Skip to content
InsemOct 20232019 patternTE Electrical

Power Electronics SPPU Insem Question Paper Oct 2023

All 4 questions from this SPPU insem paper, as printed. Read them here or open the PDF.

Open the PDFMost repeated Power Electronics questions
Subject code
303142
Pattern
2019 pattern
Exam
Insem
Session
Oct 2023
Max. marks
30
Time
1 Hour
Semester
I
Paper code
[6187]-434

Printed for: T.E. (Electrical Engineering) (Insem)

Instructions to the candidates

  1. Solve Q.1 or Q.2, Q.3 or Q.4.
  2. Figures to the right indicate full marks.
  3. Neat diagrams must be drawn wherever necessary.
  4. Assume suitable additional data if, necessary.
  5. Use of non-programmable calculator is allowed.

Questions

  1. Q1

    1. a)

      Draw and explain constructional details of SCR and GTO, specify constructional difference between them.

      [7]
    2. b)

      What is commutation of SCR? Explain class ‘C’ and ‘D’ commutation with the help of necessary circuit and waveforms.

      [8]

  2. Q2

    1. a)

      With the help of constructional diagram, explain construction and working of TRIAC.

      [7]
    2. b)

      Draw the dynamic characteristics of SCR and define all related time spans for switching ON.

      [8]

  3. Q3

    1. a)

      Explain the working of calss ‘D’ chopper with appropriate waveforms to demonstrate its operation in first and fourth quadrants. Indicate the range of duty cycle for which it operates in first and fourth quadrants.

      [7]
    2. b)

      What is “Duty Cycle Control” of a chopper? How PWM and FM control is used? Compare. 2

      [8]

  4. Q4

    1. a)

      A step-up chopper has an input voltage of 150V. The voltage output needed is 450V. Given that the thyristor has a conducting time of 150  seconds. Calculate the chopping frequency. If T ON is halved, keeping chopping frequency constant, what will be output voltage.

      [7]
    2. b)

      Draw output and transfer characteristics of MOSFEFT and explain the terms: i) Pinch off voltage ii) Threshold voltage iii) Trans conductance iv) Turn on & turn off characteristics   

      [8]