Power Electronic Class Test Question Paper

Unit 1

Q.1. Explain the two transistor analogy of SCR with equivalent circuit and give three application

Q.2 Explain the operation of IGBT with VI and Switching characteristics.

Q.3. Draw & explain the necessity of static and dynamic equalizing circuit for series connected SCR’s? Derive relations used for determining the valus of shunt resistor Rand capacitor C in this circuit.

Q.4. describe the operation of LASCR, give its industrial applications. Draw circuit diagram and waveform of time delay using SCR & UJT for AC load.

Q.5. what are the different methods to turn on the Thyristor?

Q.6. draw V-I characteristics of DIAC. is DIAC equally sensitive in both the directions ? give two application of DIAC.

Q.7. compare power BJT, power MOSFET and IGBT.

Q.8. states any two features of power MOSFET which makes it suitable for medium power application.

Q.9. Explain the role of the following power devices and their application 

• Power MOSFET

• IGBT

• GTO

• SCR

Q.10. Describe the different modes of operation of a thyristor with help of its static VI characteristics.

Unit 2

Q.11. Draw the single phase full wave bridge type controlled rectifier Draw the waveforms of input voltage, load voltage and voltage across SCR.

Q.12. Differentiate between single phase controlled half wave rectifier and single phase controlled full wave rectifier.

Q.13. Explain the Effect of freewheeling diode.

Q.14. Explain the Comparison of mid-point & Bridge rectifier circuits.

Q.15. Describe the Uncontrolled and Controlled Rectifier Circuit With Resistive.

Q.16. Estimation of average load voltage and load current for the Half wave & Full Wave rectifier circuits active and reactive power input.

Unit 3

Q.17. Explain the Series and parallel inverter.

Q.18. Explain the Voltage source & current source inverter.

Q.19. Explain the Single phase and three phase bridge inverter.

Q.20. Explain the Mc- Murray & MC Murray bedford inverters.

Q.21. Explain the Voltage control of single phase and three phase bridge inverter.

Q.22. Explain the Harmonics & their reduction techniques.

Unit – 4

Q.23. Explain the Principle of chopper operation.

Q.24. Explain the Various control strategies in the chopper.

Q.25. Explain the step up & step-up/step down choppers.

Q.26. Explain the chopper configuration (Type A, B, C, D, & E).

Q.27. Explain the Steady state analysis of chopper circuits.

Q.28. Explain the Current & voltage commutation of chopper circuits Jones.

Q.29. Explain the Morgens chopper.

Unit - 5

Q.30. Explain the Single phase (mid-point & bridge configuration) cyclo-convertor.

Q.31. Explain the three phase cyclo-convertor configuration and operating principles.

Q.32. Explain the AC voltage controllers (using SCRs & Traics) single phase full wave controller with R and RL load.

Q.33. Explain the Estimation of RMS load voltage.

Q.34. Explain the RMS load current and input power factor.

Q.35. Explain the three-phase AC voltage controller (Without analysis).

Q.36. Explain the Dual converter Switched mode voltage regulator buck.

Q.37. Explain the Ck regulators.