Download PTU B-Tech EEE 2020 Dec 5th Sem 70557 Power Electronics Question Paper

Download PTU (I.K.Gujral Punjab Technical University (IKGPTU)) B-Tech (Bachelor of Technology) (EEE)- Electrical And Electronics Engineering 2020 December 5th Sem 70557 Power Electronics Previous Question Paper

Roll No.
Total No. of Pages : 02
Total No. of Questions : 18
B.Tech. (EE) (2012 Onwards) (Sem.?5)
B.Tech. (Electrical & Electronics Engg.) (2012 Onwards)
B.Tech. (Electrical Engineering & Industrial Control)/
(Electronics & Electrical Engg.) (2012 to 2017)
POWER ELECTRONICS
Subject Code : BTEE-504
M.Code : 70557
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
Answer briefly :
1.
What is the function of heatsink in SCRs?
2.
What are the different methods to turn off the thyristor?
3.
What are the applications of cycloconverter?
4.
Define latching current.
5.
Draw the circuit of snubber circuit.
6.
Discuss the significance of freewheeling diode.
7.
List various types of commutations.
8.
Draw the symbol and characteristics of TRIAC.
9.
What are line commutated inverters?
10. What is resistance firing circuit?
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SECTION-B
11. Describe the principle of dc chopper operation. Derive an expression for its average dc
output voltage.
12. SCRs with a rating of 2000V and 200 A are available to be used in a string to handle
6KV and 2 KA. Calculate the number of series and parallel units required in case of
derating factor is 0.1 and 0.2.
13. What do you mean by commutation? Discuss class C and class D commutation with
circuit diagram and waveforms.
14. What is the use of AC voltage controller? Discuss the single-phase AC voltage controller
with RL load.
15. What is the use of cycloconverter? Discuss three phase to single phase cycloconverter
with waveforms.
SECTION-C
16. Draw and explain single phase voltage source bridge inverter. Also give its steady state
analysis.
17. Draw and explain the static and dynamic characteristics of Silicon controlled rectifier.
18. What do you mean by phase control rectifier? Draw and explain the voltage waveforms
for three phase full converter. Also give the expressions for output voltage.
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.
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