Important RGPV Question
EX-502, Power Electronics
V Sem, EX
UNIT 1
Q.1 Explain the principle of operation of IGBT with its switching characteristics. (RGPV June 2020)
Q.2 Explain the principle of operation of MOSFET with its switching characteristics. (RGPV June 2020)
Q.3 Explain the principle of operation of SCR with its switching characteristics. (RGPV June 2020)
Q.4 Explain the different type of over current and over voltage protection in SCR. (RGPV June 2020)
Q.5 Draw the block diagram and explain the operation of SMPS which can be employed for low power applications and other for high power applications. (RGPV June 2020)
Q.6 Draw and explain the operation of single phase half wave converter drive and also draw the related voltage and current waveforms. (RGPV June 2020)
Q.7 What are the different methods to turn on the Thyristor? (RGPV Dec 2020)
Q.8 Describe LASCR. Give its industrial applications. Draw circuit diagram and waveform of time delay relay using SCR and UJT for AC load. (RGPV Dec 2020)
Q.9 Explain the two transistor analogy of SCR with equivalent circuit and give three applications. (RGPV Dec 2020)
Q.10 Draw V-I characteristics of DIAC, is DIAC equally sensitive in both the directions? Give two application of DIAC. (RGPV Dec 2020)
Q.11 Compare power BJT, power MOSFET and IGBT (any four points). (RGPV Dec 2020)
Q.13 Draw the single phase full wave bridge type controlled rectifier. Draw the waveforms of input voltage, load voltage and voltage across SCR. (RGPV Dec 2020)
Q.14 Draw the labelled layer diagram of N-channel IGBT. Draw its VI characteristics. (RGPV Dec 2020)
Q.15 State any two features of power MOSFET which makes it suitable for medium power applications. (RGPV Dec 2020)
Q.16 Explain the two transistor analogy of SCR with equivalent circuit and give three applications. (RGPV Nov 2023)
Q.17 Explain the operation of IGBT with VI and switching characteristics. (RGPV Nov 2023)
Q.18 Draw and explain the necessity of static and dynamic equalizing circuit for series connected SCR’S? Derive relations used for determining the values of shunt resistor R and capacitor C in this circuit. (RGPV Nov 2023)
Q.19 Derive the output voltage and current expressions for firing angle of 45 degrees. (RGPV Nov 2023)
UNIT 2
Q.1 What is meant by rectification mode and inversion mode in single phase fully controlled converter? (RGPV June 2020)
Q.2 What is the function of freewheeling diodes in controlled rectifier? (RGPV June 2020)
Q.3 Differentiate between single phase controlled half wave rectifier and single phase controlled full wave rectifier. (RGPV Dec 2020)
Q.4 A 3-phase bridge rectifier has the average output voltage as 286.48 V. Find the maximum value of line voltage. (RGPV Dec 2020)
Q.5 Find the triggering frequency when the average gate power dissipation = 0.3W and the peak gate drive power is 5 Watts. The gate source has a pulse width of 20 µsec duration. (RGPV Dec 2020)
UNIT 3
Q.1 What is meant by rectification mode and inversion mode in single phase fully controlled converter? (RGPV June 2020)
Q.2 What is the function of freewheeling diodes in controlled rectifier? (RGPV June 2020)
Q.3 Differentiate between single phase controlled half wave rectifier and single phase controlled full wave rectifier. (RGPV Dec 2020)
Q.4 A 3-phase bridge rectifier has the average output voltage as 286.48 V. Find the maximum value of line voltage. (RGPV Dec 2020)
Q.5 Find the triggering frequency when the average gate power dissipation = 0.3W and the peak gate drive power is 5 Watts. The gate source has a pulse width of 20 µsec duration. (RGPV Dec 2020)
UNIT 4
Q.1 Explain the operation of step-down and step-up chopper with duty cycle and derive its output equation. (RGPV June 2020)
Q.2 What are the advantages and disadvantages of load commutated chopper? (RGPV June 2020)
Q.3 Explain the operation of Voltage commutated chopper and current commutated chopper. (RGPV June 2020)
Q.4 Define circuit turn-off time. Why circuit turn-off time should be greater than the thyristor turn-off time? (RGPV June 2020)
Q.5 Explain the working principle of multiphase chopper. (RGPV Dec 2020)
Q.6 What is the principle of chopper? What is the function of inverter chopper in SMPS? (RGPV Dec 2020)
Q.7 A step-down delta-star transformer, with per-phase turns ratio of 5 is fed from a 3-phase 1100V, 50Hz source. The secondary of this transformer is connected through a 3-pulse type rectifier, which is feeding an R load. Find the average value of output voltage. (RGPV Dec 2020)
Q.8 Write short notes on: (RGPV Nov 2023)
i) Jones chopper
ii) Current limit control of de-de converter
Q.9 A de on-off chopper operating at 1 kHz and duty cycle of 10% is supplied from a 200V source. If the load inductance is 10 mH and resistance 102. Compute the maximum and minimum circuit in the load. (RGPV Nov 2023)
UNIT 5
Q.1 Is there any Single-Phase to Three-Phase Cyclo-converter existing? How does it operate? (RGPV Dec 2020)
Q.2 What is meant by Cyclo-converter? What are the types of Cyclo-converters? (RGPV Dec 2020)
Q.3 Explain the operation of single phase fully controlled converter with RL load. (RGPV Nov 2023)
Q.4 Explain the effect of source impedance on the performance of single phase fully controlled bridge converter. (RGPV Nov 2023)
Q.5 Derive an expression for rms value of output voltage of single phase bridge type ac voltage controller. (RGPV Nov 2023)
Q.6 Draw the circuit of single phase voltage controller with anti-parallel connection of two thyristors and an R-Lload. Explain its working. Sketch load voltage and load current waveforms. Derive an expression for output voltage. (RGPV Nov 2023)
Q.7 Write short notes on any three: (RGPV Nov 2023)
a) AC voltage controllers
b) Harmonics and their reduction
c) GTO and its VI characteristics
d) Forced commutation technique of thyristor
— Best of Luck for Exam —
