Download PTU (Punjab Technical University) B.Tech (Bachelor of Technology) / BE (Bachelor of Engineering) 2021 January EE 7th Sem 71943 High Voltage Direct Current Transmission Previous Question Paper
Total No. of Pages : 02
Total No. of Questions : 18
B.Tech. (EE) (2012 Onwards E-III) (Sem.?7)
HIGH VOLTAGE DIRECT CURRENT TRANSMISSION
Subject Code : BTEE-805B
M.Code : 71943
Time : 3 Hrs. Max. Marks : 60
INST RUCT IONS T O CANDIDAT ES :
1 .
SECT ION-A is COMPULSORY cons is ting of TEN questions carrying TWO marks
each.
2 .
SECT ION-B c ontains F IVE questions c arrying FIVE marks eac h and s tud ents
have to atte mpt any FOUR q ues tions.
3 .
SECT ION-C contains THREE questions carrying T EN marks e ach and s tudents
have to atte mpt any T WO questio ns.
SECTION-A
Write briefly :
1.
Differentiate the AC and DC transmission system.
2.
Enlist any two applications of HVDC transmission system.
3.
Draw the circuit diagrams of different type of DC links.
4.
State briefly the process of starting and stopping of DC links during operation.
5.
What are the surge arresters?
6.
What is the effect of proximity of AC and DC transmission lines?
7.
What are the two measures of reliability of HVDC system?
8.
"Increase in voltage level is always feasible or not". Give you comment.
9.
Draw the distance verses cost graph of AC and DC transmission system.
10. What is selective harmonic elimination in HVDC system?
1 | M - 7 1 9 4 3
( S 2 ) - 8 1 4
SECTION-B
11. How will you select the converter configuration of HVDC system? What is the effect of
proximity of AC and DC transmission lines?
12. Why reactive power requirement is high in DC system? What is the effect of firing angle
over the power factor angle of the system?
13. Describe the modeling of AC and DC networks. Explain the planning and recent
development in HVDC system in details.
14. Explain the principle of DC link control. Draw the equations for DC current in HVDC link.
15. What are modern trends in HVDC transmission system? Explain any three with suitable
example.
SECTION-C
16. Analyze the 3-phase converter circuit with 6-pulses. Find the effective communication
resistance of a 6-pulse rectifier, which is fed from 400kV, 3-phase AC voltage, when the
DC current in HVDC link is 3kA and the rectifier DC voltage is 500kV at firing angle of
15?.
17. Describe the converter bridge characteristics. Explain the working of 12-pulse voltage
source converter with and without overlap, in detail.
18. What is the insulation coordination and smoothing reactor? Explain the protection against
over current and over voltage in a converter station.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
2 | M - 7 1 9 4 3
( S 2 ) - 8 1 4
This post was last modified on 26 June 2021