Seat No.: ________ Enrolment No.
___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER–VI (NEW) EXAMINATION – SUMMER 2023
Subject Code:3160921 Date:14-07-2023
Subject Name:HVDC Transmission Systems
Time:10:30 AM TO 01:00 PM Total Marks:70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
4. Simple and non-programmable scientific calculators are allowed.
MARKS
Q.1 (a) Compare of AC and DC Transmission. 03
(b) Describe harmonic elimination techniques. 04
Describe
(c) Explain selective
various typesharmonic
of HVDCelimination
systems. technique. 07
Describe
Q.2 (a) Describe selective harmonic
Commutation elimination technique.
Process. 03
(b) Explain six pulse converter with neat diagram. 04
Describe
(c) Explain selective
twelve pulseharmonic elimination technique.
converters. 07
OR
(c) Enlist components of HVDC transmissiontechnique.
Describe selective harmonic elimination system and explain any 07
two in details.
Q.3 (a) Write short note on DC breaker. 03
(b) Write short note on “corona effect”. 04
(c) Explain power flow and dc voltage control in VSC based HVDC 07
system.
OR
Q.3 (a) Classify PWM techniques. 03
(b) List out various characteristic of Harmonics. 04
(c) Write short note on high level controllers. 07
Q.4 (a) What is Current and Extinction Angle Control? 03
(b) Explain “Phase-Locked Loop” 04
(c) Explain in detail control of power in MTDC. 07
OR
Q.4 (a) Write principles of DC Link Control in a VSC based HVDC system. 03
(b) With sketch explain Sinusoidal Pulse Width Modulation. 04
(c) Enlist different types of insulators. Explain all in short. 07
Q.5 (a) Explain DC line faults in LCC systems. 03
(b) Describe voltage stability problem in AC/DC systems. 04
(c) Write short note on modular multilevel converter. 07
OR
Q.5 (a) Differentiate between synchronous and asynchronous link. 03
(b) Explain Parallel Operation of HVDC. 04
(c) Explain mono-polar operation of HVDC. 07
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