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Power Electronics Short Questions and Answers

Jun 02, 2018

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Palak Ariwala
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    SHORTQUESTIONS AND

    ANSWERS

    EEE-602-Power

    Electronics

    1. Why IGBT is very popular noa!ays"a. #oer hea$ re%uire&en$s'. #oer si$(hin) losses(. S&aller snu''er (ir(ui$ re%uire&en$s

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    *. Wha$ are $he !i+eren$ &e$ho!s $o $urn on $he $hyris$or"a. ,orar! vol$a)e $ri))erin)'. Ga$e $ri))erin)

    (. !v-!$ $ri))erin)!. Te&pera$ure $ri))erin)e. #i)h$ $ri))erin)

    . Wha$ is $he !i+eren(e 'e$een poer !io!e an! si)nal!io!e"S.No./oer !io!e Si)nal !io!e1.

    0ons$ru($e! i$h nlayer2 (alle!!ri3$ re)ion 'e$een p4 layer an!n4 layer.Dri3$ re)ion is no$ presen$.*.

    The vol$a)e2 (urren$ an! poerra$in)s are hi)her.#oer.

    /oer !io!es opera$e a$ hi)hspee!s.Opera$es a$ hi)her si$(hin) spee!.

    5. IGBT is a vol$a)e (on$rolle! !evi(e. Why"Be(ause $he (on$rollin) para&e$er is )a$ee&i$$er vol$a)e.

    6. /oer 7OS,ET is a vol$a)e (on$rolle! !evi(e. Why"Be(ause $he ou$pu$ 8!rain9 (urren$ (an 'e (on$rolle! 'y)a$esour(e vol$a)e.

    :. /oer B;T is a (urren$ (on$rolle! !evi(e. Why"

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    Be(ause $he ou$pu$ 8(olle($or9 (urren$ (an 'e (on$rolle! 'y'ase (urren$.

    in) $he (urren$ ?oin)$hrou)h i$ $o @ero.

    1. Dene la$(hin) (urren$.The la$(hin) (urren$ is !ene! as $he &ini&u& value o3ano!e (urren$ hi(h i$&us$ a$$ain !urin) $urn on pro(ess $o &ain$ain (on!u($ionhen )a$e si)nal is re&ove!.

    11. Dene hol!in) (urren$.The hol!in) (urren$ is !ene! as $he &ini&u& value o3

    ano!e (urren$ 'elohi(h i$ &us$ 3all $o 3or $urnin) o+ $he $hyris$or.

    1*. Wha$ is a snu''er (ir(ui$"I$ (onsis$s o3 a series (o&'ina$ion o3 a resis$or an! a(apa(i$or in parallel i$h $he$hyris$ors. I$ is &ainly use! 3or !v - !$ pro$e($ion.

    1. Wha$ losses o((ur in a $hyris$or !urin) or>in)(on!i$ions"a. ,orar! (on!u($ion losses'. #oss !ue $o lea>a)e (urren$ !urin) 3orar! an! reverse'lo(>in).

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    (. Si$(hin) losses a$ $urnon an! $urno+.!. Ga$e $ri))erin) loss.

    15. Dene har!!rivin) or over!rivin).When )a$e (urren$ is several $i&es hi)her $han $he &ini&u&)a$e (urren$re%uire!2 a $hyris$or is sai! $o 'e har!re! or over!riven.Har!rin) o3 a $hyris$orre!u(es i$s $urnon $i&e an! enhan(es i$s !i-!$ (apa'ili$y.

    16. Dene (ir(ui$ $urn o+ $i&e.I$ is !ene! as $he $i&e !urin) hi(h a reverse vol$a)e is

    applie! a(ross $he$hyris$or !urin) i$s (o&&u$a$ion pro(ess.

    1:. Why (ir(ui$ $urn o+ $i&e shoul! 'e )rea$er $han $he$hyris$or $urno+ $i&e"0ir(ui$ $urn o+ $i&e shoul! 'e )rea$er $han $he $hyris$or $urno+ $i&e 3or relia'le$urno+2 o$herise $he !evi(e &ay $urnon a$ an un!esire!

    ins$an$2 a pro(ess (alle!(o&&u$a$ion 3ailure.

    1C. Wha$ is $he $urno+ $i&e 3or (onver$er )ra!e S0Rs an!inver$er )ra!e S0Rs"

    Turno+ $i&e 3or (onver$er )ra!e S0Rs is 6 1 &s $urno+ $i&e 3or (onver$er)ra!e S0Rs an! inver$er )ra!e S0Rs an! 3or inver$er )ra!eS0Rs is 6 &s.

    1

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    a. Eli&ina$ion o3 (o&&u$a$ion o3 (o&&u$a$in) (o&ponen$sin 3or(e! (o&&u$a$ion2resul$in) in re!u($ion in (os$2 ei)h$ an! volu&e.'. Re!u($ion in a(ous$i( noise an! ele($ro&a)ne$i( noise !ue

    $o eli&ina$ion o3(o&&u$a$ion (ho>es.(. ,as$er $urno+2 per&i$$in) hi)h si$(hin) 3re%uen(ies.!. I&prove! e(ien(y o3 $he (onver$ers.

    1=. Wha$ is &ean$ 'y phase (on$rolle! re($ier"I$ (onver$s Fe! a( vol$a)e in$o varia'le !( vol$a)e.

    *. 7en$ion so&e o3 $he appli(a$ions o3 (on$rolle! re($ier.a. S$eel rollin) &ills2 prin$in) press2 $eF$ile &ills an! paper&ills e&ployin) !(&o$or !rives.'. D0 $ra($ion(. Ele($ro (he&i(al an! ele($ro&e$allur)i(al pro(ess!. /or$a'le han! $ool !rivese. 7a)ne$ poer supplies3. HD0 $rans&ission sys$e&

    *1. Wha$ is $he 3un($ion o3 3reeheelin) !io!es in (on$rolle!re($ier"I$ serves $o pro(ess.a. I$ preven$s $he ou$pu$ vol$a)e 3ro& 'e(o&in) ne)a$ive.'. The loa! (urren$ is $rans3erre! 3ro& $he &ain $hyris$ors $o$he 3reeheelin) !io!e2$here'y alloin) all o3 i$s $hyris$ors $o re)ain $heir 'lo(>in)s$a$es.

    **. Wha$ are $he a!van$a)es o3 3reeheelin) !io!es in a(on$rolle! in a (on$rolle! re($ier"a. Inpu$ poer 3a($or is i&prove!.

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    '. #oa! (urren$ ave3or& is i&prove! an! $hus $he loa!per3or&an(e is 'e$$er.

    *. Wha$ is &ean$ 'y !elay an)le"

    The !elay an)le is !ene! as $he an)le 'e$een $he @ero(rossin) o3 $he inpu$vol$a)e an! $he ins$an$ $he $hyris$or is re!.

    *5. Wha$ are $he a!van$a)es o3 sin)le phase 'ri!)e(onver$er over sin)le phase &i!poin$(onver$er"a. S0Rs are su'e($e! $o a pea>inverse vol$a)e o3 *& in a3ully (on$rolle! 'ri!)e

    re($ier. Hen(e 3or sa&e vol$a)e an! (urrn$ ra$in)s o3 S0rs2poer han!le! 'y&i!poin$ (on)ura$ion is a'ou$'. In &i!poin$ (onver$er2 ea(h se(on!ary in!in) shoul! 'ea'le $o supply $he loa!poer. As su(h2 $he $rans3or&er ra$in) in &i!poin$ (onver$eris !ou'le $he loa!ra$in).

    *6. Wha$ is (o&&u$a$ion an)le or overlap an)le"The (o&&u$a$ion perio! hen ou$)oin) an! in(o&in)$hyris$ors are (on!u($in) is>non as overlap perio!. The an)ular perio!2 hen 'o$h!evi(es share (on!u($ion is>non as $he (o&&u$a$ion an)le or overlap an)le.

    *:. Wha$ are $he !i+eren$ &e$ho!s o3 rin) (ir(ui$s 3or line(o&&u$a$e! (onver$er"a. U;T rin) (ir(ui$.'. The (osine ave (rossin) pulse $i&in) (on$rol.(. Di)i$al rin) s(he&es.

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    *C. Give an eFpression 3or avera)e vol$a)e o3 sin)le phasese&i(onver$ers.Avera)e ou$pu$ vol$a)e !( 8& - J9 81 4 (os J 9.

    *

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    . Wha$ is &ean$ 'y 3or(e! (o&&u$a$ion" In $his(o&&u$a$ion2 $he (urren$ ?oin) $hrou)h$he $hyris$or is 3or(e! $o 'e(o&e @ero 'y eF$ernal (ir(ui$ry.

    5. Wha$ is &ean$ 'y !( (hopper"A !( (hopper is a hi)h spee! s$a$i( si$(h use! $o o'$ainvaria'le !( vol$a)e 3ro&a (ons$an$ !( vol$a)e.

    6. Wha$ are $he appli(a$ions o3 !( (hopper"a. Ba$$ery opera$e! vehi(les

    '. Tra($ion &o$or (on$rol in ele($ri( $ra($ion(. Trolly (ars!. 7arine hois$se. 7ine haulers3. Ele($ri( 'ra>in).

    :. Wha$ are $he appli(a$ions o3 !( (hopper"0hopper provi!es

    a. Hi)h e(ien(y'. S&oo$h a((elera$ion(. ,as$ !yna&i( response!. Re)enera$ion

    C. Wha$ is &ean$ 'y s$epup an! s$ep!on (hopper"In a s$ep !on (hopper or Bu(> (onver$er2 $he avera)eou$pu$ vol$a)e is less $han$he inpu$ vol$a)e. In a s$ep up (hopper or Boos$ (onver$er2$he avera)e ou$pu$ vol$a)e is&ore $han $he inpu$ vol$a)e.

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    Avera)e ou$pu$ vol$a)e 3or s$ep !on (hopper J s2 J is$he !u$y (y(le

    =. Wri$e !on $he eFpression 3or avera)e ou$pu$ vol$a)e 3ors$ep up (hopper.Avera)e ou$pu$ vol$a)e 3or s$ep !on (hopper s2 J is$he !u$y (y(le1 J

    5. Wha$ is &ean$ 'y !u$y(y(le"Du$y (y(le is !ene! as $he ra$io o3 $he on $i&e o3 $he(hopper $o $he $o$al $i&e

    perio! o3 $he (hopper. I$ is !eno$e! 'y .

    51. Wha$ are $he $o $ypes o3 (on$rol s$ra$e)ies"a. Ti&e Ra$io 0on$rol 8TR09'. 0urren$ #i&i$ 0on$rol &e$ho! 80#09

    5*. Wha$ is &ean$ 'y TR0"In TR02 $he value o3 Ton - T is varie! in or!er $o (han)e $heavera)e ou$pu$vol$a)e.

    5. Wha$ are $he $o $ypes o3 TR0"a. 0ons$an$ 3re%uen(y (on$rol

    '. aria'le 3re%uen(y (on$rol

    55. Wha$ is &ean$ 'y ,7 (on$rol in a !( (hopper"In 3re%uen(y &o!ula$ion (on$rol2 $he (hoppin) 3re%uen(y 38or $he (hoppin)perio! T9 is varie!. Here $o (on$rols are possi'le.

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    a. On$i&e Ton is >ep$ (ons$an$'. O+ perio! To+ is >ep$ (ons$an$.

    56. Wha$ is &ean$ 'y /W7 (on$rol in !( (hopper"In $his (on$rol &e$ho!2 $he on $i&e Ton is varie! 'u$(hoppin) 3re%uen(y is >ep$(ons$an$. The i!$h o3 $he pulse is varie! an! hen(e $his$ype o3 (on$rol is >non as /ulseWi!$h 7o!ula$ion 8/W79.

    5:. Wri$e !on $he eFpression 3or $he avera)e ou$pu$vol$a)e 3or s$ep !on an! s$ep up(hopper.

    Avera)e ou$pu$ vol$a)e 3or s$ep !on (hopper is O S.Avera)e ou$pu$vol$a)e 3or s$ep up (hopper is O S F K1- 8 1 9L.

    5C. Wha$ are $he !i+eren$ $ypes o3 (hopper i$h respe($ $o(o&&u$a$ion pro(ess"a. ol$a)e (o&&u$a$e! (hopper.'. 0urren$ (o&&u$a$e! (hopper.(. #oa! (o&&u$a$e! (hopper.

    5

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    In $his pro(ess2 a (urren$ pulse is &a!e $o ?o in $he reverse!ire($ion $hrou)h$he (on!u($in) $hyris$or an! hen $he ne$ $hyris$or (urren$'e(o&es @ero2 i$ is $urne! o+.

    6. Wha$ is &ean$ 'y loa! (o&&u$a$ion"In $his pro(ess2 $he loa! (urren$ ?oin) $hrou)h $he $hyris$orei$her 'e(o&es @eroor is $rans3erre! $o ano$her !evi(e 3ro& $he (on!u($in)$hyris$or.61. Wha$ are $he a!van$a)es o3 (urren$ (o&&u$a$e!(hopper"a. The (apa(i$or alays re&ains (har)e! i$h $he (orre($

    polari$y.'. 0o&&u$a$ion is relia'le as loa! (urren$ is less $han $hepea> (o&&u$a$ion (urren$I0/.(. The auFiliary $hyris$or TA is na$urally (o&&u$a$e! as i$s(urren$ passes $hrou)h@ero value.

    6*. Wha$ are $he a!van$a)es o3 loa! (o&&u$a$e! (hopper"a. 0o&&u$a$in) in!u($or is no$ re%uire!.'. I$ is (apa'le o3 (o&&u$a$in) any a&oun$ o3 loa! (urren$.(. I$ (an or> a$ hi)h 3re%uen(ies in $he or!er o3 >H@.!. ,il$erin) re%uire&en$s are &ini&al.

    6. Wha$ are $he !isa!van$a)es o3 loa! (o&&u$a$e!(hopper"a. ,or hi)h poer appli(a$ions2 e(ien(y 'e(o&es very lo'e(ause o3 hi)hsi$(hin) losses a$ hi)h opera$in) 3re%uen(ies.'. ,reeheelin) !io!e is su'e($e! $o $i(e $he supplyvol$a)e.(. /ea> loa! vol$a)e is e%ual $o $i(e $he supply vol$a)e.

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    !. The (o&&u$a$in) (apa(i$or has $o (arry 3ull loa! (urren$a$ a 3re%uen(y o3 hal3(hoppin) 3re%uen(y.e. One $hyris$or pair shoul! 'e $urne!on only hen $he

    o$her pair is (o&&u$a$e!.This (an 'e reali@e! 'y sensin) $he (apa(i$or (urren$ $ha$ isal$erna$in).

    65. Wha$ is &ean$ 'y inver$er"A !evi(e $ha$ (onver$s !( poer in$o a( poer a$ !esire!ou$pu$ vol$a)e an!3re%uen(y is (alle! an inver$er.

    66. Wha$ are $he appli(a$ions o3 an inver$er"a. A!us$a'le spee! !rives'. In!u($ion hea$in)(. S$an!'y air(ra3$ poer supplies!. U/Se. HD0 $rans&ission

    6:. Wha$ are $he &ain (lassi(a$ion o3 inver$er"a. ol$a)e Sour(e Inver$er'. 0urren$ Sour(e Inver$er

    6C. Why $hyris$ors are no$ pre3erre! 3or inver$ers"Thyris$ors re%uire eF$ra (o&&u$a$ion (ir(ui$s 3or $urn o+hi(h resul$s inun(rease! (o&pleFi$y o3 $he (ir(ui$. ,or $hese reasons$hyris$ors are no$ pre3erre! 3orinver$ers.

    6

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    The ou$pu$ 3re%uen(y is varie! 'y varyin) $he $urn o+ $i&e o3$he $hyris$ors in $heinver$er (ir(ui$2 i.e. $he !elay an)le o3 $he $hyris$ors is varie!.

    6=. Give $o a!van$a)es o3 0SI.a. 0SI !oes no$ re%uire any 3ee!'a(> !io!es.'. 0o&&u$a$ion (ir(ui$ is si&ple as i$ involves only$hyris$ors.

    :. Wha$ is $he &ain !ra'a(> o3 a sin)le phase hal3 'ri!)einver$er"I$ re%uire a ire !( supply.

    :1. Why !io!es shoul! 'e (onne($e! in an$iparallel i$h$he$hyris$ors in inver$er (ir(ui$s",or R# loa!s2 loa! (urren$ ill no$ 'e in phase i$h loa!vol$a)e an! $he !io!es

    (onne($e! in an$iparallel ill allo $he (urren$ $o ?o hen$he &ain $hyris$ors are$urne! o+. These !io!es are (alle! 3ee!'a(> !io!es.

    :*. Wha$ $ypes o3 inver$ers re%uire 3ee!'a(> !io!es"SI i$h R# loa!.

    :. Wha$ is &ean$ a series inver$er"An inver$er in hi(h $he (o&&u$a$in) ele&en$s are(onne($e! in series i$h $heloa! is (alle! a series inver$er.

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    :5. Wha$ is $he (on!i$ion $o 'e sa$ise! in $he sele($ion o3 #an! 0 in a series inver$er"R* M 5#0

    :6. Wha$ is &ean$ a parallel inver$er"An inver$er in hi(h $he (o&&u$a$in) ele&en$s are(onne($e! in parallel i$h $heloa! is (alle! a parallel inver$er.

    ::. Wha$ are $he appli(a$ions o3 a series inver$er"The $hyris$orise! series inver$er pro!u(es an approFi&a$elysinusoi!al ave3or&

    a$ a hi)h ou$pu$ 3re%uen(y2 ran)in) 3ro& * H@ $o 1>[email protected]$ is (o&&only use! 3orFe! ou$pu$ appli(a$ions su(h asa. Ul$rasoni( )enera$or.'. In!u($ion hea$in).(. Sonar Trans&i$$er!. ,luores(en$ li)h$in).:C. Ho is $he inver$er (ir(ui$ (lassie! 'ase! on(o&&u$a$ion (ir(ui$ry"

    a. #ine (o&&u$a$e! inver$ers.'. #oa! (o&&u$a$e! inver$ers.(. Sel3 (o&&u$a$e! inver$ers.!. ,or(e! (o&&u$a$e! inver$ers.

    :

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    !. Syn(hronous &o$or s$ar$in).

    C. Wha$ is &ean$ 'y /W7 (on$rol"

    In $his &e$ho!2 a Fe! !( inpu$ vol$a)e is )iven $o $heinver$er an! a (on$rolle!a( ou$pu$ vol$a)e is o'$aine! 'y a!us$in) $he on an! o+perio!s o3 $he inver$er(o&ponen$s. This is $he &os$ popular &e$ho! o3 (on$rollin)$he ou$pu$ vol$a)e an! $his&e$ho! is $er&e! as /W7 (on$rol.

    C1. Wha$ are $he a!van$a)es o3 /W7 (on$rol"

    a. The ou$pu$ vol$a)e (an 'e o'$aine! i$hou$ any a!!i$ional(o&ponen$s.'. #oer or!er har&oni(s (an 'e eli&ina$e! or &ini&i@e!alon) i$h i$s ou$pu$vol$a)e (on$rol. As $he hi)her or!er har&oni(s (an 'el$ere! easily2 $he l$erin)re%uire&en$s are &ini&i@e!.C*. Wha$ are $he !isa!van$a)es o3 $he har&oni(s presen$ in$he inver$er sys$e&"

    a. Har&oni( (urren$s ill lea! $o eF(essive hea$in) in $hein!u($ion &o$ors. Thisill re!u(e $he loa! (arryin) (apa(i$y o3 $he &o$or.'. I3 $he (on$rol an! $he re)ula$in) (ir(ui$s are no$ properlyshiel!e!2 har&oni(s 3ro&poer ri!e (an a+e($ $heir opera$ion an! &al3un($ionin) (anresul$.(. Har&oni( (urren$s (ause losses in $he a( sys$e& an! (aneven so&e $i&e pro!u(eresonan(e in $he sys$e&. Un!er resonan$ (on!i$ions2 $heins$ru&en$a$ion an!&e$erin) (an 'e a+e($e!.!. On (ri$i(al loa!s2 $or%ue pulsa$ion pro!u(e! 'y $hehar&oni( (urren$ (an 'euse3ul.

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    C. Wha$ are $he &e$ho!s o3 re!u($ion o3 har&oni( (on$en$"a. Trans3or&er (onne($ions'. Sinusoi!al /W7

    (. 7ul$iple (o&&u$a$ion in ea(h (y(le!. S$eppe! ave inver$ers

    C5. 0o&pare 0SI an! SI.S. No. SI 0SI1.

    Inpu$ vol$a)e is &ain$aine!(ons$an$Inpu$ (urren$ is (ons$an$ 'u$a!us$a'le*.

    The ou$pu$ vol$a)e !oes no$!epen! on $he loa!

    The ou$pu$ (urren$ !oes no$ !epen!on $he loa!

    .The &a)ni$u!e o3 $he ou$pu$(urren$ an! i$s ave3or&!epen!s on $he na$ure o3 $heloa! i&pe!an(e

    The &a)ni$u!e o3 $he ou$pu$ vol$a)ean! i$s ave3or& !epen!s on $hena$ure o3 $he loa! i&pe!an(e5.I$ re%uires 3ee!'a(> !io!es I$ !oes no$ re%uires 3ee!'a(>!io!es6. 0o&&u$a$ion (ir(ui$ is(o&pli(a$e! i.e. i$ (on$ains(apa(i$ors an! in!u($ors.0o&&u$a$ion (ir(ui$ is si&ple i.e. i$(on$ains only (apa(i$ors.

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    C6. Wha$ are $he !isa!van$a)es o3 /W7 (on$rol"S0Rs are eFpensive as $hey &us$ possess lo $urnon an!

    $urno+ $i&es.

    C:. Wha$ !oes a( vol$a)e (on$roller &ean"I$ is !evi(e hi(h (onver$s Fe! al$erna$in) vol$a)e in$o avaria'le vol$a)ei$hou$ (han)e in 3re%uen(y.

    CC. Wha$ are $he appli(a$ions o3 a( vol$a)e (on$rollers"

    a. Do&es$i( an! in!us$rial hea$in)'. #i)h$in) (on$rol(. Spee! (on$rol o3 sin)le phase an! $hree phase a( &o$ors!. Trans3or&er $ap (han)in)

    C

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    ONO,, (on$rol In $his &e$ho!2 $he $hyris$ors are e&ploye!assi$(hes $o (onne($ $he loa! (ir(ui$ $o $he sour(e 3or a 3e(y(les o3 $he loa! vol$a)e an!

    !is(onne($ i$ 3or ano$her 3e (y(les. /hase (on$rol In $his&e$ho!2 $hyris$or si$(hes(onne($ $he loa! $o $he a( sour(e 3or a por$ion o3 ea(h hal3(y(le o3 inpu$ vol$a)e.

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    e+e($ive R7S ou$pu$ vol$a)e (an 'e varie! 'e$een C.CPan! 1P.'. The inpu$ (urren$ an! ou$pu$ vol$a)e are asy&&e$ri(alan! (on$ain a !(

    (o&ponen$.I3 $here is an inpu$ $rans3or&er2 s!a$ura$ionpro'le& ill o((ur(. I$ is only use! 3or lo poer resis$ive loa!.

  • 8/10/2019 Power Electronics Short Questions and Answers

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    I$ &eans $ha$ $he s$a)es o3 vol$a)e (on$rollers in parallel$ri))ere! in a properse%uen(e one a3$er $he o$her so as $o o'$ain a varia'leou$pu$ i$h lo har&oni( (on$en$.

    =. Wha$ are $he a!van$a)es o3 se%uen(e (on$rol o3 a(vol$a)e re)ula$ors"a. Sys$e& poer 3a($or is i&prove!.'. Har&oni(s are re!u(e! in $he sour(e (urren$ an! $he loa!vol$a)e.

    =5. Wha$ is &ean$ 'y (y(lo(onver$er"

    I$ (onver$s inpu$ poer a$ one 3re%uen(y $o ou$pu$ poer a$ano$her 3re%uen(yi$h ones$a)e (onversion. 0y(lo(onver$er is also >non as3re%uen(y (han)er.

    =6. Wha$ are $he $o $ypes o3 (y(lo(onver$ers"a. S$epup (y(lo(onver$ers'. S$ep!on (y(lo(onver$ers

    =:. Wha$ is &ean$ 'y s$epup (y(lo(onver$ers"In $hese (onver$ers2 $he ou$pu$ 3re%uen(y is less $han $hesupply 3re%uen(y.

    =C. Wha$ is &ean$ 'y s$ep!on (y(lo(onver$ers"In $hese (onver$ers2 $he ou$pu$ 3re%uen(y is &ore $han $hesupply 3re%uen(y.

    =

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    ==. Wha$ is &ean$ 'y posi$ive (onver$er )roup in a(y(lo(onver$er"

    The par$ o3 $he (y(lo(onver$er (ir(ui$ $ha$ per&i$s $he ?o o3(urren$ !urin)posi$ive hal3 (y(le o3 ou$pu$ (urren$ is (alle! posi$ive(onver$er )roup.

    1.Wha$ is &ean$ 'y ne)a$ive (onver$er )roup in a(y(lo(onver$er"

    The par$ o3 $he (y(lo(onver$er (ir(ui$ $ha$ per&i$s $he ?o o3(urren$ !urin) ne)a$ive hal3

    (y(le o3 ou$pu$ (urren$ is (alle! ne)a$ive (onver$er )roup.