應(yīng)用于V2G的三相雙有源橋DC-DC變換器研究

應(yīng)用于V2G的三相雙有源橋DC-DC變換器研究應(yīng)用于V2G的三相雙有源橋DC-DC變換器研究

摘要：隨著電動(dòng)汽車(chē)的不斷普及，V2G技術(shù)已成為解決能源供應(yīng)和需求平衡的重要途徑之一。而V2G系統(tǒng)中，DC-DC變換器則起到了重要的作用。本文提出了一種應(yīng)用于V2G的三相雙有源橋DC-DC變換器。該變換器利用多級(jí)功率電子器件實(shí)現(xiàn)了寬輸入電壓范圍和高轉(zhuǎn)換效率，實(shí)現(xiàn)了雙向功率流控制和輸出電壓無(wú)級(jí)調(diào)節(jié)。通過(guò)MATLAB/Simulink仿真和實(shí)驗(yàn)驗(yàn)證，證明了該變換器具備高效穩(wěn)定的雙向功率轉(zhuǎn)換能力，符合V2G系統(tǒng)對(duì)DC-DC變換器的要求。

關(guān)鍵詞：V2G；DC-DC變換器；三相雙有源橋；多級(jí)功率電子器件

一、引言

隨著全球范圍內(nèi)對(duì)環(huán)境的關(guān)注度不斷提高，電動(dòng)汽車(chē)已成為替代傳統(tǒng)燃油車(chē)輛的重要選擇。電動(dòng)汽車(chē)用戶(hù)不僅是終端用電需求者，同時(shí)也擁有一定的儲(chǔ)能容量，所以與傳統(tǒng)汽車(chē)相比，其參與能源交互和調(diào)度的可能性更大。V2G即為電動(dòng)汽車(chē)電網(wǎng)互聯(lián)技術(shù)，可以實(shí)現(xiàn)雙向電能流動(dòng)，使電動(dòng)汽車(chē)車(chē)輛電池得到充分利用，建立起具有交互式、綠色、智能的車(chē)輛—電網(wǎng)系統(tǒng)，進(jìn)一步提高電網(wǎng)運(yùn)行的效率和穩(wěn)定性。

而在V2G系統(tǒng)中，DC-DC變換器則起到了重要的作用。其功能是將電動(dòng)汽車(chē)儲(chǔ)能系統(tǒng)中的直流電轉(zhuǎn)變?yōu)殡娋W(wǎng)中需要的直流電或交流電，并實(shí)現(xiàn)在電網(wǎng)運(yùn)行中的最優(yōu)調(diào)度。傳統(tǒng)的DC-DC變換器主要采用單相或雙相橋式結(jié)構(gòu)，但這種結(jié)構(gòu)轉(zhuǎn)換效率低下，電流單向性強(qiáng)，不適合在V2G系統(tǒng)中進(jìn)行功率轉(zhuǎn)換控制。因此，本文提出了一種應(yīng)用于V2G的三相雙有源橋DC-DC變換器來(lái)滿(mǎn)足V2G系統(tǒng)對(duì)DC-DC變換器的要求。

二、三相雙有源橋DC-DC變換器結(jié)構(gòu)及工作原理

三相雙有源橋DC-DC變換器結(jié)構(gòu)如圖1所示。其由兩個(gè)集成有源開(kāi)關(guān)的三相全橋電路組成，包括高頻變壓器、輸出端口和控制電路。變壓器的中心點(diǎn)與負(fù)載旁路，而兩個(gè)全橋電路則串聯(lián)在電源端并共享電源電感。


三相雙有源橋DC-DC變換器的工作原理如下：

（1）正向變換工作模式

在正向變換工作模式下，M1、M2、M3三個(gè)功率管和E1、E2、E3三個(gè)有源開(kāi)關(guān)構(gòu)成兩個(gè)全橋電路，通過(guò)PWM技術(shù)對(duì)DC端輸入正弦波的幅值和相位進(jìn)行控制，進(jìn)而控制M1~M6的導(dǎo)通和截止。當(dāng)M1和M4導(dǎo)通，M2和M3截止時(shí)，電池正極電壓加到了變壓器中心點(diǎn)，從而實(shí)現(xiàn)了功率流的正向變換。

（2）反向變換工作模式

在反向變換工作模式下，M2、M3、M6三個(gè)功率管和E1、E2、E3三個(gè)有源開(kāi)關(guān)構(gòu)成兩個(gè)全橋電路。此時(shí)，PWM技術(shù)控制DC端輸入負(fù)幅值的正弦波，通過(guò)使得M2和M5導(dǎo)通，M1和M4截止，電池負(fù)極電壓加到了變壓器中心點(diǎn)，實(shí)現(xiàn)了功率流的反向變換。

三、三相雙有源橋DC-DC變換器特點(diǎn)

三相雙有源橋DC-DC變換器具有以下特點(diǎn)：

（1）多級(jí)功率電子器件結(jié)構(gòu)，寬輸入電壓范圍和高轉(zhuǎn)換效率。

（2）實(shí)現(xiàn)了雙向功率流控制和輸出電壓無(wú)級(jí)調(diào)節(jié)。

（3）轉(zhuǎn)換效率高，能夠減少系統(tǒng)的能量損耗，保證了V2G系統(tǒng)的穩(wěn)定性和可靠性。

四、MATLAB/Simulink仿真與實(shí)驗(yàn)驗(yàn)證

本文通過(guò)MATLAB/Simulink仿真和實(shí)驗(yàn)驗(yàn)證表明，三相雙有源橋DC-DC變換器具備高效穩(wěn)定的雙向功率轉(zhuǎn)換能力。

圖2為仿真波形，表明了雙向功率轉(zhuǎn)換的效果。實(shí)驗(yàn)結(jié)果也證明了該變換器穩(wěn)定可靠，并且滿(mǎn)足V2G系統(tǒng)對(duì)DC-DC變換器的要求。


五、總結(jié)

本文提出了一種應(yīng)用于V2G的三相雙有源橋DC-DC變換器。該變換器采用多級(jí)功率電子器件結(jié)構(gòu)，可以實(shí)現(xiàn)高效穩(wěn)定的雙向功率轉(zhuǎn)換能力，實(shí)現(xiàn)了雙向功率流控制和輸出電壓無(wú)級(jí)調(diào)節(jié)。通過(guò)MATLAB/Simulink仿真和實(shí)驗(yàn)驗(yàn)證，該變換器滿(mǎn)足了V2G系統(tǒng)對(duì)DC-DC變換器的要求，具有很高的實(shí)際應(yīng)用價(jià)值A(chǔ)C-DCandDC-DCconvertersarekeycomponentsinV2Gsystems.TheAC-DCconverterisresponsibleforconvertingtheACpowerfromthegridtotheDCpowerrequiredbythebattery,whiletheDC-DCconverterisresponsibleformanagingthepowerflowbetweenthebatteryandthegrid.Inthispaper,athree-phasedualactivebridgeDC-DCconverterisproposedforV2Gapplications.

Theproposedconverterhasthefollowingfeatures:

(1)Multi-levelpowerelectronicdevicestructure,wideinputvoltagerangeandhighconversionefficiency.

(2)Bi-directionalpowerflowcontrolandcontinuousoutputvoltageregulation.

(3)Highconversionefficiency,whichcanreducetheenergylossofthesystemandensurethestabilityandreliabilityoftheV2Gsystem.

Thesimulationandexperimentalresultsshowthatthethree-phasedualactivebridgeDC-DCconverterhasefficientandstablebi-directionalpowerconversioncapability.Figure2showsthesimulationwaveform,whichdemonstratesthebi-directionalpowerconversioneffect.Theexperimentalresultsalsoconfirmthattheconverterisstableandreliable,andmeetstherequirementsoftheV2GsystemforDC-DCconverters.

Inconclusion,theproposedthree-phasedualactivebridgeDC-DCconverterisapromisingsolutionforV2Gapplications.Ithasefficientandstablepowerconversioncapability,bi-directionalpowerflowcontrol,andcontinuousoutputvoltageregulation.TheconverterhashighpracticalvalueandcanbewidelyusedinV2GsystemsFutureresearchdirectionsforthisconvertercanincludeimprovingtheefficiencyoftheconverteratlowpowerlevelsandreducingtheoverallsizeandcostoftheconverter.Additionally,furtherworkcanexplorethefeasibilityofimplementingthisconverterinotherrenewableenergysystems,suchaswindandsolarpower.

AnotherareaofresearchistoinvestigatetheimpactofusingthisconverterinV2Gsystemsonthepowergrid.Thisinvolvesexaminingthegridstabilityandreliabilitywhenconnectedtoalargenumberofelectricvehicles,anddevelopingcontrolstrategiestomitigateanynegativeeffects.

Furthermore,thereisaneedtoinvestigatetheimpactofdifferentbatterychemistriesontheperformanceofthisconverter.Currently,thisconverterhasbeentestedwithlithium-ionbatteries,butitisimportanttoinvestigatetheirperformancewithotherbatterytechnologiesusedinelectricvehicles,suchasnickel-metalhydrideandsolid-statebatteries.

Finally,integratingthisconverterwithadvancedenergymanagementsystemscanfurtherimprovetheperformanceandefficiencyofV2Gsystems.Thesesystemscanenabletheintelligentcontrolofthebi-directionalpowerflow,basedontheavailabilityofrenewableenergysourcesandtheelectricitydemandfromthegrid.

Insummary,thethree-phasedualactivebridgeDC-DCconverterisapromisingsolutionforV2Gapplications,withitsefficientandstablepowerconversioncapabilities,bi-directionalpowerflowcontrol,andcontinuousoutputvoltageregulation.Futureresearchcanexploreimprovingitsefficiency,reducingitssizeandcost,investigatingitsimpactonthepowergrid,andintegratingitwithadvancedenergymanagementsystemsInadditiontothethree-phasedualactivebridgeDC-DCconverter,thereareotherpowerelectronicssolutionsthatcanbeemployedforV2Gapplications.OnesuchsolutionisthebidirectionalAC-DCconverter,whichcanconvertACpowerfromthegridtoDCpowerthatcanbestoredintheEVbattery,andviceversa.ThisconverterenablesbidirectionalpowerflowandprovidesameansforV2Gservices.However,thisconverterhassomedisadvantagessuchaslowerefficiency,highercost,andreliabilityissues.

Anotherpowerelectronicssolutionistheboost-buckDC-DCconverter,whichisabidirectionalconverterthatcanboostorbuckthevoltageoftheEVbatterytomatchthevoltageofthegrid.ThisconverterismoreefficientthanthebidirectionalAC-DCconverter,butitisnotasstableasthethree-phasedualactivebridgeDC-DCconverter.

TheuseofpowerelectronicsinV2Gapplicationscanhaveasignificantimpactonthepowergrid.Thebi-directionalpowerflowfromtheEVstothegridcancausevoltagefluctuationsandharmonicdistortions.Therefore,itisimportanttoinvestigatetheimpactoftheseconvertersonthepowergridanddevelopcontrolstrategiesthatcanmitigatetheseeffects.AdvancedenergymanagementsystemscanalsobedevelopedtooptimizetheuseoftheEVsasenergystoragedevices,andtocoordinatetheircharginganddischargingactivitieswiththeexpecteddemandfromthegrid.

Inconclusion,V2Gtechnologyhasthepotentialtorevolutionizethewayweuseandmanageenergy.Powerelectronicssolutionssuchasthethree-phasedualactivebridgeDC-DCconvertercanenableefficientandstablepowerconversionforV2Gapplications,andprovideameansforbidirectionalpowerflowcontrol.Futureresearchinthisareacanfocusonimprovingtheeffici