svpwm thesis

7/22/2019 Svpwm Thesis

1/61

UPTEC E12001

Examensarbete 30 hpFebruari 2012

Space Vector Pulse Width Modulationfor Three-Level Converters

- a LabVIEW Implementation

Pbyggnadsprogrammet till civilingenjrsexamen i elektroteknik

Master Programme in Electrical Engineering


2/61

Teknisk- naturvetenskaplig fakultetUTH-enheten

Besksadress:ngstrmlaboratorietLgerhyddsvgen 1Hus 4, Plan 0

Postadress:Box 536751 21 Uppsala

Telefon:018 471 30 03

Telefax:018 471 30 00

Hemsida:http://www.teknat.uu.se/student

Abstract

Space Vector Pulse Width Modulation for Three-LevelConverters - a LabVIEW Implementation

Bengi Tolunay

This thesis explains the theory and implementation of the Space Vector Pulse WidthModulation (SVPWM) using the graphical programming environment LabVIEW as itsbasis. All renewable energy sources are in need of multilevel power electronics inform of multilevel inverters. The mind behind the pulses created by the inverters isthe SVPWM. This modulation type uses a space vector, referred to as the referencevector, to locate and create the desired sinusoidal-shaped waveform. Using LabVIEWas the software makes it easy to read real-time output from the integrated circuit ofthe hardware (FPGA). The SVPWM shows good utilization of the DC-link voltage,low current ripple and is relatively easy to implement in the hardware, making itsuitable for any high-voltage, high-power application.

ISSN: 1654-7616, UPTEC E12001Examinator: Nora Masszimnesgranskare: Mats Leijon

Handledare: Remya Krishna


3/61

Table of Contents

1% I0T2(.TI20%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%3

1%1 4ac)#round5 The Lyse)il Wa$e Po&er Pro6ect%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%3

1%/ 2$er$ie&5 *rom Sea to +rid%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%7

1%8 ultile$el .on$erters and odulation Strate#ies%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%19

1%: +uidelines5 Purpose and ethod%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%11

/% (LTILEVEL .20VETES5 T2P2L2+IES' .20T2LES A0 I+ITAL

.2P20E0TS%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%1/

/%1 ultile$el Strate#ies%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%1/

/%1%1 .ascaded ;-4rid#e ultile$el .on$erters%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%18

/%1%/ *lyin# .apacitor ultile$el .on$erters%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%1 k

d

dti

> k=

!

Li

>k

1

Lv

> ke

>kwi

dk

The V. $ariation is #i$en by5

d

dt%#C=

1

C ic dt

.-.1 T0e Current as a Reference

The current control is dri$en &ith help from future $alues' calculatin# the minimum in$erter $olta#e

reuired to ma)e the inductor current follo& the current reference as much as possible 1:J% *i#% 18sho&s the parts that has to be considered calculatin# the $alues for the current control%

The load current at k1t- instant is #i$en in the formula for the instant output $olta#e% These

are the instant output $olta#e parameters in the complex D-plane5

vdk1=!idk1 Ld

dtidk1widk1 edk1

/8

Figure 1): Overview of t-e Current Cotroller Ccalculations

SVPWMSVPWM

1Load

CurrentPrediction

[i k1i k1]

Calculation

'imi?ationof

Cost Function1=i ref@

respecting/

/Aeutral

%oltage#eviation

[ vc k1 ]

Calculation for Current Control


24/61

v> k1=!i> k1Ld

dti> k1wi>k1 e> k1

The currents $aryin# in time is defined as5

d

dtid k1=

idk1i d k,s

d

dti > k1=

i > k1id k,s

*inally #i$in# the load current at k1t- instant5

id k1= 1

!,sL[Lid k w,sLi> k1,s %d k1edk1 ]

i> k1=1

!,sL[Li> kw,sLi> k1,s %>k1 e> k1]

Prediction for the #rid $olta#e $alues can be calculated &ith the La#ran#e extrapolation methodM' a

process that constructs ne& data points that are not included in the ran#e of the measurements% This

may not be appropriate for unpredictable functions' ho&e$er if the samplin# is lo&' extrapolation

can be a$oided 1J%

ost control systems need a cost function that can determine if the reuired criterion is achie$ed or

not% The cost function compares the calculated predicted current &ith the current reference% A lo&

$alue for the cost calculation is to desire% It is #i$en as5

c1=1idk1refi dk1/i > k1refi> k1 ' &here O 1 and O / are &ei#htin# factors' the

&ei#htin# factor bein# a number bet&een 9-1% The &ei#htin# factor O/ also determines the accuracy

of the reacti$e po&er control' thus compensatin# for the po&er factor $ariation% The instantaneous

reacti$e po&er can be predicted 6ust li)e for the current5 Bk=e> kidkedki >k 1:J

.-. DC #oltage unbalance

The problem is caused by une$en char#in#@dischar#in# of the .-lin) capacitors &hen the output

is connected to the ,ero-point% Each output terminal !Va9' Vb9' Vc9" can be connected to this point

and deli$ers in that case 9V% When that is the case' the neutral point current' i9' causes this une$en

char#in# pattern% It is )no&n that multile$el neutral point clamped in$erter has a .-balancin#problem% The reason for the unbalance lies in the capacitors% When a output phase $olta#e is shorted

to the capacitor middle point' the correspondin# phase current is transferred to the neutral point% To

pre$ent this the neutral point current $alues should be ,ero% The solution to this problem is the

re#ulation of the s&itchin# of the capacitors 1:J% The .-lin) currents are5

is=i c1i1ic1=i9ic2ic2=isi1

/:


25/61

If the system is balanced the follo&in# relation is $alid5 i1i9i1=9 and #i$es the currents5

i1=sa1sa2 iasb1sb2 ibsc1sc2 ici9=sa2sa)iasb2sb) ibsc2sc)ic

i1=sa)sa3 ia sb3sb3i bsc3sc3 ic

This #i$es the current flo&in# throu#h capacitor c1and c/5

i c1i c2=1 1 1

1 1 9 isi 1

i1

With this also the .-lin) $olta#e can be calculated5

c/= vc k1

voltagedifferencebetween c1c

/

This is the )ey &hen minimi,in# the $olta#e unbalance% Another &ay of decreasin# the unbalancin#

problem is throu#h re#ulation of the ener#y5

=p k1=1

/Cvc1

/ =1

/Cvc1 k

,s

Cic1

/

=nk1=1

/Cvc2

/ =1

/Cvc2 k

,s

Cic2

/

In the same &ay as for the capacitor $olta#e-comparison5

c/=[=p k1=nk1 ]=determinest-e allowed neutral voltage variation

2.& %onclusions

There are se$eral differnt types of multil$el con$erters on the mar)et and the most studied

con$erters has been described in this chapter5 .ascaded ;-4rid#e ultile$el .on$erters' *lyin#

.apacitor ultile$el .on$erters and iode .lamped ultile$el .on$erters% .hoosin# the ri#ht

con$erter it is important to consider the $olta#e le$el to implement% ;i#h-le$el con$erters #i$es lo&

distortion but hi#her $olta#e unbalance' so there has to be a compromise bet&een those t&o factors'

but also other issues such as increase of euipment for hi#her le$els% *or hi#h-$olta#e hi#h-po&er

applications the in$erter also can be used as a control for the $olta#e and reacti$e po&er re#ulation%

This is done &hen the in$erter is connected to a L-load' a current controller% esi#nin# the

multile$el application a soft&are !LabVIEW" directly connected to the hard&are !*P+A" &ill be

used for this pro6ect%

/


26/61

-. $&AC" #"CTOR !ODULATION AL'ORIT)! FOR!ULTIL"#"L CON#"RT"R$ IN T)"OR AND IN &RACTIC"

If the si#nal' recei$ed from the output of the po&er con$erter' is #oin# to be connected to the #rid it

has to be synchroni,ed &ith it% The in$erters pro$ide for this &ith help from the PW s&itchin#

information% The in$erters &ill #et the s&itchin# information from the calculations made by the

modulation formed in LabVIEW% There are se$eral different types of modulation strate#ies% This

chapter &ill present the most common modulation strate#ies' the theory behind t&o-' and three-

le$el SVPW' and also the implementation done in Simulin) and LabVIEW%

#.1 $odulation To'ologies

The basic structure of a multile$el po&er con$erter is formed by small discrete .-$olta#e sources

19J% The modulation strate#ies can be di$ided into t&o parts5 *undamental s&itchin# freuency

and hi#h s&itchin# freuency PW% The latter part is the main focus in this chapter' because this is

the part that is rele$ant for hi#h $olta#e con$ersion% There are se$eral different PW methods%

;ere' some of the most common modulation topolo#ies &ill be discussed%

/?Figure 13: Overview of different modulation strategies

*undamental S&itchin#

*reuency

*undamental S&itchin#

*reuency;i#h S&itchin#

*reuency PW

;i#h S&itchin#

*reuency PW

ultile$el odulation

Strate#ies

ultile$el odulation

Strate#ies

Space Vector.ontrol

Space Vector.ontrol Selecti$e

;armonicsElimination

Selecti$e;armonicsElimination

SVPWMSVPWM

Sinusoidal,rape?oidal

StaircaseStepped

,-ird 4armonic

(n


27/61

.hoosin# the modulation it is important to consider follo&in# thin#s5

inimi,ation of load current harmonics and s&itchin# freuency

Pro$idin# uniform s&itchin# freuency for all s&itchin# de$ices and a balanced .

capacitor $olta#e 19J

ifferent PW - approaches ha$e the same #oal5 To reduce the T; of the current% Increasin# the

s&itchin# freuency reduces the lo&er-harmonics' &hich contributes to a lo&er T;' achie$in# the

#oal of a $olta#e output &a$eform &ith the reuested rms $alues and freuency and a sinusoidal

&a$eform resemblance ?J%

Turnin# the s&itches 20 and 2** creates pulses &ith the same amplitude but &ith different &idth%

These pulses are #enerated in the output to replace the sinusoidal &a$eform /9J% The easiest &ay

of creatin# this is by usin# a intersection method' ie comparison &ith a sa&tooth@trian#le &a$eform

!carrier &a$e"% When the reference &a$e !sinus" is lar#er than the trian#ular &a$eform' the PW

si#nal is s&itched 20 !$alue5 1" and &hen it is smaller it is s&itched 2** !$alue5 9"%

The most common method is called the Sinusoidal PWM% Althou#h it is commonly used it has a

bi# disad$anta#e F it has lo& output $olta#e' &hich also can be seen in Table :% There are ho&e$er

other methods that can meet these demands in a better &ay' usin# similar carrier-based systems &ithdifferent forms5

Trapezoidal modulation5 .omparison of a trian#ular &a$e and a modulatin# trape,oidal&a$e%

Staircase modulation5 The modulation si#nal is formed as a stair' the le$els bein#calculated to eliminate certain harmonics% 0ot recommended for cycles that ha$e less than

1< pulses%

Stepped modulation5 Each step bein# a certain time portion !in de#rees" &hich isindi$idually controlin# the amplitude and is used to elimate harmonics% +i$es lo& distortion'

but hi#h amplitude%

Third harmonic injected PWM5 Implementation in the same &ay as for the SPW' butthe references si#nal is not a sinusoidal &a$e% It consists of a 1" fundamental component /"

Third harmonic component% This method #i$es hi#her amplitude and a better utili,ation of

the .-source%

Space Vector Pulse width Modulation!SVPW" #enerates the appropriate #ate dri$e &a$eform

for each PW cycle% The in$erter is treated as one sin#le unit and can combine different s&itchin#

states !number of s&itchin# states depends on le$els"% The SVPW pro$ides uniue s&itchin# time

/=


28/61

calculations for each of these states ?J% This techniue can easily be chan#ed to hi#her le$els and

&or)s &ith all )inds of multile$el in$erters !cascaded' capacitor clamped' diode clamped"% The

three $ectors that form one trian#le &ill pro$ide duty cycle time for each' #i$in# the desired $olta#e

$ector !Vref"% This can be described &ith the formula5 %=,1 %1,/%/,8 %8/,c

odulation

Techniue

Line Volta#e

T;

Stator .urrent

T;

*undamental Volta#e

!Volt"

SPW ::%8 :%98 /?7'7

Trapi,oidal :9%93 /%ues and t-eir ,4#

SVPW also ha$e #ood utili,ation of the . lin) $olta#e' lo& current ripple and relati$e easy

hard&are implementation% .ompared to the SPW' the SVPW has a 1


29/61

#.2 !'ace ,ector Pulse Width $odulation )or two-level converters

The circuit in *i#% 1? demonstrates the foundation of a t&o-le$el $olta#e source con$erter% It has six

s&itches !s&1-s&?" and each of these are represented &ith an I+4T s&itchin# de$ice% A' 4 and .

represents the output for the phase shifted sinusoidal si#nals% ependin# on the s&itchin#

combination the in$erter &ill produce different outputs' creatin# the t&o-le$el si#nal% The bi##est

difference from other PW methods is that the SVPW uses a $ector as a reference% This #i$es the

ad$anta#e of a better o$er$ie& of the system%

-..1 Reference #ector

The reference $ector is represented in a D-plane% This is a t&o-dimensional plane transformed from

a three-dimensional plane containin# the $ectors of the three phases% The s&itches bein# 20 or

2** is determined by the location of the reference $ector on this D-plane%

/7

Figure 1/: ,-ree.level t-ree.p-ase inverter wit- a load and neutral point

nA

BC

sw1

sw2

sw3

sw4

sw5

sw6

#C

Source

Figure 17: ,-e reference vector in t-e two

and t-ree dimensional plane

j

a

c

b

Vref

V

V


30/61

Table < sho&s that the s&itches can be 20 or 2**' meanin# 1 or 9% The s&itches 1'8'< are the

upper s&itches and if these are 1 !separately or to#ether" it turns the upper in$erter le# 20 and the

terminal $olta#e !Va' Vb' Vc" is positi$e !KV."% If the upper s&itches are ,ero' then the terminal

$olta#e is ,ero"%

Switching

states

a b c

S1 S/ Van S8 S: Vbn S< S? Vcn

1 20 2** V. 20 2** V. 20 2** V.

9 2** 20 9 2** 20 9 2** 20 9

Table


31/61

represented as one rotatin# $olta#e $ector% The ma#nitude and an#le of this $ector can be calculated

&ith .lar)Gs Transformation5

%ref=%


32/61

%ref=%1,1%/,/%9,9

The total cycle is #i$en by5

,c=,1,/,9

The position of Vref' V1' V/and V9can be described &ith its ma#nitude and an#le5

%ref=%ref r


33/61

,1=,casin 8

n18 =,ca[sin

n

8 cos cos

n

8 sin ]

,/=,casinn1

8 =,ca [cossin

n18

sin cosn1

8 ]

,9

=,c

,1

,/

.hoosin# n as the number of the sector !nN1'/'8':'


34/61

-..- $2itc0ing Tie

uty .ycle

*or each sector there are = s&itchin# states for each cycle% It al&ays starts and ends &ith a ,ero

$ector% This also means that there is no extra s&itchin# state needed &hen chan#in# the sector% The

une$en numbers tra$el counter cloc)&ise in each sector and the e$en sectors tra$el cloc)&ise%

uty cycle for sector 1

*or sector 1 it #oes throu#h these s&itchin# states5 999-199-119-111-119-199-999' one round and

then bac) a#ain% This is durin# the time Tcand it has to be di$ided amon#st the = s&itchin# states'

three of them bein# ,ero $ectors5

,

c

=,9

:

,1

/

,9

/

,/

/

,1

/

,9

:

This can be calculated for all the sectors !*i#% /1"% There are different )inds of &a$eforms5 centre

ali#ned and ed#e ali#ned% Ed#e ali#n &a$eforms ma)es it easier &hen comparin# &ith the carrier

&a$e' but the centre ali#ned has the ad$anta#e of reducin# the harmonics and also reducin# noise


35/61

Sector Duty Time Upper Switches Duty Time Lower Switches

1 S1,1,/

,9

/

S/ ,9

/

S8

,/,9

/

S:

,1,9

/

S< ,9

/

S?,1,/

,9

/

2 S1,/

,9

/

S/,1

,9

/

S8,1,/

,9

/

S: ,9

/

S< ,9

/

S?

,1,/

,9

/

S1 ,9

/

S/,1,/

,9

/

S8,1,/

,9

/

S: ,9

/

Suence of switc-ing states for switc- 1 and 2 in sector

1 region 1 p-ase a

%a

9

Switc-1

Switc-2

9

9

,c

A

O

P P P P P

O O O O O

A

,b

:

,a

/

,c

/

,b

/

,a

/

,c

/

,b

/

,c

/

,a

/

,b

/

,c

/

,a

/

,b

:


48/61

-.-.3 $#&/! of )ig0er Levels and Overodulation

;i#her le$els

This report only co$ers in$erters up to three le$els of $olta#e output and the space $ector

modulation is desi#ned as in *i#% /7a% It is important to add that this only is one &ay of calculatin#

the three-le$el modulation% The sectionali,in# of the sectors in the shape of these : re#ions can be

done in different &ays% This is only one of them% With this type of se#mentation it is easier to follo&

the same pattern' as *i#% /7b is for *i#% /7a% This &ay seems ho&e$er to be the easiest one' because

of its symmetrical dimensions%

2$ermodulation

Another factor that has not been considered in this study is the o$ermodulation of the space $ector

modulation% 2$ermodulation is &hen the reference $olta#e can be considered outside the dia#ram%

*i#% /7 sho&s the reference si#nal inside the dia#ram% .alculations and implementation on

o$ermodulation techniues has sho&n positi$e results as in #ood performance /8J' but is ho&e$er

a $ery complex method to realise%

:3

Figure )1: Space vector diagram for a *a+ t-ree.level inverter *b+ five.level inverter

< <

%ref %ref

a b


49/61

-.-.6 Ipleentation in $iulin5 and Lab#I"/

Simulin) output

The theoretical three-le$el calculations has been realised usin# Simulin)% *i#% 89 sho&s the output

$olta#e &a$eform for Vbc!line-to-line $olta#e"% Some specifications5 Amplitude and .-$olta#e

has been chosen as 1V' samplin# time TsN 1@19999' cycle time for the ramp TcN1@1999' the three

phases are phase shifted 1/9 de#rees apart and ha$e the freuency of a typical S&edish #rid'

/


50/61

LabVIEW output

*i#% 88 sho&s the line-to-line $olta#e output for a three-le$el in$erter% The implementation is done

in LabVIEW% Some specifications5 Amplitude and .-$olta#e has been chosen as 1V' samplin#

time TsN 9%9/s' cycle time for the ramp TcN 9%999


51/61

LabVIEW adaptation

Simulin) and LabVIEW are $ery different soft&are pro#rams% The simulations done in Simulin)

are not realistic or useful &hen usin# to#ether &ith the *P+A% The sample time in Simulin) can be

chosen as hi#h as &anted' in this case TsN 1@19999' &hich is far to complicated to produce in reality

usin# LabVIEW% This three-le$el con$erter is adapted to the Balman filter that produces sinusoidal

&a$es formed by :99 samples@period' each sample bein#


52/61

Sector Time (e'ion 1 (e'ion (e'ion ! (e'ion "

1 Ta

Tb

Tc

%b1

/%c

%a

1%c%a

%b

1

/

1

/%a

%c1

/1

/%b

%a1

/

%b

1%c

Ta

Tb

Tc

%b1

/%a

%c

%c1

/

%b1%a

1

/%c

%a 1

/1

/%b

1%a%c

%b1

/

! Ta

Tb

Tc

%a1

/%b

%c

1%b%c

%a1

/

1

/ %c

%b1

/1

/%a

%c

1

/

%a1%b

" Ta

Tb

Tc

%a1

/%c

%b

%b1

/

%a1%c

%b1

/

%c1

/1

/ %a

1

/%c

%b1

/1

/ %a

# Ta

Tb

Tc

%c1

/%a

%b

1%a%b

%c1

/

1

/%b

%a 1

/1

/%c

%b 1

/

%c1%a

$ Ta

Tb

Tc

%c1

/

%b

%a

1

/%a

%c1%b

1

/%a

1/ %c

%b1

/

1%b%a

%c 1/

,able 1): #uration time described wit- t-e p-ase voltages %a %b and %c


53/61

-.-.8 Conclusions

In chapter 8%8 the SVPW for a three-le$el neutral-point-clamped $olta#e source in$erter has been

presented% The three $olta#e le$els !9V.' 1V. and /V." can &ith help from the in$erter s&itches

create the three le$els in the in$erter output% .alculatin# the duty cycle for each s&itch' #i$es a

sinusoidal resemblin# &a$eform in the output% ;i#her le$el means lo&er distortion' but at the same

time the problem &ith the neutral point unbalance is attendin#% ealisin# the three-le$el con$erter

in LabVIEW reuires adaptation to the *P+A' in form of memory stora#e and sample time

selection%

3. CONCLU$ION$

This thesis has presented the theories behind multile$el con$erters' usin# the neutral point diode

clamped con$erter as a basis% Ad$anta#es &ith the diode-clamped in$erter is the hi#h efficiency%

The modulation chosen for the pro6ect' the space $ector pulse &idth modulation' has #ood

utili,ation of the . lin) $olta#e' lo& current ripple and is relati$e easy to implement in the

hard&are% These features ma)es it suitable for hi#h-$olta#e hi#h-po&er applications' such as

rene&able po&er #eneration% This specific desi#n ma)es it possible to increase the number of le$els

6ust by increasin# the amount of capacitors% It also &or)s &ith all )inds of multile$el in$erters%

Increasin# the $olta#e le$els decreases the harmonic distortion' because it resembles the desired

sinusoidal output more' but is also increases the $olta#e unbalancin# problems% Also' the system

becomes more complex' both in theory !more calculations" and reality !more euipment"% *or this

reason many prefer to &or) &ith the three-le$el con$erter% *or hi#h-$olta#e hi#h-po&er

applications the in$erter also is used as a control for the $olta#e and reacti$e po&er re#ulation% This

is done &hen the in$erter is connected to a L-load' a current controller% It is ho&e$er not suitable

for acti$e po&er control% Testin# the theories of the three-le$el con$erter in Simulin) can be useful

&hen ma)in# small chan#es in the code' because it does not ta)e as much time as in LabVIEW' but

there are no #uaranties that it &ill &or) &ith other sample times than the idealistic ones in Simulin)%

Implementin# the ideas behind the SVPW in LabVIEW' reuires adaptation to the *P+A% The

memory is not endless and each of the memories' lo#ic bloc)s etc used in LabVIEW are carefully

chosen so it &ill not ta)e up all the space in the *P+A% It is also important to consider that it is not

only the space $ector modulation al#orithm that &ill ta)e space in the *P+A' also the Balman filter


54/61

and the current controller al#orithm has to fit in there% In conclusion' some errors in the $olta#e

&a$eform output has been noticed5 e$iations causin# une$en pattern% This does ho&e$er not

intrude &ith the final sta#e of #rid-connection' because of the filterin# done in the end%

6. FUTUR" /OR9

Where this pro6ect ends a ne& be#ins% There are se$eral ideas that can be analysed and

implemented% These are some of the su##estions for future &or)5

.onnect the *P+A to the three-le$el in$erter and test the modulation al#orithm created in

LabVIEW%

Try the space $ector modulation strate#y &ith a unbalanced system5 %a; %b; %c;9

Impro$e the three-le$el SVPW5 educe losses &ith a filterin# system &ithin LabVIEW


55/61

8. A&&"NDIC"$


56/61


57/61


58/61


59/61

:. R"F"R"NC"$

1J os odrX#ue, et al%' YPredicti$e .urrent .ontrol of a Volta#e Source In$erterY' IEEE

transactions on industrial electronics' $ol%


60/61

19J 4um Seo) Suh et al%' ultile$el Po&er .on$ersion F An 2$er$ie& of Topolo#ies and

odulation Strate#iesM' epartment of Elec)ical and .ornputer En#ineerin#' (ni$ersity of

Wisconsin' 1773

11J Brishna et al%' irect Predicti$e .urrent .ontrol of +rid .onnected 0eutral Point

.lamped In$erter for Wa$e Po&er ExtractionM' International Symposium on Po&er

Electronics' Electrical ri$es' Automation and otion' /919

1/J arian P% Ba,mier)o&s)i et al%' .urrent .ontrol Techniues for Three-Phase

Volta#e-Source PW .on$erters5 A Sur$eyM' IEEE Transactions on industrial electronics'

$ol% : 2* AT;E0S'

epartment of Electrical and .omputer En#ineerin#

1:J Brishna' Predicti$e .urrent .ontroller for a +rid .onnected Three Le$el In$erter &ith

eacti$e Po&er .ontrolM' i$ision of Electricity' (ppsala (ni$ersity' /919

1


61/61

/9J Infineon' PW for A.IM' Published by Infineon Technolo#ies A+ 31=/? \nchen'

+ermany' /99?

/1J A)ira 0abae et al%' A 0e& 0eutral-Point-.lamped PW In$erterM' IEEE Transactions on

Industry Applications' Vol% IA-1=' 0o% 2* .;I0A'

V2L% ?' 02% /' (0E /993

/8J Subrata B ondal et al%' Space Vector Pulse Width odulation of Three-Le$el In$erter

Extendin# 2peration Into 2$ermodulation e#ionM' IEEE Transactions on Po&erElectronics' Vol% 13' 0o% /' march /998

/:J %athna)umar et al%' MA 0e& Soft&are Implementation of Space Vector PWM'

epartment of Electrical En##' +o$ernment colle#e of Technolo#y' India' /99

svpwm thesis

Documents