All-SiC ANPC Submodule for an Advanced 1.5 kV EV Charging ...

energies

Article

All-SiC ANPC Submodule for an Advanced 1.5 kV EV Charging System under Various Modulation Methods

Rafal Kopacz , Michal Harasimczuk , Bartosz Lasek , Rafal Mis?kiewicz and Jacek Rabkowski *

Institute of Control and Industrial Electronics, Warsaw University of Technology, 00-662 Warsaw, Poland; rafal.kopacz@pw.edu.pl (R.K.); michal.harasimczuk@pw.edu.pl (M.H.); bartosz.lasek@pw.edu.pl (B.L.); rafal.miskiewicz@pw.edu.pl (R.M.) * Correspondence: jacek.rabkowski@pw.edu.pl

Citation: Kopacz, R.; Harasimczuk, M.; Lasek, B.; Mis?kiewicz, R.; Rabkowski, J. All-SiC ANPC Submodule for an Advanced 1.5 kV EV Charging System under Various Modulation Methods. Energies 2021, 14, 5580. en14175580

Abstract: This work is focused on the design and experimental validation of the all-SiC active neutral-point clamped (ANPC) submodule for an advanced electric vehicle (EV) charging station. The topology of the station is based on a three-wire bipolar DC bus (?750 V) connecting an ac grid converter, isolated DC-DC converters, and a non-isolated DC-DC converter with a battery energy storage. Thus, in all types of power converters, the same three-level submodule may be applied. In this paper, a submodule rated at 1/3 of the nominal power of the grid converter (20 kVA) is discussed. In particular, four different modulation strategies for the 1.5 kV ANPC submodule, exclusively employing fast silicon carbide (SiC) MOSFETs, are considered, and their impact on the submodule performance is analyzed. Moreover, the simulation study is included. Finally, the laboratory prototype is described and experimentally verified at a switching frequency of 64 kHz. It is shown that the system can operate with all of the modulations, while techniques PWM2 and PWM3 emerge as the most efficient, and alternating between them, depending on the load, should be considered to maximize the efficiency. Furthermore, the results showcase that the impact of the different PWM techniques on switching oscillations, including overvoltages, can be nearly fully omitted for a parasitic inductance optimized circuit, and the choice of modulation should be based on power loss and/or other factors.

Keywords: ANPC converter; EV charging; multilevel converter; PWM methods; SiC MOSFETs

Academic Editors: Andrei Blinov, Sheldon Williamson and Hugo Morais

Received: 11 July 2021 Accepted: 30 August 2021 Published: 6 September 2021

Publisher's Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Copyright: ? 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// licenses/by/ 4.0/).

1. Introduction

There is no doubt that easily available fast charging infrastructure is a necessary condition in the further expansion of electric vehicles (EVs) beyond current numbers, even in the most developed countries [1,2]. In comparison to traditional cars, the charging time of EVs is, and will be, longer than refueling a tank with gasoline. However, fast charging stations may offer a reduction in time from the range of hours to tens of minutes [3]. This is associated with an increase in charging power to hundreds of kWs, and, unfortunately, a rising number of such stations is challenging for the power system. Therefore, an answer to this problem may be a battery energy storage, reducing power peaks during fast charging periods [4,5]. Additionally, the storage may also act as local energy storage for a PV plant, and perform short-time grid support services. All in all, the EV charging station with energy storage becomes a high-power and complex power electronics system, as can be seen in Figure 1. Moreover, to decrease current levels and conduction losses in a common DC-link (750?800 V), a bipolar topology may also be taken into account [6]. All three types of power converters in such a system: grid-connected AC-DC, isolated DC-DC, and non-isolated DC-DC, should be based on one of the multilevel topologies. Furthermore, in the optimal scenario, all of them should be based on the same topology to reduce the complexity and cost of the whole system, and to introduce modularity into the system. While the isolation stage of the AC-side is omitted in this paper, as the focus is on the

Energies 2021, 14, 5580.



Energies 2021, 14, x FOR PEER REVIEW Energies 2021, 14, 5580

2 of 15 2 of 15

presented ANPC submodule, it is worth noting that either conventional low-frequency trapnrsefsoernmteedrsAoNr PsColisdu-bsmtaotedutrlea,nistfiosrwmoerrtsh[n7o]tainreg athpaptleicitahbelrecionntvheentEioVnaclhlaorwgi-nfrgeqsuyesntecym.

transformers or solid-state transformers [7] are applicable in the EV charging system.

FigFuirgeu1re. B1.ipBoiplaorlaDr DCCggrirdid-b-baasseedd EEVV cchhaarrggininggstsattaiotinonwiwthitehneerngeyrgstyorsatgoer.age.

Several multilevel converter topologies are applicable in EV charging systems [8].

MoSsetvneoratalbmly,unlteiuletrvaellpcooinntvcelratmerpetodp(oNloPgCi)e, sT-atyrepea,pflpyliincgabclaepaincitEoVr (FcCh)a,ragnindgmsoydsutelamr s [8].

Momstunltoilteavbelyc,onevuerttrearl (pMoMinCt )ctloapmoploegdie(sNcPanCb),eTn-atympeed,. fIlnyitnhge dcaispcaucsisteodr c(aFsCe,),thaenadctmivoedular

munletiuletrvael lpocoinntvcelarmtepre(dM(AMNCP)Ct)otpopoolologgieysofcathne bsuebnmaomduedle., iInntrtohdeucdeidsciuns[s9e],dwcaasssee,letchtedactive

neuatsriatlispcohinartaccltaemrizpeeddb(yAmNoPreCfl) etoxipbolelocgonytorofltahnedsuthbempoosdsuibliel,itiynttorordeauccheda mino[r9e]b, awlaanscseedlected as iptoiws cehr alorsasctdeirsitzriebdutbiyonmaomroenfgletxhieblseemcoincotrnodluacntodrsthceompopsasriebdiltiotythtoe croenacvhenatimonoarleNbPaClanced powtoeprolloogsys, dwishtirleibkueteiopningamthoenpgotwheer sdeemviicceonstdreuscstoorns acosmimpilaarreldevteol t[h10e,1c1o].nvMenorteioonvaerl, NPC topwtoohlpoeognloycg,oiemws,phtaihlreeedfkoteromepoetirhniegsrlctehossmeempffioocwnieemnrtufdloterilvethviceeelssyststrtrueecmstsusrioenn, ssuuacchhsivmaosilTltaa-trgyeplereavanengl de[1(F10C5,10c01o]Vn. v)Methrotaernreover, whtehne cNoPmCp-daereridvetdo tootphoelrogcoiems m[12o]n, wmhuelrteilaesvtehlestlaruttcetrucraen, nsoutchbeaesmTp-tlyopyeedanindaFsCysctoemnverter topwoiltohgiaesb,ipthoelafroDrmCebruiss lfeosrsoebfvfiicoiuesntrefaosrotnhse. sFyisntaelmly,swinhesuncahcvoomltpaagreisroannwgeit(h15M0M0 VC-) than thebNasPedC-sdyesrteivmesd[t1o3p] oislocgoinessid[1e2re]d, w, AhNerPeCasctohnevleartteerrs csaenemnomt boereemappplrooyperdiatien, aassyMstMemC with

a biinptoroladruDceCs abbuuslkfioer ostbruvciotuurse,raenadsoandds.sFfuinrtahlelyr,cwomhpelnexaitcyotmo tphaersiyssotnemw[i8t]h. FMuMrthCer-mbaosreed, sys-

temAsN[P1C3]siysscteomnssiwdeerreedp,oAsitNivPeCly cvoenrivfieerdteinrstesremems ofmboorteh tahprpeer-owpirriea[t1e4, ]aasnMd EMVCchinatrrgoindguces a

bulskyisetremstsru[1c5t]u. re, and adds further complexity to the system [8]. Furthermore, ANPC sys-

tems wMeroerepoovseitr,ivaeslythveeSriiCfietdecihnntoelormgys iosfcboontshtanthtlryeed-ewvierleop[i1n4g] aanndd pErVovcihdainrggipnogwseyrstems

[15st]ee.rmpiacrotsnd[1u6c?t1o8r],deesvpiececisalwlyitfhorsuthpiesrsioprecpifiercfovromltaagneceracnogmep, aaprepdlytiongcoSniCveMntOioSnFaEl TSsi

counto the

swMitcohreesolveaedr,taos, athmeoSnigCsttmecahnnyo, ilnocgryeaissecdoenffistcaienntlcyy danedvehliogphienrgpoawnderpdreonvsiidtyi.nHgopwoewveerr, sem-

icobnrdieuflcytoarftderevthiceecsomwmitherscuiapl einritorordpuecrtfioonrmofaSnicCepcoowmepr adreevdicteos,cwohnevnenthtieoSniaCltSeichcnooulnotgeyrparts

[16w-1a8s]s,teilslpreelcaitaivlleylyfnoerwt,htihsescpoesct iofficsuvcohlptaogweeradnegviec,easpwpalsysiinggnifiSicCanMtlyOhSigFhEeTr scotmopthareedswtoitches

leacdontov,eanmtioonnagl Ssit ImGBaTnsy. ,Tihnucsr,edaisfefedreenftfihcyiebnricdySai/nSdiChAigNhPeCr ptoopwoleorgideesnwseitrye .inHtroowduecveedr,,inbriefly

aftewrhtihche cSoiCmMmOeSrcFiEaTlsincatrnobdeuacptpiolinedofasSitCheppoowweerr ddeevviicceessf,owr thweonotrhfeoSuirCoutetcohfnsioxlodgevyicwesas still relapteirvleelgy dneepwe,ntdhinegcoosnttohfespurcehfeprroewd ePrWdMevtieccehsnwiqause,sisghnoiwficcaasnintlgyshaitgishfaecrtocroymrpesaurletds itno conventetiromnsaol fSaicIhGieBvTinsg. Ta hbualsa,ndceiffbeertewnetenhycbosrtidanSdi/pSeiCrfoArmNaPnCcet[o1p8?o2lo2]g.iNesevweertrheeilenstsr,oedvuecned, in whttihhcoehuaSglilhC-StiMhCeOshySysFbtEerimTdstiocspasnotillbolgeuiaenpsmpsahltioceuhdledadsbwtehhceoepnnsosiwdtreiecrretlddyewpvheicrefenosrtfmhoearnctowcsetoaiosnrdtafkomeuanrxioinmutoitzoaafcticsooinxundotfe, vices pereflfiecgiednecpyeanredicnognsoidnertehde [p19re].feMrroerdeoPvWer,Msucthecahncoiqnuveer,tesrhostwruccatsuirnegissaantidsfwaciltlobryecoremsue lts in termevsenomf aocrhe iceovminpgellainbga, laasntchee bweitdwe-ebeanndc-ogsatpatnecdhnpoelrofgoyrmisacnucrreen[1tl8y?b2e2c]o. mNienvgemrtohreeleasnsd, even

thomuogrhe tahdevahnycberdid, atnodpothlougs iSeisCsphoowuledr dbeevcicoensswidiellrdedevwelohpentothbee caoffsotrdisabtaleketonaingtroeaatecrcount,

theeaxltle-nStiCyesayrlsyt.em is still unmatched when strictly performance and maximization of effi-

ciency aSrinecceotnhseidneurmedbe[r19o]f. sMwoitrcehoevseirn, sthuechAaNcPoCnlveegrtiesrhsigtrhu,cstourise tihseanvdariwetiyll obfePcoWmMe even momreetchoomdspaepllpinlicga,balse tihnesuwchidaes-bysatnemd-.gMaporteeocvhenr,odleopgeynidsincgurornenthtelyfobceucsoomf ainsgpemciofirceaapnpdli-more

advanced, and thus SiC power devices will develop to be affordable to a greater extent

yearly.

Energies 2021, 14, 5580

3 of 15

cation, there are modulation techniques that can target various factors, such as efficiency or power density, ensuring equal loss distribution, or, finally lowering line filter requirements [10,23?25]. Furthermore, according to the literature, the impact of commutation path lengths is a crucial matter, determining the proper PWM method for a specific application as well. This is especially relevant when systems with SiC power devices are considered, as wide-band-gap semiconductors are capable of high-speed switching, and thus are more prone to ringing and overvoltages compared to its Si counterparts.

However, in this paper, except for validating the constructed low-volume prototype of the all-SiC ANPC single leg rated at 1500 V DC and 6.67 kVA power (1/3 of three-phase 20 kVA system), it is shown that when enough care and focus is put into the design process of the converter and thus the commutation path lengths are vastly minimized, the variances between different modulation techniques in this regard are not as apparent and the choice may be limited to other factors, namely in this case, efficiency. The conclusions are based on a parasitic inductance optimized ANPC leg that can be used as a submodule to construct full power electronic systems, e.g., three-phase bidirectional AC/DC converters as shown in Figure 1.

Furthermore, in this paper, the PWM techniques are compared based on efficiency and switching performance, strictly for an all-SiC system. In contrast, other researchers have focused on a comparison between different Si/SiC configurations with strictly bound modulation techniques, where each configuration was tested with its specific PWM method. Finally, the conclusion is drawn that while all modulation techniques are viable, two emerge as the most competent, one for lower power ratings and another for higher power ratings. Thus, the assumption is made that to operate optimally, the modulation technique should be changed according to the load. Moreover, while systems comprised of ANPC submodules have been shown in the past, they are connected with other power semiconductor device types, such as IGBTs [26,27] or IGCT [28]. There are no publications regarding SiC MOSFETbased systems rated at MV level, whereas for such an application, the impact of parasitic inductances due to high dv/dt rates and a high switching speed is much more severe, and thus also more critical during the design process [29].

The paper is organized as follows. After the introduction, in Section 2, the basic principles of the ANPC topology are explained together with the considered PWM methods and their operation principles. Then, the simulation study is shown in Section 3, and, in Section 4, the experimental model of the SiC-based submodule is presented along with the results showcasing the experimental validation and further the discussion. Finally, the paper is concluded with a summary in Section 5.

2. Modulation Strategies in Active Neutral Point Clamped (Anpc) Converter

The most popular inverter topology used in industrial power electronic is a basic three-phase two-level (2-L) inverter [30]. This is mainly due to its simple design and well-understood operation principles. However, the voltage stress of semiconductor power devices in such topology is greater than in the DC-link voltage bus. This prevents the use of 1.2 kV SiC power devices in 2-L inverters with greater DC voltage. A well-known alternative to 2-L inverters are three-level (3-L) inverters [31]. The use of such a topology provides a halved maximum voltage stress in semiconductor power devices. Furthermore, due to the three-level nature of the output filter inductor voltage in 3-L inverters, it is possible to reduce the harmonic distortion and output filter volume [32,33]. The low switching time of SiC power MOSFETs also allows a reduction in switching losses. On the other hand, the high value of stray inductance and di/dt of transistors during commutation lead to voltage overshoots, which have a negative impact on MOSFETs' lifetime, energy conversion efficiency, and EMI. In 3-L inverters' three different operation states (positive state P, zero state 0, and negative state N) can be recognized, differing in voltage applied to the inductor. A highly regarded 3-L inverter topology is the ANPC, used in the discussed submodule. The ANPC converter consists of six active switches, S1?S6, connected according to Figure 2.

Energies 2021, 14, x FOR PEER REVIEW

4 of 1

Energies 2021, 14, 5580

4 of 15

submodule. The ANPC converter consists of six active switches, S1?S6, connected accord ing to Figure 2.

FFiigguurere2.2A. Asinsignleg-lpeh-pashealseegloefgthoef tAhNePACNcPonCvcerotnervwerittehrSwiCitMh OSiSCFEMTsO. SFETs.

InInththe eAANNPCPCconcovnervteerr,twerh,ewnhtheenotuhtepouut vtpoultat gveoilstapgoesiitsivpeo, tshiteivinev, etrhteerinisvsewrtietcrhiisngswitchin bbeetwtweeenenpopsoitsiivteiv+eV+DVCDvCovltoalgteagaendanzedrozevrooltvagoel;taagned;wanhdenwthheeonutthpeutovuotlptaugtevisolnteaggaetiivsen, egative wtthhheeeinninvtvehreetretvreoirsltisaswgsiewtcihisticnphgoisbnietgtivwbeeeetawnndneeengneagntiavetgeiva-etiVvisDeCa-naVanDldoCgzaeonruodsv.zoeTlrthaoegvreeo.fClotroaeng,teri.noCl toohfnitshtraeorcltoiocnlfvet,ehrtteheecronverte dwifhfeernentthceonvtorlotlamgeetihsopdossairteivoenlaynddesncergibaetdivwe hisenanthaelovgooltuags.eTishpeoresiftoivree., PinanthdisNasrttaicteles, the dif cfaenrebnetocbotanitnreodl omnelythboydtsuranriengonolnytrdaensscisrtiobresdSw1 ahnednSt2hien vPoslttaatge,eainsdpSo3saitnidveS.4PinaNndstNates.tates ca DbueroinbgtaPinsteadteo, tnrlaynsbisytotruSrn6 icnagn boentutrrannesdisotno.rSsimS1ilaanrldy, Sd2uirninPg Nstasttaet,ea, ntrdanSs3isatonrdS5Sc4ainn N state bDeuorninags wPesltla. tTeh, itsraensuisrteosrcSo6ncstaanntbveDtSuvrnoletdagoens .eSquimaliltaorVlyD,CdounritnrganNsissttoartseS, 3traanndsiSs4tor S5 ca dbueroinngaPsswtaetell,.aTnhdisonenSs1uarneds Sco2 ndsutraintgvNDSsvtaotlet.aSgiemsuelqtaunaelotuoslVy,DiCnotnhetrAaNnsPisCtotorps oSl3oagny,d S4 dur tihnegreParsetadtieff,earnendt oapnpSro1 aacnhdesSt2odoubtrainingzNerostsatatete..SFiomuur lmtaondeuolautsiolyn,sitnratthegeieAsNofPtChetAopNoPlCogy, ther aanrde donifefeorfetnhteaNpPpCrocaocnhveesrtteoros bartaeidnezpeicrtoedstainteT.aFboleu1r manoddFuilgautrioen3.sItnrattheigsipeaspoefrt,htheeAreNPC and afcofroroonenumedfrouoeucdafrtciitdfohhfineefofrpteeNhraneetPhntrCstimnmmcroooaeddrngkuuvaerlledaadrtttiiitnoeoornnFstshisgadeurdezerseeecsdrr4coiebrbpsieybtidace2tt(deePa,dnWi(ndPiMnwW3.1hTM?iaPcb1hWl?etMPh1We4)caM.unTrd4rhe)e.FnsiteTgflPhuoWerwesMes3t.PtheIWrncohuMtnhgiqhistudeepcisfahfdpenireifeqfrne,urttehserdeifafre from each other in regard to the zero state, in which the current flows through differen

conducTtiaobnlep1.aSthwsitcmhianrgksetadteisnoFf tihgeuAreN4PCbiynv2eratnerd. 3.

State

S1

S2

S3Table 1. SSw4itching staSt5es of the ASN6 PC invCeortnedr.uction Path(s) PWM Method

P

S0tUa3te

1

1

0

0

0

1 S1

S02

S3 1 S4 0S5

S6 0

1/0

1

Co1nduction Path3(s)

1, 2, 3, 4

PW2M Method

0UP2

01

1 1

0 0 0 00 1/0 1

0U1

0

1

0

1

1

00UF3

01

0 1

1 1 0 00

1 1

0

1

2

0

2

1

3 2 and 3

1 1,2,3,4

4

32

00UL12

10

1 0

0 1 0 01

0 0

1

2

3

41

000ULL231

0 0

0

101

0

1 0

1

0 1

1

0

0 1

0NF

00

1 0

1 1 0 11

1 1/0

1 0

2

3 2

0 2 and 3 4

1 2

4

1, 2, 3, 4 3

0L1

1

0

1

0 0 1

3

4

0L2

0

0

1

0 0 1

3

1

0L3

0

1

0

1 1 0

2

2

N

0

0

1

1 1/0 0

4

1,2,3,4

EnEenrEgerniegesrieg2si0e2s201220, 1211,4,1,14x4,,Fx5O5F8RO0RPEPEERERRERVEIVEIWEW

5 of 15 5 5ofo1f 51

(a()a)

(b()b)

(c()c)

(d()d)

FFiFgigiugurureer3e3..3DD. DiiffffieefrfreeenrnettnmmtomodduouldaltuaioltainotinsotrnsattrseatgrtiaeetgseifgeosirefstohfreotArhtNehPAeCANcNPoCnPvCceorctneovrnsev(raet)ertrPesWr(saM()aP1),WP(bWM) MP1W,1(M,b()b2P,)(WPc)WMPWM2M,2(,c()cP)WPWMM 33,3,(,d(d()d)P)PWPWWMMM44..4.

FFiFgigiugurureer4e4..4AA. ANNNPPCCPCccooncnovvneervtreetrertrwewrithwithditehdpeidcpteeipcdtiecstdteradsytrsiatnrydauyincitdnaundccuteacstnaacnnedcsehasingadhnldihgihhgtihegdlhigclihognthedtduecdctoiconondnpudacutthciost.inonpaptahtsh.s.

IInnInmmmeettehhtoohddoPdPWWPMWM1M1[31[43][4,3]d4,u]d,ruidnruginrzignergzoezsretoartosetstarttaaentetsritsartnoasrnsiss, itSso2troasrn,sSd,2SSa25naadnredSo5Sna5,raaenreodnoth,nae,ncaudnrdtrhetnehtecucrurrernetn flflofolwowwssstthhtrhoruogguhhgchcoocnnoddnuudctcuitocinotinopnaptahptahtwthtowt(womo(amr(kmaerdakriekndebdilnuienbilbnuleFuieignuinFreiFg4iu)g.ruIenre4t)h4.i)sI.ncIontnhttihrsoisclomcnoetntrhtorolodml, metehtohdo,d sstdrdstitwunsstdarrwuratwarniuarsrntiiystatcnrinisrcnitihyigassihcngsniityhitgnsiondtonitirgrngrnoudtassrgdrncttuaSsSrrutsscnataa33iScirttnnnstataaai3iaisocnsnonntainnieisddncnssocstietPeodnSsSoPssLr?t66rsSo0?,LP,Ls.160raa.??a,Isn11nL0nIa.?ah?dndnLLIit3agnhie,dtinh3cen3iah,ght,ictnveniahtahnhghcdanniinthshlqivdhduLsiuncqaievLaLcsei5luqasao?ucPee55lusfLea?u?WeddesPLLe7oueid.MW/Pf7ro7uWd.diW.2fndMruWtWigh[idMnri/32neidhthig5nh/n2eet]L[dge,t3nnhwt[id5t1nt3werh],uwie5a,nLeretL]nedric,nsctLao51udriocg,ntmaormi1uLsLo,nzimnirppnestLi75grianiap,ototcrr5hgiaLnz,eaeoseruetLntzret7tarhsehheotcete7treeiehahssoc,trsueervateattarrhssauotenhaietetlsrsantsiseaiegactias,stnseguhviita,hosetrohvviirnitholsteegaohtipninilaohlengucittgnkauhievPcflengruaoiWsovrenslfPrweaoupMrdnsWlnPeesuipitk2nW/tveoMiheftdktifloosaMetoef2dflswoo2idt/nwoosdit/notsttdvhhiitttvnaeehhii onoeneininPWPWMM1,1t,hteheeqeuqiuviavlaelnetnsttsrtaryayinidnudcutcatnacneceisihs ihgihgehre,ra,nadndthtuhsu,sd, id/di/tditsihs ihgihgehrearsaws welel,l wwhihcihchlelaedasdstotoa ahihgihgehrervavlauleueofovf ovlotaltgaegespsipkiekse.sI.nInmmetehtohdodPWPWMM3 3[2[32,33,63]6, ]d, udruinrigngzezreor stsattaet,et,rtarnasnissitsotrosrSs 2S, 2S, 3S, 3S, 5S, 5a,nadndS6Sa6raereono,na,nadndcucrurrernetnftloflwows tshtrhoruoguhghcocnodnudcutciotinonpaptahtshtswtwo

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download