SHORT QUESTIONS AND ANSWERS EEE-602-Power Electronics
1. Why IGBT is very popular noa!ays" a. #oer hea$ re%uire&en$s re%uire&en$s '. #oer si$(hin) losses (. S&aller snu''er snu ''er (ir(ui$ re%uire&en$s re%uire&en$s
*. 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!e 1. 0ons$ru($e! i$h nlayer2 (alle! !ri3$ re)ion 'e$een p4 layer an! n4 layer l ayer.. Dri3$ re)ion is no$ presen$. *. The vol$a)e2 (urren$ (urren$ an! poer ra$in)s are hi)her. #oer . /oer !io!es opera$e a$ hi)h spee!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$$er vol$a)e.
6. /oer 7OS,ET is a vol$a)e (on$rolle! !evi(e. Why" Be(ause $he ou$pu$ 8!rain9 (urren$ (an 'e (on$rolle! 'y )a$esour(e vol$a)e. :. /oer B;T is a (urren$ (on$rolle! !evi(e. Why"
Be(ause $he ou$pu$ 8(olle($or9 8 (olle($or9 (urren$ (an 'e (on$rolle! 'y 'ase (urren$. <. Wha$ are $he !i+eren$ $ypes o3 poer 7OS,ET" a. N(hannel 7OS,ET '. /(hannel 7OS,ET =. Ho (an a $hyris$or $urne! o+" A $hyris$or (an 'e $urne! o+ 'y &a>in) $he (urren$ ?oin) $hrou)h i$ $o @ero. 1. Dene la$(hin) (urren$. The la$(hin) (urren$ (urren$ is !ene! as $he &ini&u& &ini&u& value o3 ano!e (urren$ hi(h i$ &us$ a$$ain !urin) $urn on pro(ess $o &ain$ain (on!u($ion hen )a$e si)nal is re&ove!. 11. Dene hol!in) (urren$. The hol!in) (urren$ (urren$ is !ene! as $he &ini&u& &ini&u& value o3 ano!e (urren$ 'elo hi(h i$ &us$ 3all $o 3or $urnin) o+ $he $hyris$or. $hyris$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).
(. 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 re%uire!2 a $hyris$or is sai! $o 'e har!re! or over!riven. Har!rin) o3 a $hyris$or re!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 $urn o+ $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+ Turno+ $i&e 3or (onver$er )ra!e S0Rs is is 6 1 &s $urn $urn o+ $i&e 3or (onver$er )ra!e S0Rs an! inver$er )ra!e S0Rs an! 3or inver$er )ra!e S0Rs is 6 &s.
1<. Wha$ are $he a!van$a)es o3 GTO over S0R"
a. Eli&ina$ion o3 (o&&u$a$ion o3 (o&&u$a$in) (o&ponen$s in 3or(e! (o&&u$a$ion2 resul$in) in re!u($ion in (os$2 ei)h$ an! volu&e. '. Re!u($ion in a(ous$i( noise an! ele($ro&a)ne$i( ele($ro&a)ne$i( noise !ue $o eli&ina$ion o3 (o&&u$a$ion (ho>es. (. ,as$er ,as$er $urno+2 $urn o+2 per&i$$in) hi)h si$(hin) 3re%uen(ies. !. I&prove! e(ien(y o3 $he (onver$ers. 1=. Wha$ is &ean$ 'y phase (on$rolle! re($ier" I$ (onver$s Fe! a( vol$a)e in$o varia'le !( vol$a)e. *. 7en$ion so&e o3 $he appli(a$ions o3 (on$rolle! re($ier re($ier. a. S$eel rollin) &ills2 prin$in) press2 $eF$ile &ills an! paper &ills e&ployin) !( &o$or !rives. '. D0 $ra($ion (. Ele($ro (he&i(al an! ele($ro&e$allur)i(al pro(ess !. /or$a'le han! $ool !rives e. 7a)ne$ poer supplies 3. HD0 $rans&ission sys$e& *1. Wha$ is $he 3un($ion 3un ($ion o3 3reeheelin) !io!es in (on$rolle! re($ier" I$ serves $o pro(ess. a. I$ preven$s $he ou$pu$ vol$a)e 3ro& 'e(o&in) ne)a$ive. '. The loa! (urren$ is $rans3erre! 3ro& $he &ain $hyris$ors $o $he 3reeheelin) !io!e2 $here'y alloin) all o3 i$s $hyris$ors $o re)ain $heir 'lo(>in) s$a$es. **. Wha$ are $he a!van$a)es o3 3reeheelin) !io!es in a (on$rolle! in a (on$rolle! re($ier" re($ier" a. Inpu$ poer 3a($or is i&prove!.
'. #oa! (urren$ ave3or& is i&prove! an! $hus $he loa! per3or&an(e is 'e$$er. *. Wha$ is &ean$ 'y !elay an)le" The !elay an)le is !ene! as $he an)le 'e$een '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 a 3ully (on$rolle! 'ri!)e re($ier. re($ier. Hen(e 3or sa&e vol$a)e an! (urrn$ ra$in)s o3 S0rs2 poer han!le! 'y &i!poin$ (on)ura$ion is a'ou$ '. In &i!poin$ (onver$er2 ea(h se(on!ary in!in) shoul! 'e a'le $o supply $he loa! poer. poer. As su(h2 $he $rans3or&er ra$in) in &i!poin$ (onver$er is !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$)oin) ou$)oin) an! in(o&in) $hyris$ors are (on!u($in) is >non as overlap perio!. The an)ular a n)ular perio!2 hen 'o$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$al rin) s(he&es.
*C. Give an eFpression 3or avera)e vol$a)e o3 sin)le phase se&i(onver$ers. Avera)e ou$pu$ vol$a)e !( 8& - J9 81 4 (os J 9. *<. Wha$ is &ean$ 'y inpu$ poer 3a($or in (on$rolle! re($ier" The inpu$ poer 3a($or is !ene! !ene! as $he ra$io o3 $he $o$al &ean inpu$ poer $o $he $o$al R7S inpu$ vol$a&pere vo l$a&peres. s. /, 8 1 I1 (os J1 9 - 8 r&s Ir&s9 here here 1 phase vol$a)e2 I1 3un!a&en$al (o&ponen$ o3 $he supply (urren$2 J1 inpu$ !ispla(e&en$ an)le2 Ir&s supply r&s (urren$. *=. Wha$ are $he a!van$a)es o3 siF pulse (onver$er" a. 0o&&u$a$ion is &a!e si&ple. '. Dis$or$ion on $he a( si!e is re!u(e! !ue $o $he re!u($ion in loer or!er har&oni(s. (. In!u($an(e re!u(e! in series is (onsi!era'ly re!u(e!. . Wha$ is &ean$ 'y (o&&u$a$ion" I$ is $he pro(ess o3 (han)in) $he !ire($ion o3 (urren$ ?o in a par$i(ular pa$h o3 $he (ir(ui$. This pro(ess is use! in $hyris$ors 3or $urnin) i$ o+. 1. Wha$ are $he $ypes o3 (o&&u$a$ion" a. Na$ural (o&&u$a$ion '. ,or(e! (o&&u$a$ion *. Wha$ is &ean$ 'y na$ural (o&&u$a$ion" Here $he (urren$ ?oin) $hrou)h $he $hyris$or )oes $hrou)h a na$ural @ero an! ena'le $he $hyris$or $o $urn o+.
. Wha$ 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! $o o'$ain varia'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$s e. 7ine haulers 3. 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)e ou$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. <. Wri$e !on $he eFpression 3or avera)e ou$pu$ vol$a)e 3or s$ep !on (hopper.
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 3or s$ep up (hopper. Avera)e ou$pu$ vol$a)e 3or s$ep !on (hopper s2 J is $he !u$y (y(le 1 J 5. Wha$ is &ean$ 'y !u$y(y(le" Du$y (y(le is !ene! as $he ra$io o3 o 3 $he on $i&e o3 $he (hopper $o $he $o$al $i&e perio! o3 $he (hopper. (hopper. I$ is !eno$e! 'y α. 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 $he avera)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 3 8or $he (hoppin) perio! T9 is varie!. Here $o (on$rols are possi'le.
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 /ulse Wi!$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 Avera)e ou$pu$ vol$a)e 3or s$ep up (hopper is O α S F K1- 8 1 α 9L.
α
S.
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<. Wha$ is &ean$ 'y vol$a)e (o&&u$a$ion" In $his pro(ess2 a (har)e! (apa(i$or &o&en$arily reverse 'iases $he (on!u($in) $hyris$or an! $urn i$ o+. 5=. Wha$ is &ean$ 'y (urren$ (o&&u$a$ion" (o&&u$a$ion"
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$or ei$her 'e(o&es @ero or 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 $he pea> (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)h si$(hin) losses a$ hi)h opera$in) 3re%uen(ies. '. ,reeheelin) !io!e is su'e($e! $o $i(e $he supply vol$a)e. (. /ea> loa! vol$a)e is e%ual $o $i(e $he supply vol$a)e.
!. The (o&&u$a$in) (apa(i$or has $o (arry 3ull 3u ll 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! reali@e! 'y sensin) $he (apa(i$or (apa(i$or (urren$ $ha$ is al$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/S e. HD0 $rans&ission 6:. Wha$ are $he &ain (lassi(a$ion o3 inver$er" in ver$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 re%uire eF$ra (o&&u$a$ion (o&&u$a$ion (ir(ui$s 3or $urn o+ hi(h resul$s in un(rease! (o&pleFi$y o3 $he (ir(ui$. ,or $hese reasons $hyris$ors are no$ pre3erre! 3or inver$ers. 6<. Ho ou$pu$ 3re%uen(y is varie! in (ase o3 a $hyris$or"
The ou$pu$ 3re%uen(y is varie! varie! 'y varyin) $he $urn $urn o+ $i&e o3 $he $hyris$ors in $he inver$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!)e inver$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 $he loa! is (alle! a series inver$er.
: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 $he loa! is (alle! a parallel inver$er. ::. Wha$ are $he appli(a$ions o3 a series inver$er" The $hyris$orise! series inver$er inver$er pro!u(es an approFi approFi&a$ely &a$ely sinusoi!al ave3or& a$ a hi)h ou$pu$ 3re%uen(y2 ran)in) 3ro& * H@ $o 1>H@. I$ is (o&&only use! 3or Fe! ou$pu$ appli(a$ions su(h as a. 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$ers. :<. Wha$ is &ean$ 'y 7(7urray inver$er" I$ is an i&pulse (o&&u$a$e! inver$er hi(h relies on #0 (ir(ui$ an! an auFiliary $hyris$or 3or (o&&u$a$ion in $he loa! (ir(ui$. :=. Wha$ are $he appli(a$ions o3 a 0SI" a. In!u($ion hea$in) '. #a))in) AR (o&pensa$ion (. Spee! (on$rol o3 a( &o$ors
!. Syn(hronous &o$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 $he inver$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 $he hi)her or!er har&oni(s (an 'e l$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! $o eF(essive eF(essive hea$in) in $he in!u($ion &o$ors. This ill re!u(e $he loa! (arryin) (apa(i$y o3 $he &o$or. '. I3 $he (on$rol an! $he re)ula$in) (ir(ui$s are no$ properly shiel!e!2 har&oni(s 3ro& poer ri!e (an a+e($ $heir opera$ion an! an ! &al3un($ionin) (an resul$. (. Har&oni( (urren$s (ause losses in $he a( sys$e& an! (an even so&e $i&e pro!u(e resonan(e in $he sys$e&. Un!er resonan$ (on!i$ions2 $he ins$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 $he har&oni( (urren$ (an 'e use3ul.
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$ers
C5. 0o&pare 0SI an! SI. S. No. SI 0SI 1. Inpu$ 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$ (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 $he loa! i&pe!an(e The &a)ni$u!e o3 $he ou$pu$ vol$a)e vol$a)e an! i$s ave3or& !epen!s on $he na$ure o3 $he loa! i&pe!an(e 5. I$ re%uires 3ee!'a(> !io!es I$ !oes no$ re%uires re%uires 3ee!'a(> !io!es 6. 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.
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$o a varia'le vol$a)e i$hou$ (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 $ap (han)in) C<. Wha$ are $he a!van$a)es o3 a( vol$a)e (on$rollers" a. Hi)h e(ien(y '. ,leFi'ili$y in (on$rol (. #ess &ain$enan(e C=. Wha$ are $he !isa!van$a)es o3 a( vol$a)e (on$rollers" The &ain !ra 'a(> is $he in$ro!u($ion in$ro!u($ion o3 har&oni(s in $he supply (urren$ an! $he loa! vol$a)e ave3or&s par$i(ularly a$ lo ou$pu$ vol$a)es. <. Wha$ are $he $o &e$ho!s o3 (on$rol in a( a ( vol$a)e (on$rollers" a. ONO,, (on$rol '. /hase (on$rol <1. Wha$ is $he !i+eren(e 'e$een ONO,, (on$rol an! phase (on$rol"
ONO,, (on$rol In $his &e$ho!2 $he $hyris$ors are e&ploye! as si$(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$a)e. <*. Wha$ is $he a!van$a)e o3 ONO,, (on$rol" Due $o @erovol$a)e an! @ero (urren$ si$(hin) o3 $hyris$ors2 $he har&oni(s )enera$e! 'y $he si$(hin) a($ion are re!u(e!. <. Wha$ is $he !isa!van$a)e o3 ONO,, (on$rol" This $ype o3 (on$rol is appli(a'le in sys$e&s sys$e&s $ha$ have hi)h &e(hani(al iner$ia an! hi)h $her&al $i&e (ons$an$. <5. Wha$ is $he !u$y (y(le in ONO,, (on$rol &e$ho!" Du$y (y(le n- 8n 4 &92 here n no. o3 ON (y(les2 & no. o3 O,, (y(les.
<6. Wha$ is &ean$ 'y uni!ire($ional or hal3ave hal3ave a( vol$a)e (on$roller" Here $he poer ?o is (on$rolle! only !urin) $he posi$ive hal3(y(le o3 $he inpu$ vol$a)e. <:. Wha$ are $he !isa!van$a)es o3 uni!ire($ional or hal3 ave a( vol$a)e (on$roller" a. Due $o $he presen(e o3 !io!e on $he (ir(ui$2 $he (on$rol ran)e is li&i$e! an! $he
e+e($ive R7S ou$pu$ vol$a)e (an 'e varie! 'e$een C.CP an! 1P. '. The inpu$ (urren$ an! ou$pu$ vol$a)e are asy&&e$ri(al an! (on$ain a !( (o&ponen$.I3 $here is an inpu$ $rans3or&er2 s!a$ura$ion pro'le& ill o((ur (. I$ is only use! 3or lo poer resis$ive loa!.
I$ &eans $ha$ $he s$a)es o3 vol$a)e (on$rollers in parallel $ri))ere! in a proper se%uen(e one a3$er $he o$her so as $o o'$ain a varia'le ou$pu$ 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$her 3re%uen(y i$h ones$a)e (onversion. 0y(lo(onver$er is also >non as 3re%uen(y (han)er. =6. Wha$ are $he $o $ypes o3 (y(lo(onver$ers" (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 $he supply 3re%uen(y. 3re%uen(y. =C. Wha$ is &ean$ 'y s$ep!on (y(lo(onver$ers" In $hese (onver$ers2 $he ou$pu$ 3re%uen(y is &ore $han $he supply 3re%uen(y. 3re%uen(y. =<. Wha$ are $he appli(a$ions o3 (y(lo(onver$er" a. In!u($ion hea$in) '. Spee! (on$rol o3 hi)h poer a( !rives (. S$a$i( AR )enera$ion !. /oer supply in air(ra3$ or ship 'oar!s
==. 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$ (ir(ui$ $ha$ per&i$s per&i$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$ (ir(ui$ $ha$ per&i$s per&i$s $he ?o o3 (urren$ !urin) ne)a$ive hal3 (y(le o3 ou$pu$ (urren$ is (alle! ne)a$ive (onver$er )roup.
