TMS320C2000™ DSP Controllers: A Perfect Fit for …

1 TrademarksApplicationReportSPRAAE3 May2006 TMS320C2000 , (PV)basedsystem,theinverterisacriticalco mponentresponsibleforthecontrolofelectri cityflowbetweenthemodule,battery,loads, ,whichconvertdirecttoalternatingcurrent, ,invertersprovideadditionalfunctionssuch asmaximizingpower,batterycharging, (DSP)basedcontrollers,suchastheTexasInst rumentsTMS320C2000 familyofcontrollers, , , May2006 TMS320C2000 , ,alternativesolutionssuchaswind, solar ,bi omass,geothermal,andsmallhydropowertechn ologiesnowsupply160 Gigawattsofgeneratingcapacity,whichisrou ghlyfourpercentoftheworld ,thefastestgrowingalternativetechnologyi ssolarpower, ,Germany,andJapanareleadingmarketsforsol arpowerandsystemdevelopment,withanumbero fcompaniesfocusedonresearch,developmenta ndmanufacturingactivitiesforthedeliveryo fphotovoltaic(PV) ;multiple-interfacedata-loggers.

2 Andcompact, ,theinverterisacriticalcomponent,respons ibleforthecontrolofelectricityflowbetwee nthemodule,battery, ,invertersperformsuchfunctionsasdisconne ctingthecircuittoprotectitfrompowersurge s,chargingthebattery,loggingdataonusagea ndperformance,andmaximumpowerpointtracki ng(MPPT) (KWp),solarinverterscanbedesignedarounds ophisticatedtopologies,eitherwithorwitho uttransformers, , ,orfeedpowerbacktothegridwithoutlocaluse , DSPC ontrollers:APerfectFitforSolarPowerInver tersSPRAAE3 , : Eachpanelmaybeservedbyasmallintegratedin verter,yieldingafewhundredwattspeak(Wp). Asingleinvertermayservetheparallelinputs ofallthePVstrings,yieldingseveralKWp. SeparateDC/DCconversionstagesmaybeapplie dtoeachPVstring, , ,thetopologywillvarywiththescaleoftheapp lication, ,ofcourse, ,soone-, ,inwhich: DC/DCconversionraisesorlowerstheincoming PVvoltage,adjustingitsoutputforgreateste fficiencyintheDC/ACconversionstage, Thecapacitorprovidesfurthervoltagebuffer ing, TheMOSFET sinthebridgeuseaswitchingfrequencyinther angeof20kHztocreateanACvoltage, May2006 TMS320C2000 , ,thesystemcaneitherstepitupwithatransfor merontheACside(afterthecoilsinFigure3) ,asdoesaphase-shiftedfull-bridgeDC/DCcon verterwithzerovoltageswitching(makingitt husequivalentlyatransformer).

3 Figure4 , DSPC ontrollers:APerfectFitforSolarPowerInver tersSPRAAE3 ,codesrequiretheuseoftransformers,whileG ermany,themajorEuropeanmarket, ,bulkandcost, ,transformersincreasecircuitprotectionan dhumansafetybyisolatingthetwosidesofthec ircuitelectrically,preventingaDCfaultfro mflowingtotheACside, ,thedesignmayincludearesidualcurrentprot ectiondevice(RCD)thatmonitorsthecurrents ofallphases,includingneutral, , , ,duetofactorssuchastheweather,timeofdaya ndheatofthepanels;andthebatterycondition saredifferent,too, , currentisatitspeak,themaximumpowerpoint( MPP).MPPtracking(MPPT) , ,say, ,theincrementalinductancealgorithm,solve sthederivativeofthepowercurvefor0,whichi sbydefinitionapeak, , , ,whilethemostefficient, May2006 TMS320C2000 ,anditsdesignneedstobebothflexibleforuse indifferentapplications, ,whileonlyneedingnear-realtimeresponse, ,combininghigh-performanceDSPsandintegra tedcontrolperipherals,offeranexcellentso lutionforreal-timecontroloftheDC/ACconve rterbridge, (ADCs)andpulse-width-modulatedoutputs(PW Ms)makeitpossibletodirectlysenseinputsan dcontrolpowerMOSFETs, , ,aswellasachievingsignificantcostreducti ons.

4 (1)Example:TMS320F28xDigitalSignalProces sorsAnexampleofsuchaprocessoristheTexasI nstruments(TI)TMS320F28x digitalsignalcontroller, , ,asingleDSPcontrollercancontrolmultiplec onversionstagesinthesameinverterandhaveo verheadremainingforperformingadditionalf unctionssuchastheMPPT algorithm,batterychargemonitoring,surgep rotection, , DSPC ontrollers:APerfectFitforSolarPowerInver tersSPRAAE3 (EPWM) ,allowingphasedelaytobeprogrammedin, , ,includingtheCANbus, , , ,asshownintheexample, , ,itmakessensetosynchronize,anda1 masterand3 ,thenallthemodulesmustbemasterswithoutsy nchronization, May2006 TMS320C2000 , ,acontrollerthatprovideshighperformance, , DSPC ontrollers:APerfectFitforSolarPowerInver tersSPRAAE3 May2006 SubmitDocumentationFeedbackIMPORTANT NOTICET exas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,enhancements, improvements, and other changes to its products and services at any time and to discontinueany product or service without notice.

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