University of Mumbai 2007-8th Sem B.E Electrical and Electronics Engineering HVDC Transmission Old - exam paper
Con/5436-07, (OLD COURSE) CD-6312
(3 Hours) [Total Marks: 100
N.B. ; (1) Attempt any five questions.
(2) All question carry equal marks.
(3) Explain with neat diagram as and when necessary.
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1 |
(a) |
State different methods of D.C. transmission. |
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(b) |
Draw a neat circuit diagram and explain working of six pulse converter. | |
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2 |
(a) |
State and explain different sources of harmonics in D.C. transmission. |
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(b) |
State and explain method of reactive power compensation in HVDC transmission. | |
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3. |
(a) |
Discuss filters usee in HVDC system on A.C. sides and D.C. side. State clearly their purpose. |
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(b) |
What are the possible faults on converter, explain how to protect converter against over'current ? | |
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4. |
W |
State and explain different HVDC links. Discuss their merits and demerits. |
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(b) |
Explain the method of reversal of flow of power in HVDC system. | |
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5. |
(a) |
What are the problems associated with low effective short circuit ratios ? |
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(b) |
Discuss as reference to power system strong system and weak system. | |
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6. |
fa) |
Discuss the causes of over voltages in converter stations and method of protection against over voltages. |
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(b) |
What are the different ratings of the transformer used in converter stations ? |
7. Write short notes on any two :
(a) Valve characteristics used in converters
(b) Starting and stopping of valves in converters
(c) Commutation methods used for converter circuits
(d) Improvement of A.C. system performance using HVDC.
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Attachment: |
| Earning: Approval pending. |
