Evolution ofMultilevel Voltage Source Inverters

9th INTERNATIONAL CONFERENCE- APEIE-2008

Evolution ofMultilevelVoltage Source Inverters

Gennadiy S. Zinoviev1, Member, IEEE, Nikolay N. Lopatkin2

JNovosibirsk State Technical University, Novosibirsk, Russia2Biysk Teacher-training State University named after V.M Shu/cshin, Biysk, Russia

Annotation - The problem of increase in power andvoltage of inverters today is provided more often byconstruction of multilevel voltage source inverten. TheformatioD of an instant curve of voltage of such ioverter gOlS basically by the amplitude modulation withPWM added between the neighboring levels of thevoltage of amplitude modulation. The known publishedEnglish-speaking reviews on multilevel inverters do notcover all variety of circuits of inverters, they do notconcern the prehistory of the problem and do Dot contain references to RUlsian-speakiDI publications. Thegiven state-of-the-art review on circuitry of multilevelvoltage souree inverters, beiDI based OD our opportunity of aeclSs to the literature, contains tbe first attempt to capture the designated problem more fully.Besides the regular analysis of known circuits of inverters in tbe review recent innovative decisions onconstruction of step-up multilevel voltale source inverten on the basis of systems with switched capacitorsare considered.

Key words -multilevel VSI. review of MLI circuits, prehistory of MLI, Russian MLI publication, step-upMLL

I. INTRODUCTION

THE PROBLEM OF INCREASE IN POWERand in value of the output voltage of voltage

source inverters and also the problem of improvement of quality of the converted energy and improvement of voltage using of semiconductorswitches have been very important for the recent 20years. Today the decision of these problems is provided due to construction of multilevel voltagesource inverters and, less often, current source inverters. As a matter of fact, a multilevel output voltage of the inverter is provided by a multilevel voltage on an input of the inverter or by using for theoutput result voltage formed by a joining-up of thecounter voltage of charged capacitances in serieswith a single-level input voltage. It allows using theclosest to the instant value of the required sinusoidofthe output voltage a level ofgenerated voltage. Asa result, formation of an instant wave of an outputvoltage of the inverter is done, basically, by usingthe amplitude modulation that is added by PWMbetween the neighboring voltage levels.

978-1-4244-2825-0/08/$25.00 ©2008 IEEE 125

During the last ten years, a number of the foreignreviews devoted to development of the multilevelinverters have been written, but all these reviewsconsider only publications in English [1-6]. A review of powerful multilevel high-voltage convertersbased on H-bridges of the design centre of theSEMIKRON fmn for purposes of the wind-powerengineering is performed in the article [7]. Thespecified reviews consider, as a rule, only the multilevel inverters implemented under the base schemes(NPC-schemes, Fe-schemes, H-bridges) and seldomconsider one more class of multilevel inverters - SIstacked inverters, absent in the specified reviews,except for [5]. Therefore the review, presented inthis work, covers the sources of decisions on multilevel inverters, generalizes modem achievements onthem for today, including still not numerous publications in Russian, and in the fmal part innovative circuitry decisions on the construction of multilevelinverters with switched capacitances as systems withvariable structure are considered.

II. PREHISTORY OF THE PROBLEM

Probably, the first prototype afthe multilevel inverter in the USSR was the scheme represented infig. 1 [8]. (All the schemes borrowed for the revieware copies from the corresponding original publications, which have been kept with loss of the qualityofgraphics.)

Fig. 1. The prototype ofthe multilevel inverter

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Its features in comparison with modem schemesof multilevel inverters are the presence of zeropauses after each voltage impulse and the absence ofadditional sine wave PWM on each voltage level(between two neighboring levels).

Development of this idea resulted in appearanceof later schemes of multilevel inverters with a seriesconnection of single-phase bridge cells (H-schemes)[9, 10]. Here again the fIrSt decisions, as shown infig. 2, either did not use PWM [9] or used a transformer output of cells with PWM [10], as shown infig. 3.

~------ .....s .....-------~

Fig. 2. The inverter with a series connection of singlc-phlsebridle cells

Separate DC-AC H-bridges are fed from thecommon inverter through high-frequency transformers. It is clear, that the output voltage is fonned similarly to the voltage of the typical multilevel inverter.Variants of the converter with the output isolatedfrom an input are possible.

Also since 1972 the scheme with a series connection of one-switch cells with the decoupled powersupplies, as shown in fil. 4 [11], has been known.Here multilevel modulation is performed on a unipolar pulsing voltage, and the alternating (two-polar)voltage is obtained by means of a single-phasebridge inverter cell.

Diodes ofone.switeh cells in the scheme in fig. 5[12] are replaced with controllable switches andthere is one more innovation here, which is widelyused in modem schemes, it corresponds to the use ofdifferent voltage levels of power supplies of cells.However, use of the separate bridge inverter cellunder a full voltage for formation of an alternatingvoltage deprives the multilevel inverter of one of itsmain advantages. This advantage is that the voltageacross each switch does not usually exceed the voltage ofseparate power supplies.

The radical step in the direction of multilevel inverters was the construction of the three-level voltage source inverter with clamping diodes initiallyeven without PWM in 1975 [13]. The scheme of theinverter is adduced in fig. 61, and voltages waveforms are in fig. 6b. Reverse current diodes arestipulated in the description of the invention, butthey are not shown in fig. 6a.

126

I

b)

Fil. 3. The scheme ofthe sinale-phase four-level converter with aseries connection of the bridae inverter cells a) and the diagram ofits operation b)

Fig. 4. The inverter with a series connection arone-switch cells



of the partitioned power supply of the inverter (heretwo sections), secondly, the implementation of theinverter leg by using of transistors connected in series (here two), thirdly, the presence of fixing(clamping) diodes for connection of common pointsof series-connected transistors of each leg of theinverter with a tap of the power supply (here withhalfof supply voltage).

Ways of regulation of the output voltage of themultilevel voltage source inverters are considered inworks [14, 1S]. Characteristics of the original inverter, in which clamping diodes are replaced withtransistors, are analyzed in work [16].

Sources of the second approach to constructionof voltage source multilevel inverters, by use of"quenching" of a part of a voltage of the power supply due to counter- series inclusion with it ofcapacitor or capacitors preliminary charged up to a certainvoltage (the schemes with floating capacitors - Flying capacitors-FC)t are seen in the schemes of theinverters presented in fig. 7 [17] and fig. 8a,b [18].The scheme of the inverter with series-connectedtransistor-capacitor cells in fig. 7 has different voltage and current loading ofcapacitors.

+,2,0."-.-.._~ .......__.-....,

Fig. 7. The inverter, which has been assembled by using ofseriesconnected U'ansistor-capacitor cells

The scheme of the inverter in fig. 8a is free fromthis disadvantage, here the factor of reduction of anoutput voltage is discrete and equal to two (at absence of PWM). Cascade inclusion of such invertercells with capacitor voltage dividers, as shown infig. 8b, allows to get the voltage division factor 2D

(here 23 == 8).Finally, the third approach to construction of

multilevel voltage source inverters, being the mostwidespread today, is based on a series connection oftransfonnerless single-phase bridge cells of voltagesource inverters (H-cell).

In the western literature, the beginning of an epoch of multilevel inverters with PWM of voltagewith clamping diodes (the CD MLI) is related toappearance in 1981 of the paper [19], which described the three-level NPC inverter with sine

..a)

i'"#,~•

VA&' It.

if••

OM

Fig. 5. The inverter with a series connection oftwo-switch cells

b)

Fig. 6. The tirst three-level voltage source inverter with clampingdiodes a) and its voltageS waveforms b)

Additional rectangular PWM is performed by theuse of the separate single-phase voltage source inverter, which is assembled of the transistors 26-29and connected by means of the transformer 24 to anoutput voltage generated by a method of three-levelamplitude modulation.

All the attributes of the three-level inverter withclamping of the zero point in modem terminology(NPC) are on hand here, that is, fll"Stly, the presence

127


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b)a)

Full schemes of three- and five-level voltagesource inverters of three basic kinds are shown intig. 10-12 respectively.

VdJ: 1J:--1'-..aVd~.

Vdl1 Va

....-,-..··0 0

a) b) c)

Fil. 9. The principles of formation of multilevel voltages of theinverters

In the second type of the multilevel inverter, theload dwing a step of switching receives a feed froma source with the in-series capacitor, which is preliminary charged up to a corresponding voltage, asschematically shown in tig. 9b. It provides a consecutive getting ofvarious load voltage levels.

In the third type of the multilevel inverter with nlevelst obtaining of various load voltage levels isprovided by creation of a series chain of 1, 2, 3, ...,n isolated sources of a direct voltage, as schematically shown in fig. 9c for a case of a joining-up inseries of four power supplies.

a)

IIIt.1 ' :1

b)

Fig. 8. The inverter cells with capacitor voltage dividers in onecascade a) II1d threc-cascade b) variants

wave PWM. The multilevel inverters with PWM onthe basis of a joining-up in series of single-phasebridges of inverters are connected with the advent ofthe work [9]t and multilevel inverters with PWMwith flying capacitors are connected with the work[20]. One more version of multilevel inverters is the51-stacked inverters, which have been engenderedby the circuitry of inverters with flying capacitors,for the present they have been included only into onereview [5].

Fig. 10. The three- a) and five-level b) inverters with clampingdiodes (NPC)

Fig. II. The three- a) and five-level b) inverters with flying ca·pacitors (Fe)

III. MODERN STATE OF CIRCUITRYOF BASIC MULTILEVEL INVERTERS

Today three base variants of construction ofstructures ofmultilevel inverters are outlined:1. Neutral point diode clamped inverters (NPC).2. Flying capacitors inverters (Fe).3. Single-phase H-bridge cells based (cascaded)

inverters (He).The principle of amplitude and pulse-width

modulation (APWM) is used in all types of the inverters~

In the first type of the multilevel inverter, load isseries-connected to various taps of sections (voltagelevels) of the input partitioned power supply of adirect voltage, as schematically shown in fig. 9a.

a) b)

128



Fig. 12. The five-level inverter with single-phase H-bridgc cells(He)

The function of the quality of the output voltageof the multilevel inverters, the value of the inductance of a required output tilter and the loss powerversus the number of voltage levels of the inverter(according to K. Corzine [21]) are plotted in fig. 13.

100

THD(~.,,)(~) so

o-1---2-

3...........

4---,5,........6 ~7~8.---.,..9----1

1000,--.-----------,

Lf(J,lH) 500

Q5 6 7 8 92 3 4

10p~

p,... (kW) S ~ p- =05 6 7 8 92 3 4

Fig. 13. The functions of the output voltage THO, the value of theinductance of the filter and the loss power versus the number ofvoltage levels

IV. MODIFICATIONS OF THE BASIC SCHEMESOF THE INVERTERS

The modified basic schemes of the inverters differ from the basic schemes of the inverters by thepresence of some addition or by the ~igher level.ofgeneralization. So, schemes of the mverters WIthclamping diodes and with flying capacitors can bereduced to the multilevel inverter generalized structure presented in fig. 14 [4]. This scheme has twicemore transistors than basic schemes, but is relievedof serious problems of balancing of capacitors voltages.

129

r-·..·•·•·..···_···..·-·_···_·····..·•·..·..·-·····..·_·..·_·..._......_._.•.•.•. ''''1

l ~. !i i1 J

! ,-! ~1 I

i ~i Ii ~i II ! '. I

II

iIi'

I "*! I

~1l1 4~ ~ '" j..; "i .i !i· _ _._ _._._._._ _._._._._~~.~ !

Fig. 14. The generalized structure of the multilevel inverter

Other opportunity of generalization appears forthe inverters with flying capacitors. Such cell of thesingle-phase inverter in fig. 11 may be considered asa half-bridge cell, in which capacitors are includedbetween the similar terminals of common points ofthe top and the bottom legs of a half-bridge. But,obviously, capacitors can also be included betweenthe similar terminals of the left and right legs of thefull bridge. This leads to the scheme of the stackedinverter at a one-dimensional line ofa package, or ata two--dimensional line of packages, as shown in fig.IS [S], or at a n-dimensional line of packages in ageneralized case.

Fig. 15; The stacked (package) multicell multilevel inverter

The direction of other researches on schemes ofthe multilevel inverters is related to search of waysof improvement of modes of operation of semic~n.duetor devices, especially in dynamics. The c~asslc~l

schemes of multilevel inverters with clampmg dIodes are characterized by different modes of operation of clamping diodes, especially at transients. Thescheme, which mission is to equalize voltages acrossclamping diodes, is shown in fig. 16 [22]. .

Removing the clamping diodes and the flymgcapacitors, which are trouble accessories in respective multilevel inverters, is possible by means ofconstructive hybrid merging of two-level and threelevel inverters, as shown in fig. 17 [23].


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Fia-16. The scheme with the equalized voltages across clampingdiodes

a)

rAO ~(1-./:S)io'~3jrl":1 3~·

o . 110

b)

Fig. 19. The four-level inverter with one power supply and theauxiliary inverter of threefold ftcqucncy with the output transformer

v. RECENT INNOVATIONSIN THE MULTILEVEL INVERTERS

Lately a number of works on modernization ofthe multilevel inverters executed on a series connection of single-phase inverter cells have been published.

First of all, this is our offer of formation of cellsby the half-bridge scheme with the controllable zeroswitches [28], as shown in fig. 22.

A different four-level inverter, using an orthogonal voltage of the auxiliary three-phase inverter withthe transformer, is shown in fig. 20a, and the diagrams of its operation are shown in fig. 20b [26].

With the purpose of decrease in power losseswhen switching oftransistors, schemes of multilevelinverters with soft switching are finding a wide development. For this purpose additional active andreactive elements are entered into their scheme. Oneof such schemes with the zero-voltage switching ispresented in fig. 21 [27]. Variants of schemes withzero-current switching and the combined schemesare possible.

Pia. 17. The three-phase four-level hybrid inverter

Another opportunity of virtual increase in number of levels in the inverter is directed to the improvement of the quality of an output voltage andrelated to use of single-phase output transformers, asshown in fig. 18 [24].

1:fJJfA,

B f u:

Fig. 18. The inverter with three-phase cells and three sinale-phasetransformers

One more decision with one power supply usesthe auxiliary inverter ofthreefold frequency with theoutput transformer, as shown in fig. 19a with diagrams in fig. 19b [25].

130


9th INTERNATIONAL CONFERENCE· APEIE..2008

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Here one transistor is always in a flow loop of acurrent, instead of two ones in the original bridgecell, it twice reduces losses in switches. However,the peak values of voltages across switches withrespect to the output voltage of a cell are here twicehigher, than in a bridge scheme.

The second modernization is connected withformation of cells like sources of the reactive voltage, as shown for a half-bridge cell in fig. 23 and fora phase of the inverter, which is assembled of suchsubmodules, in fig. 24 [29].

PCOI----V-X-l~l-1~1

•

NO

Fig. 23. The cell of the reactive voltage

Fig. 24. The phase of the inverter assembled of the cells of thereactive voltage

The formation ofthe single-phase bridge cell likethe source of the reactive voltage is also possible[30, 31]. It allows to perform one phase ofthe multilevel inverter with one voltage source, as shown infig. 2Sa with diagrams of operation in fig. 25b [32].

The number of series reactive cells can be increased, here their voltages values can have ratio 2D

or 3D• It allows to increase the number of levels of

the inverter sharply. So, in the presence of two reactive cells with capacitors voltages equal to VcJJ2 andV&14, the inverter becomes an eight-level one.

Another variant of use of single-phase reactivecells assumes their joining-up in series with outputsof three-phase inverters [29, 32] as shown in fig. 26for the case ofthe two-level three-phase inverter [33,34].

Composite inverters can be formed also by cascade connection of three-phase inverters [35-37] asshown in fig. 27 for the case of three cascades andinduction motor with six terminals of windings. Thetime-dependence simulated plots of the doublethree-eascade inverter are presented in fig. 28.

a

c,

c,

c,

CI'

Main invener

a)

......... ....-00

U\I'W

AuxiIiary

inverter U

Fig. 21. The three-level flying capacitors inverter with the zero.voltage switching

b)

Fig. 20. The four-level inverter with the auxiliary three-phaseorthogonal inverter

Fig. 22. The half-bridge cell with the controllable zero switc~

131


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:~:._.-IN·11..~I ~ ~_.._ ._~~ i ~ j~=

:===="T"-"""===--.,,!-=:~~mltll4llR~''''';''''''~''''''''''''''''''''''_ = il········~·············:······························t:······························:=::::::::1::::::::~:::::~:::::===:===..·....·~····· ..·=======----=lttl~lttl=-==-

.~- - - ....c)

Fig. 28. The time-dcpendence plots of the double three-cascadeinverter: a) phase-to-neutral voltap ofone inverter; b) the ditTerential voltqe oftwo inverters; c) the phase current of the motor

For the case of a star-connected windings thescheme of the cascade inverter [38] is shown in fig.29 (here is its six-level variant). Fig. 30 shows thetime-dependence plots of the voltages UKj· = uKIEacross switches of one phase of this inverter, herenumbers i = 1•••S are numbering at first the upperswitch, then the lower switch ofmodule M2, then, atthe same sequence, switches of module M6 and thenthe top switch of module Ml (voltages across thesecond half of switches are not shown, because ofthe- symmetry of a phase relative to its output terminal), E is value of the EMF of one level of apower supply. While in variation of output potentialof a phase (within the limits of six values of potentials of feeding bus), the greatest values of voltage,equal 3·Ud(), are applied across the upper switch andthe lower switch ofmodule MI.

VSCIawell

y----..

.. - ......._-~~-- ....

a)

Fig. 26. The cascade inclusion of the three-phase and single-phaseinverters

b)Fig. 2S. The phase of the four-level inverter with one voltaaesource

Fig. 27. The double three-eascade inverter for the induction motorwith six terminals ofwindings

Fig. 29. The six-level cascade inverter for the induction motorwith three tenninals of windings

132



': ~~~~~~~~~t~~~~~~~~~~~~~~~~~t:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~l~ ~~~~~~~~l~~:::~~~~~~~~~~~~~~~F~~~~~~~;~~:~:~~~~~;~~:~~~I

~ iuD~mmm~~mmpmm~~m~m~lItglg~~~1~1j~~~m[~~mmm~gg1mm~~11J~~~~~~~:f:~~~~~~:F1::::::=:::-:::::==f:::::::::::::::::::::::::::::l

j ti1~¥:¥:~~~m~~mmm~1~~~I~~~m~~~~1mHH1~11~¥:~I~~~~~~!~~mm~ I'

o 0.a5 0.5 0.1S I

Fig. 30. The timc-dependcncc plots of voltalcs across theswitches ofthe six-level cascade inverter

As a result, for each phase of this symmetric sixlevel voltage source inverter, the maximal voltagevalue UdO is being applied across six switches, andeach of the maximal·voltage values 3·UdO and 2·UdOis being applied across two switches. .

The cascade of inverters, which is linked onlythrough the common electromagnetic field in theasynchronous motor, can be performed under thecondition of a separate two- or multi-level inverterssupply for each separate star of three-phase windingsof the motor (the multi-star induction machine),which has two [39] or several star windings. It complicates a construction of the motor, but allows todesign the high-powered drive using the invertersgenerating conventional values ofvoltage.

The multilevel inverter can be given a propertyof increasing the output voltage in comparison withthe input one by its transfonnation into the Zinverter due to the inclusion of the cross LC-tilterbefore the invertert as shown for the three-level inverter in fig. 31 [39-41].

Fia. 31. The three-level Z-inverter

Some ways of simplification of the multilevelinverters are stated in the paper [42]. The more detailed consideration of some questions of the prehistory of the multilevel inverters is made in the works[43,44].

The recent innovations in the designing of multilevel inverters schemes deal with the construction ofsuch inverters on the base of systems of capacitors,

133

which are switched from parallel to series connection and back. Such inverters can be constructed byanalogy to the similar known schemes of DC-DCconverters. Fig. 32a shows the scheme of the boostinverter based on the Marx scheme [45], and fig. 32bshows the plots of the reference waveform, the output voltage and current at inductive loading for thecase of the differential inclusion of such twoschemes.

a)

b)

Fig. 32. The three-stage Marx inverter a) and the timedependence plots for the differential inclusion of two suchschemes b)

Fig. 33 shows the inverter with the switched capacitors, which is assembled of four-level schemesfor operation only into active load [46,47]. The corresponding time-dependence plots of the currentsand the voltages are shown in fig. 34.

I~I

Fig. 33. The inverter, based on four-level schemes with theswitched capacitors


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ZL

r--+---~~--~~--~=+-----J lez

The similar inverter, relieved of the necessity ofthe zero switch and based on the four-level modifiedMarx schemes (fig. 32a) for positive and negativehalf-wave ofthe formed voltage, is shown in fig. 36.

Fig. 36. The sinaJe-phase push-pull inverter, based on four-levelMarx schemes

Fig. 37 shows the time-dependence plots of thephase-to-ground (to the negative terminal of thelower EMF source) VAI and phase-to-neutral VAn

voltages of the Marx inverter according to thescheme above, in its three-phase variant.

It

Fig. 37. Plots of the phase-la-ground (V~ and phase-ta-neutral(VAll) voltages of the threc-phase invencr, based on Marxschemes

The scheme of the single-phase modified andagain four-level (according to the classification considering levels only of one polarity and zero) inverter with switched capacitors, which also allows tooperate into active-inductive load, is shown in fig.38. Here capacitors have an opportunity to be connected to the load at any polarity of the voltage,therefore only one EMF source and four capacitors(twQ per each ofstep cells ICI and IC2) are enough.

Data for comparison ofthe above described threesingle-phase push-pull equivalent seven-levelschemes of step-up inverters in quantity of IGBTswitches (of various ratings of voltage), EMFsources and capacitors are shown in Tab. I.

I),.. -,I II I

: : ZlI I

L. _~

... -It ilia 0 I, " ...

511,

Sill

!

r---i:t-"-r"--"--"--",...-·--"--·--·--·--"---"f·--·--"--"--"----·--="lc.:.:.·l1~__~ IC2

. .....-._.._._._......._._.--.~.- ....--....-.-.......~..... '--'

Fig. 34. Plots of the C\lJTCots and the voltages of the inverter,based on four-level schemes with the switched capacitors

The cells A1.1 and A1.2 in push-pull operation(capacitors of one of the cells are charged from asource, capacitors of the other cell at the same timeare discharged into load) form a positive half-waveof the load voltage, and the cells A2.1and A2.2 formits negative half-wave.

For operation into active-inductive load, a modification of this scheme is shown in fig. 35. The bidirectional controllable switches Sp and So, and alsothe IGST-transistors parallel to the charging diodes,are included into the both generalized inverter cellsICI, IC2 of odd and even operation steps. The zerobi-directional controllable switch SO is included intothe scheme for providing the continuity of a loadcurrent at zero voltage levels.

Fig. 35. The single-phase push-pull inverter, based on four-levelschemes with the switched capacitors, for operation into activeinductive load

134



rO-.-.--.--.-.--.-.--------.---;jJr--r'..,.-__-..... --,. ICl,,;;...__--.,...--1 1C2 REFERENCES

. .~_.-.-.......__.-.-.-..-.....~~~....~.-.~---

Fig. 38. The modified single-phase push-pull inverter with theswitched capacitors

TABLE ICOMPARISON OF THREE SINGLE-PHASE PUSH-PULL

EQUIVALENT SEVEN-LEVEL STEP-UP INVERTERS

[I] Lai J.s., Pens F.Z. Multilevel converters - a new breedof power converters /I IEEE Trans. Ind. AppliClt,May/Jun. 1996. V. 32. No.3. P. 509-517.

[2] Tolben L., Peng F.Z., Habetlcr T. Multilevel conveners for large electric drives" IEEE Trans. Ind. Applical, Jan./Feb. 1999. V. 35. No. I. P. 36-44.

[3] Teodorescu R., Blllbjerl F., Pedersen J.K., CengeleiE., Sulistijo S., Woo B., Enjeti P. Multilevel converters - a survey" Proc. lEE, 1999. CD-ROM.

[4] Rodrigues J., Lai J.-S., Peng F.Z. Multilevel inverters:a survey of topologies, control and applications /IIEEE Trans. Ind. Electron., Aug. 2002. V. 49. No.4.P.724-738. .

[5] Meynard T., Foch H., Thomas P., Couralt J., Jakov R.,Nahrstaldt M. Multicell converters - basic conceptsand industry applications /I IEEE Trans. Ind. Electron.,2002. V. 49. No.5. P.955-964.

[6] Franquelo L.G., Rodriguez J., Leon J.I., Kouro S.,Portillo R., Prats M.AM. The age of multilevel converters arrives. A review of a technology that has p0

tential in current atd future power applications /I IEEEIndustrial Electronics Magazine, 2008. V. 2. No.2. P.28-39.

[7] Kolpakov A. Circuitry of high-power high-voltageconverters /I Power intelligent electronics, 2007. No.2.P. 13-22. (in Russian)

[8] Shreyner R.T. A method of transformerless static dcto-ac conversion. USSR copyright certificateno. 165816. - Published in the Bul. no.20, 1964. (inRussian)

[9] Baker R.H. Electric power converter. US Patent00.3867643, 18.02.75.

[10] Kobzev A.V. A multi-zone pulse modulation. - Novosibirsk: Science, 1979. - 304 p. (in Russian)

[II] Tonkal V.E., Lipkovskiy K.A., Melnichuk L.P. Waysof improvement of quality of an output voltage ofvoltap source inverters. - Kiev: Preprint of UkrainianSSR academy of sciences, lED, 1972, 00.49. - 92 p.(in Russian)

[12] Orechko E.N. A thyristor inverter with pulse...amplitude modulation of an output voltage wave "Problems of engineering electrodynamics, 1975. Issue50. P. 78-80. (in Russian)

[13] Moin V.S., Voytovich I.A The transistor inverter.USSR copyright certificate 00. 57S7S 1. - Claimed25.04.1975. Published in the Bul. no.37, 1977. (inRussian)

[14] Nikitin V.M. Control ofa value ofan output voltage ofthe three-phase inverter /I Electrical engineerina. 1996.No.4. P. 34-40. (in Russian)

[15] Asanov AL., Romanovskiy E.A. Continuous regulation of a sill'aI level in the multilevel voltage sourceinverters" Electrical engineerina, 2000. No.l2. P.2126. (in Russian)

[16] Pereverzev A.V., Kuznetsov D.A, Omelcbuk: N.A,Pankov O.Yu. Analysis of characteristics of the multilevel voltap source inverter with the single-level voltage source " Technical electrodynamics, Special release "Problems ofmodem electrical engineers", Kiev:Ukraine National Academy of Sciences. 2008. Part 6.P. 70-75. (in Russian)

[17] Chcmiy 1.1. A voltage converter. USSR copyright certificate no. 413590. - Claimed 20.11.1963. Publishedin the But 110.4, 1974. (in Russian)

[18] Moin V.S., Laptev N.N. A step-down transfonnerlcssinverter. USSR copyright certificate no. 1089740. Claimed 12.01.1982. Published in the Bul. 00.16,1984. (in Russian)

r,1lUiI II..J

Scheme NE Nc Ns NSI Nsz NS3 NS4Fia.35 2 8 34 16 12 2 4FilL 36 2 8 40 24 4 8 4Fia. 38 1 4 26 6 16 4 0

VI. CONCLUSION

Thus, the opportunity of the sharp increase of thenumber of levels of an output voltage and outputpower of multilevel inverters has opened for themnot only area of the high-voltage electric drive, butalso formerly hard accessible applications in highpower energetics (active filters, compensators of areactive power, electrical energy stores, flexibletransmission lines, etc.) [48-52], that needs a separate consideration.

On the other hand, the application of the step-upmultilevel inverters as transformerless sources of thequasi-sine wave voltage with a standard level maybe rational at their feeding from low-voltage sourcesof the direct voltage (accumulators, solar batteries,fuel cells).

In addition, the independent analysis, coordinated with the quality of electrical energy conversion, is necessary for the set of algorithms and control systems ofthe multilevel inverters as well.

Here NE is the quantity of the EMF sources; Nc isthe quantity of capacitors; Ns is the total quantity ofthe switch IGST-devices; NSi is a quantity of IGBTswitches, which should maintain the applying of theforward bias voltage equal to value E·i, here E is thevalue afthe feeding EMF, i = 1...4.

As seen, the scheme requiring the smaller quantity of EMF sources and capacitors, in comparisonwith the "center-tap" schemes requiring a two-levelsupply (without considering a zero level), turns outto be quite competitive regarding rated voltagesacross switches as well.

iiiiiii'I iIii ~--+--....i ~_----.I

iii

135


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[19] Nabae A., Takahashi J., Aklli H. A new neutral-pointclamped PWM inverter /I IEEE Trans. Ind. Applicat.,1981. V. 17. No. S. P. SIS-523.

[20] Meynard T.A., Fooh H. Multi-level conversion: highvoltage choppers and voltage-source inverters /I Proceedinp of the IEEE Power Electronics SpecialistConference, 1992. P. 397-403.

[21] K. Corzin~. Operation and design of multilevel inverters. - University ofMissouri - Rolla, 2005, 79 p.

[22] Yuanand Xiaoming, Barbi Ivo. Fundamentals ofa newdiode clamping multilevel inverter 1/ IEEE Trans.Pow. Electron., 2000. V. IS. No.4. P. 711-718.

[23] Perantzakis G.S.• Xepapas F.H., Manias S.N. A novelfour-level VSI - influence of switchina strategies onthe distribution of power losses /I IEEE Trans. Pow.Electron., 2007. V. 22. No.1. P. 149-159.

[24] Ccoaelci E., Sulistijo S.U., Woo B.D., Enjeti P.,Teodorcscu R., Blaabjerg F. A new medium-voltagePWM inverter topology for adjustable-speed drives /IIEEE Trans. Ind. Applieat., 1999. V. 35. No.3. P. 628637.

[25] OIuchi K., Maki Y., Sunaga Y. There-phase multilevel voltage source converters with low switchingfrequencies and less distoned input voltages 1/ IEEETrans. Ind. Applicat., 1994. V. 30. No.5. P. 11561165.

[26] Hasad M., Iwaszkiewicz J. A novel orthOional-basedtopololY of multilevel inverters 1/ IEEE Trans. Ind.Applieat., 2002. V. 49. No.4.

[27] Song B.-M., Kim J.-H., Lai J.-S., Seong K.-e., KimH.-J., Park S.-S. A multilevel soft-switching inverterwith inductor coupling 1/ IEEE Trans. Ind. Applicat.,2001. V. 37. No.2. P.628-635.

[2S] Review on multilevel inverters and analysis of the fte·queney converter with the four-level diode clampedinverter I The report on research work for OdyniaMaritime University, Poland. Project head ZinovievG.S. Novosibirsk, NSTU, 2007. -73 p. (in Russian)

[29] Lesnicar A., Marquardt R. Concept of the new modular multilevel converter M2LC /I Proc. Powenech,2003.

[30] Zinoviev G.S. Switch compensators of a reactivepower, a power ofdistortions and a power ofasymmetry on the base ofthe voltage source inverter /I Modernproblems of converting engineering. - Kiev: lED ofUkrainian SSR academy ofsciences, 1975. Part 2. - P.247-252. (in Russian)

[31) Zinoviev G.S., Konovalov A.N., Krasikov N.A. Anadjustable ac-to-ac converter. USSR copyright certificate no. 1128350. - Claimed 11.06.1982. Published inthe But no. 45, 1984. (in Russian)

[32] Du Z., Tolbert L.M., Chiasson J.N., Ozpineci B. Acascade multilevel inverter using a sinsle DC source /IIEEE Applied Power Electronics Conference, March19-23,2006, Dallas, Texas, 2006. P. 426-430.

[33] Du Z., Ozpineci B., Tolbert L.M., Chiasson J.N. Inductorless DC-AC cascaded H-bridge multilevel boostinverter for electricJhybrid electric vehicle applicationsI 0197-2618107, (C)2OO7 IEEE.

[34] Luganskaya I.B., Mustafa G.M., Senov Yu.M. A statical compensator ofa reactive power (STATCOM), designed under the combined scheme /I VIII Symposium"ELECTRICAL ENGINEERING 2010. Perspectivekinds of the electrotechnicaJ equipment for transferand distributions of the electric power", Proceedings,Moscow, 2OOS. Report S.22. (in Russian)

[35] Kunchan R.S., Tekwam P.N., Oopakumar K. Threelevel inverter scheme with common mode voltageelimination and DC-link capacitor voltage balancingfor an open-end winding induction motor drive 1/ IEEETrans. Pow. Electron., 2006. V. 21. No.6. P. 16761683.

136

[36] Bakho~v tA., Lopatkin N.N., Usachev AP., Zinoviev G.S. Comparative analysis of three structures ofhigh-voltage frequency converters for asynchronouselectric drive 1/ EUROCON 2007, Proceedings, Warsaw, Poland, 2007. CD-ROM. P. 277S-2784.

[37] Bakhovtsev tA, Zinoviev G.S., Lopatkin N.N., Usachev A.P. Analysis and comparison of three structuresof high-voltage conveners of frequency for asynchronous electric drive" Technical electrodynamics, Special release "Power electronics and energy efficiency",Kiev: Ukraine National Academy of Sciences, 2007.Part 1. P. 98-103. (in Russian)

[38] Moin V.S. Stabilized trlnSistor converters. - M.: EneraOltomizdat, 1986. - 376 p. (in Russian)

[39] Steiner M., Deplazes R., Stemmler H. A new transfonnerless topology for AC-fed traction vehicles usingmulti-star induction motors 1/ Coof. Proc. EPE,Lausanne, 1999. CD-ROM.

[40] Lox P.C., BI~berg F., Feng S.Y., Soon R.N. PWMZ-source NPC inverter /I Proc. APEC, 2006. CDROM.

[41] Stzheletski R., Mindykovski Ya. Design, circuitry andapplication of converters of a high power and a medium vOltap with PWM, in particular in sea ships. Kiev: lED of Ukrainian academy of sciences, 2006. 25 p. (in Russian)

[42] Shavelkin AA Minimization of power circuits ofmultilevel ftequency converters for electric drives ofmedium voltap 1/ Technical electrodynamics, Specialrelease "Power electronics and energy efficiency",Kiev: Ukraine National Academy of Sciences, 2005.Part 3. P. 38-43. (in Russian)

[43] Mytsyk O.S., Pikulin V.O., Shevyakova N.B. Analysisand estimation of wavefonns of the output voltage ofconverters with pulse-amplitude modulation /I Electticity, 1979. No.ll. P. 25-30. (in Russian)

[44] Orechko E.N., Tonkal V.E. Modulation type voltagesource inverters. - Kiev: Scientific thought, 1983. 304 p. (in Russian)

[45] Rodrilues J.I., Leeb S.B. A multilevel inverter topology for inductively coupled power transfer /I IEEETrans. Pow. Electron, 2006. V. 21. No.6. P. 16061617.

[46] Zotov L.G., Zinoviev O.S. Multilevel inverters basedon step-up capacitor converters with a changing structure 1/ XXVI scientific and technical conference"Problems of efficiency and safety of operation ofcomplex technical and infonnation systems", Proceedings, Serpukhov, 2007. Part I. P. 310-314. (in Russian)

[47] Zotov L.G. A method of construction of multilevel inverters based on step-up capacitor converters with achanging structure II Electrical engineering, 2007.No.10. P. 34-40. (in Russian)

[4S] Hochgraf C., Lasseter R. A transfonner-Iess staticsynchronous compensator employing a multi-level in..verter /I IEEE Power Engineering Society, SummerMeeting 1996.96 SM 452-3 PWRD, 1996.

[49] SOlO D., Green T.C. A comparison of high-power converter topologies for the implementation of FACTScontrollers II IEEE Trans. Ind. Electron., 2002. V. 49.No. S. P. 1072·)080.

[SO] Ying C., Crow M.L. A diode-clampcd multi-level inverter for the StatComIBESS /I IEEE Power Eng.Winter Meeting, 2002. V.I P.470-47S.

[51] Wang J., Peng F.Z. Unified power flow controller using the cascade multilevel inverter /I IEEE Trans. Pow.Electron., 2004. V. 19. No.4. P. 1077-1084.

[52] Zhou G., Wu B., Donglai X. Direct power control ofamultilevel inverter based active power filter /I Proc. ofthe IEEE International Conference on Industrial Technology, 2004. V.l. P.498-S03.


Evolution ofMultilevel Voltage Source Inverters

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