Power Electronics(10EC73) - Question Bank
1. What is power electronics. Name the various families of thyristors. [ 2010 june- 06M]
2. Give different types
of converters with circuit diagram & waveforms [(2009 dec 08M]
3.What is peripheral effect. Explain the remedial [-2013
june -10M]
4. Explain the
different types of power diodes-[2014
dec-06M]
5. Explain the GTOs,SITHs, MCTs,TRIACs [ 2011-10M]
6. what is snubber circuit. Explain[2008-08M]
7. Explain the UJT
as a
relaxation oscillator[2007-10M]
8.what is
dv/dt & di/dt protection. Explain in
detail[ 2012-08]
9. Vs=200v Rl= 5Ω Load.stray capacitance & inductance is negligible Fc=2k
dv/dt=100v/
&
discharge current is 100 MA
.determine i) values Rs & Cs
ii)snubber loss iii) power rating
[2015-10M]
10. Explain RCT, Diac,
LASER,MCT , fast switching thyristors,
GTOs [2013-08M]
11.Explain the bidirectional triode
thyristors[2006-10M]
12. What is schottky diode? Mention its advantages[ 2017-07M]
13. Explain the turn on- & turn off
characteristics scr [2010,2008-10M]
|
UNIT-II: Power TransistOR :Power BJT’s, Switching characteristics,
Switching limits, Base derive control, Power MOSFET’s, Switching
characteristics, Gate drive, IGBT’s, Isolation of gate and base drives.
|
1.Explain the
serial & parallel operation of SCR[2008-10]
2. Sketch & explain the switching
characteristics of power BJT[2012-10]
3.Explain the
structure of n-channel enhancement type MOSFET[2013-10]
4.Explain the switching characteristics of
IGBT [ 2011- 08M]
5. Compare BJT & MOSFET [ 2012-06M]
6 .Compare IGBT & BJT & MOSFET [ 2015
06M]
7.Give the isolation of Gate & Base drives( Optocoupler & pulse
transformer) [10M2013]
8. Explain the SB,FBSOA,RBSOA, & power derating[ 10M 2014]
9. Expalin the base drive control methods [10M 2015]
10. Exlain the switching chacteristics of IGBT [ 08M 2016]
12. Compare
IGBT & BJT & MOSFET[ 08M
2012]
13. Give the switching characteristics of MOSFET [06M 2015]
14. Give
merits & demerits of MOSFETS [
04-2014]
UNIT-III:SCR Introduction to Thyristors:Principle of operation states
anode-cathode characteristics, Two transistor model. Turn-on Methods,
Dynamic Turn-on and turn-off characteristics, Gate characteristics, Gate
trigger circuits, di / dt and dv / dt protection, Thyristor firing
circuits.
|
15.
what is base drive control in power transistor. Explain the antisaturation control method [8M -2013dec]
1. Explain the two
transistor analogy of SCR [ 10M-2013
nov]
2.Define holding, latching, FBO ,RBO. Explain the
turn -on methods [ 10M - 2013june]
3. Explain the gate
current character of SCR
[08M- 2014]
4.Explain the turn -off chacteristics of SCR [10M - 2013nov]
5.Explain the firing circuits of SCR [
10M- 2011]
6.The Vs=200V, R=5 Ω.The load & stray capacitance is neglible
.frequency is 2KHz, dv/dt =100v/µs, i= 100A .Determine 1) values of Rs &
Cs 2)Snubber loss 3) power rating[ 10M-2015]
7. Explain
with waveform turn off
thyristors [ 06M- 2010]
|
Unit –IV:CONTROLLED RECTIFIERS
Introduction, Principles
of phase controlled converter operation, 1φ fully controlled converters,
Duel converters, 1 φ semi converters (all converters with R & RL load).
|
8.
Expalin the chacteristics of SCR with holding, Latching current
& three regions of SCR[8M]
1.Explain
HWR with R load .Derive the
equations[ 08M-2011]
2.Expalin the FWR
with R & RL load . Derive the
necessary equations [10M-
2010]
3.What is freewheeling diode. Explain in FWR [ 06M-2010]
4. Explain the FWR with inductive load . derive
equations for O/P volts & current[
10M -2015]
5. Define Displacement
factor, harmonic factor,[ 06M-2013]
6. Explain the FWR with derivations for voltage
& current
7 . A single
phase RL load having L=6.5 mH R= 0.5 Ω α=60 degree i)load current ii) average thyristor current
iii) I rms iv)average o/p current[ 10M- 2010]
8.Explain dual converters with necessary equations & wave
forms
9.Explain
the single semi converters with waveforms[08M-
2011]
10. Compare
HWR & FWR & semiconverters[ 06M-2014]
11. Explain
the advantages of HWR , FWR &
semiconverters [08M -2010]
12 Discuss effect of inductance using 1-phase
full controlled converters[08M-2013]
|
V: –Commutation: Thyristor turn off methods, natural and
forced commutation, self commutation, class A and class B types,
Complementary commutation, auxiliary commutation, external pulse
commutation, AC line commutation, numerical problems.
|
1.Define
commutation. Explain the forced commutation & line commutation[2011 – 08]
2.Explain types of
commutation. Explain the with
diagram class D commuatation [10M -2013]
3.With neat wave form explain the Class A &
Class B commutation[ 10M june 2014]
4. What is complementary commutation?[ 10M 2016]
5.What is auxiliary commutation?[ 08M 2013]
6.What is line commutation. Explain with
waveforms[ 08M 2015]
7. Explain the auxiliary commutation with
accelerating diode[2012-10M]
|
VI:-Choppers:Introduction, Principles of step down and
step up choppers, Step down chopper with RL loads, Chopper classification,
Switch mode regulators – buck, boost and buck – boost regulators.
|
8.
Explain the self commutation.Obtain the capacitor voltage & current [2011- 10M]
1.Define the chopper.
Give the classification of choppers [june10-10M]
2.Explain the principle of step up choppers[ jan 07-8]
3.what is buck -boost regulators[2013-08M]
4. Explain the principle of boost & buck
regulators [2012 dec-08]
5.Explain the step down chopper with RL load[2010-10M]
6.For step- down choppers duty cycle K=0.5 f= 5khz Vs= 220v R=10W L=15.5mH .Determine i) min instantaneous load current
ii) peak load current iii) Average load current iv) RMS load current-
[june10-10M]
7. Obtain an expression for O/P
voltage for step chopper. Expalin
how duty cycle is controlled[2007 6M]
8.Explain the working principle of a four quadrant
choppers with necessary circuit diagram [june 2010 -10M
9. A chopper is working on on time ratio control at
a frequency of 2khz on 460v & load voltage of 350v.Calculate conduction
period of thyristor in each cycle[ 2011-10M]
10. What is
choppers?. How they are classified? Explain briefly [2012-10M]
|
UNITVII:Introduction, Principles of on and off control,
Principles of phase control, Single phase controllers with restive loads
and Inductive loads, numerical problems.
|
11.
Explain impulse commutated choppers wiyh waveforms[2012-10M]
1.Give the principle of on-off controller &
phase controller [08M 2010,2013, 2012]
2.Explain with
waveform single phase ac voltage
controller with inductive load
3.Explain Ac voltage 1 phase controller with R
load [10M -2015]
4. A single phase controller
R= 10Ω vs=120v =60hz α =π/2 .i)
determine o/p Voltage ii) i/p power factor iii) the average current [10M -2011]
5. Why short duration
gate pulses are not suitable for
bidirectional AC voltage with inductive
load[2007june-07M]
|
UNIT-VIII:Introduction,
Principles of operation, Performance parameters, 1φ bridge inverter,
voltage control of 1φ invertors, current source invertors, Variable DC link
inverter
|
6. What problem caused by sharp single pulse triggered in a single phase ac voltage controller.
1. Define the
performance parameter [2013 dec-8M]
2. Explain the principle of operation single phase
inverters[ 2012-10M]
3. Explain with necessary derivation the
single phase bridge inverters[2009 june-10M]
4. Explain the current
source inverters [ 2010-8M]
5. Explain the difference between current & voltage source inverters [2014Dec-10M]
6 .What is variable Dc
link inverters[2015 june-10]
7. What is forced commutated inverters. Explain the
auxiliary & complementary commutated
inverters[2012-12M]
8.What is inverters? Mention its applications[ 04M-2017]
9. Explain the current source inverters[ 2011-06M]
Post a Comment