หลักการทำงานของขดลวด Rogowski และผู้รวมระบบ

OperatingprincipleofRogowskicoilandintegrator

WorkingprincipleofRogowskicoil

Rogowskicoilisanannularcoilwhichisuniformlywoundonanonferromagneticmaterial.Theoutputsignalisthedifferentialofcurrenttotime.Throughacircuitthatintegratestheoutputvoltagesignal, theinputcurrentcanbetrulyrestored.Thecoilhasthecharacteristicsofreal-timecurrentmeasurement, fastresponsespeedandnosaturation.ItissuitableforAC, especiallyhigh-frequencyandlargecurrentmeasurement

Rogowskicoil, alsoknownascurrentmeasurementcoilanddifferentialcurrentsensor, ismainlyusedtomeasureACcurrent.TheworkingprincipleofRogowskicoilisthatthecoilskeletonsurroundstheconductorundertest.Themagneticfieldaroundtheconductorwillchangewiththechangeofcurrentintheconductor, andtheenameledwireontheskeletonwillinduceelectromotiveforce.Accordingtothemathematicalderivation, theEMFisdirectlyproportionaltothederivativeofthecurrentintheconductor, andtheproportionalcoefficientisrelatedtothenumberofturnsofthecoil, thecrosssectionoftheskeletonandthemagneticconductivity.ThecurrentintheconductorcanbereducedbyintegratingtheEMF

Workingprincipleofintegrator

InordertoaccuratelyrestoretheoutputofinductionelectromotiveforceofRogowskicoiltothemeasuredACcurrentI, aninverseintegrationcircuitmustbeadded.BecausethevoltageinducedbyRogowskicoilisverysmall, inordertoamplifytheinducedvoltage, anamplifiercircuitmustbeaddedinfrontoftheintegrator.Integrationisaveryimportantlink.Thesignaltoberestoredisverysmall.Inordertofacilitatethemeasurement, thesignalshouldbeamplifiedandthenintegrated.Ontheonehand, therestoredsignalcanbeincreased.Ontheotherhand, theexistenceofcapacitancecanfilteroutunnecessaryinterference.TheintegratorcanrestorethemeasuredACcurrentbyamplifyingandintegratingtheinducedvoltageoftheRogowskicoil