POWER ELECTRONICS (EC-604 (C)) - Important Questions

Explain the basic structure including fast recovery type and static V-I characteristics of a power diode with neat diagram.

Describe the basic structure and V-I characteristics of a Power MOSFET. How does it operate in switching applications?

Explain the basic structure, working and V-I / transfer characteristics of an IGBT with neat diagram.

Explain the basic structure of a thyristor/SCR and its static V-I characteristics and modes of operation, including dynamic characteristics.

Explain the working of a three-phase full-wave fully controlled converter with continuous and constant load current with waveforms.

Explain series and parallel operation of thyristors, causes of unequal voltage/current sharing in steady state and transient state, and methods to achieve equal sharing.

Determine the RMS value of output voltage for a single-phase full-wave half-controlled rectifier with peak input voltage Vm = 300 V and firing angle alpha = 30 degrees.

Describe the basic circuit, working principle and operation of a single-phase PWM inverter and explain its advantages over traditional inverters.

Explain the basic operation of a single-phase full bridge inverter, including output waveforms and advantages of bridge configuration.

Explain what harmonics are in inverters, why their reduction is important, and the harmonic control/reduction techniques.

Explain the principles of on-off control and phase control in single-phase AC voltage controllers and how they regulate output voltage with resistive and inductive loads.

Explain the basic principle of operation of a cycloconverter and the working of a single-phase to single-phase cycloconverter with typical applications.

Discuss the principle of operation of a single-phase transformer tap changer. How does it control the output voltage in power distribution systems?

Explain the functionality of a buck-boost regulator and how it regulates output voltage when input can be higher or lower than the desired output.

Write short notes on any two of the following: (i) Principle of operation and analysis of switched mode power supply (SMPS) (ii) Flyback SMPS with equivalent circuit and waveforms (iii) SMPS versus linear power supplies.