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New Modified Cascaded

H-Bridge Multilevel Inverter Topology

with Reduced Switches

Sathish Cherukuru1, Clinton joel.C2, Sahaya Jeenson Jonish.A3,Dr.K.Sathiyasekar4

1,2,3UG Students, 4Proessor,!!! De"t,S.A. !n#ineerin# $olle#e

Chennai, %a&ilnadu, 'ndia.

$lintonjoel(#&ail.$o&,ksathiyasekar(#&ail.$o&

Abstract- Multilevel Inverter widely used in high

power industrial applications. This paper presents a

new odified cascaded H-Bridge ultilevel inverter

with reduction of switching coponent. In traditional

CHB inverters re!uired ore nu"er of coponents#

it see to ore cople$ control circuitry and "ul%y.

Since &ast few decade the researchers fro all over

world concentrating to iprove the efficiency of

Multilevel Inverter such as voltage "alancing#

reduction in coponents# odulation ethods and

control techni!ue etc. The 'roposed ultilevel

inverter output voltage level increasing "y using less

nu"er of switches driven "y the ulticarrier

odulation techni!ues. In this paper presents

generali(ed structure# )peration# coparison with

other traditional topology# Siulation results with

M*T&*B+SIM,&IN and e$periental results.

Index Terms- Cascaded H-Bridge CHB/ inverter#

Multicarrier Modulation# Multilevel Inverter# Total

Haronics 0istortionTH0/.

'.')%*+DUC%'+)

%he dierent ty"es $as$aded &ultileel inerterto"olo#y are aaila-le. A $ontinuous deelo"&ento &ultileel $onerter to drie hi#h olta#e andhi#h $urrent industrial a""li$ations1/. )o0adays,&ultileel inerter are #ood solutions or "o0era""li$ations due to the a$t that they $an a$hiee

hi#h "o0er usin# adan$ed "o0er se&i$ondu$tor1/. o0eer, the &ain disadanta#eo the &ultileel inerter &ore nu&-er o olta#eleel lead to in$rease the &ain s0it$hes,$o&"leity o $ontrol te$hniue and DC link$a"a$itor olta#e i&-alan$e .%here are seeral

adanta#es $o&"ared 0ith traditional or$onentional "o0er $onersion &ethods. 'n&ultileel inerter the isolated DC sour$es or -anko series $a"a$itors are used. 'solated DC sour$esare aaila-le ro& the Photooltai$ $ell or re$tiied

out"ut ro& the three "hase &ain su""ly. %hePhotooltai$ "o0er $onersion is one o the -est

suita-le a""li$ations or $as$aded rid#e&ultileel inerter. %he s&aller olta#e leelin$rease to lead the out"ut uality in ter&s oredu$e the olta#e stress 5d6dt7, !le$tro&a#neti$'ntereren$e 5!8'7 and dra0 in"ut $urrent 0ith lo0distortion. o0eer these adanta#es are ery

attra$tie to the industrial a""li$ation andresear$hers all oer the 0orld $ontri-utin# toi&"roe the "eror&an$e 5$ontrol si&"lii$ation,redu$ed %D, less nu&-er o $o&"onents and

ri""le $urrent7 o &ultileel inerter1/. Sin$e lastde$ade the interest o the resear$hers are

$ontri-utin# to urther deelo"&ent o a ne0&ultileel $onerters to"olo#y 0ith uniue&odulation strate#ies. %he resear$hers ro& alloer 0orld introdu$in# nu&-er o re$ent andadan$ed &ultileel inerters to"olo#ies. %here areseeral &ultileel $onerters are $o&&er$iali9ed

or hi#h "o0er a""li$ations su$h as :lei-leAC trans&ission syste&s5:AC%S7 Controllers,%rain %ra$tion,Auto&otie a""li$ations, rene0a-leener#y "o0er $onersion and trans&ission 2/;4/et$. So&e ne0 &ultileel inerter to"olo#ies are

su##ested 0ith dierent o"eratin# &ethods 0ithredu$ed s0it$heseel 8ulti ste" 'nerter +"ti&i9ationUsin#/ adanta#e o reuirin# the sa&e nu&-er o"o0er transistors as the leels #enerated, and

thereore, the se&i$ondu$tors are redu$ed -y hal0ith res"e$t to the "reious to"olo#ies. !en

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thou#h, it reuires &ore nu&-er o s0it$hes$o&"are 0ith "ro"osed &ultileel inerter. %here isalso another to"olo#y -y series 6 "arallel s0it$hin#

the dei$es the nu&-er o olta#e leel in$reases0hi$h reuires &ore nu&-er o s0it$hes than the"ro"osed to"olo#y or the sa&e leels. So&e o the

other to"olo#ies suer ro& the additional$o&"onents 5diodes7, $o&"leities o $a"a$itor-alan$in# et$.,

'n this "a"er &ainly deal 0ith ne0&ultileel inerter to"olo#y is sy&&etri$alto"olo#ies 0ith &ini&u& nu&-er o s0it$hes.%here are asy&&etri$al to"olo#ies 0hi$h reuireuneual olta#e sour$e. %he &ajor dra0-a$k oasy&&etri$al to"olo#y is arious ratin#s o

s0it$hes are reuired?/.

:i#ure1. General Stru$ture o Cas$aded ;rid#e 'nerter

y usin# 8ulti;0indin# transor&er $an#enerate the &ultileel out"ut, &ore $o&"le and$ost o &anua$turin# the 8ulti 0indin#

transor&er is hi#h?/. %he to"olo#y in$ludes 0ith;rid#e and Auiliary -idire$tional s0it$h, toredu$e the "o0er $ir$uit $o&"leity and &odulator

$ir$uit deelo"&ent@/, !en thou#h the nu&-er os0it$hes are &ore $o&"are 0ith the "ro"osedto"olo#y.

''. P*+P+S!D 8U>%'>!!> ')!*%!*%+P+>+GB

A. General Description:

%his to"olo#y is a si&"liied C inertersy&&etri$ to"olo#y. %he &ain adanta#e o

"ro"osed to"olo#y is less nu&-er o s0it$hes $o&"ared 0ith $onentional &ultileel inerter.

Number of Level (m)= 2n+1................(1)

Number of Main !itc"es (n s!itc") =55&;17627 4........................................527

Ehere F& is the nu&-er o out"ut olta#e leel,Fn nu&-er DC sour$e s0it$hes.:i#ure.1 sho0s the#eneral $ir$uit dia#ra& o "ro"osed &ultileelinerter. ' nu&-er leels in$reases add one s0it$h

or ea$h leel, si&"le $ontrol $ir$uitry. %he Uniue&odulation strate#ies are a""li$a-le or thisto"olo#y. %he nu&-ers o s0it$hes are reuired orea$h leel and s0it$hes $an -e $al$ulated ro& thea-oe euations 517 and 527. %o #et a Positie hal,"ro"erly turn +) the s0it$hes and the $urrent lo0

ro& the "oint A to 0ill #enerate a "ositie"olarity, the lo0 ro& to A 0ill #enerate thene#atie "olarity as sho0n in :i#ure 25a7. 'n#eneral, in order to a$hiee an eual olta#e ste"s,the eual and sa&e d$ sour$e olta#e to -e use. %heuneual d$ #enerate the dierent olta#e ste"s.

%here are seeral &ultileel inerters are$o&&er$iali9ed or hi#h "o0er a""li$ations su$has :lei-le AC %rans&ission Syste&s 5:AC%S7Controllers, %rain %ra$tion, Auto&otiea""li$ations, rene0a-le ener#y "o0er $onersionand trans&ission et$.

:i#ure 25a7. Generalised Stru$ture o Pro"osed %o"olo#y

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:i#ure 25-7. *e$onstru$ted "ro"osed C inerter to"olo#y

#. $ircuit Description:

%he ollo0in# out"ut olta#e leels

reuired to #enerate seen leel olta#e +%&c'+2%&c' +%&c' '*%&c'*2%&c'*%&c.

(i)ositive olarit,:

:or d$ the S2, S?, S3 s0it$hes are +).

%he S1 is $onne$ted in "ositie ter&inal o the loadand S3 is $onne$ted 0ith ne#atie ter&inal o theload throu#h S?.or 2d$ and3d$,s0it$hes S2and S? are $ontinuously +) or "ositie hal $y$lethe s0it$hes S4 and S< are %urn +) a$$ordin# tothe

(ii)Ne-ative olarit,:

:or ;d$ the S1, S=, S3 s0it$hes are +).%he S2 is $onne$ted in "ositie ter&inal o the loadand S3 is $onne$ted 0ith ne#atie ter&inal o the

load throu#h S=.Su$h a 0ay that s0it$hes S1 andS= are $ontinuously +) or "ositie hal $y$le thes0it$hes, S4 and S< are %urn +) a$$ordin# to thePE8 si#nals as sho0n in %a-le1.

%a-le ' . S0it$hin# "attern

'. 8+DU>A%'+) %!C)'HU!

%he "ro"osed syste& $an -e run 0itheistin# &odulation te$hniue Alternatie Phase+""osition Dis"osition 5AP+D7. ' 8I? 58 is

nu&-er o >eel7 the reuired $arrier 0aeor&s is8;1I=.

:i#ure 25d7 AP+D 8odulation

%here are seeral uniue $arrier -asedPE8 5CPE87 te$hniues are aaila-le or

&ultileel inerter. +ne o the &ost$o&&on &ethods is AP+D 5Alternatie Phase+""osition Dis"osition7.AP+D $arriers in adja$entside are "hase shited -y1@ and CPE8reuired *1 trian#ular $arrier 0aeor& and S isthe nu&-er o olta#e leel as sho0n in :i#ure 25d7

'''.S'8U>A%'+) *!SU>%S

%he si&ulated ? leel out"ut 0aeor& ini#ure3.as.,

%'8! 5S!CS7

:i#ure 3. 8atla- Si&ulation

(i)ast ourier /ransform(/) :

::% is an al#orith& to $o&"ute the

dis$rete ourier transor& 5D:%7 and 'nerse

dis$rete ourier transor&5'D:%7. A ourier

transor& $onerts ti&e to reuen$y and i$e;

ersa.::% ra"idly su$h transor&ations -y

a$tori9in# the D:% &atr into a "rodu$t o

s"arse 5 &ostly 9ero7 a$tors.

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(ii)Anal,sis or /otal 0armonic

Distorion(/0D) :

'n the 8atla-,an o"tion or "eror&in#

:ast :ourier %ransor& 5::%7 analysis to

uantiy the %D in the &odel. y #iin#, thereal alues as in"ut to these hard0are ele&ents

in the &odel,the real ti&e har&oni$ distorton

is o-tained.

y doin# so, the %D or the

"ro"osed &odel is 21.@4 L

%he %D Analysis -y &atla- is sho0n ini#ure4 as.,

:i#ure 4. ::% Analyis

.C+)C>US'+)

%his "a"er analy9ed ne0 &ultileel inerterto"olo#y 0ith redu$ed nu&-er o s0it$hes sho0nin i#ure 25a7 and 25-7. %heout"uts are eriied -y hard0are setu" as sho0n in

i#ure. %he Condu$tion losses 0ill -e less, i

nu&-er o S0it$hes is redu$ed. %he si9e o the &ultileel inerter 0ill -e

$o&"a$t than other inerters. %he oerall $ost 0ill -e redu$ed -y

redu$in# the nu&-er o &ain s0it$hes. %he a""li$ation $an -e AC drie,

Photooltai$ and :AC%S dei$es et$.,

*!:!*!)C!S

1/ >.G. :ranuelo, J.*odrM#ue9, J.'.>eon, S. Kouro, *. ortillo,and 8.A.8. Prats, N %he a#e o &ultileel $onerters arries,O

n&ustrial lectronics Ma-a3ine, June 2@

2/ !.)ajai and A..8.Bati&, NDesi#n and '&"le&entation o a

ne0 &ultileel inerter to"olo#y,O n&ustrial lelctronics,olu&e .8 %ol-ert, :.Q.Pen# and %.G a-elter, N8ultileel

Conerter or lar#e ele$tri$ dries,O /ransactions on

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