.DEGREE EXAMINATION, NOVEMBER/DECEMBER 2009
Eighth Semester(Regulation 2004)

Electrical and Electronics Engineering
EE1003 - POWER SYSTEMS TRANSIENTS
(Common to BE. (Part-Time) Seventh Semester Regulation 2005)
Time.: Three hours Maximum: 100 marks.
Answer ALL questions.

PART A- (10X2=20 marks)

1.What are the causes of transients?
2.Name the different types of transients.
3.Define Restriking Voltage.
4.What is meant by current chopping?
5.What are the protective devices used to protect power system equipments against
lightning?
6. What are the properties of a good transmission line?
7. What is the importance of Bewley's Lattice Diagram?
8. Draw the equivalent circuit for an infinitesimal element of a line.
9. Mention any four causes of switching surge.
10. State the applications of EMTP.

PARTB-(5 x 16= 80 marks)

11.(a)(i)Write a short note on voltage surge.(8)
(ii)Give a brief note about the importance of transient study in planning.(8)

or
(b)(i)What are the various types of transients?(8)
(ii)Discuss about the effects of transients on power systems.(8)

12.(a)Derive an expression for the transient currents.in a RLC circuit when:
(i)R=0(8)
(ii)R2/4V=1ILC(8)

Or

(b) Write short notes on :
(i) Current chopping(8)
(ii)Resistance Switching(8)

13.(a) i)Write short notes on cloud formation.(8)
ii)Explain about grounding a line structure.(8)

Or

(b)(i) Explain the mechanism of Lightning discharge.(8)
(ii) List some characteristics of Lightning strokes.(8)

14. (a)Explain the steps involved in Bewley's Lattice diagram construction with an example. (16)

Or

(b)Obtain the value of current in a transmission line considering its series and shunt lumped parameters.(16)

15. (a) Explain in detail abOut the switching surges in a power system.(16)

Or
(b)Explain in detail how EMTP is used for the computation of Transients in power system(16).