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03000EE305092003

Illustrate how a Thyristor based 1-phase fully controlled rectifier can be used to
convert ac into variable dc. Draw the waveforms of output voltage & output
current for both R and RL load at ೧-307.
Obtain an expression for average dc output voltage of a 1-phase fully controlled
rectifier for R load with firing angle, a.
PART C

Answer any two full questions, each carries 10 marks.
Describe the operation of a 3-phase semi-converter with RLE load having
constant output current when firing angle is 30° with output voltage waveform
and derive an expression for average dc output voltage.
Explain how four quadrant operation is possible using a 1-phase dual converter
operating in both circulating and non-circulating current modes.
A 50112 single phase full bridge square wave inverter is fed form 50017 ‏عل‎ input.
Find output rms voltage and current for a load of R=5Q and L=10mH.
Illustrate the operation of a 3-phase bridge inverter operating in 180° conduction
mode with output line voltage and phase voltage waveforms. Derive expressions
for output line voltage and phase voltage.

PART D
Answer any two full questions, each carries 10 marks.
Illustrate the generation of sine pulse width modulated control signals for a

single phase VSI with output voltage waveform.

Describe the operation of single phase AC voltage controller for R load with
waveforms and derive expression for output rms voltage.

For a 00-0௦ buck-boost converter with a ‏عل‎ input voltage of ‏0۷ذ‎ and output
voltage of 10017 calculate (i) duty cycle (ii) value of inductor if inductor ripple
current AI=10mA. Given the switching frequency is 101117

With circuit diagram and waveforms, describe the operation of a buck-boost 60-
de converter. Derive expressions for output ‏عل‎ voltage and the design equations

for filter inductor & capacitor.

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