Hall Ticket No:
Question Paper Code B3308
(AUTONOMOUS) M.Tech II Semester Regular/Supplementary Examinations, June 2017
(Regulations: VCE-R15) FLEXIBLE AC TRANSMISSION SYSTEMS
(Power Electronics and Electric Drives) Date: 09 June, 2017 FN
Time: 3 hours
Max Marks: 70
Answer any Five Questions.
All Questions carries equal marks.
1.
Why are FACTs devices essential in a transmission system? Explain the different types with relevant figures.
9M
Write a brief note on loading capability limits with relevance to flexible AC transmission system.
5M
2.
Briefly describe the transformer connections for 24 pulse operation and highlight how it is different from lower 12 pulse operation.
8M
Differentiate between single phase and three phase bridge converters.
6M
3.
How is a current source converter different from voltage source converter? Explain in detail.
6M
With relevant waveforms, explain commutation failure on the inverter output voltage.
8M
4.
How does the static shunt compensator prevent voltage instability problem? Explain in detail.
8M
Briefly explain the objectives of shunt compensation.
6M
5.
With relevant waveforms, explain the working of impedance type static VAR generator.
8M
Write a brief note on the different methods of controllable VAR generation.
6M
6.
"Power oscillations can be damped by modulating the reference current to the static VAR generator". Justify this statement with suitable function control scheme.
8M
Write a brief summary on SVC compensator control.
6M
7.
Compare and contrast the circuit diagram and performance of an SVC and STATCOM.
7M
With the help of transfer function model, explain the working of STATCOM.
7M
8.
Explain the concept of series capacitive compensation.
4M
Compare and contrast the control schemes for GSC and TCSC.
10M