Question Paper: Power Electronics 2 Question Paper - Dec 17 - Electronics Engineering (Semester 7) - Mumbai University (MU)
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## Power Electronics - Dec 17

### 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.

1.a. Compare the various triggering methods of thyristors.

(5 marks) 00

1.b. What is the need of freewheeling diode in rectifiers? Explain with an example
(5 marks) 00

1.c. Draw and explain VI characteristic of TRIAC
(5 marks) 00

1.d. Explain the commutation techniques for SCR . Draw any one, forced commutation circuit
(5 marks) 00

1.e. Explain various control strategies for DC-DC converter.
(5 marks) 00

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

2.b.

(10 marks) 00

3.a. A single phase full bridge inverter has a resistive load of 10Ω and dc input voltage of 48 V.

Calculate : i) RMS output voltage $V_{rms}$

ii) RMS output voltage at fundamental frequency $V(01)_{rms}$

iii) Total harmonic distortion (THD)

iv) Average and peak current of each thyristor

(10 marks) 00

3.b. Explain working principle of single Phase cycloconverter with circuit diagram and waveforms
(10 marks) 00

4.a. A single phase fully controlled converter is operated from 230V, 50Hz ac supply. The load resistance is 10 Ohms. The Average output voltage is 10% of max possible average output voltage

Calculate :- i) firing angle

ii) RMS and average output current

iii) Efficiency

iv) displacement factor (DF)

(10 marks) 00

4.b.

(10 marks) 00

5.a.

(10 marks) 00

5.b. Draw and explain boost converter with their forms. Also derive expression for output voltage.
(10 marks) 00

Write short notes on (any three)

6.a. Compare IGBT , MOSFET, AND GTO
(5 marks) 00

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

6.c.
(5 marks) 00

6.d. Voltage control of inverters using PWM techniques
(5 marks) 00

 modified 10 weeks ago by Ankit Pandey • 70 written 5 months ago by jeson.anthony • 0