EE2301 Power Electronics B.E Question Bank : dmice.ac.in
Name of the College : DMI College OF Engineering
Department : Electrical And Electronics Engineering
Subject Code/ Name : EE 2301- Power Electronics
Degree : B.E
Website : dmice.ac.in
Document Type : Question Bank
Power Electronics : https://www.pdfquestion.in/uploads/dmice.ac.in/1626-EE2301.docx
DMICE Power Electronics Question Paper
UNIT-1
POWER SEMICONDUCTOR DEVICES :
2-MARKS QUSTIONS :
** How SCR differs from TRIAC?
** What is snubber circuit?
** Define spread time?
** Compare and MOSFET?
Related : DMI College OF Engineering IT2041 Enterprise Resource Planning B.E Question Bank : www.pdfquestion.in/2781.html
** Why are becoming popular in their application to controlled converters?
** What are the factors that influence the turn – off time of a thyristor?
** Write the merits and demerits of MOSFET over BJT?
** Distinguish between holding current and latching current of SCR?
** What are the drawbacks of GTO?
** What is meant by pinch-off voltage of MOSFET?
** What do you mean by controlled switch?
** What is the need of driver circuit?
** What losses occur in a thyristor during working conditions?
** Define circuit turn off time.
** IGBT and MOSFET is a voltage controlled device. Why?
** Power BJT is a current controlled device. Why?
** List the various forced commutation techniques used in to turns off the SCR.
** What do you mean by load commutation?
** What are the different methods to turn on the thyristor?
** Define hard-driving or over-driving.
16 MARKS QUESTIONS :
Draw the basic structure and explain the turn – on and turn – off characteristics of IGBT with neat waveforms? (16)
(i) What is need of snubber in transistor circuit? Explain the over voltage snubber circuit. (8)
(ii) Draw and explain the thyristor gate Drive Circuit. (8)
Explain the principle of operation and draw the transfer characteristics of MOSFET? (16)
(i) Draw and explain the two transistor model of a SCR? (8)
(ii) Explain the turn off characteristics of a SCR. (8)
** Explain the switching characteristics of a MOSFET . (16)
** Explain why TRIAC is rarely operated in I quadrant with negative gate current and in III quadrant with positive gate current. (16)
** Explain the process of complementary commutation and load commutation with necessary waveforms and equations. (16)
** Explain the construction and V-I characteristics of SCR. (16)
(i) Explain the losses occur in a thyristor during working conditions. (8)
(ii) Explain the transfer characteristics of IGBT. (8)
(i) Discuss in detail the switching characteristics of BJT (8)
(ii) Explain the different methods to turn on the thyristor? (8)
UNIT-2
PHASE CONTROLLED RECTIFIER :
2-MARKS QUESTIONS :
** Define distortion factor?
** Define Total Harmonic Distortion?
** Under what conditions a single phase fully controlled converter gets operated as an inverter?
** When does the line commutated converter act as a line commutated inverter?
** Give any two differences between single phase full converter and semi converter?
** Define the term voltage ripple factor?
** What is meant by Current distortion factor?
** Why is power factor of semi converter better than full converter?
** What are the effects of source impedance in the controlled rectifiers?
** Define displacement factor?
** Define Firing angle.
** What is the function of freewheeling diodes in controlled rectifier?
** What are the advantages of freewheeling diodes in a controlled in a controlled rectifier?
** What is commutation angle or overlap angle?
** What are the advantages of six pulse converter?
** Mention the disadvantages of dual converter with circulating current mode of operation.
** What do you mean by six pulse converter?
** Write two applications of dual converter.
** What is the inversion mode of rectifier?
** Mention some of the applications of controlled rectifier.