Question Paper: Power Electronics Question Paper - Jun 18 - Electronics Engineering (Semester 7) - Mumbai University (MU)
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Power Electronics - Jun 18

Electronics Engineering (Semester 7)

Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Draw neat diagrams wherever necessary.

Q1 Answer any four

1.a. Explain different commutation techniques for SCR. Draw current commutation circuit

(5 marks) 00

1.b. Draw and explain gate characteristics
(5 marks) 00

1.c. What is the need of freewheeling diode in rectifiers? Explain with suitable diagrams
(5 marks) 00

1.d. Explain type B DC - DC converter
(5 marks) 00

1.e. Explain why harmonic neutralisation is necessary in the output of inverter
(5 marks) 00

2.a. Draw and explain single phase fully controlled converter with RL load. draw load current, low voltage ,input voltage and gating signal for $\alpha$ = 60°
(10 marks) 00

2.b. Explain the working of three phase bridge inverter in 120° conduction mode with circuit diagram and waveforms
(10 marks) 00

3.a. Draw and explain dynamic characteristics of thyristor
(10 marks) 00

3.b. Explain working principle of 1 ø cyclo converter with circuit diagram and waveforms
(10 marks) 00

4.a. Single phase fully controlled converter is operated from 230V , 50hz ac supply. The load resistance is 10Ω . The average output voltage is 10 % of max possible average output voltage

Calculate

i) Firing angle

ii) RMS and average output current

iii) Efficiency

(10 marks) 00

4.b. Draw and explain the working of 3 ø fully controlled rectifier with neat circuit diagram and waveforms
(10 marks) 00

5.a. Draw and explain AC voltage control circuit using DIAC and TRIAC . Draw the waveform with $\alpha$ = 60°
(10 marks) 00

5.b. Draw and explain buck converter with waveforms. Also derive the expression for output voltage.
(10 marks) 00

Q6 Write short notes on(Any Four)

6.a. Compare IGBT and MOSFET
(5 marks) 00

6.b. Protection circuits for SCR
(5 marks) 00

6.c. Driver circuits for power transistors
(5 marks) 00

6.d. Various PWM techniques
(5 marks) 00

6.e. Ramp and pedestal control triggering
(5 marks) 00

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modified 16 days ago by gravatar for SHUBHAM SHUKLA SHUBHAM SHUKLA0 written 29 days ago by gravatar for jeson.anthony jeson.anthony0
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