Visvesvaraya Technological University (VTU) 2005 B.E Electrical and Electronics Engineering / ELECTRICAL POWER TRANSMISSION AND DISTRIBUTION (2) - Question Paper

Page No... 2    EE53

6.    (a) What is corona? Derive expressions for the disruptive critical voltage and

visual critical voltage.    (8 Marks)

(b)    What are the effects of corona?    (3 Marks)

(c)    Find the corona characteristics of a 110 kV, 50 Hz. 3. phase transmission line 175 km long consisting of three 1 cm dia stranded conductors arranged in the form of a delta with a spacing of 3m. The barometric pressure is 74cm of mercury and temperature 26C. Surface factor is 0.85. For local corona surface factor is 0.72 and 0.82 for general corona.    ( Marks)

7.    (a) A ring main D.C distributor is as shown

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Feeder cross section of OA is ay and the cross section of distributor ABCD A is a j. If it is desired that the minimum potential in the ring at any load point

shall not be less than 230 V and the copper in the conductors is minimum, find the ratio of ay to a

- Take specific resistance of copper = 1.73 pH - cm. Voltage of feeding point A is 240V.    (10 Marks)

(b) A 3 phase 66 kV station supplies loads as shown. Calculate the current in each section. Power factor of loads are referred to point A.    (io Marks)

8. Write short notes on any FOUR :

i)    Advantages of high voltage transmission

ii)    Testing of cables

iii)    Stringing chart and its application

iv)    Radial and ring main distributors

v)    Transposition of transmission lines.

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Attachment: visvesvaraya-technological-university--vtu--2005-b-e-electrical-and-electronics-engineering-41901-1.jpg

Earning:   Approval pending.