Delta Solivia 2.5 - Technical Structure of the Solar Inverter

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4.2 Technical structure of the solar inverter
AgalvanicalisolationofthesolarinverterfromthegridisachievedthroughaDC/ACconverterwith
anintegratedhigh-frequencytransformer.Thephotovoltaicvoltageisadjustedsothatthemaximum
poweroutputofthePVmodulesisalsoachievedwithvaryingsolarirradiationlevelsandtempera-
tures(MPP-Tracking).
TheMPPrangeofthesolarinverterisbetween150Vand450V.ThisfacilitatestheuseofPV
modulesbyavarietyofmanufacturers.Measuresmustbetakentoensurethatthemaximumopen-
circuitvoltageof540VDCisneverexceeded.Pleasenotethatthemaximumopen-circuitvoltage
will occur at the lowest temperatures anticipated.You will nd more detailed information about
temperaturedependencyinthedatasheetofthePVmodules.Thedevice’spowerconsumptionis
kepttoaminimum.
Thehigh-qualityaluminumcasingcorrespondstoprotectionclassIP65(water-jet-proofanddust-
proof)andisprotectedagainstweatheringprocessesbysurfacerenement.Thecoolingcharac-
teristicproleisdesignedsothatoperationoftheinverterispossiblewithambienttemperatures
from-25°Cto+70°C.
Acoolingcharacteristicproleisusedfortheremovalofthepowerdissipationcausedthroughthe
voltage conversion.An internal temperature control protects the device against excessive tem-
peraturesintheinteriorofthesolarinverter.Incaseofhighambienttemperatures,themaximum
transferablepowerislimited.
Thesolarinverteriscontrolledbymicrocontrollers,whichalsoimplementinterfacecommunication
andthemonitoringofvaluesandmessagesonthedisplay.
Twoindependentandredundantmicrocontrollerscontrolthemonitoringofthegrid,whichiscon-
sistentwiththefeed-indirectivesofyourlocalutilitycompanyandDINVDE0126-1-1,EN50438,
ENELG.L.12/2008andRD1663(anti-islandingprotection).Thisenablesaninstallationofthesolar
inverterinthein-houseelectricalgrid.
OperatorprotectionrequirementsaremetbyelectricallyisolatingthegridfromthePVmodule.The
electricalisolationbetweenthegridandthePVmoduleisequivalenttobasicinsulation.Maximum
operatorprotectionisensuredbyreinforcedisolationbetweenthegrid,PVmodulesandaccessible
interfaces(displayandRS485interface).Relevantstandardsconcerningelectromagneticcompat-
ibility(EMC)andsafetyarefullled.
Thesolarinverterisfunctionalinon-gridoperationexclusively.Anautomatedisolationpoint,which
isapprovedbyacerticationagency,guaranteessecuredisconnectionincaseofcircuitisolationor
interruptionsinpowersupplyandavoidsisolatedoperation.
Thedisconnectionequipmentallowsforautomaticisolationforin-plantgenerationsystemsofnomi-
nalpower≤4.6kVA,withsingle-phaseparallelfeed-inthroughthesolarinverterintothepublicgrid.