XITRON XT2640 - Typical Dual Vpa Applications

XT2640OperatingManual 13July2016 Page18of187
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8.4 TYPICALDUAL VPAAPPLICATIONS
ExamplesofdualVPAapplicationsasshowninthediagrambelowinclude–
ACtoDCPowerSupplies(singleormultipleoutputs)
DCtoDCPowerSupplies(singleormultipleoutputs)
DCorfixedfrequencyACsuppliedvariableorfixedspeedmotordrives
PowerTransformers(singleormulti‐phase)
LightingBallasts(mosttypes)
StandbyorBackupPowerSupplies(ACorDC)
PhotovoltaicPowerGenerators(DCin;DCorACout)
TherearealsootherdualVPAconfigurationswhicharenotshownhere.Asexamples–
Iftheneutralcurrentistobeactuallymeasuredratherthancomputedfromtheotherphasesfora2ø3wor3ø4wsupplyor
loadthenthatisaccomplishedbyusingasecondVPAforjusttheneutralcurrentmeasuringchannelandsettingthatVPA
tobefullysynchronouswiththemainVPA.
IfaloadhasbothACandDCsupplyinputs(orviceversa),ortwodifferentfrequencyACsupplies,theneachsupplycanbe
measuredinseparateVPAsandanefficiencygroupusedtoproducethetotalinput(oroutput)powerfrombothVPAs.
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 EachVPAisindependentlyconfiguredandhasthesamecapabilitiesaspreviouslydescribedforsingleVPAapplications
(exceptonlyasingleoscilloscopeinoneVPAisallowed).
 EachVPAcanbeconfiguredasNx1ø,2ø3w,3ø3w(2ch),3ø3w(3ch)or3ø4wlimitedbythetotalnumberofchannels
installed.
 Overallefficiencyandpowerlosscanbemeasured.
 ThetwoVPAsmaybeconfiguredaseither–
Totallyindependentandhavingtotallydifferentfrequencycontentsignalstoeachother.
Or,havetotallydifferentfrequencycontentsignalsbutmakemeasurementsovertimeswhicharesynchronized
toeachother.
Or,havethesamefrequencycontentsignalsandmakemeasurementsoverexactlythesameperiodsoftime(the
oscilloscopecapturesthesignalsinbothVPAsinthiscase).
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XT2640
POWER
SOURCE
POWER
CONVERSION
VPA
1 to 4
channels
LOAD
VPA
1 to 4
channels