Hall Ticket No Question Paper Code: BPE005
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
M.Tech II Semester End Examinations (Regular) July, 2017
Regulation: IARE-R16
DC TO AC CONVERTERS
(Power Electronics and Electrical Drives)
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. Explain the principle of operation of a single phase full bridge inverter circuit with the help of a
neat circuit diagram and necessary waveforms.
A single phase half bridge inverter is operated from a 48V battery and is supplying power to a
pure resistive load of 2.4
. Determine
i. The RMS voltage a fundamental frequency
ii. Output power
iii. Average and peak currents of each transistor
2. Discuss any two methods of voltage control for single phase inverters.
Explain trapezoidal and staircase modulation techniques for single phase inverters.
UNIT II
3. What are resonant pulse inverters. Explain the principle of operation of series resonant inverters
with unidirectional switches with a neat circuit diagram and waveforms.
The half-bridge resonant inverter is operated at an output frequency of 7 kHz. If C1 C2 C
3F and L1 L2 L R 2
and supply voltage Vs 200V. Determine
i. the peak supply current
ii. average thyristor current
iii. rms thyristor current
4. Explain about voltage control of resonant inverters with a neat circuit diagram and waveforms.

Compare ZCS and ZVS resonant converters and state their limitations.
UNIT III
5. Draw a general topology of multilevel inverters. Explain the operation with a a typical output
voltage waveform.
What are the various topologies of Multilevel inverters. Explain the advantage of each type.

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6. Explain the principle of operation of a cascaded Multilevel Inverter with a neat circuit diagram.

Consider the output phase voltage waveform for 6 (including 0-level) cascaded MLI, find the
generalized Fourier series of the phase voltage waveform obtained.
UNIT IV
7. What are Switched-Mode DC power supplies. Explain the operation of a fly back converter with
a neat circuit diagram.
Draw the Full-bridge converter and derive the expression for the voltage transfer ratio.
8. Discuss about bidirectional power supplies and resonant DC power supplies.
Explain the operation of a push pull converter with the help of a neat circuit diagram.
UNIT V
9. Draw the schematic diagram of Switched-Mode AC power supplies and explain.
What are the types of power line disturbances. Explain about Power Conditioners with a neat
diagram.
10. Draw the block diagram of an UPS. Explain the function of each block.
Draw a circuit of a multistage conversion and explain.