Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 7th Sem New 2170906 Advanced Power Electronics Previous Question Paper
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VII (NEW) EXAMINATION ? WINTER 2018
Subject Code: 2170906 Date: 15/11/2018
Subject Name: Advanced Power Electronics
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Compare buck, boost and buck-boost converter with reference to technical
parameters.
03
(b) Write the advantages of resonance converter as compared to PWM converter. 04
(c) Illustrate the push pull converter with neat circuit diagram & waveform and
derive the equation of output voltage in terms of input voltage & duty cycle.
07
Q.2 (a) Define duty cycle and write its importance. 03
(b) Differentiate between continuous mode of conduction and discontinuous
mode of conduction.
04
(c) Justify the name of converter as zero voltage switching converter with
necessary diagram and waveform.
07
OR
(c) Illustrate how the harmonic current are canceled by phase shifting transformer
in 12 pulse rectifier.
07
Q.3 (a) Compare the three topologies of multilevel inverter. 03
(b) Compare HVAC and HVDC transmission line. 04
(c) The buck-boost regulator has an input voltage = 12 V, duty cycle = 0.25,
switching frequency = 25 kHz, inductor = 150 ?H, filter capacitor = 220 ?F
and average load current = 1.25 A. Determine (a) Average output voltage (b)
Peak to peak output voltage ripple (c) Peak to peak ripple current (d) Peak
current of switch (e) Critical value of L and C.
07
OR
Q.3 (a) Introduce the multi pulse converter. 03
(b) Draw circuit diagram of 9 level asymmetric cascaded H bridge multilevel
inverter and mention the switching states to generate 0 level.
04
(c) The class E resonance inverter operates at resonance and has Vs = 12 V, R=
10 ?, fs = 25 kHz and Q = 7. Determine optimum value of L, C, Ce and Le.
07
Q.4 (a) Draw block diagram of HVDC transmission system. Mention equipment
required for HVDC system.
03
(b) Justify: ZVS is better than ZCS. 04
(c) Explain in detail about rectifier and inverter control characteristic of HVDC
converter.
07
OR
Q.4 (a) State the need of reactive power compensation. 03
(b) Draw and explain bipolar HVDC power transmission system based on 12
pulse converters for each pole.
04
(c) Discuss the operation of thyristor switched capacitor.
07
Q.5 (a) Compare SVC and STATCOM. 03
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VII (NEW) EXAMINATION ? WINTER 2018
Subject Code: 2170906 Date: 15/11/2018
Subject Name: Advanced Power Electronics
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
Q.1 (a) Compare buck, boost and buck-boost converter with reference to technical
parameters.
03
(b) Write the advantages of resonance converter as compared to PWM converter. 04
(c) Illustrate the push pull converter with neat circuit diagram & waveform and
derive the equation of output voltage in terms of input voltage & duty cycle.
07
Q.2 (a) Define duty cycle and write its importance. 03
(b) Differentiate between continuous mode of conduction and discontinuous
mode of conduction.
04
(c) Justify the name of converter as zero voltage switching converter with
necessary diagram and waveform.
07
OR
(c) Illustrate how the harmonic current are canceled by phase shifting transformer
in 12 pulse rectifier.
07
Q.3 (a) Compare the three topologies of multilevel inverter. 03
(b) Compare HVAC and HVDC transmission line. 04
(c) The buck-boost regulator has an input voltage = 12 V, duty cycle = 0.25,
switching frequency = 25 kHz, inductor = 150 ?H, filter capacitor = 220 ?F
and average load current = 1.25 A. Determine (a) Average output voltage (b)
Peak to peak output voltage ripple (c) Peak to peak ripple current (d) Peak
current of switch (e) Critical value of L and C.
07
OR
Q.3 (a) Introduce the multi pulse converter. 03
(b) Draw circuit diagram of 9 level asymmetric cascaded H bridge multilevel
inverter and mention the switching states to generate 0 level.
04
(c) The class E resonance inverter operates at resonance and has Vs = 12 V, R=
10 ?, fs = 25 kHz and Q = 7. Determine optimum value of L, C, Ce and Le.
07
Q.4 (a) Draw block diagram of HVDC transmission system. Mention equipment
required for HVDC system.
03
(b) Justify: ZVS is better than ZCS. 04
(c) Explain in detail about rectifier and inverter control characteristic of HVDC
converter.
07
OR
Q.4 (a) State the need of reactive power compensation. 03
(b) Draw and explain bipolar HVDC power transmission system based on 12
pulse converters for each pole.
04
(c) Discuss the operation of thyristor switched capacitor.
07
Q.5 (a) Compare SVC and STATCOM. 03
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2
(b) Classify carrier based PWM technique for multilevel inverter. Discuss any
one in detail.
04
(c) Explain in brief about FACTS. 07
OR
Q.5 (a) Explain star/delta phase shifting transformer with phasor diagram. 03
(b) Write the advantages and limitations of SSSC. 04
(c) Explain how multilevel inverter is used as reactive power compensator with
necessary vector diagram.
07
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This post was last modified on 20 February 2020