JNTU Kakinada B-Tech 4-1 HVAC AND DC TRANSMISSION R13 March 2018 Question Paper

IV B.Tech I Semester Supplementary Examinations, February/March – 2018
HVAC AND DC TRANSMISSION (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) List the Advantages of EHV AC Transmission? [4]
b) Explain the properties of bundled conductors. [4]
c) List the advantages of HVDC transmission. [4]
d) Explain the Principle of Dc link Control? [4]
e) What are different sources of reactive power .Explain? [3]
f) What is the difference between characteristic and non- characteristic
harmonics?
[3]

PART ?B (3×16 = 48 Marks)2. a) Why is EHVAC transmission system required? What are the problems associated
in EHVAC system.
[8]
b) A power of 12,000 MW is required to be transmitted over a distance of 1000 Km.
At voltage level 750 KV, determine (i) The possible number of circuits required
with equal magnitudes for sending and receiving end voltages with 30
o
phase
difference (ii) The current transmitted and (iii) The total lines losses.

[8]

3. a) What factors affect the generation of audio noise? Explain the characteristics of
audio noise. Derive the expression for the sound pressure level if there are N
sources of audio noises.

[8]
b) Explain the different corona loss formulas that are used for evaluation in an
EHVAC system.
[8]

4. a) List and explain the inherent problems that are associated with HVDC system. [8]
b) Explain in detail about the constant extinction angle (CEA) control
characteristics of the converter.
[8]

5. a) Explain the operation of 6 pulse converter with relevant waveforms and hence
derive the equivalent circuit
[12]
b) Write a brief note on special features of a converter transformer. [4]

6. a) What are different sources of reactive power? Explain them briefly? [8]
b) What are the reactive power requirements in steady state? Also write about
alternate control strategies in HVDC systems?
[8]

7. a) What are the various sources of harmonics generation in a HVDC line?
Describe how a single tuned filter can be designed for a HVDC system?
[10]
b) Explain the effect of pulse number on harmonics? [6]
Code No: RT41022
Set No. 1
R13
1 of 1