# Power System Transients EE2027 ND11 6th Semester Question Paper

QUESTION PAPER CODE : 66183
B.E./B.Tech. DEGREE EXAMINATION, Nov/Dec - 2011
Sixth Semester
Electrical and Electronics Engineering
EE 2027 — POWER SYSTEM TRANSIENTS
(Regulation 2008)

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PART A — (10 x 2 = 20 marks)

1. Define 'Power system transients',
2. What are the effects of lightning?
3. What is the need for resistance switching?
4. What is meant by abnormal switching transients?
5. State the parameters and the characteristics of the lightning strokes,
6. What is the significance of tower footing resistance?
7. What are the specifications of a travelling wave?
8. Write down the expressions for reflection coefficient and refraction coefficient.
9. What is meant by kilometric fault?
10. Draw the Norton's equivalent circuit to model a capacitor in a network for EMTP calculation.

PART B — (5 x 16 = 80 marks)

11. (a) (i) What are the sources and effects of transients on power systems? Explain the internal causes for transients. (10)
(ii) Explain the significance of transient studies in power system planning. (6)
Or
(b) (i) Describe briefly about double frequency transients. (6)
(ii) Explain the various tj^pes of power system transients illustration, (10)

12. (a) (i) Explain load switching with equivalent circuit. (8)
(ii) Write a note on 'ferroresonance effect'. (8)
Or
(b) What is capacitance switching? Explain the effect of source regulation and capacitance switching with one and multiple restrikes. (16)

13. (a) (i) With neat sketches, explain the two different theories of charge formation in the clouds. (10)
(ii) What are the factors contributing to good transmission line design? (6)
(Or)
(b) (i) Explain the mechanisms by which lightning strokes develop and induce over voltages on overhead power lines.(10)
(ii) Explain the interaction between lightning and power system. (6)

14. (a) (i) Describe the transient response of sj^stems with series and shunt distributed parameters. (1
(ii) Explain the behavior of travelling waves at open circuited transmission line. (6)
(Or)
(b) (i) Explain Bewley's lattice diagrams with examples, (12)
(ii) Describe briefly about standing waves and Standing Wave Ratio(SWR), (4)

15, (a) (i) Derive the expressions for response and recovery voltage of a shorted line. (10)
(ii) Explain the causes of transients on closing and reclosing of transmission lines. (6)
(Or)
(b) Explain in detail about the switching surges on an integrated power system, (16)